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| Water Sci Technol, 2001, 44(11-12), 507 - 14 Heavy metal contents and mobility of artificially inundated grasslands along River Weser, Germany; Erber C et al.; At the beginning of the 20th century municipal wastewater was used to fertilize grassland in the freshwater marsh of the river Weser . In 1987, 150 ha of the marsh became part of a mitigation area with artificial inundation during winter and spring . Heavy metal input may be expected from former wastewater treatment and artificial flooding nowadays . In addition, inundation may increase the availability of heavy metals that were accumulated during municipal wastewater treatment . In order to get an idea of heavy metal content and availability, the content of Cd, Cr, Cu, Ni, Pb, and Zn of the soil, the vegetation, and the input due to inundation were determined . Metal enrichment in the epipedon is evident for Cr, Cu, Pb, and Zn . Total content of Pb and Zn exceed the precaution limit . Soils treated with wastewater seems to contain more heavy metals than the ones without . Inundation causes an input of metals, but it is very low and varies in a broad range . Metal input is higher by atmospheric deposition than the one due to inundation . Degree of enrichment can be arranged in the order: atmospheric deposition > municipal wastewater >> inundation . In shallow ditch soils heavy metals are becoming more available. Water Sci Technol, 2001, 44(11-12), 499 - 506 Treatment of laboratory wastewater in a tropical constructed wetland comparing surface and subsurface flow; Meutia AA; Wastewater treatment by constructed wetland is an appropriate technology for tropical developing countries like Indonesia because it is inexpensive, easily maintained, and has environmentally friendly and sustainable characteristics . The aim of the research is to examine the capability of constructed wetlands for treating laboratory wastewater at our Center, to investigate the suitable flow for treatment, namely vertical subsurface or horizontal surface flow, and to study the effect of the seasons . The constructed wetland is composed of three chambered unplanted sedimentation tanks followed by the first and second beds, containing gravel and sand, planted with Typha sp.; the third bed planted with floating plant Lemna sp.; and a clarifier with two chambers . The results showed that the subsurface flow in the dry season removed 95% organic carbon (COD) and total phosphorus (T-P) respectively, and 82% total nitrogen (T-N) . In the transition period from the dry season to the rainy season, COD removal efficiency decreased to 73%, T-N increased to 89%, and T-P was almost the same as that in the dry season . In the rainy season COD and T-N removal efficiencies increased again to 95% respectively, while T-P remained unchanged . In the dry season, COD and T-P concentrations in the surface flow showed that the removal efficiencies were a bit lower than those in the subsurface flow . Moreover, T-N removal efficiency was only half as much as that in the subsurface flow . However, in the transition period, COD removal efficiency decreased to 29%, while T-N increased to 74% and T-P was still constant, around 93% . In the rainy season, COD and T-N removal efficiencies increased again to almost 95% . On the other hand, T-P decreased to 76% . The results show that the constructed wetland is capable of treating the laboratory wastewater . The subsurface flow is more suitable for treatment than the surface flow, and the seasonal changes have effects on the removal efficiency. Water Sci Technol, 2001, 44(11-12), 463 - 8 Retention of selected heavy metals: Cd, Cu, Pb in a hybrid wetland system; Obarska-Pempkowiak H; The budget of heavy metals was investigated in a constructed wetland in a hybrid wetland system near Gdansk . It is a pilot wastewater treatment plant (WWTP) designed for 150 PE (person equivalent) . The system consists of two sections: a vegetated submerged bed (VSB) with horizontal flow of sewage and a cascade filter situated on a slope of a hill . Total area of the constructed wetland is about 870 m2 . Domestic sewage, after a conventional pretreatment (consisting of an Imhoff tank and a trickling filter) is pumped to the VSB filter located on the top of the hill and then flows through subsequent segments of the constructed wetland . In the period 1995-98 the measurements of several heavy metals (Cd, Cu, Pb) were carried out in sewage inflowing, outflowing and collected from the in between sections of the system . Moreover analysis of sediment collected in ditches of the cascade filter, VSB filter and reed were carried out . The content of heavy metals in suspended solids decreased along the course of treatment, starting from VSB filter, through the first ditch to the last ditch . Measurable concentrations of dissolved heavy metals were found in sewage collected from several subsequent ditches . Sorption was deemed the main mechanism of dissolved metals removal in subsequent ditches. Water Sci Technol, 2001, 44(11-12), 455 - 62 Nutrient and heavy metal uptake and storage in constructed wetland systems in Arizona; Karpiscak MM et al.; The Constructed Ecosystems Research Facility (CERF) was conceived in the early 1980s as a test facility to explore the potential for using plants to treat wastewater in the arid west of the USA . One of the major issues that has been identified in the use of constructed wetland technology is plant nutrient uptake and tissue storage of nutrients as well as heavy metals . Our approach to understanding plant uptake and storage has been to look at both controlled conditions in constructed systems and background concentrations in natural systems . Plant tissues have been collected and analyzed from natural systems and from controlled systems receiving either wastewater or municipal water . Plants studied included the herbaceous species Anemopsis californica (Yerba mansa), Scirpus spp . (bulrush) and Typha domingensis (cattail), and tree species Fraxinus velutina (ash), Populus fremontii (cottonwood) and Salix spp . (willow) . Data indicate that uptake varies not only among plant species, but also among chemical species, depending upon water quality within the wetlands . Leaf tissues of Fraxinus, Salix and Populus, contained the lowest amounts of nutrients and heavy metals studied (Na, P, K, Cu, Pb and Zn), while the root tissues of the herbaceous plants generally had the highest concentrations. Water Sci Technol, 2001, 44(11-12), 435 - 40 Rerating capacity of a constructed wetland treatment system; Jackson JA et al.; The 482-hectare (ha) City of Orlando (Florida) Easterly Wetlands (OEW) was designed to reduce nutrient concentrations in 0.90 m3/s of wastewater from the Iron Bridge Regional Water Reclamation Facility . Design influent nutrient concentrations were 6 mg/L total nitrogen (TN) and 0.75 mg/L total phosphorus (TP) . Actual TN and TP concentrations have been less than design, averaging 2.6 mg/L and 0.29 mg/L, respectively from January 1988 through December 1999 . If influent concentrations remain at these levels, the OEW may have the potential to treat significantly higher flows since less than 20% of the total area was utilized for nutrient reduction . To test this theory, a capacity study was performed for approximately nine months in 1997 and 1998 . Simulated flows of approximately 1.26 m3/s, 1.66 m3/s, and 1.93 m3/s were