Wastewater

Water Sci Technol, 2003, 48(5), 143 - 8
Horizontal sub-surface flow constructed wetland with pulsing water level; Vymazal J et al.; A constructed wetland with horizontal sub-surface flow at Dolni Mesto (Czech Republic) was put into operation in 1999 and treats municipal wastewater from 522 PE . The total area of vegetated beds of 2,646 m2 is divided into two parallel sections of equal size, each with two beds in series . Between two periods of water discharge there is no outflow from the bed . During the period of September 1999-September 2000 one bed was operated with a pulsing water level while the other one was not pulsing, i.e., was operated as regular sub-surface flow in order to evaluate the effect of pulsing on treatment efficiency, especially on removal of NH4-N . Between September 1999 and February 2000 the pulse was 8 cm, for the rest of the experimental period the pulse was 15 cm . The results indicate a positive effect of pulsing on removal of BOD5 (annual average of 53%), COD (30%) and NH4-N (27%) as compared to non-pulsing beds . For SS, a decrease in removal effect by 30% was observed . This is probably due to the higher outflow velocity of discharged water from pulsing beds which can flush out settled particles . The results also indicate that a pulsing level of 15 cm was more efficient than 8 cm.

Water Sci Technol, 2003, 48(5), 93 - 100
Phosphorus sorption characteristics of a light-weight aggregate; Zhu T et al.; A light-weight aggregate (LWA) made of expanded clay used as a filter media in wastewater treatment, was tested for sorption of phosphorus (P) in laboratory experiments . The objectives were to investigate the different P retention pools and how grain size, time, temperature and changed P concentration influenced the P binding mechanisms in this type of filter . Three different grain sizes (0-2 mm, 2-4 mm and 0-4 mm) were tested in a batch experiment . The isotherm for the P sorbed by the contact medium (including retention and fixation) was obtained under laboratory conditions . Fifty percent of the P sorption occurred in the first 4-8 hours . Temperature did not substantially influence P sorption for 0-2 mm grain size LWA . In the LWA suspension system, P desorption did not occur when the P content in the loading solution decreased . Fractionation analysis indicated that Ca-bound P, loosely-bound P, and Al-bound P were the predominant P retention pools . The loosely-bound P pool was determined primarily by the equilibrated P concentration in the system . Fe-bound P was negligible in the P sorption of LWA.

Water Sci Technol, 2003, 48(5), 85 - 92
Pumice soil: a potential wetland substrate for treatment of domestic wastewater; Njau KN et al.; Laboratory and fieldwork studies were carried out to evaluate the potential of pumice soil for use as a wetland substrate in wastewater treatment . The composition of pumice soil was analysed by x-ray fluorescence (XRF) and x-ray diffraction (XRD) techniques . Adsorption kinetic studies were carried out in a semi-batch recycle system . Fieldwork tests were carried out on Subsurface Flow Constructed Wetland (SSFCW) cells planted with Phragmites mauritianus and Vetiveria zizanioides . The results have shown that pumice soil composition contains among other elements Al, Ca, Fe and Mg, which are positive indicators for phosphorus adsorption . The main minerals observed by XRD were augite, hematite, and sodium titanium silicate . Phosphorus adsorption kinetics have shown that phosphorus is adsorbed on pumice soil following first order kinetics and the adsorption was highly influenced by mass transfer . Approximately 3% of the phosphorus was removed by plant uptake.

Water Sci Technol, 2003, 48(5), 75 - 83
Phosphorus retention in subsurface constructed wetlands: investigations focused on calcareous materials and their chemical reactions; Molle P et al.; Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water . In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible for P uptake . Two media (calcite and recycled crushed concrete (RCC)) were examined in batch and continuous systems . Batch experiments show attractive sorption capacities, however experiments carried out in open reactors pointed out some limitation in retention capacities and effluent quality . RCC is sensitive to a strong dissolution leading to a quick phosphorus precipitation but induces high conductivity and pH values in the treated water . Calcite efficiency depends on the carbonate equilibrium of the solution . Microscopic observations of the calcite surface show crystal growth of phosphorus precipitate . Crystallisation seems to be the main P uptake once a material's surface is covered.

Water Sci Technol, 2003, 48(5), 51 - 8
Phosphorus removal from municipal wastewater in an experimental two-stage vertical flow constructed wetland system equipped with a calcite filter; Arias CA et al.; Laboratory studies have indicated that calcite may be used in separate, exchangeable filter units in constructed wetland systems to remove phosphorus . Based on these studies we built a full-scale experimental constructed wetland with a calcite-based filter unit to study its performance, under real-life conditions . The system consists of a 2-m3 sedimentation tank and two vertical flow constructed wetlands . The system has three 0.09 m3 calcite filter-units to study phosphorus removal . The hydraulic loading rate varied between 1.7 and 6.2 m3/d . The residence time in filters ranged from 28 to 99 minutes . Overall the system removed 62 +/- 18% of phosphorus . The removal in the calcite filter was initially good, but after three months all P-filters were saturated . The calcite increased pH by approximately half a unit and released calcium . A total of about 2.2 kg P/m3 calcite was removed by the filter . The first-stage bed receiving effluent from the sedimentation tank consistently removed phosphorus, whereas the second bed sometimes released phosphorus . The first order area-based removal rate constant for total-P in the vertical bed averaged 0.24 +/- 0.20 m/d and was highly dependent on the loading rate . This shows that first order removal kinetics do not satisfactorily describe removal of phosphorus in vertical flow constructed wetland systems with unsaturated flow.

Water Sci Technol, 2003, 48(5), 25 - 34
Evaluation of substrate clogging processes in vertical flow constructed wetlands; Langergraber G et al.; Substrate clogging is by far the biggest operational problem of vertical flow constructed wetlands . The term "substrate clogging" summarises several processes which lead to reduction of the infiltration capacity at the substrate surface . The lower infiltration rate causes a reduced oxygen supply and further leads to a rapid failure of the treatment performance . Reasons for substrate clogging include accumulation of suspended solids, surplus sludge production, chemical precipitation and deposition in the pores, growth of plant-rhizomes and roots, generation of gas and compaction of the clogging layer . However, it is not clear how much each process contributes to the clogging process . Detailed investigations were carried out at pilot-scale constructed wetlands (PSCWs) using a variety of methods: e.g . soil physical investigations, microbial methods, and various analysis methods of drinking water and wastewater . The paper shows the results of these investigations and presents an equation to calculate the theoretical clogging time.

Environ Sci Technol, 2003 Nov 1, 37(21), 5021 - 6
High-performance Ti/BDD electrodes for pollutant oxidation; Chen X et al.; Deposition of stable boron-doped diamond (BDD) films on Ti substrates is believed to be very difficult . In the present study, the stability of Ti/BDD electrodes has been significantly improved by using an organic additive, CH2(OCH3)2 . The improved electrodes had service lives of 175-264 h under accelerated life test conditions, which are 2.3-3.0 times longer than the service lives of electrodes prepared with the conventional H2 + CH4 mixture . Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) examinations demonstrated thatthe films had well-defined diamond features . The current efficiency (CE) obtained on Ti/BDD was 46.9-78.5% in oxidizing acetic acid, maleic acid, phenol, and dyes, which is 1.6-4.3-fold higher than that obtained on the typical Ti/ Sb2O5-SnO2 electrode . We used a Ti/BDD electrode prepared with H2 + CH4 + CH2(OCH3)2 for over 300 h; its activity remained superior . The successful development of stable and active Ti/BDD electrodes significantly increases the feasibility of industrial applications of anodic oxidation in wastewater treatment.

J Ind Microbiol Biotechnol, 2003 Nov, 30(11), 656 - 60 Epub 2003 Nov 11.
Nitrate and phosphate removal by Spirulina platensis; Lodi A et al.; The cyanobacterium Spirulina platensis was used to verify the possibility of employing microalgal biomass to reduce the contents of nitrate and phosphate in wastewaters . Batch tests were carried out in 0.5 dm3 Erlenmeyer flasks under conditions of light limitation (40 micromol quanta m(-2) s(-1)) at a starting biomass level of 0.50 g/dm3 and varying temperature in the range 23-40 degrees C . In this way, the best temperature for the growth of this microalga (30 degrees C) was determined and the related thermodynamic parameters were estimated . All removed nitrate was used for biomass growth (biotic removal), whereas phosphate appeared to be removed mainly by chemical precipitation (abiotic removal) . The best results in terms of specific and volumetric growth rates (mu=0.044 day(-1), Qx=33.2 mg dm(-3) day(-1)) as well as volumetric rate and final yield of nitrogen removal (Q(N-NO3-)=3.26 mg dm(-3) day(-1), Y(N-NO3-)=0.739) were obtained at 30 degrees C, whereas phosphorus was more effectively removed at a lower temperature . In order to simulate full-scale studies, batch tests of nitrate and phosphate removal were also performed in 5.0 dm3 vessels (mini-ponds) at the optimum temperature (30 degrees C) but increasing the photon fluence rate to 80 micromol quanta m(-2) s(-1) and varying the initial biomass concentration from 0.25 to 0.86 g/dm3 . These additional tests demonstrated that an increase in the inoculum level up to 0.75 g/dm3 enhanced both NO3- and PO4(3-) removal, confirming a strict dependence of these processes on biomass activity . In addition, the larger surface area of the ponds and the higher light intensity improved removal yields and kinetics compared to the flasks, particularly concerning phosphorus removal (mu=0.032-0.050 day(-1), Qx=34.7-42.4 mg dm(-3) day(-1), Q(N-NO3-)=3.24-4.06 mg dm(-3) day(-1), Y(N-NO3-)=0.750-0.879, Q(P-PO4(3-))=0.312-0.623 mg dm(-3) day(-1), and Y(P-PO4(3-))=0.224-0.440).

Environ Toxicol, 2003 Dec, 18(6), 413 - 7
Cavitation-induced pyrolysis of toxic chlorophenol by high-frequency ultrasonic irradiation; Hao H et al.; p-Chlorophenol (4-CP) is a recalcitrant organic pollutant that is biologically toxic in industrial wastewater . A high-frequency ultrasonic device operated at 1.7 MHz was designed and used successfully to degrade 4-CP . Iodine liberation in the KI aqueous solution confirmed that effective cavitation occurred under the high-frequency ultrasonic irradiation . No products or intermediate products were detected following the sonochemical degradation by 1H-nuclear magnetic resonance spectrum and mass spectrum after ultrasonic irradiation . It was concluded that the dominant degradation mechanism was high-temperature pyrolysis to inorganic products in ultrasonic cavities rather than free-radical oxidation .

Environ Toxicol, 2003 Dec, 18(6), 395 - 402
A practical and user-friendly toxicity classification system with microbiotests for natural waters and wastewaters; Persoone G et al.; Various types of toxicity classification systems have been elaborated by scientists in different countries, with the aim of attributing a hazard score to polluted environments or toxic wastewaters or of ranking them in accordance with increasing levels of toxicity . All these systems are based on batteries of standard acute toxicity tests (several of them including chronic assays as well) and are therefore dependent on the culturing and maintenance of live stocks of test organisms . Most systems require performance of the bioassays on dilution series of the original samples, for subsequent calculation of L(E)C50 or threshold toxicity values . Given the complexity and costs of these toxicity measurements, they can only be applied in well-equipped and highly specialized laboratories, and none of the classification methods so far has found general acceptance at the international level . The development of microbiotests that are independent of continuous culturing of live organisms has stimulated international collaboration . Coordinated at Ghent University, Belgium, collaboration by research groups from 10 countries in central and eastern Europe resulted in an alternative toxicity classification system that was easier to apply and substantially more cost effective than any of the earlier methods . This new system was developed and applied in the framework of a cooperation agreement between the Flemish community in Belgium and central and eastern Europe . The toxicity classification system is based on a battery of (culture-independent) microbiotests and is particularly suited for routine monitoring . It indeed only requires testing on undiluted samples of natural waters or wastewaters discharged into the aquatic environment, except for wastewaters that demonstrate more than 50% effect . The scoring system ranks the waters or wastewaters in 5 classes of increasing hazard/toxicity, with calculation of a weight factor for the concerned hazard/toxicity class . The new classification system was applied during 2000 by the participating laboratories on samples of river water, groundwaters, drinking waters, mine waters, sediment pore waters, industrial effluents, soil leachates, and waste dump leachates and was found to be easy to apply and reliable .

Bioresour Technol, 2004 Feb, 91(3), 249 - 57
Kinetic modeling and equilibrium studies during cadmium biosorption by dead Sargassum sp . biomass; Cruz CC et al.; A basic investigation on the removal of cadmium(II) ions from aqueous solutions by dead Sargassum sp . was conducted in batch conditions . The influence of different experimental parameters; initial pH, shaking rate, sorption time, temperature and initial concentrations of cadmium ions on cadmium uptake was evaluated . Results indicated that cadmium uptake could be described by the Langmuir adsorption model, being the monolayer capacity negatively affected with an increase in temperature . Analogously, the adsorption equilibrium constant decreased with increasing temperature . The kinetics of the adsorption process followed a second-order adsorption, with characteristic constants increasing with increasing temperature . Activation energy of biosorption could be calculated as equal to 10 kcal/mol . The biomass used proved to be suitable for removal of cadmium from dilute solutions . Its maximum uptake capacity was 120 mg/g . It can be considered an optimal result when compared to conventional adsorbing materials . Thus Sargassum sp . has great potential for removing cadmium ions especially when concentration of this metal is low in samples such as wastewater streams.

J Microbiol Methods, 2003 Dec, 55(3), 859 - 64
Rains, drains and active strains: towards online assessment of wastewater bacterial communities; Forster S et al.; Wastewater treatment is one of the largest scale and arguably the most commercially important biotechnological process in the world . Bacterial breakdown of waste materials facilitates the safe disposal of effluents into receiving water bodies . Given this significance, research has focused on identifying the keystone species on which efficient treatment is based . However, unravelling the microbial diversity within such systems has proven difficult . This is highlighted by our lack of detailed knowledge of the microbial interactions within these complex populations, limiting our ability to fully exploit bacterial degradative abilities . Even with the incorporation of new emerging molecular techniques, there have been no investigations linking genetic sequence to microbial function and successful treatment operation . To reach this goal, researchers need the ability to identify, enumerate and monitor the metabolic functions of subpopulations within these complex bacterial communities . Flow cytometry (FCM) combined with fluorescence-based molecular identification techniques provides a method for such studies . Moreover, single-cell sorting provides a unique opportunity to identify and remove individual cells of interest . Laboratory culture of sorted cells is often possible and permits the use of more traditional microbiological techniques to backup molecular investigations . Utilising this approach will advance our understanding of wastewater treatment processes and help maintain and enhance plant operation to improve efficiency.

Appl Microbiol Biotechnol, 2004 May, 64(4), 599 - 603 Epub 2003 Nov 05.
Chromium and aluminum biosorption on Chryseomonas luteola TEM05; Ozdemir G et al.; Cr(VI) and Al(III) are environmental pollutants that are frequently encountered together in industrial wastewaters, e.g., from mining iron-steel, metal cleaning, plating, metal processing, automobile parts, and the manufacturing and dye industries . In this work, several variables that affect the capacity for chromium and aluminum biosorption by Chryseomonas luteola TEM05 were studied, particularly the effects of pH, metal concentration and contact time . Optimum adsorption pH values of Cr(VI) and Al(III) were determined as 4.0 and 5.0, respectively . The biosorption equilibrium was described by Freundlich and Langmuir adsorption isotherms . The value of Qo appears to be significantly higher for the Al(III) C . luteola TEM05 system . Langmuir parameters of C . luteola TEM05 also indicated a maximum adsorption capacity of 55.2 mg g(-1) for Al(III) and 3.0 mg g(-1) for Cr(VI) .

J Clin Microbiol, 2003 Nov, 41(11), 5254 - 7
Molecular surveillance of Cryptosporidium spp . in raw wastewater in Milwaukee: implications for understanding outbreak occurrence and transmission dynamics; Zhou L et al.; Six Cryptosporidium spp . were found in 50 of 179 Milwaukee wastewater samples collected weekly over a year . Of the eight subtypes of Cryptosporidium hominis and Cryptosporidium parvum present, allele Ib was found in 14 of 16 samples, and its sequence was identical to that of the subtype in human samples from the 1993 Milwaukee outbreak of cryptosporidiosis.

Water Res, 2003 Dec, 37(20), 4945 - 53
Adsorptive separation of arsenate and arsenite anions from aqueous medium by using orange waste; Ghimire KN et al.; Cellulose and orange waste were chemically modified by means of phosphorylation . The chemically modified gels were further loaded with iron(III) in order to create a suitable chelating environment for arsenate and arsenite removal . The loading capacity for iron(III) on the gel prepared from orange waste (POW) was 1.21 mmol g(-1) compared with 0.96 mmol g(-1) for the gel prepared from cellulose (PC) . Removal tests of arsenic with the iron(III)-loaded gel were carried out batchwise and by using a column . Arsenite removal was favored under alkaline condition for both PC and POW gels, however, the POW gel showed some removal capability even at neutral pH . On contrary, arsenate removal took place under acidic conditions at pH=2-3 and 2-6 for the PC and POW gels, respectively . Since iron(III) loading is higher on the POW gel than on the PC gel greater arsenic removal has been achieved by the POW gel compared with the PC gel . It can be concluded that the POW gel can be used for the removal and recovery of both arsenite and arsenate from arsenic contaminated wastewater.

Water Res, 2003 Dec, 37(20), 4835 - 42
Modeling heavy metal uptake by sludge particulates in the presence of dissolved organic matter; Wang J et al.; The uptake of the seven heavy metal ions Cd(II), Co(II), Cr(III), Cu(II), Ni(II), Pb(II), and Zn(II) by sludge particulates in single-metal systems was investigated . Results showed that under acidic and neutral pH conditions, the uptake of all heavy metals by sludge particulates increases with the increase of pH . However, in the alkaline pH region, the uptake of Cu(II), Ni(II), and Co(II) decreases with the increase of pH, primarily due to the high dissolved organic matter (DOM) concentration in high pH conditions . Based on chemical reactions among heavy metal, sludge solids, and DOM, a mathematical model describing metal uptake as functions of DOM and pH was developed . The stability constants of metal-sludge and metal-DOM complexes can be determined using this model in conjunction with experimental metal uptake data . Results showed that, for the secondary sludge sample collected from Baltimore Back River Wastewater Treatment plant on March 1997, the stability constants of Cu(II)-sludge complex (log K(S)) and Cu(II)-DOM complex (log K(L)) are 5.3+/-0.2 and 4.7+/-0.3, respectively; for Ni(II), they are 4.0+/-0.2 and 3.9+/-0.2, respectively . Results also showed that under neutral and low pH conditions (pH<8), the DOM effects on metal uptake for all heavy metals are insignificant . Therefore, the DOM term in the model can be ignored . Results showed that, for the secondary sludge sample collected from Baltimore Back River Wastewater Treatment plant on December 1996, the estimated log K(S) values of metal-sludge complexes for Cd(II), Co(II), Cr(III), Cu(II), Ni(II), Pb(II), and Zn(II) are, respectively, 3.6+/-0.2, 3.0+/-0.1, 5.5+/-0.1, 4.8+/-0.1, 3.1+/-0.1, 5.1+/-0.1, and 4.4+/-0.3.

Water Res, 2003 Dec, 37(20), 4823 - 34
Stabilized leachates: ozone-activated carbon treatment and kinetics; Rivas FJ et al.; Ozone has been used as a pre-oxidation step for the treatment of stabilized leachates . Given the refractory nature of this type of effluents, the conversion of some wastewater quality parameters has been moderate after 1 h of ozonation (i.e . 30% chemical oxygen demand (COD) depletion) . Ozone uptake was calculated in the interval 1.3-1.5 g of ozone per gram of COD degraded . An optimum dose of ozone has been experienced in terms of biodegradability of the processed effluent (60 min of treatment, 1 x 10(-3) mol L(-1) ozone inlet feeding concentration and 50 L h(-1) gas flow-rate) . pH and other typical hydroxyl radical generator systems exerted no influence on the efficiency of the process, suggesting the negligible role played by the indirect route of oxidation (generation of hydroxyl radicals) . The ozonated effluent was thereafter treated in a second adsorption stage by using a commercial activated carbon . Removal levels up to 90% of COD in approximately 120 h were experienced for adsorbent dosages of 30 g L(-1) . Both steps, the single ozonation and the adsorption stage have been modelled by using different pseudoempirical models.

Chemosphere, 2004 Feb, 54(6), 695 - 705
A holistic passive integrative sampling approach for assessing the presence and potential impacts of waterborne environmental contaminants; Petty JD et al.; As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants . The semipermeable membrane device has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler is applicable for sampling vapor phase or dissolved neutral mercury species . This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants . In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence of a wide variety of contaminants in the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants . The wetland is used for final polishing of secondary-treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area . Numerous contaminants, including organochlorine pesticides, polycyclic aromatic hydrocarbons, organophosphate pesticides, and pharmaceutical chemicals (e.g., ibuprofen, oxindole, etc.) were detected in the wastewater . Herein we summarize the results of the analysis of the field-deployed samplers and demonstrate the utility of this holistic approach.

Environ Technol, 2003 Sep, 24(9), 1165 - 73
Thermal efficiency and environmental performances of a biogas-diesel stationary engine; Bilcan A et al.; Municipal and agricultural waste, and sludge from wastewater treatment represent a large source of pollution . Gaseous fuels can be produced from waste decomposition and then used to run internal combustion engines for power and heat generation . The present paper focuses on thermal efficiency and environmental performances of dual-fuel engines fuelled with biogas . Experiments have been carried out on a Lister-Petter single cylinder diesel engine, modified for dual-fuel operation . Natural gas was first used as the primary fuel . An empirical correlation was determined to predict the engine load for a given mass flow rate for the pilot fuel (diesel) and for the primary fuel (natural gas) . That correlation has then been tested for three synthesized biogas compositions . Computations were performed and the error was estimated to be less than 10% . Additionally, NOx and CO2 contents were measured from exhaust gases . Based on exhausts gas temperature, the activation energy and the pre-exponential factor of an Arrhenius law were then proposed, resulting in a simpler mean to predict NOx.

Environ Technol, 2003 Sep, 24(9), 1135 - 45
Application of electrochemical process for landfill leachate treatment with emphasis on heavy metal and organic removal; Thaveemaitree Y et al.; This study was conducted to investigate the mechanisms of electrochemical treatment of a landfill leachate with emphasis on lead and organic removal . Laboratory electrochemical experiments were conducted using both synthetic wastewater and landfill leachate samples . From the synthetic wastewater experiments, the lead removal efficiencies were found to be more than 99% . The lead removal was observed to be dependent on: the electrical current, ratio between reacting surface area and volume of reactor and operation time, and following a first-order reaction . Similar results on lead removal were obtained when the landfill leachate samples were treated in the electrochemical reactor; the percent removal of soluble biological oxygen demand and soluble chemical oxygen demand concentrations from the landfill leachate during the electrochemical treatment were 30-60%, while the color removal was 70% . The sludge generated from the electrochemical reactions using the synthetic lead wastewater, analyzed by X-ray diffractometry, was found to be composed mainly of maghemite, magnetite, and laurionite . Based on the X-ray fluorescence spectrometry analysis, the percent contents of iron and lead were 68.6% as maghemite and 10.1% as lead oxide, respectively . The sludge generated from the landfill leachate treatment containing lead, analyzed by X-ray diffractometry, was found to be composed mainly of maghemite . Based on the X-ray fluorescence spectrometry analysis, the percent contents of iron and lead in the sludge were 69.49% as maghemite and 0.63% as lead oxide, respectively . The sludge volume index, capillary suction time and leachability values of the sludge were in suitable range for settling, dewatering and disposal.

Bioresour Technol, 2004 Jan, 91(2), 207 - 14
Assessing the feasibility of achieving biological nutrient removal from wastewater at an Irish food processing factory; Mulkerrins D et al.; In Ireland, wastewaters emanating from the food industry typically contain elevated levels of nitrogen and phosphorus before treatment . Two pilot scale studies were performed to determine the feasibility of achieving biological N and P removal on-site at a food ingredients plant . The wastewater treated by the pilot reactors was that which resulted from the day-to-day production in the full-scale food ingredients plant . Both reactors were of the anaerobic/anoxic/oxic (A/A/O) design, however the sizing of the zones was varied in this study . In the first pilot study, while treating a wastewater of the following strength: 1008 mg COD/l; 30.1 mg NH4-N/l and 26.7 mg P/l, removal efficiencies of 93%, 99% and 98% were obtained for COD, NH4-N and P, respectively . In the second study, while operating at reduced hydraulic retention times and lower recycle rates, the pilot plant treated a wastewater of the following strength: 1757 mg COD/l; 62 mg NH4-N/l and 57 mg P/l, with removal efficiencies of 94%, 97% and 75% obtained for COD, NH4-N and P, respectively . This work showed that biological nutrient removal could be successfully applied to treatment of food industry wastewaters.

Water Environ Res, 2003 Sep-Oct, 75(5), 412 - 21
Evaluation of constructed wetland treatment performance for winery wastewater; Grismer ME et al.; Rapid expansion of wineries in rural California during the past three decades has created contamination problems related to winery wastewater treatment and disposal; however, little information is available about performance of on-site treatment systems . Here, the project objective was to determine full-scale, subsurface-flow constructed wetland retention times and treatment performance through assessment of water quality by daily sampling of total dissolved solids, pH, total suspended solids, chemical oxygen demand (COD), tannins, nitrate, ammonium, total Kjeldahl nitrogen, phosphate, sulfate, and sulfide across operating systems for winery wastewater treatment . Measurements were conducted during both the fall crush season of heavy loading and the spring following bottling and racking operations at the winery . Simple decay model coefficients for these constituents as well as COD and tannin removal efficiencies from winery wastewater in bench-scale reactors are also determined . The bench-scale study used upward-flow, inoculated attached-growth (pea-gravel substrate) reactors fed synthetic winery wastewater . Inlet and outlet tracer studies for determination of actual retention times were essential to analyses of treatment performance from an operational subsurface-flow constructed wetland that had been overloaded due to failure to install a pretreatment system for suspended solids removal . Less intensive sampling conducted at a smaller operational winery wastewater constructed wetland that had used pretreatment suspended solids removal and aeration indicated that the constructed wetlands were capable of complete organic load removal from the winery wastewater.

Environ Toxicol Chem, 2003 Nov, 22(11), 2622 - 9
Quantification of steroid hormones with pheromonal properties in municipal wastewater effluent; Kolodziej EP et al.; Many fish use steroid hormones as pheromones to initiate behavioral and physiological changes during spawning . To assess the occurrence of steroid hormones with pheromonal properties in the aquatic environment and to evaluate the possibility that municipal wastewater discharges contain compounds that could affect fish reproduction by interfering with pheromones, several estrogens, androgens, and progestins were quantified by gas chromatography/tandem mass spectroscopy in effluent samples from 12 municipal wastewater treatment plants . Samples also were analyzed from an engineered treatment wetland, three groundwater wells, and one reservoir . Estrogens (17beta-estradiol and estrone) were detected in wastewater effluent at maximum concentrations of 4 and 12 ng/L, respectively . Androgens (testosterone and androstenedione) were detected at concentrations as high as 6.1 and 4.5 ng/L, respectively, whereas the synthetic progestin medroxyprogesterone was detected at concentrations up to 15 ng/L . Data from an effluent-receiving engineered treatment wetland and shallow groundwater wells suggested that these compounds were not rapidly attenuated . The measured concentrations of steroids often exceeded olfactory detection thresholds at which fish detect these steroids, and in several cases, the steroid concentrations were comparable to levels at which pheromonal responses have been observed in fish.

Biotechnol Lett, 2003 Oct, 25(19), 1657 - 9
Removal of low molecular weight phenols from olive oil mill wastewater using microalgae; Pinto G et al.; The treatment of olive oil mill wastewater (OMW) with two phenol resistant algae, Ankistrodesmus braunii and Scenedesmus quadricauda, showed a limited reduction of phenol content after 5 d of treatment, irrespective of algal concentration . Otherwise, cultures of both algae, grown in the dark, degraded over 50% of the low molecular weight phenols contained in OMW, but they were not completely removed, but were biotransformed into other non-identified, aromatic compounds.

Waste Manag, 2003, 23(9), 817 - 24
Assessment and analysis of industrial liquid waste and sludge disposal at unlined landfill sites in arid climate; Al Yaqout AF; Municipal solid waste disposal sites in arid countries such as Kuwait receive various types of waste materials like sewage sludge, chemical waste and other debris . Large amounts of leachate are expected to be generated due to the improper disposal of industrial wastewater, sewage sludge and chemical wastes with municipal solid waste at landfill sites even though the rainwater is scarce . Almost 95% of all solid waste generated in Kuwait during the last 10 years was dumped in five unlined landfills . The sites accepting liquid waste consist of old sand quarries that do not follow any specific engineering guidelines . With the current practice, contamination of the ground water table is possible due to the close location of the water table beneath the bottom of the waste disposal sites . This study determined the percentage of industrial liquid waste and sludge of the total waste dumped at the landfill sites, analyzed the chemical characteristics of liquid waste stream and contaminated water at disposal sites, and finally evaluated the possible risk posed by the continuous dumping of such wastes at the unlined landfills . Statistical analysis has been performed on the disposal and characterization of industrial wastewater and sludge at five active landfill sites . The chemical analysis shows that all the industrial wastes and sludge have high concentrations of COD, suspended solids, and heavy metals . Results show that from 1993 to 2000, 5.14+/-1.13 million t of total wastes were disposed per year in all active landfill sites in Kuwait . The share of industrial liquid and sludge waste was 1.85+/-0.19 million t representing 37.22+/-6.85% of total waste disposed in all landfill sites . Such wastes contribute to landfill leachate which pollutes groundwater and may enter the food chain causing adverse health effects . Lined evaporation ponds are suggested as an economical and safe solution for industrial wastewater and sludge disposal in the arid climate of Kuwait.

J Environ Manage, 2003 Nov, 69(3), 239 - 47
Water issues in comprehensive municipal planning: a review of the Motala River Basin; Gullstrand M et al.; The performance level for water management is rising in Sweden after the passing of a number of Governmental Bills (1997-2000) that establish national environmental quality objectives, and furthermore after the adoption of the Water Framework Directive of the European Union (2000) . The presentation of water issues in municipal physical planning is important because the municipalities have a local planning monopoly . We investigate to what extent water resources are considered in one of the most important tools for the regulation of physical infrastructure, namely the Comprehensive Municipal Plans . Thirteen plans from municipalities within the Motala River Basin in southern Sweden were studied . To characterise the comprehensiveness of the plans we used twelve criteria, divided into five groups: description, preventive measures, goal-setting, implementation strategy and future-oriented considerations . Descriptions of water quality, water use, wastewater plants, and urban water and wastewater systems were the most frequent items . These topics could be found in all plans in the study, along with more or less elaborated river basin perspectives . Issues related to national environmental quality objectives were mentioned in only five of the plans, and considerations about water flows were even more rare . We found, that the emphasis on water issues is not correlated with the size of the municipal population but rather with the age of the plans . In the old plans from the early 1990s water management is less recognised than in the newly revised ones . After their adoption the national water quality objectives, and suggested measures to fulfil them, are being translated into regional and local levels, and this has happened in the new plans . However, it seems that water has not yet gained the same importance as land in municipal physical planning, and strategies for public participation in the planning process are lacking.

J Environ Manage, 2003 Nov, 69(3), 229 - 38
The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth; Al-Ghouti MA et al.; The feasibility of using diatomite for the removal of the problematic reactive dyes as well as basic dyes from textile wastewater was investigated . Methylene blue, Cibacron reactive black and reactive yellow dyes were considered . Physical characteristics of diatomite such as pHsolution, pHZPC, surface area, Fourier transform infrared, and scanning electron microscopy were investigated . The surface area of diatomite was found to be 27.80 m2g(-1) and the pHZPC occurred around pH of 5.4 . The results indicated that the surface charge of diatomite decreased as the pH of the solution increased with the maximum methylene blue removal from aqueous solution occurring at basic pH of around (10-11) . Adsorption isotherms of diatomite with methylene blue, hydrolysed reactive black and yellow dyes were constructed at different pH values, initial dye concentrations and particle sizes . The experimental results were fitted to the Langmuir, Freundlich, and Henry models . The study indicated that electrostatic interactions play an important role in the adsorption of dyes onto diatomite . A model of the adsorption mechanism of methylene blue onto diatomite is proposed.

Chemosphere, 2004 Jan, 54(3), 435 - 41
Color and COD removal from wastewater containing Reactive Black 5 using Fenton's oxidation process; Meric S et al.; In this study, Reactive Black 5 (RB5) was removed from synthetic wastewater using Fenton's oxidation (FO) process . Experiments were conducted on the samples containing 100 and 200 mg l(-1) of RB5 to remove the dye toxicity . Seventy-five milligram per litre of RB5 caused 25% toxicity on 24-h born daphnids whereas 100 mg l(-1) of RB5 displayed 100% toxicity on Daphnia magna . The study was performed in a systematic approach searching optimum values of FeSO(4) and H(2)O(2) concentrations, pH and temperature . Optimum pH and temperature for 100 mg l(-1) of RB5 were observed as 3.0 and 40 degrees C, respectively, using 100 mg l(-1) of FeSO(4) and 400 mg l(-1) of H(2)O(2) resulted in 71% chemical oxygen demand (COD) and 99% color removal . For 200 mg l(-1) of RB5, 84% COD removal was obtained using 225 mg l(-1) of FeSO(4) and 1000 mg l(-1) of H(2)O(2) yielding 0.05 molar ratio at pH 3.0 and 40 degrees C . Color removal was also more than 99% . The optimum conditions determined in accordance with the literature data . The H(2)O(2) requirement seems to be related to initial COD of the sample . FeSO(4)/H(2)O(2) ratios found were not changed for both concentrations . The temperature affected the COD removal significantly at high degrees . Toxicity was completely removed for each concentration of RB5 at optimum removal conditions.

Chemosphere, 2004 Jan, 54(3), 413 - 7
Recovery of astaxanthin from seafood wastewater utilizing fish scales waste; Stepnowski P et al.; The paper presents basic data on astaxanthin adsorption from fisheries wastewater to fish scales . This process has been proposed to be applicable in fisheries and shrimp waste management {Helgason, Recovery of compounds using a natural adsorbent, Patent WO 01/77230, 2001} . The innovative feature of the method is the application of a solid waste (fish scales) as a natural adsorbent for a carotenoid pigment (astaxanthin) from the seafood industry wastewater . The model investigations were performed with pure synthetic carotenoids to exclude the role of matrix in which astaxanthin is present in the wastewater . Under the experimental conditions used, the maximum loading capacity of astaxanthin onto the scales is 360 mg kg(-1) dry wt . Studies of the thus formed value added product indicated that drying causes significant loss of astaxanthin activity . Due to the effective filtration characteristics of the studied sorption material, we suggest the scale/astaxanthin sorption process to be suitable for treatment of wastewater from different industries.

Chemosphere, 2004 Jan, 54(3), 325 - 33
Removal of cyanide by woody plants; Larsen M et al.; Hydrogen cyanide is a high volume production chemical that causes severe environmental problems . The toxicity of potassium cyanide (KCN) to basket willow trees (Salix viminalis) was tested . In aqueous solution, 2 mg CN l(-1) as KCN depressed the transpiration after 72 h about 50% . Trees exposed to 0.4 mg CN l(-1) in aqueous solution showed initially a depression of transpiration, but recovered . Doses of 8 and 20 mg CN l(-1) in aqueous solution were quickly mortal to the trees . At the end of the test, almost all cyanide had disappeared from the solutions . Levels of cyanide in plants were related to the toxicity, with no elevated levels of cyanide in plants exposed to 0.4 mg CN l(-1) . Willows grown in sand survived 423.5 h irrigation with 20 mg CN l(-1) . Willows grown in sand irrigated with 50 mg CN l(-1) died within a few days . The roots of the surviving willows were able to consume about 10 mg CN kg fresh weight(-1)h(-1) . Vascular plants possess the enzymes beta-cyanoalanine synthase and beta-cyanoalanine hydrolase, which convert free cyanide to the amino acid asparagine . The in vivo capacity of woody plants (willow, poplar, elder, rose, birch) to remove cyanide was evaluated . Tests were performed with detached leaves and roots in KCN solutions of different concentrations . The highest removal capacity was obtained for basket willow hybrids (Salix viminalis x schwerinii) . The Michaelis-Menten kinetics was determined . Realistic values of the half-saturation constant, K(M), were between 0.6 and 1.7 mg CN l(-1); the maximum metabolic capacity, v(max), was around 9.3 mg CN kg fresh weight(-1)h(-1) . The removal of cyanide by plants might be useful in phytoremediation and treatment of wastewater from gold mining.

Chemosphere, 2004 Jan, 54(3), 273 - 81
Sorption equilibria of metal ions on bone char; Ko DC et al.; The ability of bone char to adsorb three metal ions, namely, copper(II), zinc(II) and cadmium(II) ions from wastewater has been studied . Three single-component equilibrium systems and three binary equilibrium systems have been measured experimentally . The three single-component equilibrium data were analyzed using the Langmuir and the Sips equilibrium isotherm equations . The Sips isotherm gave a better fit of the experimental data than the Langmuir isotherm based on the sum of squares errors (SSE) analysis . The Cu-Zn, Cu-Cd and Cd-Zn binary equilibrium experimental data were examined by incorporating the Langmuir and the Sips isotherm equations into the ideal adsorbed solution theory (IAST) . The solution methods and the predicted results for the three binary systems at different metal ion compositions have been evaluated . In addition, the application of the IAST to the model prediction for the fixed bed system is presented.

Chemosphere, 2004 Jan, 54(3), 235 - 42
Treatment of chemical mechanical polishing wastewater by electrocoagulation: system performances and sludge settling characteristics; Lai CL et al.; Treatment of copper chemical mechanical polishing (CMP) wastewater from a semiconductor plant by electrocoagulation is investigated . The CMP wastewater was characterized by high suspended solids (SS) content, high turbidity (NTU), chemical oxygen demand (COD) concentration up to 500 mgl(-1) and copper concentration up to 100 mgl(-1) . In the present study, electrocoagulation was employed to treat the CMP wastewater with an attempt to simultaneously lower its turbidity, copper and COD concentrations . The test results indicated that electrocoagulation with Al/Fe electrode pair was very efficient and able to achieve 99% copper ion and 96.5% turbidity removal in less than 30 min . The COD removal obtained in the treatment was better than 85%, with an effluent COD below 100 mgl(-1) . The effluent wastewater was very clear and its quality exceeded the direct discharge standard . In addition, sludge settling velocities after electrocoagulation were measured and the data were employed to verify the empirical sludge settling velocity models . Finally, the sludge settling characteristic data were also utilized to establish the relation between the solids flux (G) and the initial solids concentration.

Anal Bioanal Chem, 2004 Feb, 378(3), 688 - 96 Epub 2003 Oct 22.
Combined biological and chemical assessment of estrogenic activities in wastewater treatment plant effluents; Aerni HR et al.; Five wastewater treatment plant effluents were analyzed for known endocrine disrupters and estrogenicity . Estrogenicity was determined by using the yeast estrogen screen (YES) and by measuring the blood plasma vitellogenin (VTG) concentrations in exposed male rainbow trout (Oncorhynchus mykiss) . While all wastewater treatment plant effluents contained measurable concentrations of estrogens and gave a positive response with the YES, only at two sites did the male fish have significantly increased VTG blood plasma concentrations after the exposure, compared to pre-exposure concentrations . Estrone (E1) concentrations ranged up to 51 ng L(-1), estradiol (E2) up to 6 ng L(-1), and ethinylestradiol (EE2) up to 2 ng L(-1) in the 90 samples analyzed . Alkylphenols, alkylphenolmonoethoxylates and alkylphenoldiethoxylates, even though found at microg L(-1) concentrations in effluents from wastewater treatment plants with a significant industrial content, did not contribute much to the overall estrogenicity of the samples taken due to their low relative potency . Expected estrogenicities were calculated from the chemical data for each sample by using the principle of concentration additivity and relative potencies of the various chemicals as determined with the yeast estrogen screen . Measured and calculated estradiol equivalents gave the same order of magnitude and correlated rather well (R(2)=0.6).

Anal Bioanal Chem, 2004 Mar, 378(5), 1243 - 50 Epub 2003 Oct 22.
Establishment of traceability of ammonium nitrogen determination in wastewater; Drolc A et al.; A case study is presented for the establishment of traceability for ammonium nitrogen determination in wastewater in a routine laboratory in order to fulfil the requirements of ISO/IEC standard 17025 . The necessary relevant information was obtained from the method validation data, the quality control data and equipment calibration certificates . The method of measurement is described together with the measurement equation, selected traceable reference standards and the associated measurement uncertainty . The major sources of uncertainty of the result of measurement were identified and the combined uncertainty was calculated . Identification of the main uncertainty sources represents the basis for target operations for reducing the measurement uncertainty of this determination.

J Hazard Mater, 2003 Oct 31, 103(3), 247 - 61
Anodic oxidation with doped diamond electrodes: a new advanced oxidation process; Kraft A et al.; Boron-doped diamond anodes allow to directly produce OH* radicals from water electrolysis with very high current efficiencies . This has been explained by the very high overvoltage for oxygen production and many other anodic electrode processes on diamond anodes . Additionally, the boron-doped diamond electrodes exhibit a high mechanical and chemical stability . Anodic oxidation with diamond anodes is a new advanced oxidation process (AOP) with many advantages compared to other known chemical and photochemical AOPs . The present work reports on the use of diamond anodes for the chemical oxygen demand (COD) removal from several industrial wastewaters and from two synthetic wastewaters with malic acid and ethylenediaminetetraacetic (EDTA) acid . Current efficiencies for the COD removal between 85 and 100% have been found . The formation and subsequent removal of by-products of the COD oxidation has been investigated for the first time . Economical considerations of this new AOP are included.

Environ Sci Technol, 2003 Oct 1, 37(19), 4449 - 56
Removal of hexavalent chromium from wastewater using a new composite chitosan biosorbent; Boddu VM et al.; A new composite chitosan biosorbent was prepared by coating chitosan, a glucosamine biopolymer, onto ceramic alumina . The composite bioadsorbent was characterized by high-temperature pyrolysis, porosimetry, scanning electron microscopy, and X-ray photoelectron spectroscopy . Batch isothermal equilibrium and continuous column adsorption experiments were conducted at 25 degrees C to evaluate the biosorbent for the removal of hexavalent chromium from synthetic as well as field samples obtained from chrome plating facilities . The effect of pH, sulfate, and chloride ion on adsorption was also investigated . The biosorbent loaded with Cr(VI) was regenerated using 0.1 M sodium hydroxide solution . A comparison of the results of the present investigation with those reported in the literature showed that chitosan coated on alumina exhibits greater adsorption capacity for chromium(VI) . Further, experimental equilibrium data were fitted to Langmuir and Freundlich adsorption isotherms, and values of the parameters of the isotherms are reported . The ultimate capacity obtained from the Langmuir model is 153.85 mg/g chitosan.

Ambio, 2003 Aug, 32(5), 358 - 61
Disinfection of septic tank and cesspool wastewater with peracetic acid; Heinonen-Tanski H et al.; Wastewaters of private household septic tanks and cesspools have been treated with peracetic acid (1-2 g L(-1)) . Adding 1 g L(-1) peracetic acid to wastewaters was easy and has been found to be effective in destroying enteric indicator microorganisms . The careful mixing of peracetic acid and wastewater was found to be important . Winter periods with frozen soil, ice and snow did not constitute extra problems . The bad smell of these wastewaters almost totally disappeared during the treatment . When wastewaters treated with peracetic acid were emptied into animal slurry tanks, hygienization still continued in the mixture of animal slurry and the wastewaters . These wastewaters could thus be released into agricultural soil without risk of microbiological pollution to groundwaters.

J Hazard Mater, 2003 Oct 1, 103(1-2), 65 - 78
Development of a high performance electrochemical wastewater treatment system; Feng C et al.; In order to construct a high performance electrochemical system for practical use in industrial and municipal wastewater treatment, laboratory scale electrochemical experiments were performed to select anode materials by applying pulse voltage . Based on the results obtained from laboratory experiments, a pilot plant of electrochemical treatment system (0.3 m3 h(-1)) was successfully developed, in which electrocoagulation and electrooxidation processes were used . The performance of the treatment system was evaluated by treating domestic wastewater, pond water containing algae and wastewater from hog raising . As a result, production of hydroxyl radicals detected with p-nitrosodimethylaniline (RNO) at Ti/RuO(2)-TiO(2) anode was larger than with a platinum anode, and hydroxyl radicals were not detected at Ti anode . Moreover, a significant difference in electrocatalytic properties for ammonia oxidation between platinum and Ti/RuO(2)-TiO(2) electrodes was not observed from the cyclic voltammogram . The removal of T-N, T-P, NH(4)-N and COD from domestic wastewater and pond water containing algae was approximately 90%, while the removal of chlorophyll-a (chl-a) of algae was approximately 100% . Although the electrochemical treatment system was effective on biologically treated wastewater from hog raising, the treatment of raw wastewater was not remarkable . Therefore, the electrochemical treatment system requires pretreatment when used with wastewater containing high concentrations of suspended solids.

FEMS Microbiol Lett, 2003 Oct 10, 227(1), 101 - 6
Isolation of Brachymonas petroleovorans CHX, a novel cyclohexane-degrading beta-proteobacterium; Rouviere PE et al.; A new bacterium that grows aerobically on cyclohexane was isolated from the wastewater plant of a petroleum refinery . This strain grows on a range of light hydrocarbons (C5-C10) as well as on some aromatic compounds such as toluene and m-cresol . Growth on hydrocarbons requires the presence of yeast extract and other complex media components that are not substrates for growth themselves . Strain CHX is resistant to cyclohexane and grows at concentrations up to 2 g l(-1) . Strain CHX branches deeply within the Comamonadeae family of beta-proteobacteria and is tentatively assigned to the Brachymonas genus as Brachymonas petroleovorans CHX.

Water Res, 2003 Nov, 37(19), 4645 - 56
Evolution of antibiotic occurrence in a river through pristine, urban and agricultural landscapes; Yang S et al.; A river along the semi-arid Front Range of Colorado was monitored for antibiotics including five tetracycline and six sulfonamide compounds . Existing analytical methods were adapted to measure these compounds in a surface water matrix at environmentally relevant concentrations (0.05 microg/L) . Natural organic matter present in surface waters was confirmed to significantly impact the low-level analysis of tetracyclines (TCs) necessitating the use of standard addition quantification techniques . Five sites along the Cache la Poudre River were monitored for antibiotics encompassing pristine areas without anthropogenic influence, urban areas impacted by wastewater discharges and agricultural areas susceptible to non-point source contaminant runoff . The only site at which no antibiotics were detected was the pristine site in the mountains before the river had encountered urban or agricultural landscapes . By the time the river had exited the urban area, 6 of the 11 antibiotic compounds that were monitored were found in the samples . At Site 5, which had both urban and agricultural influences all five of the TCs monitored were detected indicating both urban and agricultural influences . The concentration of TCs at Site 5 ranged from 0.08 to 0.30 microg/L.

Water Res, 2003 Nov, 37(19), 4605 - 12
Nylon fibers as supporting media in anaerobic hybrid reactors: it's effects on system's performance and microbial distribution; Chaiprasert P et al.; The performances of three anaerobic hybrid reactors with various nylon fiber densities per packed bed volume (33, 22, and 11 kg/m(3) in R1, R2, and R3, respectively) as supporting media were evaluated through their ability to remove organic compounds in cassava starch wastewater . In addition, the distributions of non-methanogenic and methanogenic population in the reactors were investigated . During a 6-month operation, the organic loading rate was increased in stepwise from 0.5 to 4.0 kg COD/m3/day and the hydraulic retention time (HRT) shortened to 5.4 days . The COD removal efficiency was more favorable in R1 (87%) and R2 (84%) than in R3 (70%) . The total biomass in the reactors with greater nylon fiber densities was also higher and increased from 20.4 to 67.3 g VSS and to 57.5 g VSS in R1 and R2, respectively . When the HRT was further shortened to 3 days, however, the efficiency of both reactors demonstrated a declining trend and reached 74% in R1 and 61% in R2 . The distribution of microbial populations involved in the reactors was determined using the Most Probable Number technique . The result showed the lowest number of methanogens in R3 which correlated well to its relatively low efficiency . The number of non-methanogens in all reactors was, nonetheless, comparable . By shortening the HRT to 3 days, the methanogenic population in R2 diminished in both attached and suspended biomass whereas a slight reduction was detected only in the attached biomass of R1.

Anal Bioanal Chem, 2004 Jan, 378(2), 470 - 8 Epub 2003 Oct 16.
The chromatographic behavior of group (IIB) metal ions on polyurethane foam functionalized with 8-hydroxyquinoline; El-Shahat MF et al.; Polyurethane foam functionalized with 8-hydroxyquinoline has been prepared by coupling the foam matrix with 8-hydroxyquinoline (oxine) through an azo spacer . The oxine-bonded foam (Ox PUF) was characterized by use of different tools (UV-Vis spectra, IR spectra, density, and stability) . Ox PUF was found to be very suitable for separation and preconcentration of trace metals, e.g . Zn(II), Cd(II), and Hg(II) ions, from wastewater in the pH ranges 2-12, 9-12, and 3-6, respectively . Various conditions influencing the sorption of these metal ions on to Ox PUF were optimized . Extraction of the metal ions was accomplished in 15 to 20 min . Study of the variation of the sorption of the tested metal ions with temperature yielded average values for DeltaH, DeltaS, and DeltaG of 41.99, 158.23, and -5.1 kJ mol(-1), respectively . The capacities of the foam material were 0.27, 0.16, and 0.09 mmol g(-1) for Zn(II), Cd(II), and Hg(II), respectively . Preconcentration factors >50 were achieved (RSD approximately 6.18) . The quantitative results were obtained from experiments performed using certified reference materials.

J Environ Sci (China), 2003 Sep, 15(5), 697 - 700
Treatment of black liquor from the papermaking industry by acidification and reuse; Yang WB et al.; Two different kinds of black liquor from the papermaking industry were treated by acidification and reuse . The experimental parameters and conditions were discussed in detail . The experimental results indicated that the treatment process mentioned in this article is an effective process for the treatment of black liquor from the papermaking industry . By the treatment, the solid materials in black liquor are transferred into two by-products and the other components are reused or evaporated . Thus, no wastewater except some condensation water would be discharged in pulping process and the problem of pollution of black liquor would be effectively solved.

J Environ Sci (China), 2003 Sep, 15(5), 652 - 61
United membrane biological reactor in the treatment of wastewater; Zhou JT et al.; The united membrane biological reactor( UMBR) was studied for the treatment of some simulate and municipal wastewater . The removal efficiency for COD and turbidity are greater than 80% and 99% respectively . Effluent COD is less than 100 mg/L while turbidity less than 5 . The removal of LAS in bath wastewater is greater than 70% . In treatment of dinning-hall wastewater, removal of fatty oil is greater than 90%, and its concentration in effluent is less than 5 mg/L . The match of biological reactor and the membrane separation component were calculated . The stable performance of wastewater treatment can be maintained by the optimization of operation conditions and the cleanout of membranes.

J Environ Sci (China), 2003 Sep, 15(5), 633 - 8
Immobilized chitosan as a selective absorbent for the nickel removal in water sample; Wu JM et al.; Method for preparation of chitosan immobilized on silica gel (CTS-silica) was described . The CTS-silica was used as absorbent for the absorption of nickel in water . The results showed that this absorbent had relatively high selectivity and strong affinity to nickel . The maximum absorption capacity for nickel can reach 667 mg/g of chitosan . Factors that affect the absorption capacity, such as pH, ion strength and the presence of calcium, EDTA and the mechanism of absorption were discussed in detail . The absorbent can be regenerated with acid and reused for several times . The recovery rate for nickel can reach 99.99% . This absorbent filled in a column can be used in nickel removal from wastewater and drinking water.

J Environ Sci (China), 2003 Sep, 15(5), 628 - 32
Comparison of decolorization of reactive microorganisms isolated from various sources; Padamavathy S et al.; Azo dyes are among the oldest man-made chemicals and they are still widely used in the textile, printing and the food industries . About 10% - 15% of the total dyes used in the industry is released into the environment during the manufacturing and usage . Some dyes and some of their N-substituted aromatic bio-transformation products are toxic and/or carcinogenic and therefore these dyes are considered to be envionmental pollutants and health hazards . These azo dyes are degraded by physico-chemical and biological methods . Of these, biological methods are considered to be the most economical and efficient . In this work, attempts were made to degrade these dyes aerobically . The organisms which were efficient in degrading the following azo dyes-Red RB, Remazol Red, Remazol Blue, Remazol Violet, Remazol Yellow, Golden Yellow, Remazol Orange, Remazol Black- were isolated from three different sources viz., wastewater treatment plant, paper mill effluent treatment plant and tannery wastewater treatment plant . The efficiency of azo dye degradation by mixed cultures from each source was analyzed . It was found that mixed cultures from tannery treatment plant worked efficiently in decolorizing Remazol Red, Remazol Orange, Remazol Blue and Remazol Violet, while mixed cultures from the paper mill effluent worked efficiently in decolorizing Red RB, Golden Yellow and Remazol Yellow . The mixed cultures from wastewater treatment plant efficiently decolorized Remazol Black.

J Environ Sci (China), 2003 Sep, 15(5), 622 - 7
Plants grown on sewage sludge in South China and its relevance to sludge stabilization and metal removal; Samake M et al.; The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government . The main sludge disposal method is landfill owing to heavy metal contamination, but it presents an attractive potential for agricultural land application . Experiments were carried out to study the simultaneous metal removal and sludge stabilization by plants . The sludge samples were collected from Datansha Wastewater Treatment Plant of Guangzhou, it contained excessive Cu and Zn compared with the Chinese National Standard for Agricultural Use of Sewage Sludge . Plants growing on sludge beds were investigated to follow their growth and metal uptake . 30 sludge plants were identified during 1 year's observation . A Zn high-accumulating and high growth rate plant(Alocasia macrorrhiza) was selected and grown on sludge beds in plots . The water, organic matter, heavy metals and nutrients contents, the E . coli number and the cress seed germination index were monitored for the sludge samples collected monthly . The plant growth parameters and its heavy metals contents were also determined . The sewage sludge treated by plants could be stabilized at about 5 months, the E . coli number was significantly decreased and the cress seed germination index attained 100% . Crop on sludge could ameliorate the sludge drying . The experiments are continuing to find out the appropriate plant combination for simultaneous sludge stabilization and metal removal for an acceptable period . Comparisons between the proposed processes and other methods for treating produced sludge such as composting, chemical andbacterial leaching were discussed.

Int J Epidemiol, 2003 Oct, 32(5), 772 - 7
Poliovirus detection in wastewater and stools following an immunization campaign in Havana, Cuba; Mas Lago P et al.; BACKGROUND: Recent outbreaks of poliomyelitis caused by vaccine-derived virus have raised concerns that vaccine-derived poliovirus may continue to circulate after eradication . In these outbreaks, the virus appears to have replicated for > or =2 years before detection . Early detection is critical for an effective response to these outbreaks . Although acute flaccid paralysis (AFP) surveillance will remain the standard for poliovirus detection, wastewater sampling could be a useful supplement . In this study, we evaluated the sensitivity of wastewater sampling by concurrently collecting stools from children aged < 3 years attending two neighbourhood clinics in Havana, Cuba, and wastewater from the same neighbourhoods . METHODS: Sample collection was begun during the third week after the national immunization campaign, continued weekly through the seventh week, and was repeated during weeks 15 and 19 . Virus detection and titration were performed using both cell culture and polymerase chain reaction techniques . RESULTS: Wastewater sampling was found to be at least as sensitive as stool sampling under these conditions . Poliovirus was isolated from children through week 7, suggesting that viral shedding reached undetectable levels between weeks 8 and 14 . The last virus-positive wastewater sample was collected during week 15 . CONCLUSIONS: Wastewater sampling under the conditions studied can be a sensitive supplement to AFP surveillance . Similar studies under different conditions are needed to determine the role of wastewater sampling in post-eradication surveillance.

Comp Biochem Physiol C Toxicol Pharmacol, 2003 Oct, 136(2), 117 - 25
Effects of municipal effluents on serotonin and dopamine levels in the freshwater mussel Elliptio complanata; Gagne F et al.; Sex differentiation and gametogenesis represent critical steps in the reproductive process and are subject to hormonal control by serotonin, dopamine and steroids such as estradiol-17beta and testosterone . The purpose of this study sought to examine the endocrine-disrupting activity that a primary-treated municipal effluent might have on the metabolism of biogenic amine levels . First, serotonin receptors transfected in Chinese hamster ovary (CHO) cells were used to screen for the presence of serotonin receptor agonist or antagonist . Second, one group of Elliptio complanata mussels were exposed to single compounds likely to be found in municipal wastewaters and another group was exposed in situ to the municipal effluent plume for 90 days in experimental cages . Results showed that solid phase C-8 extracts of surface water downstream a municipal effluent could activate the transport of serotonin by receptors at a distance of at least 5 km from its outfall thereby indicating the presence of serotonin mimics in the effluent dispersion plume . Levels of serotonin and monoamine oxidase (MAO) activity in nerve ganglia of mussels exposed for 90 days to the municipal effluent were, respectively, reduced and increased at a distance 10-km downstream . Injections of estradiol-17beta and nonylphenol in mussels decreased the levels of serotonin and dopamine, but increased MAO activity in the gonad and nerve ganglia . Exposure to estrogenic chemicals present in municipal effluents may therefore alter the normal metabolism of serotonin and dopamine, both of which are involved in sexual differentiation in bivalves and fish . Chemicals acting through E2 receptor-mediated pathways and serotonin receptors are likely to cause the observed effects.

J Chromatogr A, 2003 Oct 3, 1014(1-2), 129 - 39
Potential of microemulsion electrokinetic chromatography for the separation of priority endocrine disrupting compounds; Fogarty B et al.; This work examines the potential of microemulsion electrokinetic chromatography for the separation of several priority endocrine disrupting compounds (EDCs) . The optimised microemulsion system comprised 25 mM phosphate buffer pH 2, 80 mM octane, 900 mM butanol, 200 mM sodium dodecyl sulphate and was further modified with 20% propanol . The use of a low pH buffer resulted in the suppression of electroosmotic flow within the capillary . Reversal of the conventional electrode polarity resulted in faster migration of hydrophobic compounds . Test analytes included the octylphenol, nonylphenol and nonylphenol diethoxylate, which are breakdown products of the alkylphenolic detergents . The synthetic oestrogens diethylstilbestrol and ethynyloestradiol were also included in the separation along with the plastic monomer bisphenol-A . Test analytes were selected due to their reported presence in environmental samples namely industrial and domestic wastewater treatment effluents and sludges . Using the optimised method a separation of six EDCs was achieved within 15 min . The optimised method was then applied to the analysis of a spiked wastewater influent sample with UV detection of all six compounds at 214 nm.

Huan Jing Ke Xue, 2003 Jul, 24(4), 105 - 8
{Phosphorus removal of agriculture wastewater through subsurface constructed wetland}; Zhang R et al.; Phosphorus removal in subsurface constructed wetland treating agriculture non-pointed wastewater was studied in pilot-scale . The experimental results showed that the removal rates of TP increased with HRT increasing when the nominal hydraulic retention time was less than 5 days . The pH decreased distinctly when the retention time was too longer in the batch and sequence style, it may bring on a lower removel rate of TP . The amount of TP that can be removed by harvesting were about 15.8% and 9.5% compared to the total quantity of removing in Phragmitas communis and zizania caduciflora constructed system respectively . Temperature impacted on the removel of TP, the removel rate of TP decreased 30% in the winter compared to summuer.

Huan Jing Ke Xue, 2003 Jul, 24(4), 68 - 72
{Bulking controls induced by nitrogen insufficiency in yeast system}; Han Y et al.; The effect of nitrogen addition to salad oil manufacturing wastewater system was studied . The results of batch experiments demonstrated: 1 . addition of nitrogen was helpful to improve oil removal, and the oil removal rate was above 90% when COD/N value was between 50/1 and 20/1; 2 . addition of nitrogen improved the sludge settleability, which was much better under COD/N value of 50/1 and 20/1 . In the continuous experiment, the value of slude volume index(SVI) was between 100 and 200, and the removal rates of oil and COD were above 95% and 90%, respectively when the COD/N ratio was kept at value of 20/1 . Nitrogen addition to salad oil manufacturing wastewater system is an effective method for preventing or controlling sludge bulking.

Huan Jing Ke Xue, 2003 Jul, 24(4), 35 - 40
{Effect of inorganic nitrogen compounds and pH on the growth of duckweed}; Chong Y et al.; The use of duckweed in domestic wastewater treatment was paied increasing attention recently . But inorganic nitrogen compounds and pH of wastewater possibly affect the growth of duckweed . The effect of ammonia, nitrate and pH on the growth of Lemna minor L., a common spiece in China, was assessed with laboratory scale experiments . The experiments used artificial culture with different levels of pH, ammonia and nitrate concentrations . The experimental results indicated that the lowest value of pH Lemna minor can tolerate was between 5-6, and it can grow well in pH from 6 to 9 . The growth rate of Lemna minor was inhibited gradually with increasing concentration of ammonia . The toxicity of ammonia was a result of both forms, NH3 and NH4+ . Compared to NH4+, the effect of NH3 was much stronger . Nitrate had few inhibitory on the growth of Lemna minor . The increase in ammonia and nitrate concentrations can increase the chloropyll content of Lemna minor . Activity of peroxidase of Lemna minor in ammonia culture was higher than that in nitrate culture because of the toxicity of ammonia.

J Environ Manage, 2003 Oct, 69(2), 193 - 200
Fed-batch and batch operating mode analysis of a stirred anaerobic sequencing reactor with self-immobilized biomass treating low-strength wastewater; Rodrigues JA et al.; This work presents an analysis of a stirred anaerobic sequencing discontinuous reactor with different substrate feeding strategies resulting in batch, fed-batch/batch and fed-batch operating modes . The reactor, containing granulated biomass, was fed with approximately 2.0L of synthetic domestic wastewater with Chemical Oxygen Demand of nearly 500 mg/L per cycle and operated at 30 degrees C and 50 rpm . Three feeding strategies with a total cycle time of 6 h, including 30-min settling, were adopted: batch mode with a fill cycle of 6 min, a fed-batch/batch mode with fill cycles of 60, 120 and 240 min and fed-batch mode with a fill cycle of 320 min . The system attained average non-filtered and filtered substrate removal efficiency of 78 and 84%, respectively, for all operating conditions, presenting good stability, solid retention and no granule break-up . A first order kinetic model with a residual organic matter concentration was proposed to analyze the influence of the feeding strategy on the performance during a cycle and bicarbonate alkalinity and total volatile acids concentration profiles were also quantified in order to verify the transient stability behavior.

J Environ Manage, 2003 Oct, 69(2), 187 - 91
Removal of heavy metals in rinsing wastewater from plating factory by adsorption with economical viable materials; Katsumata H et al.; The removal of heavy metals from plating factory wastewater with economical materials was investigated by the column method . Montmorillonite, kaolin, tobermorite, magnetite, silica gel and alumina were used as the economical adsorbents to wastewater containing Cd(II), Cr(VI), Cu(II) and Pb(II) . This removal method of heavy metals proved highly effective as removal efficiency tended to increase with increasing pH and decrease with increasing metal concentration . The removal percentages by adsorption onto montmorillonite, tobermorite, magnetite, and silica gel showed high values for all metals . From the results for the heat of adsorption, the adsorption process in the present study might be chemisorption . The proposed method was successfully applied to the removal of Cd(II), Cr(VI) and Cu(II) in rinsing wastewater from plating factory in Nagoya City, Aichi Prefecture, Japan . Since the economical adsorbents used can be obtained commercially because they are easily synthesized, the wastewater treatment system developed is rapid, simple and cheap for the removal of heavy metals.

Chemosphere, 2003 Dec, 53(10), 1211 - 20
Experimental design of Fenton and photo-Fenton reactions for the treatment of cellulose bleaching effluents; Torrades F et al.; Multivariate experimental design was applied to the treatment of a cellulose conventional bleaching effluent in order to evaluate the use of the Fenton reagent under solar light irradiation . The effluent was characterised by the general parameters total organic carbon (TOC), chemical oxygen demand and color, and it was analysed for chlorinated low molecular weight compounds using GC-MS . The main parameters that govern the complex reactive system: Fe(II) and H(2)O(2) initial concentration, and temperature were simultaneously studied . Factorial experimental design allowed to assign the weight of each variable in the TOC removal after 15 min of reaction . Temperature had an important effect in the organic matter degradation, especially when the ratio of Fenton reagents was not properly chosen . Fenton reagent under solar irradiation proved to be highly effective for these types of wastewaters . A 90% TOC reduction was achieved in only 15 min of treatment . In addition, the GC-MS analysis showed the elimination of the chlorinated organic compounds initially detected in the studied bleaching effluents.

Biotechnol Adv, 1988, 6(4), 725 - 70
The potential of microalgal biotechnology: a review of production and uses of microalgae; de la Noue J et al.; An overview of the various aspects, promises and limitations of microalgal biotechnology is presented . The factors of importance in microalgal cultivation as well as the culture systems are briefly described . Microalgal biomasses can fulfil the nutritional requirements of aquatic larvae and organisms . The biochemical composition of algae can be improved by the manipulation of culture conditions . The nutritive value of the microalgal biomasses for human and animal consumption is also commented upon as well as some socio-economical aspects . Among the sources of required nutrients (N, P), wastewaters and manures can upgraded as culture media for microalgae the safety of which has to be evaluated . Harvesting of the biomass is one of the bottlenecks . The various techniques, physical, physico-chemical and biological are outlined and their feasibility and economic interest examined . Microalgal biomasses can be submitted to various technological transformations . Various processes are reviewed in the light of their effects on safety and nutritional value . The possible extraction of fine chemicals and the preparation of protein concentrates is also reported on . The various uses of microalgae lead to a possible competition, to be evaluated, between systems for the production of food, energy and chemicals . The review finally covers the application of genetic manipulation to microalgae.

Biotechnol Adv, 1984, 2(2), 357 - 75
Anaerobic fluidised bed for the purification of effluents from chemical and mechanical pulping; Salkinoja-Salonen M et al.; Anaerobic treatment has seldom been used for wastewaters from the pulp and paper industry and other branches of the chemical industry . Escape of volatile pollutants to the atmosphere, which always occurs during aerobic treatment, is avoided, and much less sludge is being produced than in an aerobic process . The greatest obstacle for using anaerobic treatment in the pulp and paper industry is the large wastewater volume, which necessitates short hydraulic detention times, because the treatment is to occur in an enclosed space . We used solid carrier particles to prevent wash-out of biomass from the reactor at high hydraulic loading, and an up-flow system in order to be able to use very small carrier particles, maximizing the surface area for biomass attachment . In this paper we describe and discuss the results obtained with this type of anaerobic reactor (fluidised bed) at bench and semitechnical scale for wastewaters from pressurized ground wood pulping and paper manufacture, sulphite pulp evaporator condensate and bleach waste . Earlier work with Kraft pulp bleaching effluent and thermomechanical pulping wastewater and evaporator condensates using anaerobic reactors is also discussed . The results obtained thus far show that there are several wastewater streams from the pulping industry, where 60 to 90% of the dissolved organic pollutants (measured as COD(Cr) or TOC) was biodegraded within 4 to 24 h . The high strength waste streams (COD(Cr) >2000 mg O(2) 1(-1)) allowed organic space load of 4 to 10 kg COD(Cr) m(-3) reactor volume d(-1) . With low strength wastes the hydraulic loading was the limiting factor.

Biotechnol Adv, 1992, 10(4), 549 - 59
Bioaugmentation for enhancing biological wastewater treatment; Stephenson D et al.; The literature on bioaugmentation products has been reviewed . Their manufacture and method of use is explained . The various applications are listed and the independent investigations, as opposed to manufacturers accounts, at laboratory and full scale are reviewed . The economics and kinetic modelling are also discussed . In laboratory investigations bioaugmentation often failed, whereas at full scale it was often successful, probably due to the imposition of steady state at laboratory scale . Most products require a period of acclimatisation before working; this and other possible reasons for failure are discussed.

Biotechnol Adv, 1993, 11(4), 781 - 812
Bioremoval of heavy metals by the use of microalgae; Wilde EW et al.; Bioremoval, the use of biological systems for the removal of metal ions from polluted waters, has the potential to achieve greater performance at lower cost than conventional wastewater treatment technologies for metal removal . Bioremoval capabilities of microalgae have been extensively studied, and some commercial applications have been initiated . Although microalgae are not unique in their bioremoval capabilities, they offer advantages over other biological materials in some conceptual bioremoval process schemes . Selected microalgae strains, purposefully cultivated and processed for specific bioremoval applications, have the potential to provide significant improvements in dealing with the world-wide problems of metal pollution . In addition to strain selection, significant advances in the technology appear possible by improving biomass containment or immobilization techniques and by developing bioremoval process steps utilizing metabolically active microalgae cultures . The latter approach is especially attractive in applications where extremely low levels of residual metal ions are desired . This review summarizes the current literature, highlighting the potential benefits and problems associated with the development of novel algal-based bioremoval processes for the abatement of heavy metal pollution.

J Environ Qual, 2003 Sep-Oct, 32(5), 1851 - 6
Biosolids-derived nitrogen mineralization and transformation in forest soils; Wang H et al.; Utilization of biosolids through land application is becoming increasingly popular among wastewater managers . To minimize the potential contamination of receiving waters from biosolids-derived nitrogen (N), it is important to understand the availability of N after land application of biosolids . In this study, four secondary biosolids (two municipal and two pulp and paper industrial biosolids) were used in a laboratory incubation experiment to simulate N mineralization and transformation after land application . Municipal biosolids were from either aerobically or anaerobically digested sources, while pulp and paper industrial biosolids were from aerated wastewater stabilization lagoons . These biosolids were mixed with two New Zealand forest soils (top 100 mm of a volcanic soil and a brown soil) and incubated at two temperatures (10 and 20 degrees C) for 26 wk . During incubation, mineralized N was periodically leached from the soil-biosolids mixture with 0.01 M CaCl2 solution and concentrations of NH4 and NO3 in leachate were determined . Mineralization of N from aerobically digested municipal biosolids (32.1%) was significantly more than that from anaerobically digested biosolids (15.2%) . Among the two pulp and paper industrial biosolids, little N leached from one, while as much as 18.0% of total organic N was leached from the other . As expected, mineralization of N was significantly greater at 20 degrees C (average 22.8%) than at 10 degrees C (average 9.7%) . It was observed that more N in municipal biosolids was mineralized in the brown soil, whereas more N in pulp and paper industrial biosolids mineralized in the volcanic soil . Transformation of NH4 to NO3 was affected by soil type and temperature.

J Environ Qual, 2003 Sep-Oct, 32(5), 1677 - 83
Assessing the application of an additive model to estimate toxicity of a complex effluent; Ross KE et al.; A number of industries monitor levels of chemicals in their effluent, but few have undertaken prolonged biological monitoring of this wastewater . The focus of the present study was to determine whether past chemical data for effluent from a lead smelter could be used to estimate its past toxicity . Since the interactive effects of metals in effluents are often assumed to be additive, it was hypothesized that an additive model, 100/{sigma(metal concentration in effluent/EC50 for individual metal)}, could be used to generate an EC50 from chemical data (where EC50 is the concentration of test material that affects 50% of the test organisms) . To test the approach, a larval development toxicity test with the marine polychaete, Galeolaria caespitosa, was used to test 26 separate samples of effluent from a lead smelter, generating empirical EC50 values . EC50 values for each individual metal in the effluent were also generated using the larval development toxicity test . The concentrations of trace metals in each effluent sample were determined and, using the additive model, EC50 values were calculated . For the majority of effluent samples tested, the additive model underestimated toxicity, suggesting the presence of additional unidentified contaminants in the effluent samples . Additionally, a nonlinear rather than linear regression curve was found to best describe the relationship between the model and empirically derived EC50 values . This relationship was then used to estimate past trends in toxicity of the smelter effluent . Forty-eight percent of the variability in measured toxicity was explained by the model, with the model underestimating toxicity in the majority of samples.