tested . It was found that approximately 15% of the area was utilized for nutrient reduction during the 1.26 m3/s simulation, 35% in the 1.66 m3/s, and 1.93 m3/s simulations . Based on these testing results, an application was submitted to the state in early 2000 to increase the permitted capacity to 1.57 m3/s. Water Sci Technol, 2001, 44(11-12), 427 - 33 Wastewater treatment by algal turf scrubbing; Craggs RJ; Algal turf scrubbing (ATS) is a novel wetland technology that has been designed and engineered to promote natural wastewater treatment processes . Algal turf scrubbing improves water quality by passing a shallow stream of wastewater over the surface of a gently sloped floway . The floway is colonised by a natural heterogeneous assemblage of periphyton consisting of cyanobacteria, filamentous algae and epiphytic diatoms together with aerobic bacteria and fungi . Algal photosynthesis provides oxygen for aerobic breakdown of wastewater by heterotrophic bacteria . Pollutants are extracted from the wastewater by several processes including assimilation, adsorption, filtration and precipitation . The algal turf is harvested periodically to remove the accumulated periphyton biomass and associated pollutants from the system . This paper will present results from a demonstration ATS facility in Patterson, California which was used to polish secondarily treated wastewater . The design and operational factors that influence the treatment performance of ATS systems is discussed . Results indicate the potential of the ATS for nutrient removal from secondarily treated wastewater and agricultural drainage waters. Water Sci Technol, 2001, 44(11-12), 413 - 20 Long-term performance summary for the Boot Wetland Treatment System; Martin JR et al.; The Boot WTS is a 46.5-ha, hydrologically altered cypress-gum wetland in Polk County, Florida . Poinciana Wastewater Treatment Plant No . 3 has discharged advanced secondary treated effluent to the Boot WTS since August 1984 . Comprehensive operational monitoring has been ongoing since 1990 . The Boot WTS has provided consistent removal of nitrogen and phosphorus . Influent total nitrogen (TN) and total phosphorus (TP) concentrations averaged approximately 10.0 mg/L and 2.5 mg/L at an average hydraulic loading rate (HLR) of 0.2 cm/d . Wetland effluent concentrations for TN and TP averaged 1.8 mg/L and 1.2 mg/L . Available flow and water quality data were used to develop estimates of the first-order removal rate, k, for TN (14 m/y) and TP (1.8 m/y) . These removal rates are within the range of values for other forested treatment wetlands . Biochemical oxygen demand (2.2 mg/L) and total suspended solids (4.9 mg/L) in the influent are near background levels for forested wetlands and are not significantly reduced with passage through the system. Water Sci Technol, 2001, 44(11-12), 407 - 12 Zero-discharge of nutrients and water in a willow dominated constructed wetland; Gregersen P et al.; A novel constructed wetland system has been developed to treat sewage, evaporate water and recycle nutrients from single households at sites where effluent standards are stringent and soil infiltration is not possible . Main attributes of the willow wastewater cleaning facilities are that the systems have zero discharge, the willows evapotranspire the water, and nutrients can be recycled via the willow biomass produced in the system . The willow wastewater cleaning facilities generally consist of c . 1.5 m deep high-density polyethylene-lined basins filled with soil and planted with clones of willow (Salix viminalis L.) . The surface area of the systems depends on the amount and quality of the sewage to be treated and the local annual rainfall . For a single household the area needed typically is between 200-300 m2 . Settled sewage is dispersed underground into the bed under pressure . When correctly dimensioned, the willow will--on an annual basis--evapotranspire all water from the sewage and rain falling onto the system, and take up all nutrients and heavy metals from the sewage . The stems of the willows are harvested on a regular basis to remove nutrients and heavy metals and to stimulate the growth of the willows . Initial experiences from full-scale systems in Denmark show promising results. Water Sci Technol, 2001, 44(11-12), 399 - 405 Reciprocating constructed wetlands for treating industrial, municipal and agricultural wastewater; Behrends L et al.; Scientists at the Tennessee Valley Authority (TVA), and in collaboration with the U.S . Environmental Protection Agency (EPA), are continuing to develop and refine an innovative wastewater treatment system referred to as reciprocating subsurface-flow constructed wetlands . Reciprocation relates to patented improvements in the design and operation of paired subsurface-flow constructed wetlands, such that contiguous cells are filled and drained on a frequent and recurrent basis . This operating technique turns the entire wetland system into a fixed-film biological reactor, in which it is possible to control redox potential in alternating aerobic and anaerobic zones . Reciprocating systems enable manipulation of wastewater treatment functions by controlling such parameters as hydraulic retention time, frequency of reciprocation, reciprocation cycle time, depth of reciprocation, and size and composition of substrate . These improved wetland technologies have been used for treating municipal/domestic wastewater, high strength animal wastewater, and mixed wastewater streams containing acids, recalcitrant compounds, solvents, antifreeze compounds, heavy metals, explosives, and fertilizer nutrients . Results from selected treatability studies and field demonstrations will be summarized with respect to conceptual design and treatment efficacy. Water Sci Technol, 2001, 44(11-12), 39 - 46 The use of macrophyte-based systems for phosphorus removal: an overview of 25 years of research and operational results in Florida; DeBusk TA et al.; Phosphorus (P) removal from wastewaters and surface runoff using macrophyte-based systems (MBS) has been a topic of great interest in Florida for over 25 years . During this period, P removal by both treatment wetlands and floating aquatic macrophyte systems has been evaluated from both a research and operational standpoint . Several factors have contributed to the increased focus on the use of MBS for P removal . First, there exist no conventional technologies that can cost-effectively achieve the low outflow P concentrations required to protect the integrity of Florida's relatively pristine surface waters . Second, because MBSs typically provide some water storage, they can accommodate the wide ranges of flows typical for runoff sources such as agricultural drainage waters . Finally, many regions in Florida have sufficient area for deployment of the relatively land-intensive MBS technologies . The first P removal work in Florida was initiated in the mid-1970s, and involved pilot-scale research on domestic wastewater treatment by natural wetlands . Parallel studies were performed with managed (periodically harvested) floating plant systems (i.e., Eichhornia crassipes) for tertiary treatment . Since that time, the range of operational systems that have been deployed include emergent macrophyte-based and forested wetlands, managed floating plant systems, and submerged macrophyte-based systems . Waters treated by MBS include domestic effluents, agricultural runoff and eutrophic lake waters . Phosphorus removal targets for MBS in Florida have been as low as 10 microg/L . In this paper, we summarize research and operational results for MBS in Florida over the past 25 years. Water Sci Technol, 2001, 44(11-12), 381 - 6 Application of constructed wetlands for wastewater treatment in Nepal; Shrestha RR et al.; Surface water pollution is one of the serious environmental problems in urban centers in Nepal due to the discharge of untreated wastewater into the river-system, turning them into open sewers . Wastewater treatment plants are almost non-existent in the country except for a few in the Kathmandu Valley and even these are not functioning well . Successful implementation of a few constructed wetland systems within the past three years has attracted attention to this promising technology . A two-staged subsurface flow constructed wetland for hospital wastewater treatment and constructed wetlands for treatment of greywater and septage is now becoming a demonstration site of constructed wetland systems in Nepal . Beside these systems, five constructed wetlands have already been designed and some are under construction for the treatment of leachate and septage in Pokhara municipality, wastewater in Kathmandu University, two hospitals and a school . This paper discusses the present condition and treatment performance of constructed wetlands that are now in operation . Furthermore, the concept of the treatment wetlands under construction is also described here . With the present experience, several recommendations are pointed out for the promotion of this technology in the developing countries. Water Sci Technol, 2001, 44(11-12), 369 - 74 Constructed wetlands for wastewater treatment in the Czech Republic; Vymazal J; The first constructed wetland (CW) for wastewater treatment was built in the Czech Republic in 1989 . This recent survey shows that at the end of 1999 101 systems are in operation and several more are under construction . 95 CWs are designed with sub-surface horizontal flow, 6 systems are hybrid with a combination of vertical and horizontal flow beds . Most systems (56) were designed for the treatment of municipal and domestic sewage while 38 CWs were designed for the treatment of wastewater from combined sewer systems . The most commonly used size of vegetated beds is 1,001-2,500 m2 (31 systems) followed by the area between 51-250 m2 (19%) . The area of vegetated bed of the largest system is 4,493 m2 . Size distribution is quite evenly spread from very small systems (PE = 3 or 4) up to 1,000 PE . However, most systems (44) were sized to treat wastewater from sources between 101 and 500 PE . The most commonly used macrophyte is Common reed (Phragmites australis) which is used in 34 systems as a monotypic stand and in 44 systems in combination with other macrophytes, most frequently with Reed canarygrass (Phalaris arundinacea) (31 systems) and cattails (Typha spp.) (8 systems). Water Sci Technol, 2001, 44(11-12), 361 - 7 Removal of hydrogen sulphide BOD from brackish water using vertical flow wetlands in a Caribbean environment; Giraldo E et al.; Wastewater from a 550-inhabitant community had been treated and discarded using an anaerobic filter . Due to seawater intrusion in the aquifer that supplies the water, high concentrations of hydrogen sulphide were detected in the effluent . A vertical flow wetland was designed in 1998 for treating this effluent . Four parallel reed beds with a total area of 556 m2 were constructed . During the first months of operation, a mean BOD5 removal efficiency of 91% was obtained, with loads to the wetland system up to 4 g/m2/d of grease and oils (G&O) . In 1999, problems of soil clogging were found due to high G&O content in the wastewater, with loads up to 15 g/m2/d of G&O, which highly influenced the hydraulic conductivity of the beds, generating the clogging problems . The low hydraulic conductivity and the high effluent G&O content, caused low BOD5 and COD removal efficiencies . As G&O accumulated in the soil, the removal efficiencies decreased . Despite the clogging problems, there has been a high sulphide removal throughout the system operation . The wetlands removed sulphides successfully, under loads up to 20 g S=/m2/d . Four native species of macrophytes were planted: Paspalum penisetum, Typha sp, Conocarpres erectus and Scirpus lacustris . All of them but Typha sp . were established in the system. Water Sci Technol, 2001, 44(11-12), 331 - 8 Natural wastewater treatment in Hungary; Szabo A et al.; Over the last few decades more and more natural wastewater treatment systems have been built in Hungary . The present study is the first step in creating a broad database on the water quality parameters and on the pollutant removal efficiency of these systems . The investigation included 78 plants out of which we analysed 16 systems in detail . Four types of natural methods are evaluated: wetlands, ponds, biomechanical combined oxidation (BMKO) systems, and poplar plantations . Pond systems are efficient in ammonium-nitrogen (NH4-N) removal, reducing it with 83% (41-88%) . Their chemical oxygen demand (COD(Cr)) removal capacity is only 55% (37-81%) . The only BMKO system that could be evaluated performs high COD(Cr) (77%) and total suspended solid (TSS) (89%) removal . Removal of NH4-N and total nitrogen (TN) declines during the years of operation giving an average value of 39% and 49%, respectively . The system is not efficient in phosphorus removal (13%) . In wetlands the 71% COD(Cr) (53-96%), and 57% TSS (33-91%) removal provides satisfactory effluent quality most of the time . Wetlands performed low nutrient removal, i.e., 17% (-21-46%) for TN and 26% (-20-92%) for phosphorus . Poplar plantations are very effective in pollutant removal . Even the average removal of each nutrient type is above 75% . Several problems have occurred in the operation of natural treatment systems . However, if carefully planned and constructed, and the required maintenance work is done properly, they can be possible alternatives for wastewater treatment. Water Sci Technol, 2001, 44(11-12), 317 - 24 Ecological characteristics of a natural wetland receiving secondary effluent; Martin JR et al.; The Boot wetland treatment system is a 115-acre, hydrologically altered cypress-gum wetland in Polk County, Florida . The Poinciana Wastewater Treatment Plant No . 