J Environ Qual, 2003 Sep-Oct, 32(5), 1583 - 90
The capacity of duckweed to treat wastewater: ecological considerations for a sound design; Korner S et al.; Duckweed species are promising macrophytes for use in sustainable wastewater treatment due to their rapid growth, ease of harvest, and feed potential as a protein source . This paper reviews growth rates of different duckweed species on wastewater and ammonia toxicity to duckweed and summarizes insights into the mechanism of organic matter and nutrient removal . Results were gained from laboratory experiments in small, shallow, duckweed-covered semicontinuous batch systems . Growth rates on different types of wastewater vary considerably among different species . Ammonia is toxic for duckweed in both the ionized and un-ionized forms . Duckweed, however, can be used to treat wastewater containing very high total ammonia concentrations as long as certain pH levels are not exceeded . The degradation of organic material is enhanced by duckweed through both additional oxygen supply and additional surface for bacterial growth . The duckweed mat with attached bacteria and algae is, independent of the loading rates, responsible for three-quarters of the total nitrogen (N) and phosphorus (P) loss in very shallow systems . Based on our results we suggest that full-scale pilot plants with duckweed should be shallower than the range encountered in the literature . A harvesting schedule that allows doubling times of 2 to 3.5 d, maintenance of a full coverage, and plug flow conditions are recommended.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(11), 2621 - 31
Removal of reactive dye from wastewater by adsorption using ECH cross-linked chitosan beads as medium; Chiou MS et al.; The feasibility of the removal of reactive dye from wastewater using a novel adsorbent, ECH cross-linked chitosan beads, as medium was examined . The effect of the pH and the initial concentration of the dye (RR222) solution on the adsorption capacity of the ECH cross-linked chitosan beads were also investigated . It was found that the initial dye concentration and the pH of the solution significantly affected the adsorption capacity . An increase in initial dye concentration results in the increase of adsorption capacity while an acidic pH was found to be favorable for the adsorption of dye . It was also found that the equilibrium adsorption of RR222 could be adequately described by using the Langmuir model (r2 > or = 0.999) . Moreover, results showed that the adsorption rate of RR222 onto ECH cross-linked chitosan beads could be described by using the second-order kinetic model, suggesting that chemical sorption instead of mass transfer was the rate-limiting step for the adsorption process . The maximum monolayer adsorption capacity obtained from the Langmuir model was extremely high as compared to the data reported in literature; 2252 g/kg at 30 degrees C with a pH of 3.0 . Therefore, ECH cross-linked chitosan beads could be a feasible medium for the removal of reactive dye from wastewater and potentially an alternative for the decolorization of wastewater.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(11), 2537 - 47
Odor control in evaporation ponds treating olive mill wastewater through the use of Ca(OH)2; Lagoudianaki E et al.; Different amounts of Ca(OH)2 were added in 2 L beakers containing 1 L of olive mill wastewater (OMW) . The mixture was stirred for 45 min and left to settle . Wastewater analysis was used in order to determine the effect of the different amounts of calcium hydroxide in the treating process, three days after the application . The Odor Detection Threshold was used for determining the effect of the treatment in the odors produced in the beakers, three and 30 days after . Both sets of measurements indicated an important reduction in wastewater pollutants and odor emission when 10 g/L of Ca(OH)2 were added . In order to evaluate these results in more realistic conditions . 10 L plastic containers were filled with 6 L of OMW, relevant amounts of Ca(OH)2 were added, the mixture was stirred manually and left to settle in the open . Again, 10 g/L of calcium hydroxide produced the best results in odor reduction and wastewater treatment.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(11), 2521 - 35
VOC emission characteristics of petrochemical wastewater treatment facilities in southern Taiwan; Cheng WH et al.; The wastewater treatment plants (WWTPs) of three representative petrochemical plants in southern Taiwan were sampled to investigate their VOC emission characteristics . Generally, emissions decline along the process flow, while the VOC concentration accumulates to as much as around 2400mg/m3 (as total hydrocarbons) at several closed vessel vents during the primary treatment . VOC emission rates (g/s) and fluxes (g/m2 hr) exhibit a similar trend of reducing concentrations in the WWTPs . From the field analysis data . VOC emission potential is best indicated by the concept of emission flux rather than concentration or emission rate . The Water 8 emission model version 4, developed by the U.S . EPA in 1995, was used to simulate the emission rate . The output results were compared to the calculated VOC liquid-gas mass equilibrium based essentially on the saturated gas concentration (Cg*) of the individual VOC components in wastewater . The comparisons clearly identified the proposed mass transfer approach using (Cg* as a reliable timesaving alternative to Water 8, which requires numerous input parameters and water analysis data.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2369 - 79
Anaerobic digestion of municipal sludges with high silt content using granular seed; Atilla B et al.; The performance of anaerobic digestion of municipal sludge having high inorganic solid/silt in Tuzla Wastewater Treatment Plant (TWWTP) in Istanbul was evaluated using granular seed . High silt/solid content is the main problem related to wastewater collection system in TWWTP . Due to high TSS concentration of the influent, inorganic solid ratio reaches to 60-70% in the primary sludge that makes sludge digestion very difficult . The aim of this study was to evaluate the detrimental effects of inorganic silt/clay on anaerobic sludge solubilization of the primary sludge (PS), of the biological sludge (BS), and of the mixed sludge (50%PS + 50%BS) . Anaerobic solubilization was carried out in continuously stirred anaerobic reactors at mesophilic temperature (35 degrees C) . Results indicated significant total biogas productions in all reactors during digestion period . The biogas production of the primary sludge was higher than the biogas productions of the mixed sludge and the biological sludge . The methane contents of the primary, biological . and mixed sludges were found as around 72, 78, and 75%, respectively . When all types of sludges were used as substrates, the reactors removed VSS with a corresponding production of Soluble COD (SCOD) . The greatest degree of hydrolysis/acidogenesis was observed in all types of sludges in about 10 days of operation and became almost stable which indicated that the reactors were still in the hydrolysis/acidogenesis phase . VFAs measurements were well matched with SCOD results . In all reactors, observation of the conversion into methanogenic phase in about 1.5 month was not possible which might be attributed to high inorganic silt/clay and salinity content of TWWTP . High inorganic silt/clay and salinity might have decreased the biodegradability of all sludges and methanogenesis could not operate in early periods of digestion . Higher SCOD decreases might have been possible if longer treatment time and more optimal conditions for anaerobic solubilization were applied . The pH did not fall below the unfavorable range in all reactors during the study.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2339 - 48
Recycling and reuse of wastewater from a new-developed community using sand filtration, ultrafiltration, and ozonation; Ni CH et al.; In this study, the pilot apparatus combined with sand filtration, ozonation and ultrafiltration was established . Wastewater from the secondary treatment effluent in the new-developed community was taken as the sample for looking into the feasibility of domestic wastewater reuse and recycling . The test results by sand filtration, sand filtration/ultrafiltration, sand filtration/ozonation, and sand filtration/ultrafiltration/ozonation were compared for looking for appropriate treatment processes applied in the domestic wastewater reuse and recycling . Finally, cost analysis was carried out and sand filtration/ozonation process was suggested to be one of the best processes . The total cost is about 0.1-0.32 USD dollars per cubic meter of produced water by considering the capital and operation cost for five years in the small domestic wastewater treatment plant (50-750 CMD).

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2329 - 38
Operational strategies for a small wastewater treatment plant using OUR, microscopic analysis, and toxicity test; Meric S et al.; This study was focused on determining the optimal operational conditions of a small domestic wastewater treatment plant (SWP) with a flow rate of 1000 m3 d(-1) using oxygen uptake rate (OUR) data, microscopic analyses, and effluent toxicity testing with Daphnia magna in parallel to wastewater characterization . Chemical analyses of nine samples, taken from different points of the treatment plant over a nine months period, presented strong domestic wastewater characteristics . The plant performance for meeting discharge standards was not sufficient enough for TP parameter . Aeration capacity and sludge recycle ratio were adjusted to improve the performance of the system and to prevent any operational problems, such as bulking . Although the inflow was 100% toxic, effluent toxicity following treatment was decreased to 5% . Filamentous bacteria were in "excessive" amount . The dominant filamentous bacteria species were determined as Nostocoioda limicola II . Reevaluation of the discharge limits with respect to nutrient removal, geographic location, and receiving water quality subject to treatment effluent discharges.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2301 - 15
Aromatic amine degradation in a UASB/CSTR sequential system treating Congo Red dye; Isik M et al.; In this study an anaerobic (upflow anaerobic sludge blanket reactor)/aerobic (completely stirred tank reactor) sequential system was used to treat a synthetic wastewater with minerals and co-substrate together with 100-4000 mg L(-1) of Congo Red dye (Direct red 28) (CR), which is a banned azo dye in Turkey . The effect of hydraulic retention time (HRT) on the decolorization and the COD removal efficiency was investigated at constant 100 mg L(-1) Congo Red concentration . 77% of COD and 95% of color was removed at a HRT of 0.486 days and a maximum organic loading rate of 6.656 kg COD m(-3) day(-1) in the anaerobic/aerobic stage . In the continuous operations, 88% of COD, 99% of color and 91% of total aromatic amine (TAA) were removed at a HRT of 3.60 days and at a CR concentration of 4000 mg L(-1) . This corresponds to an organic loading rate of 1.81 kg COD m(-3) day(-1), and a CR dye loading rate of 46.37 g dye m(-3) h(-1), respectively, in the whole system . The TAA produced under anaerobic conditions was ultimately removed in the aerobic stage, resulting in very low aromatic amine recoveries (5-18%) in the last one . Therefore the aerobic effluents exhibited higher IC50 and specific methanogenic activities (SMA) compared to anaerobic and dye containing samples, indicating the reduced toxicity.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2251 - 8
Clay mineral batch process for color removal of textile wastewaters; Armagan B et al.; Textile industry effluents exhibit large amounts of dye chemicals, which create severe water pollution . It is therefore important to reduce the dye concentration in the wastewater before discharging into the environment . In this study, the ability of sepiolite to uptake different reactive dyes is investigated . The dyes used in the experiments are Everzol Black B, Everzol Yellow 3RS H/C, and Everzol Red 3BS . A number of parameters on adsorption has been investigated in order to establish the adsorption pattern of sepiolite . The effect of conditioning time, solid/liquid ratio, pH, temperature, and dye concentrations on adsorption are studied . Adsorption isotherms for different reactive dyes have been obtained using both natural and modified sepiolites . The maximum capacity of natural sepiolite for the reactive dyes occurs at around 0.1-1 mg/g . Therefore, the natural sepiolite appears to have a little capacity for reactive dyes . The zeta potential profiles of natural and modified sepiolites against pH are also examined . The modified sepiolite exhibited ten times higher performance than the natural sepiolite.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2219 - 28
Treatment of Cr(VI) and phenol by illuminated TiO2; Lee SM et al.; Industrial wastewater from organic chemical manufacturing and metal plating industries may contain significant amounts of refractory organic matter and heavy metals . Heavy metals such as Cr(VI) and refractory organic matter like phenol were simultaneously removed by reduction and mineralization, respectively, during photocatalytic process . Therefore, this study was carried out to evaluate the effects of phenol on the removal of Cr(VI) in several environmental conditions . Cr(VI) and phenol were more effectively eliminated in UV/TiO2 condition than either by UV or TiO2-alone . The removal efficiencies of Cr(VI) increased as the pH of the TiO2 slurry decreased, the concentration of phenol increased up to 10 mg L(-1), and nitrogen gas was used . Otherwise, the removal efficiencies of phenol were higher at O2-purged system and neutral pH . Without regard to purging gases, complete Cr(VI) removal was observed at pH 4 after 80 min while 90% phenol destruction and 60% mineralization were found after 120 min . It wasfound that application of photocatalytic reaction by using illuminated TiO2 to treat wastewater containing both Cr(VI) and phenol was possible.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2209 - 18
Comparative evaluation of the results for the synthetic and actual reactive dye bath effluent treatment by nanofiltration membranes; Koyuncu I et al.; In this study, the results of nanofiltration experiments carried out on reactive dye house wastewaters are presented . The experiments were performed using lab-scale membrane system . Permeate quality was appropriate to reuse permeate in dyeing process again . Pretreatment and neutralization were the parameters which are very important for the recovery of high amounts of salt and water at the permeate stream . In addition, use of HCl instead of H2SO4 for neutralization increased the NaCl recovery.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2125 - 34
Design of sequencing batch reactors for biological nitrogen removal from high strength wastewaters; Artan N et al.; This paper covers an evaluation of more than twenty full-scale industrial wastewater treatment plants employing sequencing batch reactor (SBR) process mainly for carbon removal and a pilot-scale SBR designed for carbon and nitrogen removal from tannery effluent . The study highlights the major features of the SBR technology and proposes a rational dimensioning approach for carbon and nitrogen removal SBRs treating high strength industrial wastewaters based on scientific information on process stoichiometry and modeling, also emphasizing practical constraints in design and operation.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2101 - 11
Treatment of mixed pharmaceutical industry and domestic wastewater by sequencing batch reactor; Ileri R et al.; Raw mixed pharmaceutical industry and domestic wastewater characteristics are such as BOD5 = 90-130 mg L(-1), COD = 200-300 mg L(-1), SS = 900 mg L(-1), pH = 6.4-6.8, T = 20 degrees C, NH3 = 26 mg L(-1), PO4(3-) = 8.5 mg L(-1) . In treatment plant, the parameters such as BOD5, NH3, PO4(3-), SS, MLVSS, pH, temperature, sludge volume and microorganisms predominance are studied, under constant sedimentation time (30 min) against variable aeration times . As a second step, the same parameters are studied under the constant aeration time (4 h) against variable sedimentation times . Effluent concentrations from sequencing batch reactor (SBR) are determined BOD5 = 13-18 mg L(-1), COD = 25-37 mg L(-1), SS= 9-21 mg L(-1), pH = 7.3-7.6, TDF = 1-2, T = 23 degrees C, NH3 = 1 mg L(-1), PO4(3-) = 8.1 mg L(-1) . At the end of 6 h of aeration time, the efficiency of BOD5 reaches to 83% . The efficiency of BOD5 reaches to 81% under a 4 h aeration time and at 90 min sedimentation time . As a result, the optimum treatment efficiency has been taken under 4 h of aeration time and of 60 min of sedimentation time.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2069 - 76
A dynamic model for anaerobic filter; Cakir FY et al.; Anaerobic filters are frequently used to treat medium to high strength wastewater (2000-20000 mg/L COD), but have fewer applications to low strength wastewater (< 1000 mg/L COD) . In order to understand the applicability of anaerobic treatment for low strength wastewater, such as domestic sewage, a dynamic mathematical model was developed . This Monod-type kinetic model, which predicts treatment efficiency and gas production, was used to describe literature observations and is offered as a predictive tool.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003, 38(10), 2019 - 28
Degradation of organic substances and reactive dye in an immobilized-cell sequencing batch reactor operation on simulated textile wastewater; Pasukphun N et al.; Textile wastewater generally consists of high organic substances and is strongly colored . Reactive dye has been used extensively in the textile industries . It is water soluble and difficult to remove by chemical coagulation . Removal of organic substances simultaneously with dye can be achieved by a biological process . This study aims to investigate the treatability of the organic substances and reactive dye in immobilized-cell sequencing batch reactors (SBR) . Three different supporting medias namely activated carbon, steel slag and plastic were used . The performance of each reactor was compared with a conventional sequencing batch reactor . The simulated textile wastewater containing the reactive azo dye Procion Red H-E7B of a concentration of 40 mg/L and COD 300 mg/L, was fed into the reactors . The supporting media in the SBR system, it will enhance the capability of COD and dye operating of the SBRs consisted of 5 periods; Fill 1.5 h, React (anoxic:oxic) 20 (14:6) h, Settle 1.5 h, Draw 0.5 h and Idle 0.5 h . The results revealed that by adding removal . During a steady state of operation, the COD and dye concentrations of each period were investigated . In addition, the prolonged anoxic period brought about better decolorization efficiency.

Environ Sci Technol, 2003 Sep 15, 37(18), 4281 - 7
Co-removal of hexavalent chromium through copper precipitation in synthetic wastewater; Sun JM et al.; The mechanisms of hexavalent chromium {Cr(VI)} co-removal with copper {Cu(II)} during homogeneous precipitation were studied with batch tests using a synthetic solution containing Cr(VI) and Cu(II) . Metal precipitation was induced by adding Na2CO3 stepwise to different pH, and the respective removals of Cu(II) and Cr(VI) were measured . At the same time, the relative quantities of Cu(II) and Cr(VI) in the precipitates were also analyzed to establish their stoichiometric relationship . The results indicated that, in a solution containing 150 mg/L Cu(II) and 60 mg/L Cr(VI), the initial co-removal of Cr(VII with Cu(II) began at pH 5.0 and completed at pH 6.2 . At pH 5.0-5.2, coprecipitation took place through the formation of copper-chromium-bearing solids {such as CuCrO4 and/or CuCrO4 x 2Cu(OH)2} . Thereafter, the remaining soluble copper started to react with carbonate in a heterogeneous environment to form the negatively charged basic copper carbonate precipitates {CuCO3 x Cu(OH)2}, which subsequently adsorbed additional Cr(VI) (or HCrO4-) at pH 5.2-6.2 . The maximum Cr(VI) co-removal took place at pH 6.2 . Between the two mechanisms, co-precipitation accounted for about 29% of the total chromium's co-removal while the remaining 71% was attributed to surface adsorption, mainly through electrostatic attraction and ligand exchange . When the solution pH was increased to beyond 7.5, a surface charge reversal took place on the basic copper carbonate solids, and this led to some Cr(VI) desorption . Thus, the extent of Cr(VI) adsorption is highly pH dependent.

Environ Sci Technol, 2003 Sep 15, 37(18), 4269 - 73
Use of copper shavings to remove mercury from contaminated groundwater or wastewater by amalgamation; Huttenloch P et al.; The efficacy of copper shavings (Cu(0)) for the removal of Hg2+ from aqueous solution by amalgamation is demonstrated . Two kinds of copper shavings were investigated: (a) chemically processed shavings (Fluka) and (b) recycled shavings from scrap metal . Batch sorption experiments yielded very high retardation coefficients of 28 850-82 830 for the concentration range studied (1-10 000 microg/L Hg2+ dissolved in distilled water or in a 0.01 M CaCl2 matrix solution) . Sorption data were well-described bythe Freundlich isotherm equation . Kinetic batch sorption experiments showed that 96-98% of Hg2+ was removed within 2 h . Column experiments were performed with a mercury solution containing 1000 microg/L Hg in a 0.01 M CaCl2 matrix with a flow rate of 0.5 m/d . No mercury breakthrough (c/c(0) = 0.5) could be detected after more than 2300 percolated pore volumes, and the high retardation coefficients determined in the batch studies could be confirmed . Copper was released from the shavings due to the amalgamation process and to copper corrosion by oxygen, resulting in concentrations of mobilized copper of 0.2-0.6 mg/L . Due to their high efficiency in removing Hg2+ from aqueous solution, the use of copper shavings for the removal of mercury from contaminated water is suggested, employing a sequential system of mercury amalgamation followed by the removal of mobilized copper by an ion exchanger such as zeolites . Possible applications could be in environmental technologies such as wastewater treatment or permeable reactive barriers for in situ groundwater remediation.

Waste Manag, 2003, 23(8), 709 - 17
Technical assessment of fuel cell operation on anaerobic digester gas at the Yonkers, NY, wastewater treatment plant; Spiegel RJ et al.; This paper summarizes the results of a 2-year field test to assess the performance of a specially modified commercial phosphoric acid 200-kW fuel cell power plant to recover energy from anaerobic digester gas (ADG) which has been cleansed of contaminants (sulfur and halide compounds) using a patented gas pretreatment unit (GPU) . Specific project goals include characterization of the fuel cell power plant emissions and verification of the GPU performance for removing sulfur contaminants . To remove halide contaminants from the ADG, a halide guard, consisting of a vessel with a metal oxide supported on alumina, was incorporated into the fuel cell reactant supply . This first-of-a-kind demonstration was conducted at the Yonkers, NY, wastewater treatment plant, a sewage processing facility owned and operated by Westchester County . Results have demonstrated that the ADG fuel cell power plant can produce electrical output levels close to full power (200 kW) with negligible air emissions of CO, NO(x), and SO(2) . The GPU removed virtually 100% of H(2)S and 88% of organic sulfur, bringing the overall sulfur removal efficiency of the GPU to over 99% . The halide guard removed up to 96% of the halides exiting the GPU.

Water Res, 2003 Jul, 37(13), 3061 - 9
Fenton oxidation of cork cooking wastewater--overall kinetic analysis; Guedes AM et al.; In the present work, the possibility of using chemical oxidation through Fenton's reagent for the pre-treatment of cork cooking wastewaters was exploited . Aiming both the selection of the best operating conditions (pH, Fe2+:H2O2 ratio and initial H2O2 concentration) and the evaluation of the overall reaction kinetics, trials were performed in a batch reactor . Operating at pH = 3.2, H2O2 concentration = 10.6 g/L and Fe2+:H2O2 ratio = 1:5 (by weight), about 66.4% of total organic carbon (TOC), 87.3% of chemical oxygen demand (COD) and 70.2% of biochemical oxygen demand (BOD5) were removed and an increase of the BOD5/COD ratio from 0.27 to 0.63 was achieved . In the temperature range 20-50 degrees C, the best performance was obtained at 30 degrees C . The kinetic study was undertaken at different initial TOC concentrations and temperatures . Overall kinetics can be described by a second-order followed by a zero-order rate equation and the apparent kinetic constants at 30 degrees C are k = 2.3 x 10(-4) L/mg min and k0 = 26.0 mg/L min, respectively . The experiments performed at different temperatures confirmed the global kinetic model and allowed to calculate the global activation energy for the second-order reaction (70.7 kJ/mol).

Water Sci Technol, 2003, 48(3), 25 - 30
Temperature effect on UASB reactor operation for domestic wastewater treatment in temperate climate regions; Lew B et al.; The performance of an upflow anaerobic sludge blanket (UASB) reactor was investigated for the treatment of domestic wastewater at different operational temperatures (28, 20, 14 and 10 degrees C) and loading rates . For each temperature studied a constant COD(t) removal was observed as long as the upflow velocity was lower than 0.35 m/h: 82% at 28 degrees C, 68% at 14 degrees C and 44% at 10 degrees C . At 20 degrees C the COD removal increased with the HRT, reaching similar values as at 28 degrees C for long HRT . At upflow velocities higher than 0.35 m/h, a reduction in total COD removal was observed due to washout of influent TSS . At 28 degrees C, a constant 200 g sludge mass was observed and COD removal was attributed to biological degradation only . At lower temperatures, COD removal resulted from degradation and solids accumulation in the reactor . The increase in reactor sludge was greater as the temperature decreased and explains the similar overall COD removal efficiency at 28 degrees C, 20 degrees C and 14 degrees C . During the transition from winter to summer conditions (10 degrees C to 28 degrees C), methane production initially increased due to the degradation of accumulated solids . Afterwards, methane production gradually declined and an increase in COD removal was observed, indicating that the TSS accumulated during the winter was exhausted and influent degradation remained.

Anal Bioanal Chem, 2004 Feb, 378(4), 926 - 31 Epub 2003 Sep 25.
HPLC-MS investigations of acidic contaminants in ammunition wastes using volatile ion-pairing reagents (VIP-LC-MS); Schmidt TC et al.; In order to hyphenate ion pairing chromatography and MS detection we used several types of formates as volatile ion pairing reagents (IPRs) instead of common tetraalkylammonium salts, as these salts tend to precipitate in the ion source . The formates were prepared by mixing formic acid with the corresponding amine . Both tributyl- and trihexylammonium formate proved to be valuable IPRs for the separation of acidic compounds like nitrobenzoic acids, nitrobenzenesulfonic acids and nitrated phenols . Due to the weaker retention of the ion-pairs with trialkylammonium formates compared with tetraalkylammonium compounds, either less organic modifier or a higher concentration of the IPR had to be used . With negative atmospheric pressure chemical ionization mass spectrometry and electrospray ionization mass spectrometry it was possible to unambiguously identify several acidic oxidation products of 2,4,6-trinitrotoluene (TNT) in ammunition wastewater and soil extracts . 2-amino-4,6-dinitrobenzoic acid was often found to be the main metabolite of TNT in such water samples.

Chemosphere, 2003 Dec, 53(9), 1131 - 6
Electrochemical degradation of bromopyrogallol red in presence of cobalt ions; Chen J et al.; This paper summarizes the results of a degradation test of bromopyrogallol red (BPR) and textile dye wastewater (TDW) with a conventional three-electrode potentiostatic system in the presence of cobalt ions (electro Co(2+)-H2O2 system) . H2O2, produced by the two-electron reduction of O2 at the cathode, would react with Co2+ ions, leading to the generation of hydroxyl radicals (*OH), which caused the degradation of the organic pollutants . With BPR degradation process as the reference point, the optimal conditions (pH=4.0 and the concentration of Co2+ is 0.1 mM) and the treating capacity of the system were both studied and compared with electro-Fenton's reagent . Many benefits were shown by the electro Co(2+)-H2O2 system, such as less metal ions consumption, more moderate conditions and faster reaction process . Treated with the system for 0.5 h, chemical oxygen demand and biological oxygen demand of TDW (pH=5.2), without pH adjustment, were reduced by 95.7% and 92.7%, respectively . These characteristics make the method another appropriate solution for wastewater treatment, especially for those contaminated by organic pollutants.

J Biotechnol, 2003 Oct 9, 105(1-2), 135 - 63
Nonlinear modeling and adaptive monitoring with fuzzy and multivariate statistical methods in biological wastewater treatment plants; Yoo CK et al.; A new approach to nonlinear modeling and adaptive monitoring using fuzzy principal component regression (FPCR) is proposed and then applied to a real wastewater treatment plant (WWTP) data set . First, principal component analysis (PCA) is used to reduce the dimensionality of data and to remove collinearity . Second, the adaptive credibilistic fuzzy-c-means method is used to appropriately monitor diverse operating conditions based on the PCA score values . Then a new adaptive discrimination monitoring method is proposed to distinguish between a large process change and a simple fault . Third, a FPCR method is proposed, where the Takagi-Sugeno-Kang (TSK) fuzzy model is employed to model the relation between the PCA score values and the target output to avoid the over-fitting problem with original variables . Here, the rule bases, the centers and the widths of TSK fuzzy model are found by heuristic methods . The proposed FPCR method is applied to predict the output variable, the reduction of chemical oxygen demand in the full-scale WWTP . The result shows that it has the ability to model the nonlinear process and multiple operating conditions and is able to identify various operating regions and discriminate between a sustained fault and a simple fault (or abnormalities) occurring within the process data.

Water Res, 2003 Nov, 37(18), 4544 - 52
Removal of As(V) from wastewaters by chemically modified fungal biomass; Loukidou MX et al.; Biosorption has been demonstrated to be a useful alternative to conventional treatment systems for the removal of toxic metals from dilute aqueous solution . The objective of this paper was to examine the main aspects of a possible strategy for the removal of arsenates, employing P . chrysogenum biomass . The pretreatment of biomass with common surfactants (as hexadecyl-trimethylammonium bromide and dodecylamine) and a cationic polyelectrolyte was found to improve the biosorption efficiency . The initial biomass showed a relative low affinity for metallic anions, whereas with the application of modified samples a significant uptake of arsenic was observed . Sorption data were well described by typical Langmuir and Freundlich adsorption isotherms . Promising results were obtained in laboratory experiments and effective As(V) removals were observed.

Water Res, 2003 Nov, 37(18), 4506 - 12
Direct spectrophotometric determination of alkylphenol polyethoxylate nonionic surfactants in wastewater; Zhu Z et al.; A new spectrophotometric method is proposed for direct determination of alkylphenol polyethoxylate, RO(CH(2)CH(2)O)(n)H (where R is alkylphenyl and n is the degree of polymerization), in wastewater . The method is based on the formation of ternary complex, Pb(II)-meso-tetra-(3,5-dibromo-4-hydrooxyphenyl)-Porphyrin (T(DBHP)P)-alkylphenol polyethoxylate (APE) . Under optimum reaction conditions, T(DBHP)P reacts with lead(II) and APE to form a yellow ternary complex with the maximum absorption peak at 479 nm . The color reaction is rapidly completed and the absorbance remains stable for at least 24h under room temperature . The apparent molar absorption coefficients were 0.4-4.3 x 10(4) L mol(-1) cm(-1) for n=5-50 . As little as 0.02 microg mL(-1) of APE can be detected . The effects of various substances on the determination of APE were also investigated in detail . It was found that all the studied co-existing substances, especially cationic and anionic surfactants, which always seriously interfere in some reported methods, could be tolerated in considerable amounts . The method offered the advantages of simplicity, rapidity, sensitivity and selectivity without any prior separation or extraction.

Water Res, 2003 Nov, 37(18), 4444 - 52
Interactions of silver with wastewater constituents; Wang J et al.; The interactions of silver ion with wastewater constituents including chloride, sludge particulates, and dissolved organic matter (DOM) were investigated using fresh and processed sludge samples from various municipal wastewater treatment plants . Fresh sludge samples were used to examine the silver removal characteristics in the presence of chloride . Processed sludge samples that were subjected to a deionized-water washing procedure to remove the chloride ion were used to examine the interactions among Ag(I), sludge solids, and DOM . Results showed that, under field conditions, most of the silver can be removed through precipitation with chloride and adsorption by sludge particulates . Results obtained using washed sludge samples showed that Ag(I) adsorption by sludge particulates increases with the increase of pH in the acidic pH range, but decreases with the increase of pH in the alkaline pH range . Since the DOM concentration increases significantly with the increase of pH in the alkaline pH region, it can be concluded that the formation of Ag(I)-DOM complexes reduces the Ag(I) adsorption by sludge . Fitting of the Langmuir isotherm to the adsorption data indicated that adsorption constants have a slight increase with the increase of pH in the acidic pH range, but decrease significantly with the increase of pH in the alkaline pH range . The decrease of the Ag(I) adsorption constants in the alkaline pH range can be attributed to the formation of Ag(I)-DOM complexes which weaken the Ag(I) binding strength by sludge surface sites . The fitted isotherms also showed that the Ag(I) adsorption capacity increases with the increase of pH in the entire pH range.

Water Sci Technol, 2003, 48(2), 357 - 64
Seasonal influence of waste stabilisation pond effluent on DAF/F (dissolved air flotation/filtration) process operation; Buisine F et al.; The Bolivar wastewater treatment plant (WWTP), North of Adelaide, South Australia encompasses the largest waste stabilisation pond (WSP) system in the Southern hemisphere . The wastewater effluent will ultimately be fully reused for agriculture irrigation . A dissolved air flotation/filtration (DAF/F) plant was installed for tertiary treatment downstream of the stabilisation lagoons for supply to the irrigation scheme . Chemical treatment in the form of coagulation and flocculation is required to assist the separation process . The DAF/F plant operation is highly dependent on the raw water algal population . Seasonal variations seem to be the main abiotic factors affecting the algal population growth . Significant doses of chemical can be required to respond to rapid changes of water quality . United Water International is currently assessing the appropriate chemical treatment for short-term response, and is also working with Flinders University of South Australia on determining ways to manage the lagoons and to control the water quality feeding the DAF/F plant in the long-term . This paper outlines the effect of seasonal variations of WSP effluent quality on the DAF/F process operation, the findings for an adapted chemical treatment, and the eventual possibilities for lagoon management.

Water Sci Technol, 2003, 48(2), 341 - 8
Effect of duckweed cover on greenhouse gas emissions and odour release from waste stabilisation ponds; van der Steen NP et al.; Treatment of wastewater in stabilisation pond systems prevents the negative environmental impact of uncontrolled disposal of sewage . However, even a natural treatment system may generate secondary negative environmental impacts in terms of energy consumption, emission of greenhouse gases and emission of odorous compounds . Whereas natural systems have an advantage over electro-mechanical systems in that they use less hardware and less energy, it is not yet known whether secondary environmental effects in the form of greenhouse gas emissions are lower for these systems . This research intends to be a first step in the direction of answering this question by assessing gas emissions from two types of natural systems, namely algae-based and duckweed-based stabilisation ponds . The H2S volatilisation from laboratory scale pond-reactors has been determined by drawing the air above the water surface continuously through a solution of 1 M NaOH for absorption of sulphide . The amount of H2S that volatilised from the algae pond-reactor, and was trapped in the NaOH trap, was found to be 2.5-86 mg/m2/day . The H2S volatilisation from the duckweed pond-reactor was found to be negligible, even though the sulphide concentration was 9.7 mg/l S(2-) . The duckweed cover was a physical barrier for volatilisation, since bubbles were trapped in the cover . In addition the duckweed layer was found to be afavourable environment for both aerobic sulphide oxidisers (Beggiatoa gigantae) as well as for photosynthetic purple sulphur bacteria belonging to the genus Chromatium . These may also have contributed to the prevention of H2S volatilisation . Results on methane emissions were not conclusive so far, but the same mechanisms that prevent H2S volatilisation may also prevent methane volatilisation . Therefore it was concluded that duckweed covers on stabilisation ponds may reduce the emission of both odorous and greenhouse gases.

Water Sci Technol, 2003, 48(2), 331 - 9
Linking pond and wetland treatment: performance of domestic and farm systems in New Zealand; Tanner CC et al.; Wetland systems have been used extensively to supplement and upgrade waste stabilisation pond treatment systems in New Zealand . Key attributes of wetlands, such as low operational costs, minimal reliance on machinery and external energy inputs, high wildlife habitat values, and perceived "naturalness", complement those of pond systems . Performance data for a range of New Zealand post-pond constructed wetlands treating sewage, dairy farm and piggery wastewaters show BOD and SS concentrations can be readily reduced to low levels . Bacterial indicators are commonly reduced by at least one log unit, but levels below 500 cfu (100 mls)(-1) are difficult to achieve consistently . Nutrient removal efficiency is highly dependent on loading rates and wastewater characteristics . Plant establishment and maintenance, wildlife management, hydraulic design and adequacy of preceding treatment are identified as key practical issues in the implementation and management of constructed wetland systems.

Water Sci Technol, 2003, 48(2), 323 - 30
An evaluation of duckweed-based pond systems as an alternative option for decentralised treatment and reuse of wastewater in Zimbabwe; Nhapi I et al.; A study was carried out in Zimbabwe to evaluate the performance of duckweed ponds as an option for treating and reusing wastewater in small, decentralised communities . The study focused on nitrogen and phosphorus removal, operational problems, and duckweed application . Two full-scale trial plants at Nemanwa and Gutu-Mupandawana growth points were used . Sewage samples were collected and analysed monthly from September 2000 to August 2001 for NO3, NH4(-)1 TKN, TP, COD, and other field measurements . The duckweed was harvested daily and fed to chickens . The Nemanwa plant had high nutrient levels due to nil outflows caused by water rationing in the area . The Gutu effluent had averages of 38.7 +/- 23.1 mg/l TN and 7.5 +/- 2.4 mg/l TP which are above the respective Zimbabwean standards of 10 mg/l TN and 1 mg/l TP . COD removal efficiency at Gutu was poor at 45% . The performance of Gutu and Nemanwa plants suffered from inappropriate design especially pond depth and short-circuiting . The duckweed died off in the November-January period, this being attributed to excessive levels of ammonia . It was concluded that the duckweed pond systems would offer a good alternative for managing and reusing wastewater at community level provided due regard is paid to appropriate design criteria.

Water Sci Technol, 2003, 48(2), 307 - 14
Removal of organics and nutrients from tannery effluent by advanced integrated Wastewater Pond Systems technology; Tadesse I et al.; In this study, a pilot-scale experiment was carried out on a pre-settled combined tannery effluent from Modjo tannery, Ethiopia, to evaluate the feasibility of the Advanced Integrated Wastewater Pond Systems or AIWPS Technology, for the treatment of tannery effluent . The pilot-scale AIWPS Facility was comprised of an Advanced Facultative Pond (AFP), Secondary Facultative Pond (SFP) and Maturation Pond (MP) all arranged in series . Three feed phases with low, moderate and overloading organic loading rates were applied to assess the organics and nutrients removal performances of the AIWPS reactors . The overall organics removal performance of the AIWPS Process was high, with removal efficiencies in the range of 90-98% for BOD5 and 86-92% for COD . Among the AIWPS reactors, the AFP attained the highest organics removal efficiency with a BOD5 removal of 70-89% . BOD5 removal efficiencies of the SFP and MP were 34-65% and 30-40%, respectively . The AFP was also able to withstand a much higher volumetric organic loading rate (70% more) than the conventional open anaerobic ponds . The drop in BOD5 removal efficiency of the AFP at the overloading condition was only 7%, while the corresponding drop in the SFP was 29% . AIWPS reactors achieved a cumulative ammonia removal efficiency of 85% . The highest ammonia removal (50-60%) occurred in the SFP, followed by the MP with removal efficiency of 20-26% . At the overloading condition the overall ammonia removal efficiency of the AIWPS Facility decreased by 50%, while the BOD5 organics removal dropped by only 6%, signifying the higher vulnerability of ammonia removal mechanism to high loading conditions than the organics removal . The phosphorus removal in the AIWPS Facility was erratic, with highest removal (up to 75%) occurring in the AFP . The lack of H2S odour nuisance from the AFP was mainly due to the proliferation of sulphide oxidizing anoxygenic photosynthetic pink bacteria of the genera: Thiocystis, Rhodobacter, Rhodospirillum and Rhodopseudomonas in the upper solar illuminated water layers of the AFP.

Water Sci Technol, 2003, 48(2), 299 - 305
Selenium and nitrate removal from agricultural drainage using the ALWPS technology; Green FB et al.; Monthly Maximum Discharge Limits (MMDL) have been established for selenium in irrigation drainage by the State of California and the U.S . Environmental Protection Agency following observations of avian teratogenesis at the Kesterson Reservoir in the San Joaquin Valley of California . As a result of these and other adverse effects, farmers and drainage districts on the western side of the San Joaquin Valley must reduce selenium concentrations in irrigation drainage discharged to the San Joaquin River . Drainage treatment will be required in the near future to meet existing MMDL and future Total Maximum Discharge Limits (TMDL) for the San Joaquin River . A 0.4-hectare Algal Bacterial Selenium Removal (ABSR) Facility was designed and constructed at the Panoche Drainage District in 1995 and 1996 using the Advanced Integrated Wastewater Pond Systems or AIWPS Technology . Each of two physically identical systems combined a Reduction Pond (RP) with a shallow, peripheral algal High Rate Pond (HRP) . A Dissolved Air Flotation (DAF) unit and a slow sand filter were used to remove particulate selenium from the effluent of each system . The two systems were operated under different modes of operation and the bacterial substrate varied in each system . The rates of nitrate and selenium removal were compared . Microalgae were harvested using DAF and used as a carbon-rich substrate for nitrate- and selenate-reducing bacteria . Mass removals of total soluble selenium of 77% or greater were achieved over a three-year period . Nitrate and selenate were removed by assimiliatory and dissimiliatory bacterial reduction, and nitrate was also removed by algal assimilation . The final removal of particulate selenium is the focus of ongoing investigations . The removal of particulate selenium is expected to increase the overall removal of selenium to greater than 90% and would allow farmers and drainage districts to discharge irrigation drainage in compliance with regulatory discharge limits.

Water Sci Technol, 2003, 48(2), 259 - 67
Advanced pond system: performance with high rate ponds of different depths and areas; Craggs RJ et al.; Many domestic Wastewater Stabilisation Ponds (WSPs) or oxidation ponds in New Zealand require upgrading to reduce pollution of receiving waters . Advanced Pond Systems (APS) consisting of an Advanced Facultative Pond, High Rate Pond, Algae Settling Pond and Maturation Pond may provide a cost effective upgrade option . This paper presents the results of a 2-year study of the performance of two pilot APS systems with High Rate Ponds of different depths and areas . The HRPs of the APS systems both had the same flow rate (5 m3 d(-1)), volume (37.5 m3) and thus hydraulic retention time (7.5 d) . However, the East HRP had an operating depth of 0.30 m and a surface area of 128 m2, and the West HRP had an operating depth of 0.45 m and a surface area of 85 m2 . APS system performance was compared in terms of improvement of water quality . For nearly all parameters measured, there was little difference in performance between the two systems suggesting that the system with the smaller area could be used without affecting treatment . Comparison of final effluent with typical effluent of New Zealand WSPs showed that APS effluent was of higher quality and much less variable over time.

Water Sci Technol, 2003, 48(2), 243 - 50
Biogas production, sludge accumulation and mass balance of carbon in anaerobic ponds; Picot B et al.; This work concerned the application of anaerobic ponds for the primary treatment of urban wastewater in a Mediterranean climate . It was carried out on anaerobic ponds at large scale in Meze (France) . The anaerobic ponds constitute a good primary treatment with the removal of 55% of SS and 30% of BOD5, with a small surface area . The accumulation rate of sludge was only 0.017 m3/capita.year, due to their intensive anaerobic degradation . The anaerobic digestion reached equilibrium after one year of operation . The accumulation of sludge then showed seasonal variations with a substantial accumulation in winter and the digestion of the stock in summer . This change can be related to the influence of the temperature on methanogenesis . The production of biogas (83% CH4) was measured by gas collectors especially developed for this study and was also strongly dependent on temperature . The mass balance of carbon showed that 74% of the removed organic carbon was converted into CH4, 13% into dissolved inorganic carbon and 15% was stored in sludge . However, the anaerobic ponds presented a risk of creating odor nuisances with the emission of H2S.

Water Sci Technol, 2003, 48(2), 227 - 34
Emission of H2S and mass balance of sulfur in anaerobic ponds; Paing J et al.; Anaerobic ponds are highly efficient at removing BOD from wastewater with a reduced land area requirement . However, their use is often limited because of the problem of odor release, primarily due to the emission of hydrogen sulfide (H2S) . The experiments were conducted on full scale anaerobic ponds used for the primary treatment of urban wastewater under Mediterranean climatic conditions (south of France) . A model was developed to estimate the emission of H2S from water characteristics (temperature, pH and sulfides concentration) . The emission rate from anaerobic ponds varied between 20 and 576 mg-S/m2.d, leading to concentrations of H2S in the surrounding atmosphere between 0.2 and 5.2 ppm . These concentrations risked creating odor nuisances for nearby inhabitants . The whole of the results and the analysis of sulfur species in sludge permitted the production of a complete mass balance for sulfur . Methods of reducing the emission of odorous compounds were tested on a large scale . The recirculation of secondary effluent and the use of impermeable or permeable covers appeared to be the most interesting solutions.

Water Sci Technol, 2003, 48(2), 189 - 96
A computer simulation of the oxygen balance in a cold climate winter storage WSP during the critical spring warm-up period; Banks CJ et al.; The paper considers factors that determine the oxygen balance in extreme climate waste stabilisation ponds during the critical spring warm-up period . At this time BOD load on the pond is a maximum, due to accumulation of wastewater under the ice during the winter . The paper describes the operation of a typical cold climate WSP and the events leading to a balanced steady state system as spring develops into summer . A mathematical model to simulate conditions within a batch fed experimental pond over the transient period is described . To model temperature changes in the water body experimental data were fitted to a generalised equation based on diurnal fluctuations in air temperature . The results are plotted in a normalised form and show the diurnal fluctuation and time lapse as the depth of the pond increases . Maximum daily water temperature lags behind maximum light intensity . Bacterial growth is simulated by a Monod kinetic model in which growth rate depends on initial substrate concentration; temperature compensation is applied using a temperature activity coefficient . Oxygen utilisation is calculated from substrate removal . Algal growth rate is more complicated as it is affected by temperature and light availability . Algal oxygen production potential is considered in terms of its primary metabolite yield, which is then used in a Monod equation to estimate the growth rate . The model uses a mass balance approach to determine dissolved oxygen concentration in the pond . The model is still in a simple form but shows reasonable agreement, in terms of events and time lapses, to measured parameters in experimental ponds recovering from ice cover.

Water Sci Technol, 2003, 48(2), 181 - 8
Influence of the dispersion number on the estimation of coliform removal in ponds; von Sperling M; The paper uses the technique of Monte Carlo simulation in order to investigate the sensitivity to the Dispersion Number (d) of the effluent coliform concentration from facultative and maturation ponds . The Dispersion Number is one of the coefficients used in the dispersed-flow model for ponds . Initially, four empirical equations available in the literature for the estimation of d were compared, using the results from 1,000 runs of the Monte Carlo simulation . A second different set of Monte Carlo simulations (1,000 runs) was undertaken, allowing a sensitivity analysis of d, in conjunction with other coefficients and input data used in the design of facultative and maturation ponds (e.g., population, wastewater flow, coliform removal coefficient and others) . The results of the simulations suggest that, when considering the high level of uncertainty in all input variables used in the design of the ponds for coliform removal, the Dispersion Number d does not present a greater influence in the model prediction, compared with the other input variables . Based on these considerations, it is likely that, for design purposes, simple models for the prediction of d can be used, without significantly affecting the estimation of the effluent coliform concentration, considering the existing uncertainty in all other input variables.

Water Sci Technol, 2003, 48(2), 145 - 51
Investigation of pond velocities using dye and small drogues: a case study of the Nelson City waste stabilisation pond; Barter PJ; The city of Nelson, New Zealand, has a 27 hectare oxidation pond as its primary wastewater treatment facility . Recent changes in the configuration of the pond and installation of a mixer/aerator raised concerns that pond treatment rates and effluent quality may be affected by high internal pond velocities and short retention times . This paper presents the findings of an investigation into wastewater velocity and movement within the pond using qualitative dye dispersion and tracking of small-scale "holey-sock" drogues . Simultaneous deployment of drogues and dye allowed methods to be compared, since small-scale drogues have not commonly been used in wastewater ponds . Dye dispersion was assessed using low-level aerial photography from a tethered helium blimp to track short term movement and mixing, while a datalogger and fluorometer were used to measure pond retention time . Drogue movement was tracked in conjunction with the dye study from a small boat using hand-held GPS . The dye study found that: (i) the first portion of pond influent discharged from the pond after 37.5 hours, substantially quicker than the theoretical pond retention time of 27 days . However, the measured retention time was with a mixer in place and the theoretical time was without a mixer; (ii) the position of the paddle wheel mixer/aerator was not optimally placed for mixing the influent and a quiescent region existed adjacent to the influent point; and (iii) the low-level aerial photography was an effective method of evaluating larger pond systems . The "holey-sock" drogue studies showed that: (i) the drogues accurately followed the movement and velocity of dyed influent within the pond; (ii) wastewater velocity and movement was dominated by the paddle wheel mixer/aerator; and (iii) wind direction had a minor influence on wastewater velocity and movement in areas not directly affected by the paddle wheel mixer/aerator . The study demonstrated that the combined use of dye and drogues was a relatively low-cost and effective means of determining internal pond velocities and movement . Future studies using similar methods will be useful in helping validate computer-modelled movement and velocity.

Water Sci Technol, 2003, 48(2), 121 - 8
Suitability of macrophytes for nutrient removal from surface flow constructed wetlands receiving secondary treated sewage effluent in Queensland, Australia; Greenway M; From a botanical perspective the major difference between waste stabilisation ponds and wetlands is the dominance of algae or floating plants in the former and emergent plants in the latter . Algae, floating and submerged plants remove nutrients directly from the water column whereas emergent species remove nutrients from the sediment . Water depth is a crucial factor in determining which plant types will become established . Surface flow constructed wetlands offer the greatest potential to grow a wide variety of different types of macrophytes . In assessing the suitability of plant species for nutrient removal, consideration must be given not only to nutrient uptake for growth but also storage of nutrients as plant biomass . A survey of macrophytes in 15 surface flow constructed wetlands treating secondary effluent was conducted in Queensland; 63 native species and 14 introduced species were found . Emergent species have been able to tolerate deeper water than in their natural environment and permanent waterlogging . All species grew well in the higher nutrient enriched wastewater . Submerged, floating leaved-attached and free floating species had the highest tissue nutrient content, followed by aquatic creepers . All these species remove nutrients from the water column . Emergent species had lower nutrient content but a greater biomass and were therefore able to store more nutrients per unit area of wetland . In order to maximise the efficiency of constructed wetlands for nutrient removal, a range of species should be used . Native species should be selected in preference to introduced/exotic species.

Water Sci Technol, 2003, 48(2), 113 - 20
Valuation and modelling of helminth eggs removal in baffled and unbaffled ponds treating anaerobic effluent; von Sperling M et al.; The paper evaluates and models helminth eggs removal in a combined UASB (Upflow Anaerobic Sludge Blanket) reactor-maturation pond system (one baffled and one unbaffled pond in parallel) . The system is comprised of demonstration-scale units, treating actual domestic sewage from Itabira city, Brazil . The paper addresses the following points: (i) removal of helminth eggs from the wastewater in the system; (ii) comparison of the observed removal efficiency with the predictions using the Ayres et al . model; (iii) accumulation of helminth eggs in the sludge; (iv) viability of eggs in the sludge; (v) distribution of helminth species in the sludge . The removal efficiency of helminth eggs from the wastewater in both ponds was 100% for most of the time (0 counts in the final effluent) . The predictions of helminth eggs removal according to the Ayres et al . model can be considered reasonable . After one year of operation, 88% of the eggs in the sludge remained viable . Helminth eggs counts in the sludge tended to decrease along the baffled pond length (from first to last compartment) . The prevailing helminth species found in the sludge from both ponds was Ascaris lumbricoides.

Water Sci Technol, 2003, 48(2), 97 - 104
Parasite removal by natural wastewater treatment systems: performance of waste stabilisation ponds and constructed wetlands; Stott R et al.; Parasite removal and low cost systems for wastewater treatment have become increasingly important requirements in developed and developing countries to safeguard public health from wastewater-associated intestinal diseases . Pilot and field-scale ponds and wetlands in Brazil and Egypt have been investigated for the fate and removal of eggs of human intestinal parasites from domestic wastewater . In northeast Brazil, parasite removal was investigated for a series of five waste stabilisation ponds treating raw wastewater . In Egypt, parasite removal was studied for Gravel Bed Hydroponic constructed wetlands treating partially treated wastewater . Influents to ponds and wetlands contained a variety of parasite helminth eggs (e.g . Ascaris, hookworm, Trichuris, and Hymenolepis spp.) . The ponds consistently removed parasite eggs though rate of removal by individual ponds may have been related to influent egg numbers and extent of short-circuiting . Parasite eggs were reduced on average by 94% and 99.9% in the anaerobic and facultative ponds respectively . No eggs were found in effluent from the second maturation pond . In the wetland system, parasite removal varied with reedbed length . The majority of parasite eggs were retained within the first 25 m . Parasite eggs were reduced on average by 98% after treatment in 50 m beds and completely removed after treatment in 100 m beds.

Water Sci Technol, 2003, 48(2), 61 - 8
Characterisation of oxygen dynamics within a high-rate algal pond system used to treat abattoir wastewater; Evans RA et al.; As part of a study examining the efficacy of high-rate algal pond treatment of high-strength abattoir wastewater, the oxygen dynamics of a pilot scale system were characterised . The relationship between photosynthesis and irradiance was investigated using online data collected throughout a year of operation under varying conditions of climate and wastewater quality . Changes in climate were reflected in changes in the net rate of photosynthesis in deep ponds, consistent with adaptation of algal populations to changing light intensity, whilst the response of shallow ponds was more varied . The use of online monitoring and the calculation in real time of photosynthetic rates should allow for improved design and management of full scale treatment systems and further the understanding of factors driving biological reactions within these systems.

Water Sci Technol, 2003, 48(2), 25 - 33
Waste stabilisation ponds in extreme continental climates: a comparison of design methods from the USA, Canada, northern Europe and the former Soviet Union; Heaven S et al.; The paper presents a brief review of the application of WSPs in extreme climates where ice formation occurs during winter . Design standards and methods are compared and different systems are described . Design equations developed by the US EPA and normative standards from the former Soviet Union are compared in a simple example using typical wastewater and performance characteristics . The results are similar except at low temperatures, where the Soviet method can give pond depths outside the prescribed limits . The paper examines construction and operational aspects of extreme climate WSPs, comparing North American, Northern European and Russian standards . It considers why WSP systems have not been widely adopted in Russia and the NIS, and looks at the advantages these systems may have in countries in economic transition.

Water Sci Technol, 2003, 48(2), 9 - 15
Waste stabilisation pond developments in New Zealand; Archer HE et al.; Waste stabilisation ponds have been a popular form of wastewater treatment in New Zealand both for large cities and small communities . Over 100 systems have been constructed ranging in size from over 500 ha to less than 0.1 ha . The largest pond system in New Zealand was at Manukau, Auckland and consisted of four ponds with a total of 530 ha . However, ongoing odour and midge releases and an algae parasite problem plus a requirement to reduce ammonia and total nitrogen in summer, led to the decision to decommission the ponds and allow the area to revert to tidal mudflats . The second largest pond system is at Christchurch and totals 226 ha . In contrast to Manukau, the Christchurch ponds have not caused significant odours and final effluent quality has been good . Christchurch has two parallel trains each with three ponds in series . It is proposed to retain and develop the ponds into a seven cells in series arrangement to reduce short-circuiting . Odour emissions from the Manukau and Christchurch ponds have been measured by the use of olfactometry . Dispersion of odours has been modelled and the extent of "odour travel" determined on a statistical probability basis using actual meteorological data . It can be demonstrated that residential areas can co-exist with ponds, which are not overloaded, with separation distances of 200 metres.

Water Sci Technol, 2003, 48(2), 1 - 7
Research on waste stabilisation ponds in the United Kingdom--initial results from pilot-scale facultative ponds; Abis KL et al.; Three pilot-scale facultative ponds were constructed at Esholt wastewater treatment works in Bradford, West Yorkshire, UK . The ponds were operated in parallel to test the effect of surface BOD loading on performance and the maintenance of facultative conditions . The performance criteria adopted were BOD, SS and ammonia removal . The criterion for facultative conditions was the presence of an algal population maintaining aerobic conditions at the pond surface . Filtered BOD removal was found to be more than 90%, non-seasonal, and related to areal BOD loading . SS removal was also found to be non-seasonal, at around 95% but not related to areal BOD load . Ammonia removal was seasonal (32-48% October to March; 60-81% March to July) and related to areal BOD load . At the test loadings (60, 110 and 169 kg/ha.d) an algal population was not maintained in winter . The initial results indicate that a much lower loading is required to maintain facultative conditions than to optimise BOD and SS removal.

Water Res, 2003 Jul, 37(13), 3269 - 78
A dual membrane UF/RO process for reclamation of spent rinses from a nickel-plating operation--a case study; Qin JJ et al.; The objective of this work was to conduct treatability studies on rinse wastewater from process lines of a typical nickel-plating plant for reuse . The study comprised of three steps: (1) a plant process review and the treatability of different combinations of simulated spent rinses in the laboratory; (2) a variability monitoring of a combined rinse at the plant and a treatability study on a combined rinse in the laboratory; (3) a pilot study for reclamation of the combined rinse on site . The study established an optimum dual membrane ultrafiltration (UF)/reverse osmosis (RO) process for treating a combined liquor of spent alkaline, acidic and nickel-plating rinses which resulted in a treated water of a quality suitable for reuse as substitute for town water for the purpose of rinsing . The results of this study provided a good guide to the selection of a UF pretreatment combined with an RO membrane unit as the treatment system . The pilot plant had successfully operated for 6 months, consistently producing a high quality product water (< 95 microS cm-1) at an overall water recovery of 67.5% . The quality of reclaimed water was better than town water used at the factory . The product water from the pilot plant has been used as substitute of town water for in-process rinsing at the factory with no detrimental effects for 3 months.

Water Res, 2003 Jul, 37(13), 3205 - 15
Oxidative transformation of phenols in aqueous mixtures; Gianfreda L et al.; The transformation by an oxidoreductase (a laccase from Rhus vernificera) of a mixture of four phenols (catechol, methylcatechol, m-tyrosol and hydroxytyrosol) that simulates a typical wastewater derived from an olive oil factory was investigated . Results achieved in this study confirm that laccase-mediated transformation of phenols depends on the nature and the initial concentration of the involved phenol, the time course of the reaction, and mainly, on the complexity of the phenolic incubation mixture . Actually, the four phenols each have a completely different response to enzyme action both in terms of quantitative and kinetic transformation . For example, after 24-h incubation, methylcatechol was completely removed, whereas 30% of untransformed hydroxytyrosol and catechol and more than 65% of m-tyrosol were still present in the reaction mixture . A reduction of enzyme activity occurred for all phenols after enzymatic oxidation . No correspondence between phenol transformation and disappearance of enzymatic activity was observed, thus suggesting that different mechanisms are probably involved in the laccase-mediated transformation of the four phenols . The behavior of phenols became more complex when an increasing number of phenols was present in the reaction mixture, and even more so when different concentrations of phenols were used . Competitive effects may arise when more than one phenol is present in the reaction solution and interacts with the enzyme.

Water Res, 2003 Jul, 37(13), 3180 - 8
Application of the colloidal stability of TiO2 particles for recovery and reuse in solar photocatalysis; Fernandez-Ibanez P et al.; TiO2-catalyst suspensions work efficiently in photocatalysis for wastewater treatment . Nevertheless, once photocatalysis is complete, separation of the catalyst from solution becomes the main problem . Catalyst recovery has been enhanced through charge neutralisation and coagulation with electrolytes at lab and pilot-plant scale (40 L) to evaluate the potential for its separation after photocatalytic degradation of pollutants . Zeta-potential analysis showed that the isoelectric point (IEP) of TiO2 suspensions is near pH 7 . Settling rates and hydrodynamic diameter of TiO2 particles are maximum at the IEP . However, suspensions are stable at different pH . TiO2 was reused in solar photocatalysis pilot-plant (40 L) for treatment of tetrachloroethylene (C2Cl4) comparing two procedures: reuse of the entire suspension after destruction of the organics without separation of the catalyst, and reuse of the catalyst after it had settled to the bottom and clear water had been removed . Photocatalytic efficiency worsens with successive runs when catalyst and water are reused without separation, whereas, when TiO2 is separated, the photocatalyst is not deactivated.

Water Res, 2003 Jul, 37(13), 3136 - 44
Mechanisms of floc destruction during anaerobic and aerobic digestion and the effect on conditioning and dewatering of biosolids; Novak JT et al.; Laboratory anaerobic and aerobic digestion studies were conducted using waste activated sludges from two municipal wastewater treatment plants in order to gain insight into the mechanisms of floc destruction that account for changes in sludge conditioning and dewatering properties when sludges undergo anaerobic and aerobic digestion . Batch digestion studies were conducted at 20 degrees C and the dewatering properties, solution biopolymer concentration and conditioning dose requirements measured . The data indicated that release of biopolymer from sludges occurred under both anaerobic and aerobic conditions but that the release was much greater under anaerobic conditions . In particular, the release of protein into solution was 4-5 times higher under anaerobic than under aerobic conditions . Both the dewatering rate, as characterized by the specific resistance to filtration and the amount of polymer conditioning chemicals required was found to depend directly on the amount of biopolymer (protein + polysaccharide) in solution . Little difference in dewatering properties and conditioning doses was seen between the two activated sludges from different plants . Differences in the cations released between anaerobic and aerobic digestion suggest that the digestion mechanisms differ for the two types of processes . Enzyme activity data showed that during aerobic digestion, polysaccharide degradation activity decreased to near zero and this was consistent with the accumulation of polysaccharides in aerobic digesters.

Water Res, 2003 Jul, 37(13), 3118 - 24
Electrochemical treatment of industrial wastewater containing 5-amino-6-methyl-2-benzimidazolone: toward an electrochemical-biological coupling; Torres RA et al.; We studied the electrochemical oxidation, on Pt anodes, of industrial wastewaters containing 5-amino-6-methyl-2-benzimidazolone (AMBI) . Electrolysis of this non-biodegradable effluent produces simultaneous oxidation of AMBI and chloride ions . Highly oxidative chlorine intermediate species further boost the degradation of AMBI . Solution temperature, pH and current density affect little the degradation of AMBI . At our best conditions, AMBI was 100% degraded in 45 min . However, because the reaction intermediates exhibited high toxicity and non-biodegradability, the electrolysis had to continue for 3 more hours in order to obtain a biocompatible solution . Then, complete mineralization of the outputs from the electrolytic cells was readily achieved in a fixed bed biological reactor.

Environ Technol, 2003 Aug, 24(8), 1031 - 9
Adsorption and catalytic oxidation of phenol in a new ozone reactor; Lin SH et al.; Phenolic wastewater treatment in a new ozone reactor was investigated . The reactor was designed in such a fashion that gas induction was created in the reactor headspace by the high-speed action of an impeller turbine inside a draft tube to maximize the ozone utilization . Another important feature of the present reactor design was incorporation of granular activated carbon bed in a circular compartment between the reactor wall and the shaft tube . The fixed granular activated carbon bed was observed to significantly enhance the phenol decomposition and the chemical oxygen demand removal when compared to gas-induced ozonation alone, providing evidence of the synergistic effects of adsorption, catalytic reaction and ozonation . In addition to the enhanced phenol decomposition and chemical oxygen demand, ozonation was found to provide in-situ regeneration of granular activated carbon which was considered crucial in the present reaction system . Kinetic investigations were also made using a proposed complex kinetic model in an attempt to elucidate the possible decomposition reaction mechanisms of the present gas-induced ozonation system.

Environ Technol, 2003 Aug, 24(8), 1025 - 30
Photocatalytic transformation of dyes and by-products in the presence of hydrogen peroxide; Subba Rao KV et al.; The efficiency of the photocatalytic degradation of dyes and dyeing industry pollutants on immobilized photocatalysts can be improved by addition of hydrogen peroxide, due to its photocatalytic decomposition on TiO2 . Experiments were carried out with two azodyes, Acid Orange-7 (AO-7) and Tartrazine (Tart), with 3-nitrobenzenesulfonic add (3-NBSA) which is a chemical intermediate in the dye industry and with real industrial wastewaters, using a thin-film fixed bed reactor . The effect of hydrogen peroxide is only significant for concentrations higher than 5 x 10(-3) M (170 mg l(-1)).

Environ Technol, 2003 Aug, 24(8), 999 - 1006
Inhibition of the acetoclastic methanogenic activity by phenol and alkyl phenols; Olguin-Lora P et al.; Chemical and petrochemical industries are important sources of aromatic pollutants . Petrochemical processes like caustic washing of middle distillates produce the spent caustic liquors highly concentrated in phenol and alkyl phenols . The anaerobic technology is considered a feasible strategy for petrochemical wastewater pre-treatment although high concentrations of phenol could limit its efficiency . The goal of this work was to determine the toxicity of both selected alkyl phenols and a synthetic "spent-caustic phenols mixture" on the acetoclastic Specific Methanogenic Activity (SMA) of unadapted and phenol-adapted granular sludge . Alkyl phenols were responsible for 50% (IC50) and 100% (IC100) inhibition of the SMA at concentrations ranging from 1.6 to 5.0 mM and from 4.1 to 27.5 mM, respectively, for un-adapted granular sludge . In the case of phenol-adapted granular sludge, the inhibitory concentrations ranged from 1.7 to 14.9 mM and from 4.0 to 83.0 for IC50 and IC100, respectively, highlighting the impact of sludge acclimation . The inhibition produced by 2-ethylphenol was more acute compared to phenol and was not reduced by the phenol acclimation process . The IC50 and IC100 values obtained for the synthetic "spent-caustic phenols mixture" were 9.5 mM and 88.4 mM, respectively . The inhibitory concentrations of phenol compounds were closely correlated with compound apolarity (log P), indicating that the lipophilic character of the tested compounds was responsible for their methanogenic toxicity . An inhibition model is confirmed to estimate the IC50 and IC100.

Occup Environ Med, 2003 Oct, 60(10), 722 - 9
Mortality of employees of a perfluorooctanesulphonyl fluoride manufacturing facility; Alexander BH et al.; AIM: To evaluate the mortality experience of a cohort of employees of a perfluorooctanesulphonyl fluoride (POSF) based fluorochemical production facility . METHODS: A retrospective cohort mortality study followed all workers with at least one year of cumulative employment at the facility . The jobs held by cohort members were assigned to one of three exposure subgroups; high exposed, low exposed, and non-exposed, based on biological monitoring data for perfluorooctane sulphonate (PFOS) . RESULTS: A total of 145 deaths were identified in the 2083 cohort members . Sixty five deaths occurred among workers ever employed in high exposed jobs . The overall mortality rates for the cohort and the exposure subcohorts were lower than expected in the general population . Two deaths from liver cancer were observed in the workers with at least one year of high or low exposure (standardised mortality ratio (SMR) 3.08, 95% CI 0.37 to 11.10) . The risk of death from bladder cancer was increased for the entire cohort (three observed, SMR 4.81, 95% CI 0.99 to 14.06) . All three bladder cancers occurred among workers who held a high exposure job (SMR 12.77, 95% CI 2.63 to 37.35) . The bladder cancer cases primarily worked in non-production jobs, including maintenance and incinerator and wastewater treatment plant operations . CONCLUSION: Workers employed in high exposure jobs had an increased number of deaths from bladder cancer; however it is not clear whether these three cases can be attributed to fluorochemical exposure, an unknown bladder carcinogen encountered during the course of maintenance work, and/or non-occupational exposures . With only three observed cases the possibility of a chance finding cannot be ruled out.

Adv Space Res, 2003, 31(7), 1799 - 804
Advantages of using subsurface flow constructed wetlands for wastewater treatment in space applications: ground-based Mars Base prototype; Nelson M et al.; Research and design of subsurface flow wetland wastewater treatment systems for a ground-based experimental prototype Mars Base facility has been carried out, using a subsurface flow approach . These systems have distinct advantages in planetary exploration scenarios: they are odorless, relatively low-labor and low-energy, assist in purification of water and recycling of atmospheric CO2, and will support some food crops . An area of 6-8 m2 may be sufficient for integration of wetland wastewater treatment with a prototype Mars Base supporting 4-5 people . Discharge water from the wetland system will be used as irrigation water for the agricultural crop area, thus ensuring complete recycling and utilization of nutrients . Since the primary requirements for wetland treatment systems are warm temperatures and lighting, such bioregenerative systems may be integrated into early Mars base habitats, since waste heat from the lights may be used for temperature maintenance in the human living environment . "Wastewater gardens (TM)" can be modified for space habitats to lower space and mass requirements . Many of its construction requirements can eventually be met with use of in-situ materials, such as gravel from the Mars surface . Because the technology requires little machinery and no chemicals, and relies more on natural ecological mechanisms (microbial and plant metabolism), maintenance requirements are minimized, and systems can be expected to have long operating lifetimes . Research needs include suitability of Martian soil and gravel for wetland systems, system sealing and liner options in a Mars Base, and wetland water quality efficiency under varying temperature and light regimes . c2003 COSPAR . Published by Elsevier Science Ltd . All rights reserved.

Adv Space Res, 2003, 31(7), 1629 - 39
The legacy of Biosphere 2 for the study of biospherics and closed ecological systems; Allen JP et al.; The unprecedented challenges of creating Biosphere 2, the world's first laboratory for biospherics, the study of global ecology and long-term closed ecological system dynamics, led to breakthrough developments in many fields, and a deeper understanding of the opportunities and difficulties of material closure . This paper will review accomplishments and challenges, citing some of the key research findings and publications that have resulted from the experiments in Biosphere 2 . Engineering accomplishments included development of a technique for variable volume to deal with pressure differences between the facility and outside environment, developing methods of atmospheric leak detection and sealing, while achieving new standards of closure, with an annual atmospheric leakrate of less than 10%, or less than 300 ppm per day . This degree of closure permitted detailed tracking of carbon dioxide, oxygen, and trace gases such as nitrous oxide and ethylene over the seasonal variability of two years . Full closure also necessitated developing new approaches and technologies for complete air, water, and wastewater recycle and reuse within the facility . The development of a soil-based highly productive agricultural system was a first in closed ecological systems, and much was learned about managing a wide variety of crops using non-chemical means of pest and disease control . Closed ecological systems have different temporal biogeochemical cycling and ranges of atmospheric components because of their smaller reservoirs of air, water and soil, and higher concentration of biomass, and Biosphere 2 provided detailed examination and modeling of these accelerated cycles over a period of closure which measured in years . Medical research inside Biosphere 2 included the effects on humans of lowered oxygen: the discovery that human productivity can be maintained with good health with lowered atmospheric oxygen levels could lead to major economies on the design of space stations and planetary/lunar settlements . The improved health resulting from the calorie-restricted but nutrient dense Biosphere 2 diet was the first such scientifically controlled experiment with humans . The success of Biosphere 2 in creating a diversity of terrestrial and marine environments, from rainforest to coral reef, allowed detailed studies with comprehensive measurements such that the dynamics of these complex biomic systems are now better understood . The coral reef ecosystem, the largest artificial reef ever built, catalyzed methods of study now being applied to planetary coral reef systems . Restoration ecology advanced through the creation and study of the dynamics of adaptation and self-organization of the biomes in Biosphere 2 . The international interest that Biosphere 2 generated has given new impetus to the public recognition of the sciences of biospheres (biospherics), biomes and closed ecological life systems . The facility, although no longer a materially-closed ecological system, is being used as an educational facility by Columbia University as an introduction to the study of the biosphere and complex system ecology and for carbon dioxide impacts utilizing the complex ecosystems created in Biosphere '.The many lessons learned from Biosphere 2 are being used by its key team of creators in their design and operation of a laboratory-sized closed ecological system, the Laboratory Biosphere, in operation as of March 2002, and for the design of a Mars on Earth(TM) prototype life support system for manned missions to Mars and Mars surface habitats . Biosphere 2 is an important foundation for future advances in biospherics and closed ecological system research . c2003 Published by Elsevier Science Ltd on behalf of COSPAR.

Indian J Environ Health, 2002 Apr, 44(2), 138 - 53
Mixed streams wastewater treatment using adsorption; Rathi AK et al.; Mixed samples prepared from known pure solutes are reported to have synergetic efforts with respect to single solute and multi-solute adsorption . Attempt is made to extend the theory of enhancement ratios to the mixed stream wastewater samples collected from dyes manufacturing industries . Synergetic effect of the multi-solutes as well as of mixture of adsorbents is observed for mixed streams of wastewater samples, containing a number of pollutants, on given inexpensive adsorbents . The Rathi Puranik model developed for single wastewater streams can be extended to the mixed stream wastewater samples using the rate of COD reduction prediction . The concept of average apparent enhancement factor is discussed.

Sci Total Environ, 2003 Oct 1, 314-316, 727 - 36
Dissolved nutrients in the Tweed Estuary, UK: inputs, distributions and effects of residence time; Uncles RJ et al.; Results are presented from a campaign in which dissolved inorganic nutrients were measured in the Tweed Estuary, UK . The data utilised here were derived from surveys undertaken on a monthly basis from January to August 1997 . There was consistency between the nutrient concentrations observed in the freshwater reaches of the tidal estuary and earlier measurements made several km upstream, in the freshwater river . Typically, nitrate was of the order of 100 microM and silicate approximately half this, whereas phosphate and nitrite were typically approximately 1 microM . Seasonal fluctuations in freshwater nitrate and silicate were very large, with concentrations exceeding (respectively) 300 and 100 microM in winter and less than 30 and 10 microM in summer . The estuarine nutrients surveyed followed this general seasonal pattern . A simple box model was used to investigate the temporal behaviour of a hypothetical estuarine nutrient . The model demonstrated that large deviations from the 'broad-brush' seasonal pattern for nitrate and silicate could be expected to occur within the estuary as a result of runoff and residence-time variations . The model also demonstrated that mid-estuarine peaks observed in the longitudinal distributions of phosphate could only have arisen as a result of non-freshwater, wastewater phosphate inputs to the estuary . Without this mid-estuarine input, rapid flushing rates would have ensured that transients due to changing freshwater phosphate concentrations, runoff and tides (via the residence time) would have had relatively little impact on the classic, linear 'conservative' mixing diagram for the estuary . Conservative mixing was largely applicable to the other nutrients.

J Air Waste Manag Assoc, 2003 Sep, 53(9), 1042 - 51
The reuse of biosludge as an adsorbent from a petrochemical wastewater treatment plant; Chiang HL et al.; Biosludge was obtained from a petrochemical industry's biological wastewater treatment plant . Zinc chloride (ZnCl2) was used as a sludge activation agent during the pyrolytic process . Scanning electron microscope (SEM) image photographs, element composition, surface functional group, and pore structure were analyzed for the sludge adsorbent characteristics . Results indicated the proper ZnCl2-immersed concentration, pyrolytic temperature, and time could produce adsorbent from the biosludge . The optimal conditions for a larger surface area adsorbent were 3 M ZnCl2-immersed sludge pyrolyzed at 600 degrees C for 30 min and washed with 3 N hydrochloric acid (HCl) solution and distilled water . The predominant pore size of the sludge adsorbent was the mesopore.

Indian J Environ Health, 2002 Oct, 44(4), 290 - 7
Modelling of Buckingham Canal water quality; Abbasi SA et al.; The paper presents a case study of the modelling of the water quality of a canal situated in a petrochemical industrial complex, which receives wastewaters from Madras Refineries Limited (MRL), and Madras Fertilizers Limited (MFL) . The canal well known Buckingham Canal which passes through Chennai (Madras), India has been modelled using the software QUAL2E-UNCAS . After testing and validation of the model, simulations have been carried out . The exercise enables forecasting the impacts of different seasons, base flows, and waste water inputs on the water quality of the Buckingham Canal . It also enables development of water management strategies.

J Environ Biol, 2003 Apr, 24(2), 161 - 4
Certain haematological responses in Swiss albino mice following exposure to textile dye wastewater; Mathur N et al.; Adults Swiss mice were administered 5% solution of textile industry wastewater orally for 25 days and haematological parameters like RBC, WBC, Hb, and PCV were studied . Red cell indices like MCV, MCH and MCHC were calculated . Results indicate significant reduction in RBC, Hb and PCV levels . It is inferred that toxic effluents cause metabolic alteration in erythrocytes and reduce their Hb carrying capacity.

J Environ Biol, 2003 Apr, 24(2), 141 - 6
Response of sugarcane to treated wastewater of oil refinery; Ahmad A et al.; The crop of sugarcane (Saccharum officinarum) was grown at the agricultural farm of the Mathura Oil Refinery in a simple randomized block design . The experimental plots were irrigated with ground water (GW) or treated wastewater (TW) as and when required The plants gave better response to the latter than the former . The quantity of the required nutrients was comparatively more in TW than GW . The soil receiving wastewater did not show any significant change in its physico-chemical characteristics . The soil accumulated all the heavy metals but the plant samples receiving TW only exhibited the presence of Ni, Pb and Zn whose values are far below the permissible limits.

J Environ Sci (China), 2003 Jul, 15(4), 525 - 30
Assessment of the environmental impact of artificial effluent lagoon in Jiayuguan City of China; Pei YS et al.; An artificial effluent lagoon for storing wastewater were excavated in Jiayuguan City since 1994 . As a part of a demonstration project of Sino-Australia cooperation, an assessment of the environmental impact of the lagoon was carried out . The assessment was based on field and laboratory tests and predictive model . The main impacts from the lagoon site are likely to be on the groundwater system, and, to a lesser extent, on ambient air quality in the vicinity . Currently it is expected that groundwater is being polluted with effluent from the effluent lagoon . Air pollution (odor nuisance) is mainly caused by untreated effluent in the irrigation channel . The impact of high total dissolved salt (TDS) on groundwater is likely to be significant in the long run if the lagoon is continuously used . There is, consequently, no likelihood of contamination of surface water system, particularly of the city water supply system, from infiltration of effluent at the lagoon.