3 has discharged secondary effluent to the bermed Boot wetland since August 1984 . Before that time this natural wetland had been affected adversely by forestry, drainage, and surrounding development which contributed to dying trees and a groundcover of invasive upland plants . In accordance with the Florida Department of Environmental Protection's Wetlands Application Rule (Chapter 62-611, F.A.C.), a routine biological and water quality monitoring program has been in effect since October 1990 . Components of the biological monitoring program include surveys of canopy and subcanopy, herbaceous and shrub groundcover species, benthic macroinvertebrates, fish, and nuisance mosquitoes . Effluent addition to the Boot wetland has resulted in continuous wetland inundation with atypical water depth of 2.5 to 3.0 feet for the past 15 years . Dominance and density of trees has steadily increased, upland invader species were eliminated, and stable plant, fish, and invertebrate communities were established . The long term biological data from this treatment wetland is compared to data from other natural treatment wetlands and a control wetland. Water Sci Technol, 2001, 44(11-12), 281 - 7 Accumulation of organic matter fractions in a gravel-bed constructed wetland; Nguyen L; The function of a gravel-bed wetland in treating wastewaters is dependent on the turn-over rate of organic matter (OM) fractions in accumulated solids . Organic deposits from a gravel-bed planted (Schoenoplectus tabernaemontani) wetland, which had experienced pore clogging after 5 years of receiving farm dairy wastewater were therefore collected and determined for labile (water-soluble) and stable (humic acid, fulvic acid and humin) OM fractions, total carbon (C), microbial biomass and microbial respiration rate . Over 90% of the accumulated organic solids was present as stable fractions, with humic compounds at least 2-fold higher in surface deposits and the top 100 mm of the gravel bed than the lower gravel substratum . Clogging of the gravel pore spaces over a 5-year wetland operation was probably due to the accumulation of refractory (stable) organic solids, particularly in the top 100 mm of the gravel bed . Microbial respiration rate and microbial biomass were significantly correlated with stable OM fractions, suggesting that these microbial parameters may be used to predict the nature of accumulated OM fractions . Further research is required to evaluate the use of these parameters as indicators of labile and stable fractions in wetlands with a range of OM loadings and accumulation. Water Sci Technol, 2001, 44(11-12), 273 - 80 Development of a conceptual model for vertical flow wetland metabolism; Giraldo E et al.; Four parallel vertical constructed wetlands, with a total area of 556 m2, are used to treat domestic wastewater, coming from a community of 550 inhabitants . The system includes pre-treatment with an anaerobic filter and post-treatment with chlorine, before discharging the effluent to the ocean . Four native species of macrophytes were planted: Paspalum penisetum, Typha sp, Conocarpres erectus and Scirpus lacustris . In situ measurements of gas content were performed for each bed during an operation cycle . After a feeding discharge, an unaltered sample of sand from each bed was taken, and a respirometric test was implemented to measure the metabolic activity in terms of oxygen consumption kinetics, CO2 production and organic matter degradation . The results were used to develop a conceptual model of the microbiologic metabolism for the process of organic matter removal from wastewater . Sorption in the bed is the main mechanism for organic matter removal from the wastewater, with subsequent biological oxidation during the resting period . The degradation rate for dissolved organic matter is found to be dependent on its concentration and on oxygen content in the gaseous phase . During the days of major activity, the oxygen content was not fully recovered when a new discharge occurred, finding anaerobic activity within the bed. Water Sci Technol, 2001, 44(11-12), 267 - 72 Behavior of organic carbon during subsurface wetland treatment in the Sonoran Desert; Quanrud DM et al.; We examined the fate of organics during wetland treatment of secondary effluent and groundwater (control) flows in parallel, research-scale, subsurface-flow (SSF) wetland raceways at the Constructed Ecosystem Research Facility (CERF) located in Tucson, Arizona . The CERF facility enabled us to distinguish experimentally among effects on effluent quality due to season-dependent processes of evapotranspiration (ET) and wetlands-derived production of organics . Organics of wastewater and wetlands origin were compared in terms of their contributions to dissolved organic carbon (DOC) in wetland effluent . Elevated temperatures and associated biochemical activities increased DOC levels in wetland effluents during summer . In other words, DOC removal efficiency was negatively correlated to temperature . The contributions of ET and wetland-derived organics to elevation of DOC in wetland effluents during summer were roughly comparable . The elevation of organic carbon concentration during wetland polishing of wastewater effluent will lead to higher levels of disinfection by-products when treated waters are chlorinated prior to reuse . Results of this work are relevant to water managers in arid regions, which may incorporate wetlands into sequential wastewater treatments leading to potable reuse of reclaimed water. Water Sci Technol, 2001, 44(11-12), 259 - 65 Cold climate wetlands: design and performance; Wallace S et al.; Constructed wetlands are gaining widespread use as a simple, low cost means of wastewater treatment . Introduction of constructed wetlands technology into the northern United States has been limited by the ability of conventional wetland systems to operate without freezing during the winter . A design approach using subsurface-flow constructed wetlands covered with an insulating mulch layer has been demonstrated to prevent freezing . However, introduction of a mulch layer will affect oxygen transfer rates, pollutant removal performance, and plant establishment . These factors must be addressed for successful application of constructed wetlands technology in cold climates. Water Sci Technol, 2001, 44(11-12), 231 - 5 Performance modeling of subsurface-flow constructed wetlands systems; Dahab MF et al.; A subsurface flow constructed wetlands (CW) system, located at a neighborhood consisting of a small housing development and golf courses outside of Lincoln, NE, was studied for its effectiveness as a small community wastewater system . Extensive monitoring was conducted biweekly between June 1996 and December 2000 . Prediction models for soluble CBOD5 NH3-N, and TP removal in CW were employed for comparison with the field data . It was found that the disappearance of BOD5 and NH3-N could be approximated using first-order kinetics, but the kinetics of TP removal were unclear . The reduction rate constants regressed from the field data were found to be lower than literature reported values. Water Sci Technol, 2001, 44(11-12), 211 - 4 Biota participating in wastewater treatment in a horizontal flow constructed wetland; Vymazal J et al.; During the period 1996-1997, three constructed wetlands with sub-surface horizontal flow were investigated . All systems are designed to treat municipal sewage from small villages (150, 200 and 300 PE) . The survey included microscopical identification of organisms in both wastewater and filtration substrate . The organisms were used as an indication of oxygen conditions (aerobic, anoxic and anaerobic) in the particular microenvironment . Saprobiological terms characterizing different levels of saprobity were employed to characterize inflowing wastewater, filtration bed and outflowing water . The occurrence of organisms was correlated with BOD5 values in particular profiles . It has been found that the biocenosis in the inflowing wastewater differs from those found in the filtration bed and water outflowing from the vegetated beds . The organisms were grouped into those living under anaerobic and anoxic conditions and those living under aerobic conditions . More than 70 species of bacteria, amoebae, ciliates, rotifers, colorless flagellates, cyanobacteria and algae were found and the most important 45 species were figured in a plate together with saprobiological information for