J Environ Sci (China), 2003 Jul, 15(4), 475 - 81
2-Chlorophenol oxidation kinetic by photo-assisted Fenton process; Xu XH et al.; Experimental data are presented to test and validate a kinetic model for the oxidation of 2-chlorophenol wastewater by photo-assisted Fenton process . The data showed that this process had produced good effects under acidic conductions . Up to 90% 2-chlorophenol was removed after 90-minute reaction time with H2O2 of 25% COD(Cr, in), while in UV/H2O2 system only 16.8% 2-chlorophenol was removed after one hour treatment . The optimal pH in this reaction occurred between pH 3.0 and pH 4.0 . The reaction kinetics for photo-assisted Fenton process experimented in this research was investigated . Kinetic models were proposed for the treatment of 2-chlorophenol wastewater . The reaction was found to follow the 2nd order . The equations of reaction kinetics are as follows: -d{RH}/dt = K(RH) {RH} {H2O2}0 exp(-K(H2O2) t); -d{COD(Cr)}/dt = K(COD(Cr)) {COD(Cr)} {H2O2}0 exp(-K' t) . The prediction of the models was found to be in a good agreement with experimental results, thus confirming the proposed reaction mechanism.

J Expo Anal Environ Epidemiol, 2003 Sep, 13(5), 403 - 16
Historical reconstruction of wastewater and land use impacts to groundwater used for public drinking water: exposure assessment using chemical data and GIS; Swartz CH et al.; Land use in geographic areas that replenish groundwater and surface water resources is increasingly recognized as an important factor affecting drinking water quality . Efforts to understand the implications for health, particularly outcomes with long latency or critical exposure windows, have been hampered by lack of historical exposure data for unregulated pollutants . This limitation has hindered studies of the possible links between breast cancer risk and drinking water impacted by endocrine disrupting compounds and mammary carcinogens, for example . This paper describes a methodology to assess potential historical exposure to a broad range of chemicals associated with wastewater and land use impacts to 132 groundwater wells and one surface water body supplying drinking water to 18 public distribution systems on Cape Cod, MA . We calculated annual measures of impact to each distribution system and used the measures as exposure estimates for the residential addresses of control women in the Cape Cod Breast Cancer and Environment Study (Cape Cod Study) . Impact was assessed using (1) historical chemical measurements of nitrate at the water supply sources (performed as required by the Safe Water Drinking Act) and (2) a geographic information system analysis of land use within the zones of contribution (ZOCs) delineated for each well in a state-mandated wellhead protection program . The period for which these impact estimates were developed (1972-1995) was constrained by the availability of chemical measurements and land use data and consideration of time required for groundwater transport of contaminants to the water supply wells . Trends in these estimates for Cape Cod suggest increasing impact to drinking water quality for land use over the study period . Sensitivity analyses were conducted to assess the effect on the distribution of controls' cumulative exposure estimates from (1) reducing the area of the ZOCs to reflect typical well operating conditions rather than extreme pumping conditions used for the regulatory ZOCs, (2) assuming residences received their drinking water entirely from the closest well or cluster of wells rather than a volume-weighted annual district-wide average, and (3) changing the travel time considered for contaminants to reach wells from land use sources . We found that the rank and distribution of controls' cumulative exposure estimates were affected most by the assumption concerning district mixing; in particular, assignment of exposure estimates based on impact values for the closest well(s) consistently produced a larger number of unexposed controls than when a district-wide average impact value was used . As expected, the results suggest that adequate characterization of water quality heterogeneity within water supplies is an important component of exposure assessment methodologies in health studies investigating impacted drinking water.

J Hazard Mater, 2003 Aug 29, 102(2-3), 257 - 75
Kinetics of removal of chromium from water and electronic process wastewater by ion exchange resins: 1200H, 1500H and IRN97H; Rengaraj S et al.; The removal of chromium from aqueous solution by an ion exchange resin is described . Ion exchange resins 1200H, 1500H and IRN97H show a remarkable increase in sorption capacity for chromium, compared to other adsorbents . The adsorption process, which is pH dependent show maximum removal of chromium in the pH range 2-6 for an initial chromium concentration of 10mg/l . The metal ion adsorption obeyed linear, Langmuir and Freundlich isotherms . The adsorption of chromium on these cation exchange resins follows first-order reversible kinetics and pseudo-first-order kinetics . The intraparticle diffusion of chromium on ion exchange resins represents the rate-limiting step . The uptake of chromium by the ion exchange resins was reversible and thus have good potential for the removal/recovery of chromium from aqueous solutions . We conclude that such ion exchange resins can be used for the efficient removal of chromium from water and wastewater.

J Hazard Mater, 2003 Aug 29, 102(2-3), 231 - 41
Photodegradation of direct yellow-12 using UV/H2O2/Fe2+; Rathi A et al.; A detailed investigation of photodegradation of direct yellow-12 (DY12) using UV/H(2)O(2)/Fe(2+) has been carried out in a photochemical reactor . Experiments studied degradation as a function of concentration, decolorization and reduction in chemical oxygen demand (COD) . The effect of operating parameters, such as UV, pH, amount of Fenton's reagent (H(2)O(2) and FeSO(4)), and amount of DY12 dye has also been determined . It has been observed that simultaneous utilization of UV irradiation with Fenton's reagent increases the degradation rate of DY12 dye . The dye quickly losses its color and there is an appreciable decrease in COD value, indicating that the dissolved organic have been oxidized . The kinetics of degradation of the dye in dilute aqueous solutions follows pseudo-first order kinetics . Final products detected at the end of the reaction include NO(3)(-), NO(2)(-), N(2)O, NO(2), SO(2), CO(2) and CO . Results indicate that dye degradation is dependent upon pH, UV-intensity, concentration of Fenton's reagent and dye . Acidic pH has been found to be more suitable in comparison to neutral and alkaline . The optimum concentration of Fenton's reagent (H(2)O(2)/Fe(2+)) was found as 1500/500 mg l(-1) for 50 mg l(-1) DY12 dye in water at pH 4 . The results indicate that the treatment of DY12 dye wastewater with UV/Fe(2+)/H(2)O(2) system is efficient.

J Hazard Mater, 2003 Aug 29, 102(2-3), 217 - 29
Photocatalytic degradation of phosphamidon on semiconductor oxides; Rabindranathan S et al.; The photocatalytic degradation of a small concentration of an organo-phosphorous (OP) insecticide phosphamidon, in water, on ZnO and TiO(2) is investigated . Of the two semiconductor oxides, TiO(2) is found to be more effective as a photocatalyst for this reaction . Several factors such as concentration of phosphamidon, pH of the system, catalyst loading and presence of anions are found to influence the degradation rate . The reaction follows apparent first-order kinetics, though at higher concentrations, there is a reduction in the order of the reaction . There is a simultaneous formation and decomposition of H(2)O(2) in the system, resulting in a periodic increase and decrease in its concentration . The catalyst TiO(2) is effective for the degradation of phosphamidon in direct sunlight and thus opens the possibility of solar decontamination of wastewater containing small amounts of OP pesticides.

Southeast Asian J Trop Med Public Health, 2003 Mar, 34(1), 72 - 80
Role of wastewater irrigation in mosquito breeding in south Punjab, Pakistan; Mukhtar M et al.; Mosquito breeding within the wastewater irrigation system around the town of Haroonabad in the southern Punjab, Pakistan, was studied from July to September 2000 as part of a wider study of the costs and benefits of wastewater use in agriculture . The objective of this study was to assess the vector-borne human disease risks associated with mosquito species utilizing wastewater for breeding . Mosquito larvae were collected on a fortnightly basis from components of the wastewater disposal system and irrigated sites . In total, 133 samples were collected, about equally divided between agricultural sites and the wastewater disposal system . Overall, 17.3% of the samples were positive for Anopheles, 12.0% for Culex and 15.0% for Aedes . Four anopheline species, viz, Anopheles stephensi (84.3% of total anophelines), An . subpictus (11.8%), An . culicifacies (2.0%) and An . pulcherrimus (0.2%) were present, as were two species of Culex, viz, Cx . quinquefasciatus (66.5% of culicines) and Cx . tritaeniorhynchus (20.1%) . Aedes were not identified to species level . The occurrence of different species was linked to particular habitats and habitat characteristics such as physical water condition, chemical water quality and the presence of fauna and flora . Anophelines and Aedes mosquitos were mainly collected during the month of July, while Culex were collected in September . The prevalence of established vectors of human diseases such as An . stephensi (malaria), Cx . tritaeniorhynchus (West Nile fever, Japanese encephalitis) and Cx . quinquefasciatus (Bancroftian filariasis, West Nile fever) in the wastewater system indicated that such habitats could contribute to vector-borne disease risks for human communities that are dependent upon wastewater use for their livelihoods . Wastewater disposal and irrigation systems provide a perennial source of water for vector mosquitos in semi-arid countries like Pakistan . Vector mosquitos exploit these sites if alternative breeding sites with better biological, physical, and chemical conditions are not abundant.

Environ Sci Technol, 2003 Sep 1, 37(17), 3989 - 94
Photocatalytic oxidation using a new catalyst--TiO2 microsphere--for water and wastewater treatment; Li XZ et al.; Since the suspended TiO2 powder enjoys free contact with UV irradiation in a photoreactor system, it can generally achieve better efficiency than the immobilized TiO2 catalysts . However, the separation and reuse of this catalyst powder from treated water often limit its application in practice . In this study, a new type of TiO2 catalyst called TiO2 microsphere was prepared by a sol-spraying-calcination method, which can easily settle in its aqueous suspensions under gravity . The SEM image of the TiO2 microsphere samples demonstrated that they had an almost spherical shape with a particle size of 30-160 microm, while the XRD analysis indicated that these TiO2 microspheres still had a crystal size of 8.1 nm . Since these TiO2 microspheres had a porous structure with higher specific surface area and pore volume than normal TiO2 powders, they appeared to have strong adsorption ability in its aqueous suspensions . The photocatalytic activity of the TiO2 microspheres was evaluated in the photodegradations of salicylic acid (SA) and sulfosalicylic acid (SSA) . The experimental results showed that the reaction rate using the TiO2 microspheres was similar to that using the TiO2 powders in the SA suspensions and even higher than that in the SSA suspensions . Chemical and physical properties of the TiO2 microspheres and powders that are attributed to photoactivity were discussed based on the Langmuir-Hinshelwood kinetic model . The prepared TiO2 microsphere samples were reused in the photooxidation reaction more than 50 times . It was found that there was no significant weakening in their photoactivity and no change in their particle shape . This TiO2 microsphere catalyst can be simply used to conduct an effective photooxidation in its suspension for water and wastewater treatment with ease of recovery from treated water.

Environ Sci Technol, 2003 Sep 1, 37(17), 3853 - 8
Determination of kinetics and stoichiometry of chemical sulfide oxidation in wastewater of sewer networks; Nielsen AH et al.; A method for determination of kinetics and stoichiometry of chemical sulfide oxidation by dissolved oxygen (DO) in wastewater is presented . The method was particularly developed to investigate chemical sulfide oxidation in wastewater of sewer networks at low DO concentrations . The method is based on continuous measurement of the reactants allowing the kinetics to be determined at varying reactant concentrations during the course of the experiment . The kinetics determined was simulated by a rate equation . The precision of the method was assessed in terms of the standard deviation of the kinetic parameters determined in a triplicate experiment . The kinetic parameters determined in 25 experiments on wastewater samples from a single site exhibited good constancy with a variation of the same order of magnitude as the precision of the method . It was found that the stoichiometry of the reaction could be considered constant during the course of the experiments although intermediates accumulated . This was explained by an apparent slow oxidation rate of the intermediates . The method was capable of determining kinetics and stoichiometry of chemical sulfide oxidation at DO concentrations lower than 1 g of O2 m(-3).

Biotechnol Lett, 2003 Jul, 25(14), 1185 - 90
Characterization of decrystallized chitosan and its application in biosorption of textile dyes; Trung TS et al.; Decrystallized chitosan was produced from shrimp shells with a low degree of crystallinity (10%) and a high anionic dye binding capacity . Raw, mixed dye wastewater from a textile factory was efficiently decolorized using decrystallized chitosan that was more efficient than using normal chitosan and activated carbon . Decolorization reached 90% within 10 min and could be carried out from pH 4.5 to 8.1 . Decrystallized chitosan can be regenerated by 2 M H2SO4 and was reusable more than 10 times . It is, therefore, an attractive candidate for the removal of dyes from textile wastewater.

Biotechnol Lett, 2003 Jul, 25(14), 1155 - 9
Laccase from a non-melanogenic, alkalotolerant gamma-proteobacterium JB isolated from industrial wastewater drained soil; Bains J et al.; A gram-negative, alkalotolerant bacterium, isolated from the soil continually drained with industrial wastewater and identified as gamma-proteobacterium by partial 16S rRNA sequence analysis, produced a polyphenol oxidase, which showed laccase but not tyrosinase activity . The organism grew well from pH 6 to 10 and produced laccase maximally at pH 10 . The enzyme was stable from pH 3 to 10.6 for at least 24 h and was optimally active at 55 degrees C and pH 6.5 in a 5 min assay.

Environ Sci Technol, 2003 Aug 1, 37(15), 3361 - 6
Effect of microbial activity on trace element release from sewage sludge; Qureshi S et al.; The microbial role in mobilization of trace elements from land-applied wastewater sludge is not well-defined . Our study examined the leachability of trace elements (Cd, Cr, Cu, Mo, Ni, P, Pb, S, and Zn) from dewatered sludge as affected by treatments designed to alter microbial activity . Different levels of microbial activity were achieved by incubating sludge columns at 4, 16, 28, and 37 degrees C and by the addition of AgNO3 biocide at each temperature . Columns (with inert glass bead support beds) were subjected to six consecutive incubation-leaching cycles, each consisting of 7.3-d incubation followed by 16-h leaching with synthetic acid rain . Glucose mineralization tests were used to assess overall microbial activity . Significant acidification and trace element leaching occurred when conditions favored microbial activity (16 and 28 degrees C) . Extent of mobilization was element-specific with Zn, Ni, and Cu showing the greatest mobilization (99, 67, and 57%, respectively) . Mobilization was reduced but still substantial at 4 degrees C . Conditions that best inhibited microbial activity (37 degrees C or biocide at any temperature) resulted in the least mobilization . Characterization of enrichments performed using thiosulfate as the sole energy source revealed the presence of both known and putative S-oxidizing bacteria in the sludge . The results suggest that microbial acidification via S oxidation can mobilize trace elements from sludge . Elemental mobility in field situations would also be governed by other factors, including the capacity of soil to buffer acidification and to adsorb mobilized elements.

Chemosphere, 2003 Nov, 53(6), 655 - 65
Removal of PCBs from wastewater using fly ash; Nollet H et al.; Liquids and sludges containing polychlorinated biphenyls (PCBs) can be treated to concentrate the PCBs in a solid residue . The latter can then be handled to destroy the PCBs . A study on sorption kinetics of PCBs on fly ash was conducted in controlled batch systems . TCB and HeCB are removed at 25 degrees C by adsorption on fly ash up to 97% at pH 7, with an adsorbent dose of 5 g/l . An examination of the thermodynamic parameters shows that the adsorption of TCB and HeCB by fly ash is a process occurring spontaneously at ambient conditions . Activation energies for the sorption process ranged between 5.6 and 49.1 kJ/mol . It was observed that the rate at which TCB and HeCB are adsorbed onto fly ash showed a diffusion limitation . The uptake rate of TCB and HeCB increases with increasing initial concentration and gradually tends to a constant value . A decrease in the adsorption of TCB and HeCB was observed when interfering ions and other PCB congeners were present . Changing the pH in the aqueous solution from 2 to 10 had no effect on the adsorption process . Overall, fly ash can be used for an efficient removal of PCBs from several aqueous solutions.

J Colloid Interface Sci, 2003 Sep 15, 265(2), 265 - 75
Polydisperse adsorbability composition of several natural and synthetic organic matrices; Li F et al.; The polydisperse composition of nine dissolved organic materials (DOMs) from two river water sources, one ground water source, two biologically treated wastewater sources, and two commercial sources was analyzed based on their adsorbabilities by activated carbon . For each DOM, batch adsorption isotherms measured for both TOC and UV260 were analyzed using an overall isotherm model derived from the IAST-Freundlich expression . By accounting for the heterogeneity of each DOM with a log-normal distribution of the Freundlich parameter (K), its adsorption behavior was characterized with only four parameters (including three fitting ones) . The average adsorptive strength (KM) and heterogeneity (sigma) determined for all DOMs, which were defined by the mean value and the standard deviation of the log-normal distribution of the Freundlich K, changed over the ranges 2.5-62.2 and 0.22-0.97 (mg/g)/(mg/l)(1/n), respectively, when the TOC index was used . Among all DOMs studied, a river water DOM at the upper stream was found least heterogeneous: the Freundlich K of its organic constituents varied in the range 10.8-190 (mg/g)/(mg/l)(1/n), as compared to a commercial humic acid that exhibited the broadest Freundlich K distribution of 0.01-1494.3 (mg/g)/(mg/l)(1/n) . KM and sigma, along with other two parameters (the Freundlich exponent 1/n and the nonadsorbable organic fraction parameter Cnon/CT0), changed with both indices of TOC and UV260 in a regular manner, indicating that UV-absorbing organic molecules possessed adsorbabilities different from non-UV-absorbing ones . Also based on HPSEC chromatograms measured for solutions before adsorption, the molecular weight composition of all DOMs was also assessed and the molecular size impacts on adsorption characteristics of DOMs were briefly discussed.

J Colloid Interface Sci, 2003 Sep 15, 265(2), 257 - 64
Equilibrium uptake and sorption dynamics for the removal of a basic dye (basic red) using low-cost adsorbents; Gupta VK et al.; Waste carbon slurries (generated in fertilizer plants) and blast furnace slag (generated in steel plants) have been converted into low-cost potential adsorbents . The adsorbents have been characterized and tried for the removal of the dye basic red from wastewater . Studies were performed at different pH to find the pH at which maximum adsorption occurs . Equilibrium isotherms were determined to assess the maximum adsorption capacity of the adsorbents . Adsorption capacities are compared for activated carbon developed from fertilizer waste and activated slag developed from blast furnace waste . The adsorption data are correlated with Freundlich and Langmuir isotherms in each system . The kinetics of adsorption depends on the adsorbate concentration and the physical and chemical characteristics of the adsorbent . Studies were conducted to delineate the effect of pH, temperature, initial absorbate concentration, particle size of the adsorbent, and solid-to-liquid ratio . The adsorption of basic red was found to be endothermic and first-order in nature.

Ambio, 2003 Jun, 32(4), 264 - 8
Greening of arid cities by residual water reuse: a multidisciplinary project in northern Chile; Villanueva LC et al.; This paper describes a project in northern Chile aimed to promote the development of appropriate green areas and gardens for arid regions under prevalent conditions of shortage of water and high salt content in soil and water . Field studies were conducted to test the suitability of selected salt-tolerant native and introduced plants for ornamental use . Plant growth, water and soil quality, marine spray, climate, wastewater treatment and irrigation operating problems were the subject of specific studies and discussion.

J Am Dent Assoc, 2003 Aug, 134(8), 1054 - 65
Purchasing, installing and operating dental amalgam separators: practical issues; McManus KR et al.; BACKGROUND: Growing environmental concern over the accumulation of mercury in some fish has led some state and local environmental agencies to pursue stricter regulation of mercury in wastewater . Dental offices are an identifiable source of mercury in the form of dental amalgam . Although mercury in dental amalgam is not immediately bioavailable (that is, it has not been shown to contribute significantly to the problem of mercury in fish tissue), environmental agencies in some locales are asking dental offices to install amalgam separators in an effort to reduce amalgam discharges beyond those already achieved through chairside traps and vacuum filters . Field experience indicates that the configuration and operation of the dental office infrastructure can significantly affect the choice of separator, as well as the operation and maintenance of the installed equipment . OVERVIEW: The authors review factors related to office infrastructure and operation that dentists should consider when investing in an amalgam separator . They also provide a cost-analysis worksheet and checklist that may be useful to dentists who are considering purchasing a separator . CONCLUSIONS AND CLINICAL IMPLICATIONS: Before purchasing or installing an amalgam separator, dentists should consider factors specific to the available models, including size and maintenance requirements . In addition, office-specific actors should be considered (such as the plumbing configuration, available space for installation and subsequent access to that space for equipment replacement and maintenance) . Dentists also should research whether any local or state regulations exist that might influence product selection or installation . Dentists should consider the effect an amalgam separator could have on existing suction equipment . Finally, dentists will want to consider the short- and long-term costs (including maintenance and parts replacement) of the available options.

Coll Antropol, 2003, 27 Suppl 1, 31 - 9
Toxic metals in freshwater fish from the Zagreb area as indicators of environmental pollution; Bosnir J et al.; The aim of this investigation was to determine the levels of heavy metals and metalloids in freshwater fish from the Zagreb area . A total of 216 freshwater fish samples from 5 sites were examined: Sava river upstream from Zagreb, Sava river at Zagreb, Sava river downstream from Zagreb, Jarun Lake, and 5 "ecologic" fishponds from the Zagreb surroundings . The metals lead, cadmium, mercury and the metalloid arsenic were determined by the method of atomic absorption spectrometry . The mean pooled levels of lead, cadmium and arsenic in all fish samples were 112.3 +/- 95 micrograms/kg, 8.5 +/- 11 micrograms/kg and 23.5 +/- 36 micrograms/kg, and did not exceed the allowed levels of 1,000 mg/kg, 100 micrograms/kg and 200 micrograms/kg, respectively . In 4 fish samples, the levels of mercury exceeded the allowed limit of 500 micrograms/kg (509, 596, 605 and 788 micrograms/kg), however, the pooled mean level of mercury was 127.8 +/- 90 micrograms/kg . There was no major difference in the levels of heavy metals between the two fish families observed, although the levels of lead, cadmium and mercury were higher in the family Ictaluridae (144 vs . 107 micrograms/kg, 10.4 vs . 8.2 micrograms/kg, and 153 vs . 124 micrograms/kg, respectively), whereas the level of arsenic was higher in the family Cyprinidae (23.8 vs . 21.8 micrograms/kg) . Although the Sava river at Zagreb is the main recipient of sewage and wastewater in the Republic of Croatia, the levels of heavy metals were within the allowed limits in all groups of freshwater fish samples, with the exception of 4 samples that contained moderately elevated levels of mercury . Study results suggest that only mercury could be considered a good indicator of environmental pollution, because higher levels of mercury were measured in the fish from the Sava river than in the fish from the Jarun Lake and fishponds from the Zagreb surroundings, considering both pooleded and fish family specified data.

Appl Microbiol Biotechnol, 2003 Dec, 63(2), 107 - 14 Epub 2003 Sep 04.
Anaerobic ammonium oxidation by marine and freshwater planctomycete-like bacteria; Jetten MS et al.; Recently, two fresh water species, " Candidatus Brocadia anammoxidans" and " Candidatus Kuenenia stuttgartiensis", and one marine species, " Candidatus Scalindua sorokinii", of planctomycete anammox bacteria have been identified . " Candidatus Scalindua sorokinii" was discovered in the Black Sea, and contributed substantially to the loss of fixed nitrogen . All three species contain a unique organelle--the anammoxosome--in their cytoplasm . The anammoxosome contains the hydrazine/hydroxylamine oxidoreductase enzyme, and is thus the site of anammox catabolism . The anammoxosome is surrounded by a very dense membrane composed almost exclusively of linearly concatenated cyclobutane-containing lipids . These so-called 'ladderanes' are connected to the glycerol moiety via both ester and ether bonds . In natural and man-made ecosystems, anammox bacteria can cooperate with aerobic ammonium-oxidising bacteria, which protect them from harmful oxygen, and provide the necessary nitrite . The cooperation of these two groups of ammonium-oxidising bacteria is the microbial basis for a sustainable one reactor system, CANON (completely autotrophic nitrogen-removal over nitrite) to remove ammonia from high strength wastewater.

J Environ Monit, 2003 Aug, 5(4), 604 - 9
Occurrence of dissolved PAHs in the Jinsha River (Panzhihua)--upper reaches of the Yangtze River, Southwest China; Huang J et al.; 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in water samples from the Jinsha River (Panzhihua part), Southwest China . Total dissolved PAH concentrations varied from 21.89 microg l(-1) to 382.8 microg l(-1) . It was found that the concentration of PAHs decreased along the flow direction due to the higher density distribution of coal chemical industry in the upstream of our study rivers . The pollution levels in our study area are significantly higher than previously reported values in other waters both in China and other countries . The predominance of benzo{k}fluoranthene and indeno{1,2,3-cd}pyrene was clearly observed in all water samples . On average these two compounds accounted for 98.3% of the total dissolved PAH concentration in water . The results showed the positive correlations among total dissolved PAHs, benzo{k}fluoranthene and indeno{1,2,3-cd}pyrene, which suggested that these two predominant PAHs have similar source and environmental behaviors in our study area . When compared with the survey results of organic micropollutants two decades ago, it was found that hydrocarbon pollution both predominated and even increased with the development of coal chemical industry in this area during the past 20 years . The results therefore provide important information on the current contamination status of a key industrial city in China, and points to the need for urgent action to investigate the relationship between the PAH composition and concentration in water from the Jinsha River and the wastewater discharge from coal chemical industry, and to identify the source, transport pathway and fate of PAHs in the area . It should then be necessary to adopt appropriate and instant measures to control the pollution around this area.

Water Res, 2003 Oct, 37(17), 4295 - 303
Characterization of DOM as a function of MW by fluorescence EEM and HPLC-SEC using UVA, DOC, and fluorescence detection; Her N et al.; To investigate the composition of dissolved organic matter (DOM) as a function of apparent molecular weight (MW) by rapid analytical methods, high performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) was conducted with sequential on-line detectors consisting of UV, fluorescence, and quantitative DOC measurement . Fluorescence excitation-emission matrix (EEM) spectrophotometry was used to select wavelengths for the HPSEC on-line fluorescence system . The chosen peak maxima locations of excitation-emission wavelengths were 278-353 nm for protein-like substances and 337-423 nm for fulvic-like substances based on an analysis of EEM spectra for various samples and reference materials . This system provides quantitative and qualitative information on the specific MW components of DOM, including proportion of DOC (by DOC measurement), aromaticity (by comparison of UV and DOC measurements), and chemical properties (by fluorescence measurement) . It further allows determination of organic matter characteristics (e.g., fulvic-like, protein-like, and polysaccharide-like substances) as a function of MW . Three types of samples (Irvine Ranch ground water (IRWD-GW), Barr Lake surface water (BL-SW), and Hawaii wastewater secondary effluent) were analyzed by the HPSEC-UVA-fluorescence-DOC system . These results were compared with fluorescence EEM for samples fractionated by HPLC-SEC . The DOM fraction in the high apparent MW range (over 10,000g/mol) consisted of polysaccharide-like substances for IRWD-GW and a mixture of polysaccharide-like/protein-like substances for BL-SW and wastewater secondary effluent . Minimal amounts of fulvic-like substances were found in the wastewater secondary effluent sample . The DOM fractions in a medium apparent MW range (5000-1000 g/M) showed higher aromaticity (fulvic in character) than any other fractions for all samples . For the DOM fraction in the low apparent MW range (below 680 g/M), additional aliphatic organic matter was found in IRWD-GW, while BL-SW contained protein-like processes . DOM plays an important role in drinking water and wastewater treatment processes . An enhanced HPSEC technique with multiple on-line detectors enables a better understanding of quantitative and qualitative DOM properties and can help to design and optimize water/wastewater treatment facilities.

Water Res, 2003 Oct, 37(17), 4243 - 9
Use of a single air segment to minimise dispersion and improve mixing in sequential injection: turbidimetric determination of sulphate in waters; Morais IP et al.; In this work, we propose the use of an air segment in a sequential injection system to simultaneously improve the overlapping of the stacked zones and minimise dispersion . This strategy was developed for the determination of sulphate in natural and wastewaters . Barium chloride was used as a precipitating agent and the turbidity of the suspension formed was measured at 420 nm . Analysis was performed without sample pre-treatment and the system was able to monitor sulphate concentration at a rate of at least 20 determinations per hour . Slightly different analytical sequences were developed for natural and wastewaters in order to minimise specific interferences . Direct determination of sulphate was possible within a concentration range of 10-100 and 16-100 mg SO(4)(2-) L(-1) for natural and wastewaters, respectively . Results obtained were comparable with those of the reference method with relative deviations lower than 5% . Relative standard deviations between 1.6% and 3.3% were found.

Water Res, 2003 Oct, 37(17), 4099 - 108
Anaerobic filter reactor performance for the treatment of complex dairy wastewater at industrial scale; Omil F et al.; The wastewaters discharged by raw milk quality control laboratories are more complex than the ones commonly generated by dairy factories because of the presence of certain chemicals such as sodium azide or chloramphenicol, which are used for preserving milk before analysis . The treatment of these effluents has been carried out in a full-scale plant comprising a 12 m(3) anaerobic filter (AF) reactor and a 28 m(3) sequential batch reactor (SBR) . After more than 2 years of operation, a successful anaerobic treatment of these effluents was achieved, without fat removal prior to the anaerobic reactor . The organic loading rates maintained in the AF reactor were 5-6 kg COD/m(3) d, with COD removal being higher than 90% . No biomass washout was observed, and most of the fat contained in the wastewaters was successfully degraded . The addition of alkalinity is crucial for the maintenance of a proper buffer medium to ensure pH stability . The effluent of the AF reactor was successfully treated in the SBR reactor, and a final effluent with a COD content below 200 mg/l and total nitrogen below 10mg N/l was obtained.

Guang Pu Xue Yu Guang Pu Fen Xi, 2001 Aug, 21(4), 529 - 30
{Spectrophotometric determination of trace copper in electroplating wastewater}; Huang N et al.; In the presence of CPB and OP, the chromogenic reaction of DBH-PF with Cu(II) was studied . The results show that the purple micelle reaction has high sensitivity in the medium of (CH2)6N4-HCl(pH = 5.4) buffered solution, the molar absorptivity is 1.8 x 10(5) L.mol-1.cm-1, and Beer's law is obeyed for Cu(II) in the range of 0.0-9.0 micrograms.25 mL-1 at 540 nm . Combined with solvent extraction separation, the method has been applied to the determination of trace Cu in electroplating wastewater with satisfactory results.

J Ind Microbiol Biotechnol, 2003 Sep, 30(9), 549 - 52 Epub 2003 Aug 27.
Effects of pH and temperature on the survival of coliphages MS2 and Qbeta; Feng YY et al.; The RNA F-specific coliphages, MS2 and Qbeta, have been used as virus indicators in water and wastewater studies . It is therefore useful to have a good understanding concerning the effects of environmental factors on their survival in order to choose an appropriate candidate for assessing microbial safety in relation to water quality management . The effects of pH and temperature on the survival of these two coliphages were investigated . MS2 survived better in acidic conditions than in an alkaline environment . In contrast, Qbeta had a better survival rate in alkaline conditions than in an acidic environment . The inactivation rates of both coliphages were lowest within the pH range 6-8 and the temperature range 5-35 degrees C . The inactivation rates of both coliphages increased when the pH was decreased to below 6 or increased to above 8 . The inactivation rates of both coliphages increased with increasing temperature . Qbeta behaved peculiarly in extreme pH buffers, i.e . it was inactivated very rapidly initially when subjected to an extreme pH environment, although the inactivation rate subsequently decreased . In general, MS2 was a better indicator than Qbeta . However, within the pH range 6-9 and at temperatures not above 25 degrees C, either MS2 or Qbeta could be used as a viral indicator.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Sep, 38(9), 1903 - 14
Photocatalytic treatment of cibacron brilliant yellow 3G-P (reactive yellow 2 textile dye); Aye T et al.; The photocatalytic treatment of a textile dye wastewater, cibacron brilliant yellow 3G-P (reactive yellow 2), under the presence of UV-A radiation was studied . Treatment of test solutions containing 100 mg/L cibacron brilliant yellow dye with two types of photocatalysts, Degussa P25 and Hombikat UV 100 titanium dioxide, were investigated . The efficiency of these two commercial photocatalysts was compared in the presence and absence of hydrogen peroxide (H2O2) . H2O2 concentration of 15 mM showed the best efficiency toward the photocatalytic treatment of the textile dye at the concentrations tested . Both decolorization and mineralization were significantly improved by using 15 mM H2O2 . The treatment efficiency of the photocatalytic degradation of reactive yellow 2 was determined in terms of both adsorption kinetics and total mineralization . The decolorization and mineralization followed first order kinetics with a rate constant of 0.09 min(-1) for decolorization with Degussa P25 titanium dioxide in the presence of H2O2 . 71.3% chloride and 27.9% sulphate were yielded after complete decolorization in the photocatalytic treatment of the dye . However, only 0.78% yield of the nitrate was obtained by photocatalysis . The formation of intermediates was not significant compared to the original dye solution in terms of absorbance.

J Environ Sci (China), 2003 May, 15(3), 413 - 6
Removal of heavy metals through adsorption using sand; Awan MA et al.; The removal of four heavy metals i.e . Pb, Cr, Cu, and Zn from their aqueous solutions, using ordinary sand as an adsorbent, was studied at 20 degrees C . The amount of metal adsorbed to form monolayer on sand (a(m)), obtained from Langmuir isotherm, exhibited the preference of metals for sand in the order Pb > Cr > Cu > Zn . The heavy metal-sand adsorption phenomena can be illustrated on the basis of the interaction between surface functional group of silicates (sand) and the metal ions . It is deduced that sand can be used as a low cost adsorbent for the removal of heavy metal from wastewater (containing low conc . of metals), especially in the developing countries.

J Environ Sci (China), 2003 May, 15(3), 388 - 95
Impact of wastewater reuse on cobalt status in Egyptian environment; Abdel-Sabour MF; Cobalt is used in the manufacture of alloys, catalysts in the petroleum industry, catalytic converters, and paint pigments . Thus the potential for Co releases into the environment is highly increased . Use of waste sludges and sewage effluent to fertilize and irrigate soils has also increased soil Co concentrations . Total cobalt contents of alluvial delta soil of Egypt show considerable variation ranging from 13.1 to 64.7 ppm . The impact of either wastewater irrigation or industrial activities on soil total Co was obvious due to accumulation of organic matter and solid waste in the surface soil samples . Food crops and vegetables should not be grown on soil highly contaminated by Co . It is noteworthy that the delayed neutron activation analysis (DNAA) technique could be used successfully for total Co determination due to its high sensitivity . It is quit clearly that dust samples of Cairo City contains higher Co level, as compared to Suez Canal Region (Ismailia, Port Said an El-Sues cities) . The high values in Cairo City may be due to the existence of industries around the city and the intensive traffic . To minimize Co environmental hazards, waste effluents should be treated on site . Thus, levels of potentially toxic Co needs to be continuously monitored and should be removed during several treatment processes before the disposal of these wastes.

J Environ Sci (China), 2003 May, 15(3), 346 - 50
Application of numerical simulation on optimum design of two-dimensional sedimentation tanks in the wastewater treatment plant; Zeng GM et al.; The paper establishes the relationship between the settling efficiency and the sizes of the sedimentation tank through the process of numerical simulation, which is taken as one of the constraints to set up a simple optimum designing model of sedimentation tank . The feasibility and advantages of this model based on numerical calculation are verified through the application of practical case.

J Environ Sci (China), 2003 May, 15(3), 334 - 8
Micro-electrolysis technology for industrial wastewater treatment; Jin YZ et al.; Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants . Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater . Lower initial pH could be advantageous to the removal of chromaticity . A retention time of 30 minutes was recommended for the process design of micro-electrolysis . For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

J Hazard Mater, 2003 Aug 1, 101(3), 323 - 37
Adsorbents made from waste ashes and post-consumer PET and their potential utilization in wastewater treatment; Zhang FS et al.; This study was carried out to prepare low-cost adsorbents from different types of waste ashes and post-consumer PET for use in industrial wastewater treatment . PET was melted and blended with ashes . The mixture was then carbonized to form different types of adsorbents . Heavy metal leaching from the adsorbents was greatly reduced compared to leaching from the bulk ashes . The BET surface area of the adsorbents ranged from 115 to 485m(2)/g . The acidic sites on the adsorbents varied from 0.84 to 1.56meq./g, higher than that of the PET carbon . The adsorption of methylene blue (MB) or heavy metals on the adsorbents was not in accordance with their surface areas because acidic sites reaction, affinity adsorption and cation exchange all contribute to the adsorption of the adsorbents . The isotherm for MB adsorption on the adsorbents can be well described by the Langmuir or Freundlich equation but heavy metal adsorption cannot . It is believed that the adsorbents produced in this manner can be used in wastewater treatments for discoloration and heavy metal removal.