each species . Biota of the inflowing water is usually restricted to bacteria, ciliata and colorless flagellata while the organisms found in outflowing water as well as in periphyton growing on outflow structures indicate 2-3 levels better quality. Water Sci Technol, 2001, 44(11-12), 191 - 8 Protozoan predation as a mechanism for the removal of cryptosporidium oocysts from wastewaters in constructed wetlands; Stott R et al.; The removal of the protozoan parasite, Cryptosporidium parvum, from wastewaters is becoming of increasing importance in the UK, especially since contamination of raw waters by sewage effluents has been implicated in major waterborne outbreaks of cryptosporidiosis in recent years . Compared to conventional wastewater-treatment processes, constructed wetlands have demonstrated favourable removal rates for Cryptosporidium oocysts . The removal mechanisms, however, remain unknown . Predation by free-living ciliated protozoa, which are commonly found in constructed wetlands, was investigated as a possible mechanism for oocyst removal . In laboratory feeding experiments, ciliates (Euplotes patella, Stylonychia mytilus, Paramecium caudatum and an unidentified wetland ciliate species), were exposed to doses ranging from 10 to 10(6) oocysts/ml for between 5 and 60 minutes . Ciliate predatory activities were assessed by enumerating fluorescently labelled ingested oocysts using epifluorescence microscopy . Oocysts were found to be ingested by all species investigated . Paramecium demonstrated the highest mean ingestion rates (up to 170 oocysts/hr) followed by Stylonychia (up to 60 oocysts/hour) . Euplotes and the wetland ciliate had lower mean grazing rates (4 and 10 oocysts/hr respectively) . These results indicate that protozoan predation may be an important factor in the removal of Cryptosporidium oocysts from wastewaters in constructed wetlands. Environ Toxicol Chem, 2002 Jan, 21(1), 37 - 46 Occurrence and distribution of nonionic surfactants, their degradation products, and linear alkylbenzene sulfonates in coastal waters and sediments in Spain; Petrovic M et al.; Spain is one of the European countries that still discharges untreated wastewaters and sewage sludge to the sea . A total of 35 samples of coastal waters and 39 samples of harbor sediments was analyzed . Samples were collected from several hot spots on the Spanish coast, such as the harbors of Tarragona, Almeria, and Barcelona, the mouths of the Besos and Llobregat rivers, the Bay of Cadiz, and various yacht harbors at the Mediterranean coast . A generic analytical procedure based on solid-phase extraction-liquid chromatography-atmospheric pressure chemical ionization/electrospray ionization mass spectrometry (SPE-LC-APCI/ESI-MS) was employed for determining the concentrations of alcohol ethoxylates (AEO), nonylphenol ethoxylates (NPEO), coconut diethanol amides (CDEA), nonylphenoxy-monocarboxylates (NPEC), nonylphenol (NP), octylphenol (OP), and linear alkylbenzene sulfonates (LAS) in sediment and water samples . The analysis revealed the presence of considerably high concentrations of NPEOs and NP near the points of discharge of industrial and urban wastewaters . Nonylphenol was found in 47% of water samples and in 77% of all sediment samples analyzed . Values for NP ranged from <0.15 to 4.1 microg/L in seawater and from <8 to 1,050 microg/kg in sediments . Levels of AEOs and CDEAs in seawater and marine sediments are reported for the first time . Concentrations of CDEAs in sediment, which were predominated by C11 through C15 homologues, ranged from 30 to 2,700 microg/kg, while in seawater, concentrations found were up to 24 microg/L . The AEOs were found to accumulate in a bottom sediment and they were detected in all analyzed sediment samples in concentrations from 37 to 1,300 microg/kg. Bioresour Technol, 2002 Feb, 81(3), 201 - 6 Uptake and recovery of gold ions from electroplating wastes using eggshell membrane; Ishikawa S et al.; The animal byproduct, hen eggshell membrane (ESM), was evaluated for its ability to sorb gold ions (dicyanoaurate(I) and tetrachloroaurate(III)) from solutions and electroplating wastewater . The gold uptake was dependent on pH, temperature and co-ions present in the solutions, with pH 3.0 being the optimum value . The equilibrium data followed the Langmuir isotherm model with maximum capacities of 147 mg Au(I)/g dry weight and 618 mg Au(III)/g, respectively . Desorption of sorbed gold(I) with 0.1 mol/l NaOH resulted in no changes of the biosorbent gold uptake capacity through five consecutive sorption/desorption cycles . In column experiments, selective recovery of gold from electroplating wastewater containing various metal ions was noted . The affinity of metal sorption was in the order Au > Ag > Co > Cu > Pb > Ni > Zn. Water Sci Technol, 2001, 44(10), 9 - 18 Conditioning, thickening, and dewatering: research update/research needs; Dentel SK; The production of sludges that are amenable to beneficial reuse (and thereby merit the term "biosolids") has become a high priority concern in wastewater treatment . Regulations in many countries have become stringent in this regard, and the production of suitable biosolids now influences the selection, design, and operation of upstream processes . Among these are the conditioning, thickening, and dewatering of sludges . This paper briefly reviews current technology trends in these process areas, placing them in the context of overall needs for improved biosolids management . It is foreseen that conditioning, thickening and dewatering processes will need to operate at higher performance and reliability levels to maintain disposal and reuse flexibility . The chemistry of conditioning must be more clearly determined since secondary interactions of the conditioning additives may be important in ways that are not currently recognized. Water Sci Technol, 2001, 44(10), 47 - 52 Factors affecting the distribution of heavy metals in wastewater treatment processes: role of sludge particulate; Huang CP et al.; The distribution of heavy metals, namely, Ag(I), Cd(II), Co(II), Cr(III,VI), Cu(II), Hg(II), Ni(II), Pb(II), and Zn(II) in 4 municipal wastewater treatment plants was evaluated as a function of several parameters including pH, COD, ionic strength and SS . Although there are variations in pH, alkalinity, COD and ionic strength, the results show that wastewater samples containing less than 5 g/L suspended solids concentration have similar characteristics . Correlations among heavy metal distribution (as the ratio between dissolved to total metals) and wastewater characteristics were attempted . Correlation between the parameters monitored and metal distribution is poor . In the case of pH, no apparent relationship could be seen . In general, increasing COD and ionic strength decreases the metal distribution . Metal distribution relies almost entirely on the concentration of solids in wastewater samples . Total metal removal in primary treatment process is lower than that reported in the literature . This could be attributed to the low average solids removal observed in the treatment plants investigated . Solids reduction at the effluent were larger than 80% and total metals removal was identical to that of the primary treatment process. Water Sci Technol, 2001, 44(10), 333 - 9 Thermal processing of sewage sludge by drying, pyrolysis, gasification and combustion; Stolarek P et al.; Thermal processing of sewage sludge including drying, pyrolysis and gasification or combustion may be an alternative to other ways of utilising it . In this paper thermogravimetric analysis (TGA) was employed in the investigation of thermal decomposition of sewage sludge . The kinetic parameters of drying, pyrolysis and gasification or combustion of sewage sludge have been determined in an inert-gas (argon) and additionally some series of the sludge decomposition experiments have been carried out in air, in order to compare pyrolysis and combustion . The pyrolysis char has been gasified with carbon dioxide . A typical approach to the kinetics of thermal decomposition of a solid waste is to divide the volatile evolution into a few fractions (lumps), each of which is represented by a single first-order reaction . If these lumps are assumed to be non-interacting and evolved by independent parallel reactions the first-order kinetic parameters such as activation energy Ei and pre-exponential factor Ai can be determined from mathematical evaluation of TG or DTG curves . The object of our investigations was a municipal sludge from the two wastewater treatment plants (WTP) in Poland . The experiments have been carried out in the thermobalance Mettler-Toledo type TGA/SDTA851 LF, in the temperature range 30-1,000 degrees C . Five different values of heating rate have been applied beta = 2, 5, 10, 15 and 20 K/min . The values of Ei and Ai have been determined for all recognised lumps of gaseous products . The method employed has also revealed its usefulness for the determination of kinetic parameters for municipal sludge, that possess an undefined content . An alternative route to combustion of sewage sludge is its gasification, which significantly increases the gaseous product (pyrolytic gas + syngas) . Besides pyrolysis kinetics, gasification or combustion process kinetics have also been determined. Water Sci Technol, 2001, 44(10), 269 - 72 Reuse of industrial sludge as construction aggregates; Tay JH et al.; Industrial wastewater sludge and dredged marine clay are high volume wastes that needed enormous space at landfill disposal sites . Due to the limitation of land space, there is an urgent need for alternative disposal methods for these two wastes . This study investigates the possibility of using the industrial sludge in combination with marine clay as construction aggregates . Different proportions of sludge and clay were made into round and angular aggregates . It was found that certain mix proportions could provide aggregates of adequate strength, comparable to that of conventional aggregates . Concrete samples cast from the sludge-clay aggregates yield compressive strengths in the range of 31.0 to 39.0 N/mm2 . The results showed that the round aggregates of 100% sludge and the crush aggregates of sludge with up to 20% clay produced concrete of compressive strengths which are superior to that of 38.0 N/mm2 for conventional aggregate . The study indicates that the conversion of high volume wastes into construction materials is a potential option for waste management. Water Sci Technol, 2001, 44(10), 245 - 52 Effectiveness of anaerobic biomass in adsorbing heavy metals; Haytoglu B et al.; This study focuses on the effectiveness of waste anaerobic dead biomass (ADB) in adsorbing heavy metals, namely Pb(II), Cr(VI), Cu(II), Ni(II) and Zn(II) . The metal uptake capacity of ADB was investigated and compared with the values for various biomass types from the literature . The biomass, which was grown under laboratory conditions using a synthetic wastewater, was used throughout the study after sterilization . The maximum metal adsorptive capacities were evaluated by running isotherm tests at 25 degrees C and initial pH of 4 . It was observed that Pb(II) was adsorbed with the highest capacity . The maximum adsorptive capacity of ADB for Pb(II), Zn(II), Cu(II), Ni(II) and Cr(VI) was determined as 1250, 625, 357, 227 and 384 mg/g dry biomass, respectively . These values were significantly higher than the corresponding capacities reported in the literature for other types of biomass . In describing the adsorption equilibrium, both the Langmuir and Freundlich isotherm models were examined . The experimental data for Pb(II), Zn(II), Cr(VI), and Ni(II) fitted both the Langmuir and Freundlich models with correlation coefficients of 0.80-0.99 while Cu(II) only fitted the Langmuir model with a correlation coefficient of 0.99 . Therefore, different and distinct aspects of the interactions between the cell surfaces and the metal ions might have occurred for Cu(II) and the rest of the metals . The equilibrium pH values attained were all higher than the initial pH value of 4.0, and this indicated that both the type and the initial concentration of the metal influenced the equilibrium pH . Furthermore, there was a decrease in equilibrium pH with increasing initial metal concentration at varying levels. Water Sci Technol, 2001, 44(10), 19 - 26 Possibilities to improve the quality of wastewater sludges; Balmer P; Falling heavy metal concentrations in wastewater sludges are an indicator of the improvements in sludge quality achieved over the past thirty years . Studies of the sources of heavy metals in wastewater sludges, particularly the loads introduced by domestic and industrial wastewater and storm water, show the potential improvement that may still be made. Water Sci Technol, 2001, 44(10), 149 - 56 Treating an aged pentachlorophenol- (PCP-) contaminated soil through three sludge handling processes, anaerobic sludge digestion, post-sludge digestion and sludge land application; Chen ST et al.; The extensive pentachlorophenol (PCP) contamination and its increasing treatment costs motivate the search for a more competitive treatment alternative . In a municipal wastewater treatment plant, anaerobic sludge-handling processes comprises three bio-processes, namely the anaerobic sludge digestion, post-sludge digestion and sludge land application, which reduce sludge organic content and make sludge a good fertilizer for land application . Availability and effectiveness make the anaerobic sludge handling processes potential technologies to treat PCP-contaminated soil . The technical feasibility of using anaerobic sludge bioprocesses was studied by treating PCP soil in two pilot digesters to simulate the primary sludge digestion, in serum bottles to mimic the post-sludge digestion, and in glass pans to represent the on-site sludge application . For primary digestion, the results showed that up to 0.98 and 0.6 mM of chemical and soil PCP, respectively, were treated at nearly 100% and 97.5% efficiencies . The PCP was transformed 95% to 3-MCP, 4.5% to 3,4-DCP, and 0.5% to 3,5-DCP . For post-digestion, 100% pure chemical PCP and greater than 95% soil PCP were removed in less than 6 months with no chlorophenol residues of any kind . Complete removal of PCP by-products makes this process a good soil cleanup method . For on-site treatment, PCP was efficiently treated by multiple sludge application; however, the PCP residue was observed due to the high initial PCP content in soil . Overall, more mass PCP per unit sludge per day was processed using the primary sludge digestion than the on-site soil treatment or post-sludge digestion . And, sludge acclimation resulted in better PCP treatment efficiencies with all three processes. Water Res, 2001 Dec, 35(17), 4226 - 30 Treatment of dye wastewater