J Hazard Mater, 2003 Aug 1, 101(3), 315 - 22
Pre-oxidation of an extremely polluted industrial wastewater by the Fenton's reagent; San Sebastian Martinez N et al.; The pre-oxidation of an extremely polluted pharmaceutical wastewater (chemical oxygen demand (COD) value of 362,000mg/l) using the Fenton's reagent has been systematically studied using an experimental design technique . The parameters influencing the COD removal of the wastewater, namely temperature, ferrous ion and hydrogen peroxide concentrations have been optimized to achieve a COD global reduction of 56.4%.The total range of the proposed experimental design, however, could not be tested because under some conditions (hydrogen peroxide concentration over 5M) the Fenton's reaction became violent and could not be controlled, probably due to the high exothermic effect associated with COD oxidation . For the tested conditions, the optimal values of hydrogen peroxide and ferrous ion concentration were 3 and 0.3M, respectively, whereas temperature only showed a mild positive effect on COD removal . In addition, during the first 10min of Fenton's reaction, more than 90% of the total COD removal can be achieved.Fenton's reaction has proved to be a feasible technique for the pre-oxidation of the wastewater under study, and can be considered a suitable pre-treatment for this type of wastewaters.

Water Environ Res, 2003 Jul-Aug, 75(4), 336 - 41
The removal of chemical oxygen demand from primary-treated domestic wastewater in subsurface-flow reed beds using different substrates; Manios T et al.; Subsurface-flow experimental reed beds were designed and built based on a combination of two design methodologies . Four different growing media were used with a combination of topsoil, gravel, river sand, and mature wastewater biosolids compost to determine the best substrate for chemical oxygen demand removal . Eight units were constructed, two for each material . One bed for each pair was planted with Typha latifolia plants commonly known as cattails . Primary-treated domestic wastewater was continuously fed to the beds for more than 6 months . The best performance was achieved by the gravel reed beds, with an average removal rate higher than 50% . Soil-based beds containing topsoil and sand only managed to attain removals of approximately 10% . The reed beds containing compost in their substrate produced the worst treatment, mainly because of leaching of organic substances from the compost . Primarily as a result of channel flow, all beds showed significant deviation from the designed retention time . There was no significant difference in the performance of planted and unplanted reed beds.

Mar Pollut Bull, 2003 Sep, 46(9), 1102 - 10
Surveillance for previously unmonitored organic contaminants in the San Francisco Estuary; Oros DR et al.; The San Francisco Estuary Regional Monitoring Program initiated surveillance monitoring to identify previously unmonitored synthetic organic contaminants in the San Francisco Estuary . Organic extracts of water samples were analyzed using gas chromatography-mass spectrometry in full scan mode . The major contaminant classes identified in the samples were fire retardants, pesticides, personal care product ingredients, and plasticizers . Evidence from the literature suggests that some of these contaminants can persist in the environment, induce toxicity, and accumulate in marine biota and in higher food chain consumers . The major sources of these contaminants into the marine environment are the discharge of municipal and industrial wastewater effluents, urban stormwater, and agricultural runoff . As a proactive effort, it is suggested that surveillance studies be used routinely in monitoring programs to identify and prevent potential problem contaminants from harming the marine environment.

J Environ Qual, 2003 Jul-Aug, 32(4), 1222 - 7
Use of additives to enhance the removal of phenols from water treated with horseradish and hydrogen peroxide; Tonegawa M et al.; Use of additives, such as polyethylene glycol (PEG), selected surfactants, chitosan gel, or activated carbon, has been shown to enhance enzymatic treatment of water polluted with organic compounds . In this study, additives were used to facilitate the removal of 2,4-dichlorophenol (2,4-DCP) from water using minced horseradish (Armoracia rusticana P . Gaertn . et al.) as a carrier of peroxidase activity . The specific objectives of the study were to (i) enhance the pollutant removal activity of minced horseradish by the addition of PEG and other additives (e.g., Tween 20, Triton X-100, and rhamnolipid); (ii) eliminate colored reaction products by the addition of chitosan; and (iii) eliminate color by amending treated water with activated carbon . The disappearance of 2,4-DCP in horseradish-treated water samples amended with PEG or various surfactants (75-90%) was greatly increased over that observed in nonamended samples (29%) . The effect of PEG depended on its average molecular weight . As indicated by visible spectrophotometry, enclosing horseradish pieces between two sealed chitosan films completely eliminated colored reaction products; however, the decolorization was accompanied by a reduction in 2,4-DCP removal (from 95 to 60%) . On the other hand, commercially available activated carbon completely removed colored reaction products from the treated water without reducing the removal efficiency . Based on the results obtained, it can be concluded that the use of additives may considerably improve the quality of wastewater treated by plant materials.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Aug, 38(8), 1641 - 57
Wastewater reuse for the minimization of fresh water demand in coastal areas--selected cases from the textile finishing industry; Orhon D et al.; Availability of water to the industry often becomes prohibitive, both in terms of quality and cost, in coastal areas . This study takes the textile industry and evaluates the prerequisites of water recovery and reuse . In this context, a large spectrum are studied for their water, the general quality of wastewater generated, quality and treatability of reuse wastewater streams, and expected changes in the overall effluent quality after segregation of the recovery wastewater portion.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Aug, 38(8), 1629 - 39
Multiple use of water in industry--the textile industry case; Rott U; The main aim of this article is to give a review on the state of the art of available processes for the advanced treatment of wastewater from Textile Processing Industry (TPI) . After an introduction to the specific wastewater situation of the TPI the article reviews the options of process and production integrated measures . The available unit processes and examples of applied combinations of unit processes are described . A special place is given to the in-plant treatment, the reuse of the treated split flow or mixed wastewater and the recovery of textile auxiliaries and dyes.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Aug, 38(8), 1615 - 27
Novel catalytic photochemical and hydrothermal treatment processes for acid dye wastewater; Arslan-Alaton I; The purpose of the present study was to evaluate the catalytic effect of a heteropoly acid, namely H4SiW12O40, on aqueous Acid Orange 7, a well-known, representative textile monoazo dye applied to nylon fabrics, in sub-critical water (T = 160 degrees C-290 degrees C; P = 0.6-3.0 MPa, pH = 2.6) and under near-UV-VIS light irradiation (isopropanol: water ratio = 1:10: pH = 2.8) . SiW12O40-catalyzed photochemical Acid Orange 7 bleaching was also explored in the presence of two dye assisting chemicals as well as in simulated acid dye wastewater at its natural, acidic pH under otherwise identical reaction conditions . Though less explored than TiO2-mediated, heterogeneous photocatalytic treatment, heteropolyacid-catalyzed thermal and/or photoatalytic re-mediation could be an attractive alternative for the degradation of refractory, colored compounds using relatively mild wet oxidation operating conditions or even natural solar light.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Aug, 38(8), 1587 - 96
Application of advanced oxidation processes to different industrial wastewaters; Balcioglu IA et al.; This study examines the application of photochemical and non-photochemical advanced oxidation processes on the treatment of textile, Kraft bleaching, photoprocessing, and pharmaceutical wastewaters . Effects of reaction conditions on the treatment efficiency of industrial wastewater have been investigated . The results were evaluated in terms of biodegradability enhancement . The results indicated depending upon the composition of wastewater and applied pretreatment all applied AOPs had an ability to increase the biodegradability of studied wastewaters.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Aug, 38(8), 1469 - 78
Urban wastewater effects on water flow and solute transport in soils; Coppola A et al.; This article aims mainly to verify the consequences of urban wastewater reuse in irrigation practices on hydrological behavior of soils . Herein the effects on both the hydraulic and dispersive properties of characteristic soils in South Sardinia are illustrated . The study was carried out at the Ente Autonomo del Flumendosa (EAF) laboratory . Ten undisturbed soil monoliths, 120 cm height and 40 cm diameter, were collected from plots, the locations of which were preliminarily individuated through a prior pedological study . An experimental facility was set up and sensors for monitoring both soil water and solute concentrations were inserted horizontally in each column at different depths . A disturbed layer at the soil surface, which expands in depth with time, was observed, characterized by reduced soil porosity, translation of pore size distribution towards narrower pores and consequent drastic decrease of permeability . It will be shown that these changes occurring in the disturbed soil layer, although local by nature, affect the mean hydrological behavior of the whole soil profile.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Aug, 38(8), 1401 - 10
European union water policy--tasks for implementing "Water Framework Directive" in pre-accession countries; Sozen S et al.; Water Framework Directive aiming to maintain and improve the aquatic environment in the EU was launched by the European Parliament in 2000 . According to this directive, control of quantity is an ancillary element in securing good water quality and therefore measures on quantity, serving the objective of ensuring good quality should also be established . Accordingly, it is a comprehensive and coordinated package that will ensure all European waters to be protected according to a common standard . Therefore, it refers to all other Directives related to water resources management such as Urban Wastewater Treatment Directive Nitrates Directive, Drinking Water Directive, Integrated Pollution Prevention Control etc . Turkey, as a candidate state targeting full-membership, should comply the necessary preparations for the implementation of the "Water Framework Directive" as soon as possible . In this study, the necessary legislative, political, institutional, and technical attempts of the pre-accession countries have been discussed and effective recommendations have been offered for future activities in Turkey.

J Environ Sci Health B, 2003 Sep, 38(5), 663 - 79
Hydrogen sulfide gas treatment by a chemical-biological process: chemical absorption and biological oxidation steps; Chung YC et al.; In order to remove high concentrations of hydrogen sulfide (H2S) gas from anaerobic wastewater treatments in livestock farming, a novel process was evaluated for H2S gas abatement involving the combination of chemical absorption and biological oxidation processes . In this study, the extensive experiments evaluating the removal efficiency, capacity, and removal characteristics of H2S gas by the chemical absorption reactor were conducted in a continuous operation . In addition, the effects of initial Fe2+ concentrations, pH, and glucose concentrations on Fe2+ oxidation by Thiobacillus ferrooxidans CP9 were also examined . The results showed that the chemical process exhibited high removal efficiencies with H2S concentrations up to 300 ppm, and nearly no acclimation time was required . The limitation of mass-transfer was verified as the rate-determining step in the chemical reaction through model validation . The Fe2+ production rate was clearly affected by the inlet gas concentration as well as flow rate and a prediction equation of ferrous production was established . The optimal operating conditions for the biological oxidation process were below pH 2.3 and 35 degrees C in which more than 90% Fe3+ formation ratio was achieved . Interestingly, the optimal glucose concentration in the medium was 0.1%, which favored Fe2+ oxidation and the growth of T . ferrooxidans CP9.

J Hazard Mater, 2003 Jul 18, 101(2), 191 - 201
Sorption of zinc ions from aqueous solutions on regenerated activated carbons; Dabek L; This paper discusses the increasing use of activated carbons to remove wastewater contaminants and their contribution to producing wastes abundant in heavy metals . Considering their threat to the environment and their possible recovery, research on the regeneration of spent carbon sorbents and catalysts is advisable . It has also been shown that it is possible to recover activated carbon from spent catalyst (CC(spent)) generated by vinyl acetate synthesis by using supercritical extraction with carbon dioxide or by leaching with hydrochloric acid or a solution of nitric acid assisted by microwave energy . Activated carbon recovered in this work had a high sorption for zinc ions that was comparable to that of fresh commercial activated carbon.

J Hazard Mater, 2003 Jul 18, 101(2), 179 - 90
Studies on the extraction of phenol in wastewater; Jiang H et al.; A novel extraction procedure has been developed for treating phenolic wastewater . Alcohols, amines, and organic acids were applied as extractants in separation of phenol from the wastewater containing 6000 mg/l phenol and 5% salts discharged by chemical plants, >99% phenol was recovered by extracting with octanol . The interactions of phenol with alcohols, amines, and organic acids were studied by a theoretical calculation with GAUSSIAN 98 . The extraction efficiency is strongly dependent on the intermolecular interactions between the phenol and extractants . Based on the experimental and theoretical studies, a pilot-scale LLES was set-up and worked well.

Water Sci Technol, 2003, 47(12), 305 - 12
Water and wastewater related issues in Sri Lanka; Bandara NJ; The primary problems concerning water resources in Sri Lanka are the depletion and degradation of the resource caused by various anthropogenic activities . Surface inland waters in urban areas are polluted heavily with domestic sewage and industrial effluents, and in rural areas with agricultural runoff . With regard to ground water in certain areas of the dry zone, there is a high fluoride content and in hard, rocky, alluvial areas, there is a high concentration of iron . In urban over-crowded cities, there is biological contamination of ground water . Over-utilization, particularly through tube wells, is another major problem affecting ground water resources in Sri Lanka . Oil spills, dumping of waste from ships, coral and sand mining, and activities are the main causes of marine pollution in the country . Except for pipe-borne water supply, irrigation and hydropower schemes, in general water resources in Sri Lanka are managed very poorly . Regulations are available to control most water related problems but enforcement of these regulations is lacking . The ultimate result of degradation and depletion of water resources is the increasing health hazards . Water-borne and vector-borne diseases are prevalent, particularly amongst urban low-income communities with poor sanitary facilities and drainage . Despite government initiatives and legislation, very slow progress has been made towards combating water pollution . This paper examines the most significant water and wastewater related issues in Sri Lanka and their controlling mechanisms.

Water Sci Technol, 2003, 47(12), 247 - 54
A cost-effective method for detoxification of sludge containing lead; Banerjee K et al.; The industrial wastewater treatment plant discussed in this paper generates sludge containing heavy metals, including lead . Occasionally, the concentration of lead in the Toxic Characteristics Leaching Procedure (TCLP) extract from the sludge exceeded the U.S . Environmental Protection Agency (EPA) regulatory limit of 5 mg/l and resulted in the solid waste exhibiting the characteristic of toxicity . The technical and economic feasibility of a process for conditioning the lead-containing sludge was investigated . The results revealed that the lead-laden sludge could be made non-hazardous by chemical conditioning . The lead reduction efficiency of triple super phosphate (TSP) is higher than that of either calcium carbonate or magnesium hydroxide . The laboratory and pilot-scale tests indicated that the conditioning system consistently reduced the lead in the TCLP extract below the regulatory limit of 5 mg/l . The economic feasibility evaluation demonstrated that more than 450,000 US dollars could be saved annually by conditioning the sludge with TSP and disposing it as a non-hazardous material in a landfill . The results obtained from the laboratory as well as from the pilot-scale operation are described and discussed in this paper.

Water Sci Technol, 2003, 47(12), 239 - 46
Anaerobic hydrolysis of primary sludge: influence of sludge concentration and temperature; Ferreiro N et al.; Anaerobic hydrolysis of primary sludge from urban wastewater treatment was first studied as part of anaerobic sludge stabilisation and later as a process for readily biodegradable matter (volatile fatty acids) production in order to improve biological nutrient removal . Furthermore, hydrolysis was found to be the rate limiting step in both single- or two-step anaerobic treatment of domestic wastewater . However, the influence on the process of several factors such as sludge concentration and temperature is still barely understood, as are kinetic aspects . The aim of this work was to study the influence of sludge concentration and temperature on the hydrolytic and acidogenic conversion of primary sludge and to determine the hydrolysis kinetic coefficients at different temperatures . Specific VFA production varied from 0.17 to 0.34 gVFA(COD)/gVSS of raw primary sludge, depending mainly on the assay sludge concentration and, to a lesser extent, on the process temperature . The first-order hydrolysis constants were 0.038, 0.095 and 0.169 d(-1) for 10, 20 and 35 degrees C, respectively.

Water Sci Technol, 2003, 47(12), 223 - 30
Anaerobic hydrolysis of a municipal wastewater in a pilot-scale digester; Alvarez JA et al.; Raw domestic wastewater from the city of Santiago de Compostela (Northwest Spain) was fed into a pilot-scale hydrolytic up flow sludge bed (HUSB) digester with an active volume of 25.5 m3 . The total influent chemical oxygen demand (COD) ranged from 360 to 470 mg/l, the influent SS varied from 190 to 370 mg/l, and the temperature was between 17 degrees and 20 degrees C . The organic load rate (OLR) applied increased step by step from 1.2 to 3.9 kgCOD/m3 x d, while the hydraulic retention time (HRT) decreased from 7.1 h to 2.9 h . A high suspended solids (SS) removal of about 82-85% from the influent was reached, most of which (81 to 88%) was eliminated by hydrolysis, while the rest remained in the purge stream . The total COD removal ranged from 46 to 59% . On the other hand, a high acidification of the COD remaining in the effluent was obtained, so the percent COD in the form of volatile fatty acids (VFA(COD)) with respect to total effluent COD was about 43% for the highest HRT applied, and about 27% for the lowest HRT . The soluble to total COD ratio (CODs/CODt) increased from 25-32% for the influent to 71-86% for the effluent . The results obtained confirm the viability and interest of direct anaerobic hydrolytic pre-treatment of domestic wastewater.

Water Sci Technol, 2003, 47(12), 183 - 9
Use of ORP (oxidation-reduction potential) to control oxygen dosing for online sulfide oxidation in anaerobic treatment of high sulfate wastewater; Khanal SK et al.; In this study, oxidation-reduction potential (ORP) was used as a controlling parameter to regulate oxygen dosing to the recycled biogas for online sulfide oxidation in an upflow anaerobic filter (UAF) system . The UAF was operated with a constant influent COD of 18,000 mg/L, but with different influent sulfates of 1000, 3000 and 6000 mg/L . The reactor was initially operated under a natural ORP of -290 mV (without oxygen injection), and was then followed by oxygenation to raise its ORP by 25 mV above the natural level for each influent sulfate condition . At 6,000 mg/L sulfate without oxygen injection, the dissolved sulfide reached 733.8 mg S/L with a corresponding free sulfide of 250.3 mg S/L, thus showing a considerable inhibition to methanogens . Upon oxygenation to raise its ORP to -265 mV (i.e., a 25 mV increase), the dissolved sulfide was reduced by more than 98.5% with a concomitant 45.9% increase of the methane yield . Under lower influent sulfate levels of 1,000 and 3,000 mg/L, the levels of sulfides produced, even under the natural ORP, did not impose any noticeable toxicity to methanogens . Upon oxygenation to raise the ORP by +25 mV, the corresponding methane yields were actually reduced by 15.5% and 6.2%, respectively . However, such reductions were not due to the adverse impact of the elevated ORP; instead, they were due to a diversion of some organic carbon to support the facultative activities inside the reactor as a result of excessive oxygenation . In other words, to achieve satisfactory sulfide oxidation for the lower influent sulfate conditions, it was not necessary to raise the ORP by as much as +25 mV . The ORP increase actually needed depended on both the influent sulfate and also actual wastewater characteristics . This study had proved that the ORP controlled oxygenation was reliable for achieving consistent online sulfide control.

Water Sci Technol, 2003, 47(12), 119 - 24
Elimination costs for different wastewater compounds; Schulz A et al.; The present report presents the system and discusses the results of the cost calculation for the reduction/elimination of different wastewater and sludge compounds . These costs were calculated for different types of processes at 102 wastewater treatment plants of Emschergenossenschaft/Lippeverband and Aggerverband . Comparing enhanced biological phosphorus removal and precipitation, one of the results indicates that in general the costs for elimination of one kilogram of phosphorus are lower in the plants in which only chemical precipitation is used for P reduction . Further results of the cost calculation will be presented with a discussion of their possible influence on planning decisions.

Water Sci Technol, 2003, 47(12), 105 - 12
A new one-dimensional clarifier model--verification using full-scale experimental data; De Clercq J et al.; A new one-dimensional clarifier model was developed, including components of existing models, and extended with a height-dependent cross-sectional area and two flowrate-dependent dispersion coefficients . This model is evaluated using data from a detailed one-month measuring campaign on a full-scale wastewater treatment plant . The data included hourly sludge concentration profile, sludge heights at 10 minute intervals, sludge concentrations in inlet, effluent and recycle flows and regular settling properties characterised by batch setting tests . Due to the poor quality concentration measurements at the surface of the clarifier, the model was not calibrated to perform well in concentration predictions at this surface . However, excellent descriptive capabilities were obtained for sludge profiles and blanket level . The Cho et al . setting velocity function was found to be significantly better in terms of description capability than the more traditional Vesilind function.

Water Sci Technol, 2003, 47(12), 65 - 71
Integral and unified model for the sewer and wastewater treatment plant focusing on transformations; Huisman JL et al.; The urban drainage cycle is a very complex system with many interacting processes . Models are a great help to test different scenarios and improve the understanding of this system . At present, good models exist for the hydrodynamics of the sewer systems, for the biological conversions in the wastewater treatment plant (ASM 1 to 3) and for the receiving water (RWOM1) . However, the traditional transport and conversion models for the sewer system are incompatible with the ASM definitions, making it difficult to link the models to come an integral and unified urban drainage model . In this work, a new sewer system model that is based on ASM3 has been coupled to an advanced nutrient removal model for the wastewater treatment plant . As both models are based on ASM3, they are unified in their definitions of the state variables and processes . This new combination has been used to test different scenarios and to test the influence of the sewer system on the treatment plant.

Water Sci Technol, 2003, 47(12), 57 - 63
An intelligent controller for automated operation of sequencing batch reactors; Cohen A et al.; In this paper the results are presented of original research into the automatic and "intelligent" detection of breakpoints in Dissolved Oxygen (DO) profiles . The research has been based on a large body of data collected from laboratory SBRs operating on synthetic wastewater . Two different approaches were followed to identify the endpoints . The paper analyses and evaluates the results of automatic detection on the basis of geometric features in the DO profiles . This was followed by classification of the detected breakpoints using different soft computing techniques based on Neural Network (NN), Fuzzy Neural Network (FuNN) and Evolving Fuzzy Neural Network (EfuNN) software systems for breakpoint classification . A high rate of successful detection and classification was obtained with up to 96% of the decisions made correctly . In order to overcome the limitations of this system to adapt to dynamically changing process conditions, an intelligent control model was developed by a combination between an Evolving Fuzzy Neural Net (EfuNN) combined with a logic decision unit . This system has the ability to "learn on-the-fly" and adjust its response pattern in order to maintain a high rate of successful breakpoint detection under varying changing process conditions . This software system has been sucessfully embedded on a small programmable controller for integration into larger process control systems for the operation of SBR plants.

Water Sci Technol, 2003, 47(12), 49 - 56
New monitoring technique with an ICA algorithm in the wastewater treatment process; Lee JM et al.; A new monitoring method using independent component analysis (ICA) is suggested for the wastewater treatment process (WWTP) . ICA is an extension of PCA (Principal Component Analysis) . While PCA can only impose independence up to the second order (mean and variance) with constraint on the direction vectors to be orthogonal, ICA imposes statistical independence up to more than second order on the individual component and has no orthogonal condition . When the variables have the Gaussian distribution, PCA itself provides a satisfactory result in monitoring performance . However, the measured variables are not often normally distributed . In this case, ICA can provide better monitoring results than PCA since ICA is based on the assumption that the latent variables are not normally distributed . In this paper, the ICA monitoring algorithm with kernel density estimation was applied to fault detection and diagnosis of the wastewater simulation benchmark . ICA with kernel density estimation gives better results than PCA in disturbance detection in spite of severe periodic features of the wastewater plant.

Water Sci Technol, 2003, 48(1), 215 - 23
Nitrogen removal from tannery wastewater by protein recovery; Kabdasli I et al.; Nitrogen removal from wastewaters has gained importance in recent years . In this paper protein precipitation and recovery potential of leather tanning industry wastewaters were experimentally evaluated . A protein profile for all sources was prepared . Liming was determined to be the most important protein source . Composite samples were made up to assess the protein precipitation applications . Isoelectric pH precipitation yielded around 50% protein removal between the optimum pH interval of 2.1-3.8 . FeCl3 proved to be a very effective means of protein removal providing over 60% efficiency . Polyelectrolyte precipitation did not yield satisfactory results . Magnesium ammonium phosphate precipitation followed by acid precipitation of protein provided 85% ammonia removal in addition to 50% protein removal.

Water Sci Technol, 2003, 48(1), 179 - 84
A new phosphate-selective sorbent for the Rem Nut process . Laboratory investigation and field experience at a medium size wastewater treatment plant; Petruzzelli D et al.; P-control technologies for municipal wastewater are essentially based on "destructive" methods, that lead to formation of concentrated solid-phases (sludge), usually disposed-off in controlled landfills . Ion exchange, as a "non-destructive" technology, allows for selective removal and simultaneous recovery of pollutants, which can be recycled to the same and/or related productive lines . In this context, the REM NUT process removes nutrient species (HPO4 = , NH4+, K+) present in biologically oxidised municipal effluents and recovers them in the form of struvites (MgNH4PO4; MgKPO4), premium quality slow release fertilisers . The main limitation to the extensive application of this ion exchange based process is the non-availability of selective exchangers for specific removal of nutrient species . This paper illustrates laboratory investigation and pilot scale development of a so-called "P-driven" modified REM NUT scheme based on a new phosphate-selective sorbent developed at Lehigh University, PA, USA.

Water Sci Technol, 2003, 48(1), 171 - 8
Removal and recovery of phosphate and ammonium as struvite from supernatant in anaerobic digestion; Yoshino M et al.; Removal of phosphorus and nitrogen is required to prevent eutrophication problems in lakes and enclosed coastal seas . And recovery of phosphorus from wastewater has been attracting attention because of lack in phosphorus resources in the near future . In this study, reaction kinetics and design parameters of struvite production are experimentally investigated by using basic reaction type and a draft-tube type reactors . Struvite production rate, which is a very important parameter in reactor design and efficiency estimation, is formulated in an equation consisting of a rate constant (k2), and magnesium, phosphate and ammonium concentrations . The value of k2 is shown to be increased with struvite concentration and mixing intensity in the reactor . The developed equation is applied to the results obtained from the draft-tube type reactor experiments and verified for its applicability . High struvite concentration of 10-25% is maintained in the draft-tube reactor experiments . 92% removal and recovery efficiency with effluent phosphorus concentration of 17 mg/L is achieved under the conditions of 4 minutes reaction time, pH of 8.5 and Mg/P molar ratio of 1.1.

Water Sci Technol, 2003, 48(1), 11 - 7
Potential societal and economic impacts of wastewater nutrient removal and recycling; Randall CW; Because adequate nutrient controls were not established when there were past opportunities to do so, nutrient pollution of estuaries and coastal waters has resulted in the impairment of ecosystems and major reductions or collapse of fisheries at numerous sites around the world, resulting in major economical and societal impacts . The root of the problem is that the political policies and processes have permitted municipalities, developers, industries and farmers to expand and operate without paying the full cost of their activities, and this has been done at the expense of those who rely on the productivity and recreational value of our estuarine and coastal waters . Some governments have developed remedial nutrient control programs, but most of them have been under funded and inadequately enforced, resulting in small increments of progress that tend to be lost because of inadequate land use and immigration controls . It is believed that nutrient recovery and controlled reuse can provide a major tool for the control of nutrient pollution and should be widely implemented . Plans are currently being developed to promote widespread use of nutrient recovery and reuse in the Chesapeake Bay region of the USA . An example of phosphorus reuse is presented.

Ying Yong Sheng Tai Xue Bao, 2003 May, 14(5), 789 - 93
{Performance of a novel combined flocculant HECES}; Zhang K et al.; Combined flocculants with higher environmental safety and lower ecological risk are urgently required in the process of water and wastewater treatment . HECES, a kind of flocculants with high effect and high ecological safety was synthesized by natural and biodegradable polysaccharide starch of corn and inorganic aluminium salt . Flocculent performance includes sediment character and turbidity removal rate . The jar test results showed that the flocculent performance of HECES with the dose of 3.0 mg.L-1 was prior to the combined adding 4.5 mg.L-1 PAC and 1.0 mg.L-1 PAM in treating kaolin suspensions . The optimal concentration of HECES was 8.0 mg.L-1 and 4.0 mg.L-1 in treating domestic wastewater and municipal effluent respectively, with the comparison to 50% an 40% of PAC, the removal rate of turbidity reached 95% and 99%, respectively . It was also identified that the optimal concentration required to effect flocculation depended on kaolin concentration, and on the character of the wastewater within the range examined . It could be more effective to treat wastewater with higher concentration of HECES . The flocculating performance would be better at pH 4.0-9.5 . The superior ecological safety of HECES was due to its lower dosage and its lower concentration of residual activated aluminium.

Ying Yong Sheng Tai Xue Bao, 2003 May, 14(5), 766 - 70
{Effects of livestock wastewater on seedlings of two mangrove species}; Ye Y et al.; Effects of livestock wastewater on growth and physiology of seedlings of two mangrove species (Kandelia candel and Bruguiera gymnorrhiza) in greenhouse pot-cultivation systems were studied under different salinity conditions . In terms of stem height, stem basal diameter, leaf production, maximum leaf area and relative growth rate, livestock wastewater enhanced the growth of Kandelia candel and Bruguiera gymnorrhiza, The effects of salinity and livestock wastewater on biomass partitioning were significant for Bruguiera gymnorrhiza, but not for Kandelia candel . Under livestock wastewater application, the chlorophyll a and b contents of Bruguiera gymnorrhiza leaves increased, but the electric conductance had no significant variation . Wastewater increased the leaf electric conductance of Kandelia candel, but had no significant effects on its chlorophyll a and b contents . Under the two salinity conditions, there was no significant difference in root activity of both species . The POX activity increased in the stem and root of Kandelia candel under the two salinity conditions, while decreased in the root of Bruguiera gymnorrhiza under freshwater condition, and increased under seawater condition . The SOD activity of Bruguiera gymnorrhiza decreased, but for Kandelia candel, it had no significant change.

Ying Yong Sheng Tai Xue Bao, 2003 Apr, 14(4), 623 - 6
{Advances in the research of infiltration wetland wastewater treatment systems}; Cui L et al.; As their high purification efficiency and relatively low capital investment and treatment cost, infiltration wetland wastewater treatment systems have been popular, and are being increasingly applied in many countries . In this paper, the bed structure and filtering media, nitrogen and phosphorus removal processes and purification mechanisms, performance, current design criteria, operation and regulation mechanisms, soil clogging problem and solutions, and combination of vertical-horizontal flow wetlands treatment system and its use in different types of wastewater treatment were introduced and summarized . Finally, the future research directions of this technique were also discussed.

Ying Yong Sheng Tai Xue Bao, 2003 Apr, 14(4), 597 - 600
{Purification efficiency of vertical-flow wetland system constructed by cinder and turf substrate on municipal wastewater}; Cui L et al.; Vertical-flow constructed wetlands (VFCWs) system not only has a higher hydraulic loading rate (54-64 cm.d-1), but also has a good removal efficiency for organics, ammonia nitrogen (AN) and total phosphorus (TP) . The removal efficiencies of COD, BOD5, AN, and TP for septic tank effluent were 76-87%, 82-92%, 75-85% and 77-91%, respectively, and the average effluent concentrations of COD, BOD5, AN, and TP in the treated effluent were less than 60, 20, 25 and 2.0 mg.L-1, respectively . A comparison of planted and unplanted columns showed that plantation of Cyperus alternifolius could increase the removal rates of AN, TN, and TP by 2-3%, 4-6%, and 10-14%, respectively.

Anal Bioanal Chem, 2003 Oct, 377(4), 757 - 62 Epub 2003 Aug 12.
Synthesis and applications of poly(acryl p-aminobenzenesulfonamideamidine- p-aminobenzenesulfonylamide) chelating fiber for pre-concentrating and separating trace Bi(III), Hg(III), Au(III) and Pd(IV) from solution samples; Chang X et al.; Poly(acryl p-aminobenzenesulfonamideamidine- p-aminobenzenesulfonylamide) chelating fiber containing "S", "N", and "O" elements was synthesized from polyacrylonitrile fiber and p-aminobenzene sulfonamide and used to enrich and separate trace Bi(III), Hg(III), Au(III), and Pd(IV) ions from wastewater and ore sample solution . The enrichment acidity, flow rate, elution conditions, reuse, interference ions, saturated adsorption capacity, constant of adsorption rate, analytical accuracy, and actual samples on chelating fiber were investigated by means of inductively coupled plasma optical emission spectrometry (ICP-OES) with satisfactory results . Solutions of 100 ng mL(-1) of Bi(III), Hg(III), Au(III), and Pd(IV) ions can be enriched quantitatively by this chelating fiber at a rate of 1.0 mL min(-1) at pH 4 and desorbed quantitatively with 20 mL of 0.25 M HCl and 2% CS(NH(2))(2) solution at 50 degrees C (with recovery >/=97%) . When the chelating fiber was reused for 20 times, the recoveries of the analyzed ions enriched by the fiber were still over 95% (except for Hg(III)) . One thousand-fold excesses of Mn(2+), Ca(2+), Zn(2+), Mg(2+), Fe(3+), Cu(2+), Ni(2+), Al(3+), and Ba(2+) ions and thousands-fold excesses of Na(+ )and K(+) cause little interference in the pre-concentration and determination of the analyzed ions . The saturated adsorption capacity of Bi(III), Hg(III), Au(III), and Pd(IV) was 4.850 x 10(-4), 3.235 x 10(-4), 2.807 x 10(-4), and 3.386 x 10(-4) mol g(-1), respectively . The constants of adsorption rate were 0.409 min(-1) for Bi, 0.122 min(-1) for Hg, 0.039 min(-1) for Au, and 0.080 min(-1 )for Pd . The relative standard deviations (RSDs) for the enrichment and determination of 10 ng mL(-1) Bi(III), Hg(III), Au(III), and Pd(IV) were lower than 2.3% . The results obtained for these ions in actual samples by this method were basically in agreement with the given values with average errors of less than 1.0% . FT-IR spectra shows that the existence of -SO(2)-Ar, -H(2)N-Ar, O=C-NH-, HN=C-NH-, and -HN-SO(2) functional groups are verified in the chelating fiber . From the FT-IR spectroscopy, we can see that Hg(III), Au(III), and Pd(IV) are mainly combined with nitrogen and sulfur (or oxygen), and Bi(III) is mainly combined with nitrogen (or oxygen) of the groups to form a chelating complex.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Jul, 38(7), 1361 - 76
Peroxone process for RO-16 and RB-19 dye solutions treatment; Hsu YC et al.; To obtain a better treatment efficiency for dye or textile wastewater, a semi-batch and a continuous peroxone process using a new gas-inducing reactor were investigated in this study . In the semi-batch peroxone process, the results show that the peroxone process does not improve the color value (ADMI) removal rate, regardless of the pH value . However, the chemical oxygen demand (COD) removal rate could be enhanced in this peroxone process at higher pH value, but the extent of improvement is only slight . The optimal molar ratio of hydrogen peroxide to ozone (H2O2/O3) is 1.0, and at this condition, the mass ratio of removed COD to consumed ozone (deltaCOD/deltaO3) is twice as high as that in the ozone alone process . In the continuous peroxone process, the hydrogen peroxide addition also does not improve the ADMI removal . However, the COD removal is improved more significantly in the continuous peroxone process . The optimal H2O2/O3 molar ratio for the continuous peroxone process varies with the input liquid flow rate (QL) . For liquid flow rate of 0.5 L/min, the optimal H2O2/O3 molar ratio is 3.0 and the COD removal percentage (R(COD)) reaches 50.0 to approximately 55.8%, providing about 15 min oxidation time, for the two kinds of dye solutions that were investigated in this study . The optimal residual hydrogen peroxide concentration in the working solution ({H2O2}res.) is about 1.7 x 10(-2) mol/L, providing an input rate of ozone at 8.8 x 10(-2) mol/h.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Jul, 38(7), 1327 - 39
Treatment of textile effluents by H2O2/UV oxidation combined with RO separation for reuse; Kang SF et al.; This study evaluates the feasibility of the treatment of textile effluents by H2O2/UV oxidation combined with reverse osmosis (RO) membrane separation for water reuse in textile dying processes . The results showed that the conductivity of textile effluents was from 2340 to 4560 micros/cm . Addition of auxiliary chemicals used during the dyeing processes increased the conductivity in textile wastewaters . The H2O2/UV pre-oxidation of textile effluents can mineralize or oxidize dissolved organic carbon (DOC) effectively . However, the removal of conductivity and hardness were poor . Pretreatment of the textile effluent by H2O2/UV oxidation can decrease silt density index (SDI) values and osmotic pressure and increase permeate flux when followed by RO separation . H2O2/UV pre-oxidation and RO post-treatment can improve the textile effluent quality and meet the water quality criteria for water reuse in the textile industry . In conclusion, the combined H2O2/UV pre-oxidation and RO post-process is a promising treatment for textile effluents for water reuse.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Jul, 38(7), 1311 - 26
Oxidative degradation of malachite green by Fenton generated hydroxyl radicals in aqueous acidic media; Dutta K et al.; Fenton-generated hydroxyl radicals removes the color of the malachite green, a basic dye with triphenylmethane group, almost (approximately 98%) completely in weakly acidic aqueous media possibly through oxidative degradation pathways as evidenced from a remarkable lowering in the COD value of the product mixture in comparison to the title dye under identical conditions and almost full quenching of the reaction in presence of hydroxyl radical scavengers . The dye can most effectively be degraded at dye:Fe2+:H2O2 molar ratio of 1:3.3:81.7 for 1.08 x 10(-5) mol dm(-3) dye at pH 2.5-2.8 and at 299K . The rate law of the dye degradation process appears to be: -a{dye}/dt = k{dye} {Fe2+}0.79 {H2O2}0.12, where k = (33 +/- 5) (dm3 mol(-1))0.91 s(-1) at 299K . Salts like NaCl or NaBr retard the degradation rate markedly whereas SO4(2-) or ClO4- are rather innocent . In presence of Cl-, the radical reaction: ClOH*- + Fe2+ --> Cl- + HO- + Fe3+ may account for the gross lowering of degradation rate . The results may be helpful for designing the treatment plants of wastewater containing dyes with triphenylmethane group.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Jul, 38(7), 1247 - 58
As(V) removal from aqueous solutions by coagulation with liquid phase of red mud; Altundogan HS et al.; As(V) removal by using liquid phase of red mud (LPRM) is reported in this article . The experimental section includes characterization of LPRM, as well as As(V) removal from arsenical aqueous solution mixed with LPRM by coagulation in the column . As(V) removal study was divided into two parts; neutralization of LPRM-arsenical solution mixtures with acid solution accompanied with air-agitation and neutralization of those mixtures with CO2 gas . Effect of LPRM/(As(V) solution) volumetric ratio on the removal of As(V) by co-precipitation arsenic together with aluminum present as aluminate in the LPRM were studied . Al/As(V) molar ratio values on the removal of As(V) is evaluated . Results show that As(V) was removed effectively by LPRM with a volumetric LPRM/(As(V) solution) ratio of 0.1 from an arsenical solution in the As(V) concentration of 20 mg dm(-3) . For an efficient removal, it was found to be required an Al/As(V) molar ratio of 6-8 . The results suggest that it is advantageous to use a waste material of red mud liquid phase in the treatment of arsenical wastewater, possibly conjunction with red mud solids as adsorbent that its adsorption ability has been demonstrated earlier.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2003 Jul, 38(7), 1215 - 31
Degradation of 2-chlorophenol by Fenton and photo-Fenton processes--a comparative study; Kavitha V et al.; The oxidation potentiality of simulated aqueous solution of 2-chlorophenol (2-CP) by Fenton's reagent was assessed for wastewater treatment . Batch experiments were carried out to investigate the effects of pH, hydrogen peroxide (H2O2), and ferrous ion (Fe2+) concentrations . Degradation reaction occurred within a limited pH range of 2.5-4.0 . Maximum degradation occurred at a concentration of 22 mM of H2O2 and at 0.45 mM of Fe2+ . Influence of temperature on degradation of 2-CP was investigated . Arrhenius plot for the degradation of 2-CP at various temperatures was plotted based on the experimental data . The role of solar light and UV in photo-fenton degradation of 2-CP was investigated and compared with Fenton process . In both Fenton and photo-fenton processes, free chloride ion generated from 2-CP degradation process reached a maximum concentration at a very short interval of time . Maximum DOC removal of 39% was achieved in Fenton's process (i.e.,) only 2/5th of compound was mineralized . The efficiency of mineralization was considerably improved to 95-97% in photo-fenton processes . Low molecular weight aliphatic organic compounds like oxalic acid and acetic acid formed during the reaction were monitored for Fenton's process . The fate of these stable intermediates compounds in photo-fenton processes were also discussed.

Environ Technol, 2003 Jul, 24(7), 903 - 11
UV/H2O2 chemical oxidation for high loaded effluents: a degradation kinetic study of LAS surfactant wastewaters; Sanz J et al.; This paper describes a laboratory study conducted to elucidate the possibility of treating high loaded solutions of surfactants through an Advanced Oxidation Process . Synthetic solutions of linear alkylbenzene sulfonates are treated in this work as this is a model compound commonly used in the formulation of detergents, with a great presence in urban and industrial waste-waters . The application of UV combined with hydrogen peroxide to oxidise a surfactant effluent is shown to be suitable as a primary oxidation step since conversions of around 50% of the original compound are achieved in the most favourable cases . Initially, the influence of the operating variables on the degradation levels is analysed in this work . A kinetic model that takes into account both the contributions of direct photolysis and radical attack is also worked out . Direct photolysis is performed to determine the quantum yield in the single photodecomposition reaction . Additionally, the rate constant of the reaction between hydroxyl radicals and LAS in the oxidising system H2O2/UV is determined for different operational conditions . Finally, the contribution of each oxidation pathway is quantified; a higher contribution of the radical reaction than that of the direct photolysis was found in all cases.

Huan Jing Ke Xue, 2003 May, 24(3), 61 - 4
{Processing conditions of recirculated MBR for wastewater treatment}; Lu H et al.; In this paper, wastewater was treated with Recirculated Membrane Bio-Reactor (RMBR) and effluent quality became stable after four days running continuously . Critical membrane flux was increased with increasing crossflow velocity between 0.9-1.9 m/s . Under crossflow velocity of 1.9 m/s, critical membrane flux was enhanced from 72 L/(m2.h) to 76 L/(m2.h) or 81 L/(m2.h) respectively when powdered activated carbon (PAC) or both PAC and alum were added to the system . Between 22 degrees C-30 degrees C, the flux was elevated 1.9% per 1 degree C increased . Fouling materials were removed efficiently through cleaning physically or/and chemically with flux recovery of 47%-94%.

J Ind Microbiol Biotechnol, 2003 Sep, 30(9), 531 - 5 Epub 2003 Aug 12.
Potential of a new biotreatment: Sphingomonas cloacae S-3T degrades nonylphenol in industrial wastewater; Fujii K et al.; Sphingomonas cloacae S-3(T), a nonylphenol (NP)-degrading bacterium, was evaluated for its utility in the remediation of NP-contaminated wastewater . In flask-scale experiments, S-3(T) cells immobilized on porous polypropylene carriers (beads) efficiently degraded NP to concentrations routinely measured in aquatic environments {a few parts per billion (ppb), or micrograms per liter) . Therefore, we constructed and evaluated a laboratory-scale wastewater treatment system with a 3-l carrier-filled column . The system worked properly and consistently removed several hundred ppb of NP to ecologically safe concentrations of less than 10 ppb in industrial wastewater without the addition of nutrients . The effect of wastewater pH on the system performance was also evaluated; and wastewater samples with pH values of 6 or 8 were treated efficiently without pH adjustment . These results suggest that a biotreatment system using NP-degrading bacteria can efficiently remediate industrial wastewater and contribute to the preservation of aquatic environments.

Water Res, 2003 Sep, 37(16), 4038 - 44
Removal of cadmium and nickel from wastewater using bagasse fly ash--a sugar industry waste; Gupta VK et al.; The bagasse fly ash, an industrial solid waste of sugar industry, was used for the removal of cadmium and nickel from wastewater . As much as 90% removal of cadmium and nickel is possible in about 60 and 80 min, respectively, under the batch test conditions . Effect of various operating variables, viz., solution pH, adsorbent dose, adsorbate concentration, temperature, particle size, etc., on the removal of cadmium and nickel has been studied . Maximum adsorption of cadmium and nickel occurred at a concentration of 14 and 12 mg x l(-1) and at a pH value of 6.0 and 6.5, respectively . A dose of 10 g x l(-1) of adsorbent was sufficient for the optimum removal of both the metal ions . The material exhibits good adsorption capacity and the adsorption data follow the Langmuir model better then the Freundlich model . The adsorption of both the metal ions increased with increasing temperature indicating endothermic nature of the adsorption process . Isotherms have been used to determine thermodynamic parameters of the process, viz., free energy change, enthalpy change and entropy change.

Water Res, 2003 Sep, 37(16), 4018 - 26
Hybrid flotation--membrane filtration process for the removal of heavy metal ions from wastewater; Blocher C et al.; A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes . For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor . This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations . The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents . Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (<100 mbar) . The process was applied in lab-scale to treat wastewater from the electronics industry . All toxic metals in question, namely copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits.

Water Res, 2003 Sep, 37(16), 3905 - 12
Mechanism of lead adsorption from aqueous solutions using an adsorbent synthesized from natural condensed tannin; Zhan XM et al.; Adsorption is a method for removing lead from wastewater . The adsorption of lead on a new adsorbent synthesized from natural condensed tannin has been investigated using a series of batch adsorption experiments . The study on the adsorption mechanism indicates that the adsorbent performed in aqueous solutions as an ionic exchanger whose end group was sodium ion (Na(+)) . One lead (II) ion (Pb(2+)) was adsorbed onto the adsorbent by taking the place of two Na(+) ions . The maximum exchangeable Na(+) present on the adsorbent was measured with the proton titration experiments and it was up to 1.0 mmol x Na(+)g(-1) dry adsorbent . To a significant extent, pH influenced the extraction of lead from aqueous solutions . The lead removal efficiency was up to 71%, 87% and 91% with initial solution pH at 3.0, 3.6 and 4.2, respectively . The Langmuir equation fitted the adsorption isotherm data well . The maximum adsorption capacity of lead calculated was 57.5, 76.9 and 114.9 mg lead g(-1) dry adsorbent at initial solution pH of 3.0, 3.6 and 4.2, respectively . Therefore, the adsorbent does offer favorable characteristics in lead removal from acidic wastewater.

J Chromatogr Sci, 2003 Aug, 41(7), 367 - 70
Measurement of As, P, and S in the waste gases and water emitted from semiconductor processes by high-temperature hydrogen reduction gas chromatography; Ruimei W et al.; A quick, sensitive, and accurate method, high-temperature hydrogen reduction gas chromatography (GC) (1,2), for measuring arsenic (As), phosphorus (P), and sulfur (S) in the waste gases and water emitted from semiconductor processes is proposed in this paper . A high-temperature hydrogen reduction system that changes As, P, S, and their compounds into hydrides by atomic hydrogen has been designed . It is convenient to detect these elements in solid, liquid, and gaseous samples by high-temperature hydrogen reduction GC without pretreating samples . The lower detection limits of As, P, and S by this method are 0.01, 0.003, 0.02 mg/L, respectively, and the values of relative standard deviation are 6.2%, 8.6%, and 0.3%, respectively . Results determined by high-temperature hydrogen reduction GC are primarily accordant to those by conventional methods such as colorimetry and ion chromatography . The error statistics of this analysis method also show that high-temperature hydrogen reduction GC can be successfully used to determine trace As, P, and S in waste gases and wastewater emitted from semiconductor processes.

Mar Pollut Bull, 2003 Aug, 46(8), 954 - 8
Use of physiological responses in Mytilus trossulus as integrative bioindicators of sewage pollution; Moles A et al.; Mussels, Mytilus trossulus (average shell length 43+/-0.8 mm), were sampled from a beach in Alaska that received untreated sewage for several years, a second beach adjacent to a secondary wastewater outfall, and two nearby reference beaches . Survival time in air, byssal thread production rate, and prevalence of trematode parasites were determined for each group . Tolerances to aerial exposure was significantly lower (P<0.05) at both sewage outfall sites than at the reference sites . Mussels exposed to untreated sewage produced fewer byssal threads and had a significantly higher prevalence of encysted trematodes than mussels from the other beaches, including the secondary wastewater site . Survival in air, byssal thread production, and trematode prevalence in mussels may be useful indicators in evaluating the longterm health of beaches exposed to sewage.

Water Sci Technol, 2003, 47(11), 227 - 33
Polyhydroxyalkanoate form and polyphosphate regulation: keys to biological phosphorus and glycogen transformations?
Randall AA, Chen Y, Liu YH, McCue T.
Experimental studies with both synthetic and real domestic wastewater showed that poly-3-hydroxy-butyrate (3HB) and poly-3-hydroxy-valerate (3HV) formed in direct proportion to the acetate/propionate (Ace/Pro) ratio of the influent wastewater during Enhanced Biological Phosphorus Removal (EBPR) . Acetic acid resulted in higher anaerobic phosphorus (P) release, polyhydroxyalkanoate (PHA) yield, 3HB content, and glycogen (CH) degradation . Linear regression showed that anaerobic P release (Prel) and CH degradation (CHdeg) were both a function of Ace-->3HB, but not of Pro-->3HV . Aerobic P uptake (Pup) correlated best with preceding Prel, rather than PHA (but note Prel correlated with Ace-->3HB) . Aerobic CH formation (CHform) correlated best with CHdeg and 3HB . The results imply the acetate/propionate content of influent has a major influence on PHA, CH, and P transformations . Short-term increases in acetic or propionic acid increased Prel, but were always offset by corresponding changes in Pup to yield the same net P removal as the control reactor . Thus net P removal, and EBPR process performance, was probably a function of the population selected (i.e . XPAO fraction) during long-term cultivation.

Water Sci Technol, 2003, 47(11), 145 - 51
Fenton's reagent and coagulation-flocculation as pretreatments of combined wastewater for reuse; Duran Moreno A et al.; In Mexico City, drinking water is mainly produced from groundwater (70%) . This practice has caused collateral problems such as Mexico City's soil sinking (5-30 cm/year) . One of the most viable alternatives to palliate this problem is the treatment of wastewater for reuse in either irrigation or for groundwater artificial recharge . This paper presents the evaluation of two physicochemical pretreatment systems to treat the wastewater from the metropolitan area of the Mexican Valley that are conducted by two main sewage systems called Great Canal and Churubusco River . In this research two treatment processes were studied: 1) coagulation-flocculation and, 2) Fenton's reagent . For each one of these processes suggested, tests were performed with wastewater samples of the Great Canal and the Churubusco River mixed in a volume ratio of 1:1 . In the case of the coagulation-flocculation process, additional experiments were performed to determine the optimal conditions by applying an experimental design technique . In this experimental design, six coagulant agents were considered (alum, ferric chloride, three coagulant reagents of polymeric kind with aluminium and a coagulant reagent of natural origin), and three flocculant agents (an anionic, a cationic, and a non ionic polymers) . Concerning the application of the Fenton's reagent (Fe2+:H2O2), the experimental variables were the weight ratio of the ferrous iron and the hydrogen peroxide and the concentrations of these reagents . The pH value was controlled to be near to 4 . For the best experimental conditions, the effluent of the Fenton's method showed similar physicochemical characteristics to the wastewater treated by coagulation-flocculation . Nevertheless, Fenton's reagent showed two very important advantages compared to the coagulation-flocculation process: a disinfecting effect and a lower production of residual sludges.

Water Sci Technol, 2003, 47(11), 101 - 7
Nutrient removal from wastewaters using high performance materials; Mackinnon ID et al.; Return side streams from anaerobic digesters and dewatering facilities at wastewater treatment plants (WWTPs) contribute a significant proportion of the total nitrogen load on a mainstream process . Similarly, significant phosphate loads are also recirculated in biological nutrient removal (BNR) wastewater treatment plants . Ion exchange using a new material, known by the name MesoLite, shows strong potential for the removal of ammonia from these side streams and an opportunity to concurrently reduce phosphate levels . A pilot plant was designed and operated for several months on an ammonia rich centrate from a dewatering centrifuge at the Oxley Creek WWTP, Brisbane, Australia . The system operated with a detention time in the order of one hour and was operated for between 12 and 24 hours prior to regeneration with a sodium rich solution . The same pilot plant was used to demonstrate removal of phosphate from an abattoir wastewater stream at similar flow rates . Using MesoLite materials, >90% reduction of ammonia was achieved in the centrate side stream . A full-scale process would reduce the total nitrogen load at the Oxley Creek WWTP by at least 18% . This reduction in nitrogen load consequently improves the TKN/COD ratio of the influent and enhances the nitrogen removal performance of the biological nutrient removal process.

Water Sci Technol, 2003, 47(11), 1 - 8
The competition between PAOs (phosphorus accumulating organisms) and GAOs (glycogen accumulating organisms) in EBPR (enhanced biological phosphorus removal) systems at different temperatures and the effects on system performance; Erdal UG et al.; It is well known and firmly established that the rate of chemical and biochemical reactions slow down as temperature decreases . Nevertheless, several studies have reported that the efficiency of enhanced biological phosphorus removal (EBPR) improves as temperature decreases . However, several recent studies have reported that EBPR reaction rates decrease with temperature decrease in accordance with the Arrhenius relationship . This study was designed to more thoroughly investigate this controversy using two UCT plants fed with a synthetic wastewater consisting primarily of acetate as the COD form, and a small amount of supplemental yeast extract . Experiments were performed over temperatures ranging from 5 to 20 degrees C . The results showed that, even though the kinetic rates decrease as temperature decreases, EBPR systems perform better at colder temperatures . The reason for better system performance is apparently related to reduced competition for substrate in the non-oxic zones, which results in an increased population of PAOs and, thus, greater EBPR efficiency . The proliferation of PAOs apparently occurs because they are psychrophilic whereas their competitors are not . The experiments showed that the EBPR sludges accumulated high concentrations of both PHA and glycogen at 20 degrees C, but accumulated more PHA and much less glycogen at 5 degrees C . Although the results could be interpreted as the result of changes in the PAO-GAO competition, Mann-Whitney non-parametric comparisons of transmission electron microscopy examinations revealed no indication of the presence of GAOs population under any temperature conditions . Regardless, mass balances of the glycogen data showed that the involvement of glycogen is less at cold temperature, even though EBPR was greater . Unlike current EBPR models (e.g . Mino model), the results suggest that glycogen metabolism is not a precursor for EBPR biochemistry . The results also indicate that temperature not only may cause selective pressure on the dominant organisms, but also may force them to use a different metabolic pathway as temperature decreases.

Anal Bioanal Chem, 2003 Oct, 377(3), 397 - 407 Epub 2003 Aug 06.
Effect-directed analysis: a promising tool for the identification of organic toxicants in complex mixtures?
Brack W.
Wastewater effluents, groundwater, surface water, sediments, soils and air particulate matter are often contaminated by a multitude of chemicals . Since often no a priori knowledge of relevant toxicants exists, chemical analysis alone is not an appropriate tool for hazard assessment . Instead, a linkage of effect data and hazardous compounds is required . For that purpose, effect-directed analysis (EDA) was developed, which is based on a combination of biotesting, fractionation procedures and chemical analytical methods . Since a controversial discussion about the prospects of success in relation to the expense exists, the current methodological state of EDA for organic toxicants in complex mixtures and important results are reviewed in this paper with the aim of establishing criteria for the successful use of this promising tool . While EDA is a powerful tool to identify specifically acting individual toxicants close to the source of emission, it is inappropriate for screening purposes and often may fail in remote areas where the concentrations of specific toxicants are too low relative to the nonspecific toxicity of the whole mixture of natural and anthropogenic compounds . The biological tools have to be carefully selected with respect to their ability to detect specific effects and their significance in hazard assessment . Sophisticated chemical tools are required to identify individual toxicants in mixtures of thousands of compounds, which are typical for contaminated environments.

Dent Mater, 2003 Nov, 19(7), 675 - 9
Determination of methyl mercury in dental-unit wastewater; Stone ME et al.; OBJECTIVE: The objective of this investigation was to establish whether monomethyl mercury (MMHg) is present in dental-unit wastewater and if present, to determine the concentration relative to total mercury . METHODS: Wastewater samples were collected over an 18-month period from three locations: at the dental chair; at a 30-chair clinic, and at a 107-chair clinic . Total mercury determinations were completed using United States Environmental Protection Agency's (USEPA) method 1631 . MMHg was measured utilizing modified USEPA method 1630 . RESULTS: The total mercury levels were found to be: 45182.11 microg/l (n=13, SD=68562.42) for the chair-side samples, 5350.74 microg/l (n=12, SD=2672.94) for samples at the 30-chair clinic, and 13439.13 microg/l (n=13, SD=9898.91) for samples at the107-chair clinic . Monomethyl Hg levels averaged 0.90 microg/l (n=13, SD=0.87) for chair side samples, 8.26 (n=12, SD=7.74) for the 30-chair facility, and 26.77 microg/l (n=13, SD=34.50) for 107-chair facility . By way of comparison, the MMHg levels for the open ocean, lakes and rain are orders of magnitude lower than methyl mercury levels seen in dental wastewater (part per billion levels for dental wastewater samples compared to part per trillion levels for samples from the environment) . SIGNIFICANCE: Environmentally important levels of MMHg were found to be present in dental-unit wastewater at concentrations orders of magnitude higher than seen in natural settings.

Environ Sci Technol, 2003 Jul 15, 37(14), 3206 - 13
Chromium remediation or release? Effect of iron(II) sulfate addition on chromium(VI) leaching from columns of chromite ore processing residue; Geelhoed JS et al.; Chromite ore processing residue (COPR), derived from the so-called high lime processing of chromite ore, contains high levels of Cr(III) and Cr(VI) and has a pH between 11 and 12 . Ferrous sulfate, which is used for remediation of Cr(VI) contamination in wastewater and soils via reduction to Cr(III) and subsequent precipitation of iron(III)/chromium(III) hydroxide, has also been proposed for remediation of Cr(VI) in COPR . Instead, however, addition of FeSO4 to the infiltrating solution in column experiments with COPR greatly increased leaching of Cr(VI) . Leached Cr(VI) increased from 3.8 to 12.3 mmol kg(-1) COPR in 25 pore volumes with 20 mM FeSO4, reaching solution concentrations as high as 1.6 mM . Fe(II) was ineffective in reducing Cr(VI) to Cr(III) because it precipitated when it entered the column due to the high pH of COPR, while Cr(VI) in solution was transported away with the infiltrating solution . The large increase in leaching of Cr(VI) upon infiltration of sulfate, either as FeSO4 or Na2SO4, was caused by anion exchange of sulfate for chromate in the layered double hydroxide mineral hydrocalumite, a process for which scanning electron microscopy with energy-dispersive X-ray microanalysis provided direct evidence.

Biol Sci Space, 2003 Jun, 17(1), 18 - 23
Allelopathy as a new strategy for sustainable ecosystems development; Macias FA et al.; Natural products involved in plant-plant and plant-microorganism ecological interaction (Allelochemicals) are an important potential source for alternative agrochemicals and pharmaceuticals, in order to solve the many problems derived from inadequate culture practices and abuse of synthetic herbicides . Isolation, structural determination, bioassay techniques and applicability for these compounds in crop protection and pharmaceutical research are discussed, and future trends on Allelochemicals applications are examined . The new strategies for sustainable ecosystems controlled by allelochemicals offer a particular interest for the development of human bases in space, since these products can stimulate or inhibit plant germination and growth, and permit to develop crops with low residue amounts in water, facilitating wastewater treatment and recycling.

Bioresour Technol, 2003 Nov, 90(2), 199 - 205
Effect of feeding strategy on a stirred anaerobic sequencing fed-batch reactor containing immobilized biomass; Ratusznei SM et al.; The present work reports on the influence of feeding strategy on the stability and performance of a stirred anaerobic sequencing fed-batch reactor containing biomass immobilized on polyurethane foam . The reactor treated low-strength wastewater and was operated at 30 degrees C with an agitation rate of 200 rpm . A 180-min cycle was used to treat approximately 0.5 l of synthetic substrate with a chemical oxygen demand concentration of nearly 500 mg/l . The reactor was operated in batch mode with a 3-min feeding step and in constant rate fed-batch mode with feeding steps of 30, 60 and 180 min . During batch operation, the system attained stability and had a removal efficiency of 86% based on non-filtered substrate concentration . However, during fed-batch operation stability and efficiency were impaired and formation of suspended material was identified . Stability was achieved only for the 30-min feeding step . The poor performance and instability observed in the fed-batch experiments were credited to the formation of considerable quantities of extracellular polymers, which impeded contact between substrate and biomass with consequent negative effect on the mass transfer fluxes . The biopolymer formation was very likely a result of the fed-batch operational mode, in which part of the bioparticles were deprived of contact with the liquid medium for a relatively long period of time.

Bioresour Technol, 2003 Nov, 90(2), 133 - 8
An examination of the effects of detergents on anaerobic digestion; Mensah KA et al.; An anaerobic filter was used to examine the treatability of wastewater formulated to simulate that from the manufacture of detergents . The detergent element was a mixture (1:1:1 v/v) of concentrated washing up liquid, a non-biological hand washing detergent and a fabric softener and, thus contained a combination of cationic surfactants, anionic surfactants, non-ionic surfactants and amphoteric surfactants . A concentration of 2 ml/l caused a deterioration in the performance of the digester which was pronounced after 7 days . When the packing of the filter was modified to include two layers of granular activated carbon, 320 g in total, the reactor was capable of treating a feed containing 10 ml/l . The amount of detergent removed during this second trial was greater than the Langmuir monolayer capacity of the carbon, indicating that both adsorption and degradation were occurring . The results also showed that, at detergent concentrations greater than 1 ml/l, the theoretical COD removal was lower than the actual COD removal . This was compatible with there being an element of adsorption by the activated carbon.

Bioresour Technol, 2003 Nov, 90(2), 101 - 8
Partial characterization of the polluting load of swine wastewater treated with an integrated biodigestion system; Ferreira FL et al.; The stabilization of swine wastewaters from swine confined housing by the combination of a upflow anaerobic sludge blanket (UASB) reactor and waste stabilization ponds is a viable alternative to minimize the environmental impact caused by inadequate disposal of swine wastewaters . In the present study, the polluting load of pre-decanted swine wastewater treated with a series of two 0.705 m(3) UASB reactors and then in parallel in aerated and non-aerated stabilization tanks was investigated from January to July, 2000 . Physicochemical and microbiological analyses were made adopting standard methods (Standard Methods for Examination of Water and Wastewater, 19th ed., American Public Health Association, Washington, DC, 1995) . COD values decreased as the wastewater ran through the integrated biodigestion system dropping from about 3492+/-511-4094 mgl(-1)+/-481 to 124+/-52-490 mgl(-1)+/-230, while nitrate and nitrite levels increased in stabilization tanks, ranging respectively from 4+/-0 to 20 mgl(-1)+/-3 and 3+/-1 to 11 mgl(-1)+/-24 . Although the removal of Escherichia coli was more than 97%+/-6, the effluents of the treatment system still contained unacceptable levels of E . coli (1.6 x 10(3)-1.2 x 10(6) 100 ml(-1)) according to WHO guidelines for use of wastewater in agriculture and aquaculture . These results indicate the necessity of changes on operational characteristics of the treatment system such as an increase of the hydraulic retention time in UASB reactors or in stabilization tanks.

Int J Syst Evol Microbiol, 2003 Jul, 53(Pt 4), 1155 - 63
Gemmatimonas aurantiaca gen . nov., sp . nov., a gram-negative, aerobic, polyphosphate-accumulating micro-organism, the first cultured representative of the new bacterial phylum Gemmatimonadetes phyl . nov; Zhang H et al.; A phylogenetically novel aerobic bacterium was isolated from an anaerobic-aerobic sequential batch reactor operated under enhanced biological phosphorus removal conditions for wastewater treatment . The isolation strategy used targeted slowly growing polyphosphate-accumulating bacteria by combining low-speed centrifugations and prolonged incubation on a low-nutrient medium . The isolate, designated strain T-27T, was a gram-negative, rod-shaped aerobe . Cells often appeared to divide by budding replication . Strain T-27T grew at 25-35 degrees C with an optimum growth temperature of 30 degrees C, whilst no growth was observed below 20 degrees C or above 37 degrees C within 20 days incubation . The pH range for growth was 6.5-9.5, with an optimum at pH 7.0 . Strain T-27T was able to utilize a limited range of substrates, such as yeast extract, polypepton, succinate, acetate, gelatin and benzoate . Neisser staining was positive and 4,6-diamidino-2-phenylindole-stained cells displayed a yellow fluorescence, indicative of polyphosphate inclusions . Menaquinone 9 was the major respiratory quinone . The cellular fatty acids of the strain were mainly composed of iso-C15:0, C16:1 and C14:0 . The G + C content of the genomic DNA was 66 mol% . Comparative analyses of 16S rRNA gene sequences indicated that strain T-27T belongs to candidate division BD (also called KS-B), a phylum-level lineage in the bacterial domain, to date comprised exclusively of environmental 16S rDNA clone sequences . Here, a new genus and species are proposed, Gemmatimonas aurantiaca (type strain T-27T=JCM 11422T=DSM 14586T) gen . nov., sp . nov., the first cultivated representative of the Gemmatimonadetes phyl . nov . Environmental sequence data indicate that this phylum is widespread in nature and has a phylogenetic breadth (19% 16S rDNA sequence divergence) that is greater than well-known phyla such as the Actinobacteria (18% divergence).

Biodegradation, 2003 Jun, 14(3), 219 - 27
The role of sulphidogenesis in anaerobic treatment phase of tannery wastewater treatment in advanced integrated wastewater pond system; Tadesse I et al.; An outdoor experiment was conducted to study the competition between Sulphate Reducing Bacteria (SRB) and Methanogenic Archaea (MA) in anaerobic treatment phase of tannery wastewater treatment in pilot-scale Advanced Facultative Pond (AFP) . The relative electron flow towards sulphate reduction was higher (59-83%) than towards methanogenesis (17-41%), although the COD recovery within the reactor varied between 15 and 90% . The results also demonstrated that the flow of electrons towards SRB increased with increase of the sulphate concentration and decrease of the COD:SO4= ratio.

Biodegradation, 2003 Jun, 14(3), 207 - 17
Performance and ethanol oxidation kinetics of a sulfate-reducing fluidized-bed reactor treating acidic metal-containing wastewater; Kaksonen AH et al.; The treatment of simulated acidic wastewater (pH 2.5-5) containing sulfate (1.0-2.2 g l(-1)), zinc (15-340 mg l(-1)) and iron (57 mg l(-1)) was studied in a sulfate-reducing fluidized-bed reactor (FBR) at 35 degrees C . The original lactate feed for enrichment and maintenance of the FBR culture was replaced stepwise with ethanol over 50 days . The robustness of the process was studied by increasing stepwise the Zn, sulfate and ethanol feed concentrations and decreasing the feed pH . The following precipitation rates were obtained: 360 mg l(-1) d(-1) for Zn and 86 mg l(-1) d(-1) for Fe, with over 99.8% Zn and Fe removal, with a hydraulic retention time of 16 h . Under these conditions, 77-95% of the electrons were accepted by sulfate reduction . The alkalinity produced from ethanol oxidation increased the wastewater pH from 2.5 to 7.5-8.5 . Michaelis-Menten constants (Km) determined in batch FBR experiments, were 4.3-7.1 mg l(-1) and 2.7-3.5 mg l(-1) for ethanol and acetate oxidation, respectively . The maximum oxidation velocities (Vmax) were 0.19-0.22 mg gVS(-1) min(-1) and 0.033-0.035 mg gVS(-1) min(-1), for ethanol and acetate, respectively . In summary, the FBR process produced a good quality effluent as indicated by its low organic content and Zn and Fe concentrations below 0.1 mg l(-1).

J Chromatogr A, 2003 May 30, 999(1-2), 51 - 60
Determination of linear alkylbenzensulfonates in aqueous matrices by ion-pair solid-phase microextraction-in-port derivatization-gas chromatography-mass spectrometry; Alzaga R et al.; Trace determination (low ng/ml) of linear alkylbenzensulfonates (LASs) in water was achieved by solid-phase microextraction (SPME) of ion-pairs formed with tetrabutylammonium . This ion-pairing reagent served two purposes . First, it allowed the extraction of LAS with the polydimethylsiloxane fiber by counterion association and second, the derivatization of the formed LAS ion pairs in the GC injection port at 300 degrees C to form the corresponding sulfonated butyl esters . The methodology developed allows the isomer specific determination of LAS at low detection limits (0.16-0.8 ng/ml), depending on the alkyl chain lengths of LASs with RSDs of 10-12% . Furthermore, the developed methodology was applied to urban wastewater and sea water and compared with a solid-phase extraction (SPE) method (e.g . C18 and strong anion-exchange sorbent) to obtain concordant values for urban wastewater . Moreover, the developed SPME methodology overcame the procedural blank and matrix-dependent recoveries found in the SPE methodologies at low LAS concentrations.

Appl Microbiol Biotechnol, 2003 Aug, 62(2-3), 274 - 8 Epub 2003 Mar 26.
Removal of inorganic and organic mercurials by immobilized bacteria having mer-ppk fusion plasmids; Kiyono M et al.; Feasibility of biological mercury removal from wastewater was examined by using alginate-immobilized cells of Escherichia coli carrying mer-ppk fusion plasmid pMKB18 . Immobilized cells engineered to express mercury-transport system, organomercurial lyase and polyphosphate efficiently removed organic and inorganic mercury from contaminated wastewater over a wide concentration range of mercurials, probably via intracellular accumulation mediated by ppk-specified polyphosphate . Bioaccumulation of mercury was selective compared to other metals such as Cd(2+), Pb(2+) and Cr(6+) . The immobilized cells could be used repeatedly (at least three times) without large loss of mercury removal activity . From these results, it is concluded that the mer-ppk fusion plasmid and the immobilized cells are useful for simultaneous removal of organic and inorganic mercury from contaminated wastewater.

Occup Environ Med, 2003 Aug, 60(8), 595 - 8
Wastewater exposure and health--a comparative study of two occupational groups; Hansen ES et al.; AIMS: To investigate whether wastewater workers are at increased risk of developing cancer . METHODS: Two cohorts of workers employed by the City of Copenhagen, 591 wastewater workers and 1545 water supply workers (controls), were followed from 1965 until 1998 . These two cohorts were compared in terms of cause specific mortality and cancer incidence . RESULTS: The wastewater workers' mortality exceeded that of the controls (relative risk (RR) = 1.25, 95% CI: 1.03 to 1.51) . A similar small excess was seen for cancer incidence (RR = 1.27, 95% CI: 0.97 to 1.67) . Though rare, there was a strongly increased incidence of primary liver cancer among the wastewater workers (RR = 8.9, 95% CI: 1.5 to 51.5) . CONCLUSION: The excess mortality seen among the wastewater workers was smaller than originally feared . It may partly have been due to their occupational exposure, and for preventive purposes, exposure to wastewater and sludge should be minimised . The possibility that sewage exposure confers an increased risk of primary liver cancer deserves further investigation.

Biotechnol Lett, 2003 Apr, 25(7), 541 - 5
Novel BOD (biological oxygen demand) sensor using mediator-less microbial fuel cell; Kim BH et al.; A microbial fuel cell type of biosensor was used to determine the biochemical oxygen demand (BOD) of wastewater . The biosensor gave a good correlation between the BOD value and the coulomb produced . The BOD sensor has been operated for over 5 years in a stable manner without any servicing . This is much longer that that of previously reported BOD biosensors.

J Chromatogr A, 2003 Jun 6, 1000(1-2), 583 - 8
Analytical method for the determination of the aminoglycoside gentamicin in hospital wastewater via liquid chromatography-electrospray-tandem mass spectrometry; Loffler D et al.; A method for the determination of gentamicin residues in hospital wastewater has been developed using kanamycin as a surrogate standard . The method consists of solid-phase extraction (SPE) and detection by ion-pair chromatography with electrospray tandem mass spectrometry (LC-ES-tandem MS) . The SPE was performed on a weak cation exchanger . Filtration should be avoided in the sample preparation, otherwise a significant loss of gentamicin occurs . Chromatographic separation on a C18-column was achieved using a ternary eluent containing methanol, water and 1(-1) heptafluorobutyric acid solution . Mean relative recoveries of the analytes in hospital wastewater varied between 107 and 111% . The limit of quantification (LOQ) was 0.20 microg l(-1) in hospital wastewater . Gentamicin was found in native hospital wastewater in a concentration range between 0.4 and 7.6 microg l(-1).

Rev Epidemiol Sante Publique, 2003 Apr, 51(2), 201 - 14
{Odors and health: a descriptive epidemiological study around a wastewater treatment plant}; Segala C et al.; BACKGROUND: Following community concern regarding potential health effects associated with odors of a wastewater treatment plant, a descriptive epidemiological study was conducted to assess the complaints and the health status of the community and to identify potentially more susceptible groups . METHODS: Questionnaires were administered by telephone to nearly 3.000 subjects, randomly selected in the 8 nearby towns, using a geographical Information System . Residents of three areas were compared, according to the distance from the site: 0-1.5 km (high exposed group), 1.5-3 km (moderate exposed group) and 3-4.5 km (low exposed group) . Questions measured demographic characteristics, concerns, perceived environmental risk and health effects (symptoms in the past 1 month and in the past 1 year) . Multivariate logistic models study the relationships of complaints and health effects, with area and susceptibility factors . RESULTS: Two thousand eight hundred and sixty seven eligible adults participated in an interview . Taking in account confounding factors, population of high and moderate exposed groups reported more odor complaints than the low exposed group, with adjusted odds ratio (OR) of 4.73 (CI95%: 3.63-6.14) and 2.06 (CI95%: 1.59-2.66) respectively . But these 2 groups did not report more frequent health effects compared to the low exposed group . Several health effects were significantly more frequent in persons with self-reported chemical intolerance and in persons considering malodor in terms of health threat . In this last sub-group of population, rhinitis were significantly more frequent in the high exposed group compared to low exposed group, whereas respiratory infections and asthma attacks showed the same non significant patterns . CONCLUSION: If 24,2% of the total sample complaints from odors of the site, this study did not show a higher frequency of health effects in people living near the site (high exposed group) . But 2 susceptible groups (with a higher frequency of symptoms potentially related to odors) were identified: persons with self-reported chemical intolerance, among those, many allergic and asthmatic subjects, and persons considering malodor in terms of health threat.