containing acid orange II using a cell with three-phase three-dimensional electrode; Xiong Y et al.; The removal of color and chemical oxygen demand (COD) from simulated dye wastewater containing Acid Orange II was experimentally investigated using coagulation-electrooxidation . Two kinds of coagulation methods, ferrous-mediated coagulation and electrocoagulation were tested as pretreatment . The electrooxidation was carried out in a cell with a three-phase three-dimensional electrode using granular activated carbon as particle electrodes . Particular attention was paid to probe the effect of cell voltage, airflow rate, solution conductivity and treatment time on the electrochemical treatment efficiency . The experimental results showed that the coagulation-electrooxidation process could efficiently remove the color and the COD from the simulated dye wastewater . The overall COD and color removal efficiencies reached as high as 99% and 87%, respectively, by ferrous coagulation (molar rate of Fe(II)/ dye: 0.5) and 30-min electrolysis (cell voltage: 20.0 V and airflow: 0.1 m3 h(-1)). Water Res, 2001 Dec, 35(17), 4191 - 9 Conditions influencing the precipitation of magnesium ammonium phosphate; Stratful I et al.; Struvite precipitation in wastewater treatment works has caused substantial operational problems since the early 1960s . Struvite, magnesium ammonium phosphate hexahydrate (MgNH4PO4 6H2O), is a white inorganic crystalline mineral that precipitates in places with increased turbulence such as pumps, aerators and pipe bends . Batch experiments were conducted to examine the influence of a number of physical and chemical parameters on struvite crystallisation . This was undertaken by dosing a medium of de-ionised water with varying concentrations of Mg2+, NH4+ and PO4(3-) ions . Preliminary experiments found that struvite could be precipitated out of solution at pH 10 and increasing the ion concentration stoichiometrically could increase crystal yield . Increasing the NH4+ concentration increased purity of the precipitate . As reaction time was increased from 1 to 180 min, crystal size was found to increase from 0.1 to 3mm. Water Res, 2001 Dec, 35(17), 4150 - 8 Anaerobic treatment of fibreboard manufacturing wastewaters in a pilot scale hybrid usbf reactor; Fernandez JM et al.; The treatment of fibreboard manufacturing (FBM) wastewaters was carried out in an industrial pilot plant, which consisted of a hybrid upflow sludge bed filter (USBF) anaerobic reactor and a coagulation-flocculation unit as a pre-treatment . COD removal efficiencies of 90-93% were attained in the anaerobic reactor operating at 37degrees C at organic loading rates (OLR) of 6.5-8.5 kg COD/m3 d . Flocculant sludges were used as inoculum, and granulation was observed in the USBF reactor after 120 days of operation . The overall linear upward velocity (result of liquid and gas flow) was the key factor controlling biomass retention and, therefore, a stable operation at high OLR . According to ecotoxicity values (measured by means of bioluminescence assays), the wastewaters were partially detoxified, being EC50 values for the liquid effluent 25 times lower than those corresponding to the influent . Besides, phenolic compounds removal efficiencies of 90% were attained . The hybrid reactor configuration is an interesting alternative to treat these wastewaters since it is less sensitive to biomass clogging or floatation. Water Res, 2001 Dec, 35(17), 4137 - 49 Anaerobic treatment of domestic wastewater in temperate climates: treatment plant modelling with economic considerations; Zakkour PD et al.; Although research suggests that anaerobic treatment of low-strength domestic wastewater is possible in temperate climates, to date, full-scale applications have only been pioneered in hot regions . However, burgeoning environmental legislation in developed countries is giving the impetus to develop anaerobic wastewater treatment systems due to potential economic and environmental benefits they hold over traditional aerobic techniques . In this paper a design rationale for low-temperature, low-strength (COD < 1,000 mgl(-1)), two-phase anaerobic wastewater treatment is developed through empirical modelling of data from published research, and from assumptions arising from a literature review . Model calculations are applied to typical domestic sewage characteristics at two different flow rates, based on population equivalents . Results indicate that soluble COD production in the model hydrolytic tank are similar to those achieved in pilot scale plants in the Netherlands . Model anaerobic reactor sludge characteristics are similar to those achieved in pilot and full-scale anaerobic reactors treating low-strength wastewaters . Indicative cost figures for a two-phase anaerobic treatment plant are given, but are incomplete without an assessment of the cost of post-treatment processes . Anaerobic treatment is likely to become more attractive in the future as new legislation relating to sludge disposal and renewable energy generation are introduced. Water Res, 2001 Dec, 35(17), 4095 - 101 Flux enhancement with gas injection in crossflow ultrafiltration of oily wastewater; Um MJ et al.; The gas injection technique was introduced to achieve flux improvement in cross-flow ultrafiltration of oil emulsion . By the nitrogen gas injection, homogeneous liquid phase oil/water emulsion was changed to heterogeneous gas- liquid phase . The injected gas causes positive effect of promoting turbulence, but it also has negative effect of decreasing the effective membrane area due to the partial occupation of membrane pores by bubbles . The efficiency of the gas injection was found out to be dependent on bubble fractions in the mixture: at sufficient bubble fractions the higher flux was observed . but at lower bubble fractions the flux rather decreased compared with that without gas injection . An attempt was made to explain the mechanisms for the dual aspects of gas injection . Turbulence dampening effect was also observed when the dependence of mass transfer coefficient on cross-flow rate was investigated with gas injection. Water Res, 2001 Dec, 35(17), 4079 - 85 Biosorption of chromium(VI) from aqueous solutions by green algae Spirogyra species; Gupta VK et al.; Biosorption of heavy metals is an effective technology for the treatment of industrial wastewaters . Results are presented showing the sorption of Cr(VI) from solutions by biomass of filamentous algae Spirogyra species . Batch experiments were conducted to determine the adsorption properties of the biomass and it was observed that the adsorption capacity of the biomass strongly depends on equilibrium pH . Equilibrium isotherms were also obtained and maximum removal of Cr(VI) was around 14.7 x 10(3) mg metal, kg of dry weight biomass at a pH of 2.0 in 120 min with 5 mg/l of initial concentration . The results indicated that the biomass of Spirogyra species is suitable for the development of efficient biosorbent for the removal and recovery of Cr(VI) from wastewater. J Environ Qual, 2001 Nov-Dec, 30(6), 2188 - 94 Seven years of biosolids versus inorganic nitrogen applications to tall fescue; Cogger CG et al.; Repeated applications of municipal wastewater biosolids is cost effective for biosolids managers, but may lead to undesirable accumulations of nutrients or contaminants . We evaluated the effects of seven years of biosolids applications on tall