Environ Sci Technol, 2003 Jul 1, 37(13), 2947 - 52
Removal of B, Cr, Mo, and Se from wastewater by incorporation into hydrocalumite and ettringite; Zhang M et al.; Boron, chromium, molybdenum, and selenium often occur in high concentrations in fly ash leachates . During the leaching of fly ash in alkaline environments, hydrocalumite (Ca4Al2(OH)12(OH)2 x 6H2O) and ettringite (Ca6Al2(OH)12(SO4)3 x 26H20) form as secondary precipitates . In this study, the removal of B, Cr, Mo, and Se oxyanions from high pH waters by incorporation into hydrocalumite and ettringite was examined . Experiments were performed by precipitating these minerals in solutions containing B, Cr, Mo, and Se oxyanions at conditions relevant to lime-leaching of fly ash as well as to fly ash containing concrete . The uptake of all four anions by hydrocalumite and ettringite was high . Anion uptake by hydrocalumite was larger than that by ettringite, and hydrocalumite was able to reduce anion concentrations to below drinking water standards . Ettringite showed an anion preference in the order of B(OH)4- > SeO4(2-) > CrO4(2-) > MoO4(2-) . In contrast, borate was least preferred by hydrocalumite . Coordination, size, and electronegativity are likely the factors that result in the observed differences among the oxyanions.

Sci Total Environ, 2003 Aug 1, 312(1-3), 167 - 79
Long-term variations in dissolved trace elements in the Sagami River and its tributaries (upstream area), Japan; Iwashita M et al.; We investigated long-term variations in dissolved chemical species in water sampled from the Sagami River and its tributaries, Japan . The samples were taken monthly from May 1993 to April 2000 at 28 sampling sites in the Sagami River system . In this paper, we concentrate on 17 sites in the upper catchment . Twenty-four major to trace elements (Li, Mg, Al, Ca, V, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, W, Tl, Pb, U) were determined by using conventional Q-pole ICP-MS with direct nebulizalion . Water flux was measured from 1995 . The data for most species were subjected to fast Fourier transformation (FFT) to extract dominant periodicities, their magnitudes, and their phases . Clear seasonal variations were observed for Al, V, As, Rb and Cs at some sampling points, especially in the tributaries . The seasonal variations may be due to either anthropogenic causes, such as irrigation or wastewater discharge, or natural causes, such as water temperature, pH, redox condition, water flux, or activity of microorganisms . We found no correlation with pH . Water temperature may not be a main controlling factor, although the seasonal variability would be correlated with it . Hydrologic factors may have only minor effects . We suggest that most of the seasonal variation might be correlated with the irrigation of rice paddies . It was difficult to identify all the causes of the seasonal variability . To investigate interannual trends, we used centered 12-month moving averages to eliminate seasonal variations . The water quality of the uppermost streams was generally constant, being controlled by springs on Mt . Fuji . However, in 1993 and 1998, V, As, Rb, Cs and U were depleted briefly, possibly by dilution by overflow from Lakes Kawaguchi and Yamanaka . Hydrologic factors may be more important for interannual variability than seasonal variability . Some heavy trace elements (Zn, Ni, Cd and Sb) showed very irregular variations with high concentration peaks . These elements were discharged from either factories or abandoned mine tailings.

Environ Technol, 2003 Jun, 24(6), 735 - 43
Coupling ultrafiltration with an activated carbon cloth for the treatment of highly coloured wastewaters: a techno-economic study; Metivier-Pignon H et al.; This work investigates the coupling of a membrane technique, ultrafiltration, with a recent adsorbent, activated carbon cloth for the treatment of industrial highly coloured wastewaters . A first experimental part shows the high treatment ability of this process for fountain-pen inks effluents arising from the rinsing of vats in which inks were produced . Whereas ultrafiltration enables more than 97% of colour removal, COD and DOC are not completely retained and a residual value of 1,700 mg l(-1) of DOC is obtained in the permeate . The second step of the process, activated carbon cloth, allows residual organic matter to be removed and a complete discolouring of the permeate . Adsorption capacities of COD and DOC are high, equal to 500 and 250 mg g(-1) respectively . Furthermore, this adsorbent induces a complete removal of glycol compounds (acting as antifreeze) which were not retined by a nanofiltration technique . A second part is an evaluation of the economic feasibility of such an integrated process . Only direct costs are considered at this phase of the study, and are divided into fixed costs (equipment, depreciation, maintenance), variable costs (electricity and consumption) and labour costs . The technical-economic study is carried out for two configurations: a low capacity unit (the UF membrane area is 2.4 m2) and an industrial capacity unit (with a 100 m2 UF membrane) . Costs per treated m3 are respectively 111 and 32 euros, with costs partitioning which are dependent on the unit capacity.

Water Res, 2003 Sep, 37(15), 3733 - 41
A N-Nitrosodimethylamine (NDMA) precursor analysis for chlorination of water and wastewater; Mitch WA et al.; N-nitrosodimethylamine (NDMA) is a potent carcinogen formed during chloramination of water and wastewater treatment plant effluents . A procedure is described for quantifying the concentration of the organic precursors of NDMA that could be formed during chlorination of wastewaters and natural waters . The method involves applying a high dose of monochloramine to a pH-buffered sample followed by a 10-day contact period, during which the monochloramine decays at a rate unrelated to the composition of the sample . Analyses of samples of municipal wastewater effluents and surface waters indicate that the method provides a robust and reproducible measurement of NDMA precursors over a wide range of conditions . A sensitive GC/CI/MS/MS analytical procedure for dimethylamine also is described and used to demonstrate that NDMA formation during chlorination of wastewater and natural waters cannot be explained by dimethylamine concentrations alone.

Water Res, 2003 Sep, 37(15), 3612 - 21
Comparing microfiltration-reverse osmosis and soil-aquifer treatment for indirect potable reuse of water; Drewes JE et al.; Microfiltration (MF) followed by reverse osmosis (RO) and soil-aquifer treatment (SAT) are the two principal technologies considered for indirect potable reuse of wastewater . This study, conducted at the Northwest Water Reclamation Plant, Mesa (Arizona), evaluated MF/RO and SAT (>6 months residence time) treated tertiary effluent with respect to organics removal . Effluent organic matter was characterized as total organic carbon (TOC), by UV absorbance (UVA), solid-state carbon-13 nuclear magnetic resonance spectroscopy, and size exclusion chromatography . Several trace organic micropollutants, including EDTA, NTA, and alkylphenolethoxylate residues, were analyzed by GC/MS . The study revealed that final TOC concentrations of MF/RO and SAT are 0.3 and 1.0 mgl(-1), respectively . Based on the characterization techniques used, the character of bulk organics present in final SAT water resembles the character of natural organic matter present in drinking water . Depending on the molecular weight cut-off, RO membranes can efficiently reject high molecular weight organic matter (characterized as humic and fulvic acids) . However, approximately 40-50 percent of the remaining TOC in permeates consists of low molecular weight acids and neutrals representing a molecular weight range of approximately 500Da and less . In the SAT treated effluent, EDTA and APECs were removed to approximately 4.3 and 0.54 microg/l, respectively, but were below the detection limit in the MF/RO treated effluent.

Chemosphere, 2003 Sep, 52(9), 1615 - 21
Simulation of transboundary pollutant transport action in the Pearl River delta; Chau KW et al.; The rapid economic development in The Pearl River delta region (PRDR) has exerted serious potential pollution threats to areas in the vicinity, which have complicated the task of environmental protection in Hong Kong and Macau . In this paper, a three-dimensional numerical pollutant transport model coupled with a synchronised numerical hydrodynamic model, is developed and employed to simulate the unsteady transport of a representative water quality variable chemical oxygen demand in The Pearl River Estuary . It is demonstrated that there exists a transboundary pollutant transport action between Guangdong Province and Hong Kong for the pollutants in the wastewater discharged from PRDR.

Chemosphere, 2003 Sep, 52(9), 1571 - 9
Possible use of constructed wetland to remove selenocyanate, arsenic, and boron from electric utility wastewater; Ye ZH et al.; Wetland microcosms were used to evaluate the ability of constructed wetlands to remove extremely high concentrations of selenocyanate (SeCN-), arsenic (As), and boron (B) from wastewater generated by a coal gasification plant in Indiana . The wetland microcosms significantly reduced the concentrations of selenium (Se), As, B, and cyanide (CN) in the wastewater by 64%, 47%, 31%, and 30%, respectively . In terms of the mass of each contaminant, 79%, 67%, 57%, and 54% of the Se, As, B, and CN, respectively, loaded into the microcosms were removed from the wastewater . The primary sink for the retention of contaminants within the microcosms was the sediment, which accounted for 63%, 51%, and 36% of the Se, As, and B, respectively . Accumulation in plant tissues accounted for only 2-4%, while 3% of the Se was removed by biological volatilization to the atmosphere . Of the 14 plant species tested, cattail, Thalia, and rabbitfoot grass were highly tolerant of the contaminants and exhibited no growth retardation . Environmental toxicity testing with fathead minnow (Pimephales promelas) larvae confirmed that the water treated by the wetland microcosms was less toxic than untreated water . The data from the wetland microcosms support the view that constructed wetlands could be used to successfully reduce the toxicity of aqueous effluent contaminated with extremely high concentrations of SeCN-, As, and B, and that a pilot-scale wetland should therefore be constructed to test this in the field . Cattail, Thalia, and rabbitfoot grass would be suitable plant species to establish in such wetlands.

Chemosphere, 2003 Sep, 52(9), 1451 - 9
A preliminary study on potential of developing shower/laundry wastewater reclamation and reuse system; Lu W et al.; With the ever-increasing urban population and economic activities, water usage and demand are continuously increasing . Hence, finding/re-creating adequate water supply and fully utilizing wastewater become important issues in sustainable urban development and environmental benign aspect . Considering Hong Kong's situation, e.g., lack of natural fresh water, domination of municipal wastewater, etc., developing wastewater reclamation and reuse system is of specific significance to exploit new water resource and save natural fresh water supplied from Mainland China . We propose and have carried out some preliminary studies on the potential of categorizing municipal wastewater, developing grey and storm water recycling system in public housing estate, investigating the feasibility and potential of using reclaimed grey water, etc . Since there is very limited experience in grey water recycling, such initial studies can help to understand and increase knowledge in utilizing grey water, to foresee the feasibility of developing new water resource, to estimate the cost-effectiveness of reclaiming grey water in metropolitan city.

Water Sci Technol, 2003, 47(10), 139 - 46
Inhibitory effects of long-chain fatty acids on VFA degradation and beta-oxidation; Shin H et al.; The inhibitory effects of major long-chain fatty acids (LCFA), which have 16 or 18 carbons, not only on acetate degradation, but also on propionate degradation and beta-oxidation were examined in anaerobic serum bottle tests at 35 degrees C with the acclimated granular sludges . A modified Gompertz equation described cumulative methane production to assess the rates of VFA degradation and beta-oxidation, which were applied to a simplified noncompetitive model and a simplified substrate inhibition model, respectively . The specific methane production rates on acetate decreased as LCFA concentration increased, which was in good agreement with the noncompetitive inhibition model . Unsaturated oleate (C18:1) and linoleate (C18:2) were more inhibitory than saturated stearate (C18:0) and palmitate (C16:0) on acetate degradation . LCFA inhibition on propionate degradation was similar to that for acetate; however, propionate degradation was less inhibited than acetate degradation . Beta-oxidation was the rate-limiting step in LCFA degradation in most cases . As LCFA concentration increased, beta-oxidation rate reached the maximum value, and then decreased, which confirmed the substrate inhibition of LCFA . Oleate, the most abundant LCFA in wastewater, could be degraded more quickly than saturated LCFA containing the same or even less carbon in spite of relatively high toxicity on acetate degradation.

Water Sci Technol, 2003, 47(10), 93 - 9
Enhancing oxidation of TNT and RDX in wastewater: pre-treatment with elemental iron; Oh SY et al.; Munitions manufacturing wastewater is commonly treated by adsorption to activated carbon . We are proposing a new munitions manufacturing wastewater treatment system consisting of a reductive pre-treatment process and subsequent Fenton's oxidation to mineralize energetic compounds such as TNT and RDX . The pre-treatment involves reduction of electron-withdrawing nitro groups of TNT and RDX with elemental iron . The iron-treated explosives are then oxidized by Fenton's reagent through the addition of H2O2 . The objective of this work is to investigate the feasibility of using elemental iron to convert TNT and RDX to reduction products which may be more oxidizable in subsequent Fenton's oxidation . Results of batch reduction experiments with elemental iron showed complete removal of TNT and RDX and formation of the reduction products within 60 minutes . Results of column experiments showed a rapid and complete removal of TNTand RDX within 9.7 minutes retention time . Fitting observed effluent concentrations to a one-dimensional advection-dispersion equation, we were able to predict the concentration profiles of TNT and RDX in the iron column and calculate the iron column length required for the desired removal . The results of Fenton's oxidation experiments showed that iron pre-treatment enhanced both the rate and extent of TNT and RDX mineralization by Fenton's oxidation.

Water Sci Technol, 2003, 47(10), 71 - 7
Optimum physical-chemical pre-treatment of copper damascene wastewater; Smith E et al.; Chemical and mechanical polishing (CMP) of copper damascene circuits will typically produce copper levels in excess of regulatory limits in wastewater with a unique process chemistry, including high solids . Physical-chemical methods were investigated to determine the optimum treatment depending upon pre-treatment and/or water reuse requirements . Jar test studies revealed that an alum dose of 150-200 mg/L together with anionic polymer aid provided a good removal of turbidity . If the treatment objective is simply solids and copper reduction for discharge to a sewer system, then solids removal can combined with precipitation of copper hydroxide for relatively inexpensive pre-treatment . The presence of peroxide from the process solution, however, may make it difficult to achieve copper values below 5 mg/L, depending on the associated process conditions . If the objective is to remove solids and recover copper, which may also allow recovery of water for reuse, then solids removal by alum and polymer can be followed by ion exchange by a strong acid cation resin . As with precipitation, however, effective copper removal by ion exchange requires pre-treatment of peroxide by chemical reduction . The exchange of dissolved aluminum also reduces the capacity of the resin for copper.

Water Sci Technol, 2003, 47(10), 61 - 9
The role of organic matter lost in kraft pulping material balances ; Luonsi A et al.; Efficiency improvement in a pulp mill includes minimisation of environmental discharges simultaneously with the development of pulp quality and production economy . Material balances in production processes, including fate of sidestreams, are key in proceeding these matters . Different approaches of determining the material balances increase understanding of process behaviour . We have focused on measuring sidestream (carryovers, washing water, filtrate) dissolved organic matter (DOM) in fibreline unit process blocks of softwood ECF bleached kraft production . The DOM was analysed by traditional wastewater methods (volatile solids, organic carbon, chemical oxygen demand) . The measured data was combined with primarily simulated water balances and routine operational mill data in a simulation model . From this balance, yield estimate included, lost organic matter through complete degradation (CD) and volatile organic compounds (VOC) can be calculated throughout the fibreline . The sensitivity of this considerable amount (23-35 kgDVS/adt in total) to various factors is discussed in this paper.

Water Sci Technol, 2003, 47(10), 25 - 32
Wastewater treatment from a motor-oil reforming company using a sequencing batch reactor (SBR); Drillia P et al.; The main aim of this work was to study the ability of an aerobically operated sequencing batch reactor (SBR) to effectively treat the wastewaters produced by a motor-oil reforming company . In fact, the most important goal was to substantially reduce the organic load of these wastewaters before their disposal to an open trench, since the currently installed wastewater treatment plant, that includes an API separator followed by physico-chemical pre-treatment and an oxidation ditch, has proved today to be completely inefficient . The wastewater to be treated was mainly composed of five different streams from various points of the motor-oil reforming plant (e.g . gas washing tanks, cooling pumps, used motor oils holding tanks, etc) . The major problem faced in this work was the high organic load (about 12,000 mg COD/L) and the free and dissolved oil contained in the wastewater (around 6-7%) . Moreover, two of the streams, contributing to the mixed wastewater up to 30%, were unable to sustain dissolved oxygen and unfortunately their mixing with the other three streams resulted in the same detrimental effect . Therefore, experiments were conducted using either three or all of the contributing streams . The mixed wastewater was fed to the reactor either untreated or pre-treated with ceramic membranes in order to exclude all the free and dissolved oil . The application of pre-treated wastewater with membranes to the SBR system resulted in 75.2% and 81.9% total and dissolved COD reduction, respectively.

Water Sci Technol, 2003, 47(10), 17 - 24
Innovative reactor technology for selective oxidation of toxic organic pollutants in wastewater by ozone; Boncz MA et al.; Ozonation can be a suitable technique for the pre-treatment of wastewater containing low concentrations of toxic or non-biodegradable compounds that cannot be treated with satisfactory results when only the traditional, less expensive biological techniques are applied . In this case, the oxidation process has to be made as efficient as possible, in order to reduce the coats of ozone addition and use . An efficient oxidation process with ozone can be obtained by focusing the oxidation with ozone selectively on the direct oxidation of toxic pollutants and to minimize ozone losses due to the decay of ozone in water . Supported by data of the rate constants of the reactions involved, a mathematical model was developed . It quantifies the ozone consumption by the process, and the share of ozone consumption by undesired side reactions, in several different reactor systems . Results obtained with this model indicate that a plug flow reactor (PFR) will be the most efficient design for the oxidation reactor . As an alternative, the cascaded tank reactor system (CTR), in which the ozone feed may be realized with less practical problems, might be considered . The traditional continuous flow stirred tank reactor (CFSTR) is shown to be the least efficient system.

Water Sci Technol, 2003, 47(10), 9 - 16
Innovative developments in the selective removal and reuse of heavy metals from wastewaters; Veeken AH et al.; Sulphide precipitation of heavy metal containing wastewaters results in low effluent concentrations . However, sulphide precipitation is not widely applied in practice because the dosing of sulphide cannot adequately be controlled . A new process was developed where the combination of a sulphide-selective electrode (pS-electrode) and pH electrode controls the sulphide addition . Precipitation experiments were performed on a laboratory-scale in batch and continuous reactor systems with synthetic wastewaters containing Cd, Cu, Ni, Pb or Zn . The response of the pS-electrode during precipitation was unique for each heavy metal and was directly related to the solubility product of the corresponding metal sulphide . The metals were removed to levels < 0.05 mg l(-1) at pH 6.0 by sulphide precipitation while maintaining a total sulphide concentration < 0.02 mg l(-1) . By the control of pS at different levels and keeping the pH constant at 6.0, the metals in solutions of both Cu and Zn could be precipitated selectively from solution in a batch and continuous reactors . The use of a membrane reactor in combination with control of pH and pS offers a simple, cheap, efficient and sustainable technique with respect to obtaining very low effluent concentrations and selective removal of metals as pure metal sulphides which can be reused.

Environ Pollut, 2003, 126(1), 39 - 49
Contaminant risks from biosolids land application: contemporary organic contaminant levels in digested sewage sludge from five treatment plants in Greater Vancouver, British Columbia; Bright DA et al.; This study examines the potential for environmental risks due to organic contaminants at sewage sludge application sites, and documents metals and various potential organic contaminants (volatile organics, chlorinated pesticides, PCBs, dioxins/furans, extractable petroleum hydrocarbons, PAHs, phenols, and others) in current production biosolids from five wastewater treatment plants (WWTPs) within the Greater Vancouver Regional District (GVRD) . There has been greater focus in Europe, North America and elsewhere on metals accumulation in biosolids-amended soil than on organic substances, with the exception of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans . Another objective, therefore, was to evaluate the extent to which management of biosolids re-use based on metal/metalloid levels coincidentally minimizes environmental risks from organic contaminants . Historical-use contaminants such as chlorophenols, PCBs, and chlorinated pesticides were not detected at environmentally relevant concentrations in any of the 36 fresh biosolids samples, and appear to have virtually eliminated from sanitary collection system inputs . The few organic contaminants found in freshly produced biosolids samples that exhibited high concentrations relative to British Columbia and Canadian soil quality benchmarks included p-cresol, phenol, phenanthrene, pyrene, naphthalene, and heavy extractable petroleum hydrocarbons (HEPHs--nCl9-C34 effective carbon chain length) . It was concluded that, with the exception of these petroleum hydrocarbon constituents or their microbial metabolites, the mixing of biosolids with uncontaminated soils during land application and based on the known metal concentrations in biosolids from the Greater Vancouver WWTPs investigated provides adequate protection against the environmental risks associated with organic substances such as dioxins and furans, phthalate esters, or volatile organics . Unlike many other organic contaminants, the concentrations of petroleum hydrocarbon derived substances in biosolids has not decreased within the last decade or more in the WWTPs studied, and--unlike persistent chlorinated compounds--the associated PAHs and other hydrocarbon constituents merit careful consideration, especially in the context of repeated land-application of biosolid.

J Environ Radioact, 2003, 69(1-2), 129 - 43
The loading history of trace metals and nutrients in Altata-Ensenada del Pabellón, lagoon complex, northwestern Mexico; Ruiz-Fernandez AC et al.; This paper summarizes the geochemical investigations about the origin and loading history of some trace metals (Ag, Cu and Zn) and nutrients (N and P) in the coastal lagoon complex of Altata-Ensenada del Pabellon, Mexico, by using the radioactive chronometers 210Pb and 228Th and the stable isotopes of C and N . The examination of sediment cores collected at different locations in the lagoon system identified a slight enrichment in metals and nutrients in some points, which was mainly associated to organic matter accumulation . Stable C and N isotope ratios revealed wastewater inputs to the lagoon system and the 210Pb geochronology showed that anthropogenic impact started 50 years ago, with the beginning of the agriculture development and the associated urban growth of the surrounding area . Several atypical 210Pb and 228Th/232Th profiles demonstrated that biological and physical disturbances are common phenomena in these environments, that frequently mask the pollution records; and therefore, considering that the contaminated sediments at some locations in the lagoon system are frequently resuspended and re-oxygenated, the pollutants will continue to be easily remobilized in the food chain.

J Environ Sci Health B, 2003 Jul, 38(4), 501 - 9
Phosphate recovery from greenhouse wastewater; Yi WG et al.; A study was conducted to investigate the suitability of phosphate recovery from greenhouse wastewaters by using precipitation/crystallization process . More than 90% of the phosphate could be removed from the greenhouse wastewater . Various calcium phosphate salts were obtained in the process; hydroxyapatite {Ca5(PO4)3OH} could be the main product from the precipitates . Phosphate removal was affected by the presence of magnesium ion in wastewaters . An increase of magnesium concentrations in wastewaters decreased phosphate removal rates . The chemical contents of precipitates in terms of calcium, magnesium and phosphate were affected by calcium to magnesium molar ratio . Higher calcium contents were obtained at wastewaters with high calcium to magnesium molar ratio . An addition of magnesium did not affect the potassium contents in the precipitates . K-struvite, MgKPO4 x 6H2O, was not the major product in the precipitate, even with addition of a large quantity of magnesium.

Anal Bioanal Chem, 2003 Aug, 376(7), 1098 - 103 Epub 2003 Jul 11.
Screen-printed multienzyme arrays for use in amperometric batch and flow systems; Sapelnikova S et al.; Screen-printing technology for electrode fabrication enables construction of amperometric devices suitable for combination of several enzyme electrodes . To develop a biosensor array for characterisation of wastewaters, tyrosinase and horseradish peroxidase (HRP) or cholinesterase-modified electrodes were combined on the same array . The behaviour of the tyrosinase-modified electrode in the presence of hydrogen peroxide (required co-substrate for the HRP-modified electrode) and acetylthiocholine chloride (required co-substrate for cholinesterase) was studied . Performance of bi-enzyme biosensor arrays in the batch mode and in the flow-injection system are discussed.

J Contam Hydrol, 2003 Aug, 65(1-2), 19 - 39
Isotopes as tracers in a contaminated fractured chalk aquitard; Adar E et al.; Clusters of industrial plants often generate contaminant plumes with several potential sources . Prevention of further pollution and designing suitable remedial measures require identification of the contributing source among all potential ones and the sorting of currently active sources from historical ones . In the study area, an industrial complex in the Negev desert, Israel, contaminants could not serve as indicators for the contamination sources because of their extensive spatial distribution across the site . However, stable isotopes of oxygen, hydrogen and sulfur, as well as tritium, proved to be efficient tools for this task . The isotopic characterization of the potential end members provided the criteria for constraining a contaminating source when several alternative sources appeared viable . The isotopic fractionation of oxygen and hydrogen isotopes could be tied to the various disposal phases of the industrial wastewater . The three case studies presented here confirm the important role of isotopes as tracers in contaminated sites.

Environ Sci Technol, 2003 Jun 15, 37(12), 2743 - 9
Strong hg(II) complexation in municipal wastewater effluent and surface waters; Hsu H et al.; The speciation of mercury(II) in the aquatic environment is greatly affected by the presence of ligands capable of forming extremely strong complexes with Hg(II) . In this study, a novel competitive ligand exchange (CLE) technique was used to characterize Hg(II)-complexing ligands in samples collected from three municipal wastewater treatment plants, a eutrophic lake, a creek located downstream of an abandoned mercury mine, and a model water containing dissolved Suwannee River humic acid . These samples contained 3.3-15.9 mg/L dissolved organic carbon and were amended with 1.0-1.7 nM Hg(II) for CLE analysis . Results indicated that all samples contained labile Hg(II)-complexing ligands with conditional stability constants similar to those of reduced sulfur-containing ligands . Two wastewater effluent samples also contained approximately 0.5 nM of ligands that formed extremely strong Hg(II) complexes that did not dissociate in the presence of competing ligands . The conditional stability constant of these extremely strong or nonlabile complexes (i.e., (c)K(HgL)) were estimated to be greater than 10(30), for the reaction Hg(2+) + L' = HgL . The third wastewater sample and the eutrophic lake sample contained lower concentrations, 0.07-0.09 nM, of nonlabile Hg(II)-complexing ligands . The results suggested that these extremely strong Hg(ll)-complexing ligands should account for most of the dissolved Hg(II) species in municipal wastewater effluent and may dominate Hg(II) speciation in effluent-receiving waters.

Rev Esp Salud Publica, 2003 May-Jun, 77(3), 423 - 32
{Quality of the spring fountain water in the basic health care area of Sigüenza, Spain}; Rodriguez Garcia R et al.; BACKGROUND: Spring fountains undergo few or no analytical checks, especially those located far away from centers of population, which poses a health risk due to the possibility of disease-causing microorganisms and undesirable substances being in the water . This study is aimed at studying the spring contamination risk factors and determining the spring fountain water fitness for drinking . METHOD: A cross-sectional, descriptive study, with investigation of the frequency and spread of the contamination risk factors depending upon the developed or undeveloped location of the spring . Two analytical checks, conducted six months apart, of the physicochemical and microbiological parameters selected for assessing the fitness for drinking of the water of 38 fountains included in the study . RESULTS: The most frequent contamination risk factors were: for fountains located in developed areas, grazing (53.8%), weeds (53.8%) and crossing wastewater (53.8%); for those located in undeveloped areas, grazing (72%), weeds (32%) and falling debris (32%) . A total of 53.8% of the fountains located in developed areas and 60% of those in undeveloped areas were found fit for drinking in the first test; 76.9% and 68% having respectively been found fit in the second test . Solely 47.4% of the total were found fit for drinking in both of the tests . Microbiological contamination was found in 44.7% of the springs, and the physicochemical contamination in 13.1% . CONCLUSIONS: The contamination risk factors can have a bearing on a spring when sufficient protection is lacking, and the study thereof will provide keys as to the possibility and source of the contamination . When two analytical checks were made, there was a decrease in the percentage of fountains having water fit for drinking, which reveals the risk and susceptibility of these water supplies and the need and importance of regular health department checks.

Environ Sci Pollut Res Int, 2003, 10(3), 192 - 8
Heavy metal pollution in China: origin, pattern and control; Cheng S; GOAL, SCOPE AND BACKGROUND: Heavy metal is among one of the pollutants, which cause severe threats to humans and the environment in China . The aim of the present review is to make information on the source of heavy metal pollution, distribution of heavy metals in the environment, and measures of pollution control accessible internationally, which are mostly published in Chinese . METHODS: Information from scientific journals, university journals and governmental releases are compiled focusing mainly on Cd, Cu, Pb and Zn . Partly Al, As, Cr, Fe, Hg, Mn and Ni a included also in part as well . RESULTS AND DISCUSSION: In soil, the average contents of Cd, Cu, Pb and Zn are 0.097, 22.6, 26.0 and 74.2 mg/kg, respectively . In the water of the Yangtze River Basin, the concentrations of Cd, Cu, Pb and Zn are 0.080, 7.91, 15.7 and 18.7 microg/L, respectively . In reference to human activities, the heavy metal pollution comes from three sources: industrial emission, wastewater and solid waste . The environment such as soil, water and air were polluted by heavy metals in some cases . The contents of Cd, Cu, Pb and Zn even reach 3.16, 99.3, 84.1 and 147 mg/kg, respectively, in the soils of a wastewater irrigation zone . These contaminants pollute drinking water and food, and threaten human health . Some diseases resulting from pollution of geological and environmental origin, were observed with long-term and non-reversible effects . CONCLUSIONS: In China, the geological background level of heavy metal is low, but with the activity of humans, soil, water, air, and plants are polluted by heavy metals in some cases and even affect human health through the food chain . RECOMMENDATIONS AND OUTLOOK: To remediate and improve environmental quality is a long strategy for the polluted area to keep humans and animals healthy . Phytoremediation would be an effective technique to remediate the heavy metal pollutions.

Appl Microbiol Biotechnol, 2003 Oct, 62(5-6), 550 - 6 Epub 2003 Jul 04.
Enrichment and properties of an anaerobic mixed culture that reductively deiodinates 5-amino-2,4,6-triiodoisophthalic acid, an X-ray contrast agent precursor; Lecouturier D et al.; 5-Amino-2,4,6-triiodoisophthalic acid (ATIA), both a precursor and a degradative intermediate of triiodinated contrast media, was anaerobically converted by sludge from a wastewater treatment plant . ATIA conversion took place only when an electron donor such as ethanol was added . A stable mixed culture was established by transfer to a defined synthetic mineral medium with ATIA and ethanol . It could be maintained for 1 year when the sulfate concentration was kept below 30 microM . Transient appearance of 5-amino-2,4-diiodoisophthalic acid, iodide release (2.7 mol iodide/mol ATIA) and accumulation of 5-aminoisophthalic acid indicated that ATIA was reductively dehalogenated . The enriched mixed culture also dehalogenated ATIA derivatives but deiodination remained incomplete . ATIA was the sole terminal electron acceptor used by the mixed culture during deiodination . The ratio of electrons transferred to ATIA, 0.83, was consistent with a respiratory metabolism . Formate, acetate, lactate, butyrate and hydrogen were also used as electron donors . Deiodination was inhibited by a headspace of air or by addition of nitrate, sulfite or thiosulfate . The reaction was 2.6 times slower with sulfate than without.

Water Environ Res, 2003 May-Jun, 75(3), 263 - 72
Factors affecting ballasted flocculation reactions; Young JC et al.; Ballasted flocculation represents a relatively new technology that shows promise of bringing improvements to the field of water and wastewater treatment . Ballasted flocculation involves the addition of a ballasting agent (high-density microsand, sp gr = 2.65) to a chemically stabilized and coagulated suspension of particulate solids . Tests were conducted to determine the effect of eight independent parameters on the settling velocity of the resulting floc . Measurements showed settling velocities ranging from approximately 100 m/h for 0.5-mm diameter particles to as high as 380 m/h for particles having effective diameters up to 7 mm . Settling velocities for discrete microsand particles and discrete ballasted flocs were found to fit conventional settling theory with reasonable accuracy . The most important factors contributing to the benefits of ballasted flocculation are the large floc sizes that can be maintained, the greater roundness of the floc particles, and a lower shape factor for the ballasted floc, which all contribute to higher settling rates . Higher settling rates allow for substantially smaller sedimentation units and decreased capital costs.

Water Environ Res, 2003 May-Jun, 75(3), 238 - 45
Virus removal from wastewater in a multispecies subsurface-flow constructed wetland; Vidales JA et al.; Virus removal was studied in a multispecies subsurface-flow constructed wetland . Tracer studies and a virus survival test were conducted using bromide and bacteriophage PRD1 that were simultaneously added into a 6-year-old gravel-filled wetland . The estimated dimensionless variance and the observed bromide breakthrough curve suggest a plug-flow reactor with some dispersion . Most of the PRD1 was removed during the first 4 days; however, the PRD1 background concentration was not reached by the end of the study . Average bacteriophage removal was 98.8%, whereas bromide mass recovery was 75% . The removal rate of PRD1 was estimated to be -1.17 d(-1); in contrast, its inactivation rate in situ for a 12.4-day period was -0.16 d(-1) . Apparently, virus removal is governed by an initial irreversible attachment followed by a comparatively long inactivation period . This study suggests that a subsurface-flow wetland can decrease the virus load by approximately 99% with a 5.5-day detention time.

Environ Toxicol Chem, 2003 Jul, 22(7), 1562 - 7
Joint acute toxicity of diazinon and copper to Ceriodaphnia dubia; Banks KE et al.; Diazinon and copper are two contaminants that are widely found in urban streams and in municipal wastewater effluents . Because these contaminants may be found concurrently, the potential for their joint toxicity is of interest, particularly with regard to toxicity testing of wastewater effluents and the ecological implications of simultaneous exposures in urban streams . Although interactions between metals are well studied, relatively little is known about interactions between metals and organophosphate compounds such as diazinon . In this study, the interaction between copper and diazinon was evaluated using cladoceran (Ceriodaphnia dubia) in 48-h static tests within laboratory water . Using toxic units derived from concurrently established 48-h median lethal concentration values (LC50) of test organisms of each individual toxicant, the effects of the mixture of copper and diazinon on the survival of C . dubia were shown to be generally nonconcentration additive (LC50 significantly greater than one toxic unit) . However, evaluation of the dose-response relationship across the entire range of effect levels revealed that the mortality induced by the mixture of copper and diazinon supported concentration additivity at higher effect levels.

Bioresour Technol, 2003 Oct, 90(1), 19 - 25
A feasibility study of a Salix viminalis gravel hydroponic system to renovate primary settled wastewater; Mant C et al.; A Salix viminalis/gravel system based on hydroponics was developed for wastewater renovation in order to avoid the problems of soil damage and pollution associated with long-term application of wastewater to soil . For such a system to work the mineral elements applied must match closely the requirements of the tree species . To examine this the growth and nutrient uptake of S . viminalis in wastewater was compared with that in Long Ashton nutrient solution (1/4 strength) . S . viminalis grew more slowly in wastewater than in Long Ashton solution, but exhibited no obvious deficiency or toxicity symptoms . Since industrial wastewaters often contain metals, the extent to which copper might inhibit wastewater treatment in this system was also examined . S . viminalis was grown in wastewater amended with 10 and 100 ppm copper . Trees were unaffected by wastewater with 10 ppm copper when compared to trees grown in wastewater alone . Wastewater containing with 100 ppm copper was too toxic for the trees to thrive and wastewater treatment was reduced . Treatment efficiencies for unamended wastewater were 57.7% for nitrogen, 90.6% for phosphorus and 24.9% for potassium . These efficiencies are much greater than those quoted for a Salix/soil system, and thus Salix/gravel systems may have potential for wastewater treatment in environmentally sensitive areas or situations.

Bioresour Technol, 2003 Oct, 90(1), 11 - 7
Use of silica-immobilized humin for heavy metal removal from aqueous solution under flow conditions; de la Rosa G et al.; Humin extracted from Sphagnum peat moss was immobilized in a silica matrix and column experiments were performed in order to evaluate the removal and recovery of metal ions from aqueous solution under flow conditions . These experiments also allowed testing the recycling capacity of the column . Single-element solutions of Cu(II) and Pb(II), and a multi-metal solution containing Cd(II), Cu(II), Pb(II), Ni(II), and Cr(III) were passed through the columns at a flow rate of 2 ml/min . A 0.5 M sodium citrate solution was used as the stripping agent in the metal-ion recovery process . Humin immobilized in the silica matrix exhibited a similar, and in some cases, even a higher capacity than other biosorbents for the removal of metal ions from aqueous solutions under flow conditions . The sodium citrate was effective in removing Cu(II), Pb(II), Cd(II), and Ni(II) from the metal saturated column . The selectivity of the immobilized biomass was as follows: Cr(III)>Pb(II)>Cu(II)>Cd(II)>Ni(II) . This investigation provides a new, environmentally friendly and cost-effective possibility to clean up heavy-metal contaminated wastewaters by using the new silica-immobilized humin materialPublication Types:

	Evaluation Studies
	Validation Studies

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