fescue (Festuca arundinacea Schreb.) production and nutrient availability . We compared two types of Class A biosolids applied to tall fescue on a sandy loam in western Washington . Mean annual biosolids rates of 290, 580, and 870 kg total N ha(-1) yr(-1) were compared with inorganic N and zero-N controls using a randomized complete block design . We measured yield and N uptake for each forage harvest, plant tissue metals at selected harvests, soil nitrate each fall, diethylenetriaminepentaacetic acid (DTPA)-extractable metals after five years of applications, and soil pH, available P, and organic C after seven years . Forage yields increased with biosolids rate . Apparent nitrogen recovery (ANR) for biosolids averaged 18% in 1993 (Year 1), 35% in 1994, and 46% in 1999 . The ANR for inorganic N averaged 62% from 1994-1999 . Residual soil nitrate was less than 25 kg ha(-1) for all treatments through 1995, but increased beginning in 1996 for the high biosolids rate . Biosolids increased soil organic C levels by 2 to 5 g kg(-1) and Bray-1 P levels by 300 to 600 mg kg(-1) (0-15 cm depth) . Plant tissue Zn increased from 24 to 66 mg kg(-1) at the highest application rate . Nearly all of the DTPA-extractable metals remained in the 0- to 8-cm soil depth. J Environ Qual, 2001 Nov-Dec, 30(6), 2037 - 46 Fluorescence analysis of a standard fulvic acid and tertiary treated wastewater; Westerhoff P et al.; Fluorescence measurements (emission scan, synchronous scan, and excitation-emission matrix {EEM} scan) were used to compare characteristics of two sources of dissolved organic carbon (DOC) from distinctly different origins: (i) a standard fulvic acid from the Suwannee River (SRF sample) and (ii) an unfractionated DOC sample from a tertiary wastewater treatment plant (MWW sample) . Two methods were demonstrated that quantitatively differentiated allochthonous DOC (e.g., SRF) from autochthonous DOC (e.g., MWW) . The MWW sample exhibited fluorescence peaks undetected in the SRF sample, at shorter wavelength pairs (e.g., 220 nm:300 to 350 nm) than the dominant peaks in the SRF sample (e.g., 220 nm:450 nm) . These peaks may be associated with base or neutral fractions, potentially enriched in organic nitrogen . Effects of DOC concentration and solution pH were discussed . A simple procedure was recommended (pH = 3; DOC = 1 mg/L; dilution with 0.01 M KCl) that minimizes the need to correct spectra for inner-filter absorbance effects . A method, using synchronous fluorescence, to estimate the percentage of DOC from different sources when mixed together was also presented . Further work to understand the structural properties of DOC that fluoresce in wastewater samples, especially at shorter EEM wavelength pairs, will enable water managers to better understand the influence of wastewater on DOC in receiving waters (e.g., rivers, lakes). J Environ Qual, 2001 Nov-Dec, 30(6), 1933 - 9 A field study of virus removal in septic tank drainfields; Nicosia LA et al.; Two field studies were conducted at a research station in Tampa, Florida to assess the removal of bacteriophage PRD1 from wastewater in septic tank drainfields . Infiltration cells were seeded with PRD1 and bromide and the effects of effluent hydraulic loading rate and rainfall on virus removal were monitored . Septic tank effluent samples were collected after passage through 0.6 m of unsaturated fine sand and PRD1 was detected over an average of 67 d . Bacteriophage PRD1 breakthrough was detected at approximately the same time as bromide in all three cells except for the low-load cell (Study 1), where bromide was never detected . Log10 removals of PRD1 were 1.43 and 1.91 for the high-load cells (hydraulic loading rate = 0.063 m/d) and 2.21 for the low-load cell (hydraulic loading rate = 0.032 m/d) . Virus attenuation is attributed to dispersion, dilution, and inactivation . Significant increases in PRD1 elution with rainfall were observed in the first 10 d of the study . Approximately 125 mm of rainfall caused a 1.2 log10 increase of PRD1 detected at the 0.6-m depth . Current Florida onsite wastewater disposal standards, which specify a 0.6-m distance from the drainfield to the water table, may not provide sufficient removal of viruses, particularly during the wet season. J Environ Qual, 2001 Nov-Dec, 30(6), 1904 - 10 Hurricane-loaded soil: effects on nitric oxide emissions from soil; Tabachow RM et al.; The nitric oxide (NO) flux from eastern North Carolina soils subjected to flooding from hurricanes were studied in laboratory experiments . Three sites along the Neuse River basin in eastern North Carolina that sustained different intensities of flooding in September 1999 from Hurricane Floyd were examined . Hurricane Floyd impacted the Neuse River basin by inducing flooding that damaged and disabled hog (Sus scrofa) lagoons and municipal wastewater treatment plants . Between approximately 53 and 325 million liters (14 and 86 million gallons) of untreated hog waste and between approximately 5.7 and 34.4 billion liters (1.5 and 9.1 billion gallons) of untreated municipal wastewater are projected to have entered the Neuse River basin, increasing the concentrations of nitrogen (N), phosphorus (P), and total solids . Phosphorus and total solids are projected to have increased 3.2 and 199.2 mg/L, respectively . Total N was projected to have increased by 9.8 mg/L, which is posited to have increased the NO flux from flooded soils for months after the hurricane . Nitric oxide emissions from soil can adversely affect ozone levels in the lower troposphere . Minimization of NO flux from soil is advantageous, protecting air quality as well as conserving valued nitrogen fertilizers . Hurricane-loaded soils were found to produce more than 30 times greater NO emissions than nonflooded soils with NO fluxes ranging from 0.1 to 102.5 ng N/(m2 s). Environ Sci Technol, 2001 Sep 15, 35(18), 3786 - 91 Biomass byproducts for the remediation of wastewaters contaminated with toxic metals; Schneegurt MA et al.; Pollution of the environment with toxic metals is widespread and often involves large volumes of wastewater . Remediation strategies must be designed to support high throughput while keeping costs to a minimum . Biosorption is presented as an alternative to traditional physicochemical means for removing toxic metals from wastewater . We have investigated the metal binding qualities of two biomass byproducts that are commercially available in quantity and at low cost, namely "spillage", a dried yeast and plant mixture from the production of ethanol from corn, and ground corn cobs used in animal feeds . The biomass materials effectively removed toxic metals, such as Cu, Cs, Mo, Ni, Pb, and Zn, even in the presence of competing metals likely to be found in sulfide mine tailing ponds . The effectiveness of these biosorbents was demonstrated using samples from the Berkeley Pit in Montana . Investigations included column chromatography and slurry systems, and linear distribution coefficients are presented . X-ray spectroscopy was used to identify the binding sites for metals adsorbed to the spillage material . The results of our experiments demonstrate that the biosorption of metals from wastewaters using biomass byproducts is a viable and cost-effective technology that should be included in process evaluations. Environ Sci Technol, 2001 Sep 15, 35(18), 3620 - 5 Identification and quantification of estrogen receptor agonists in wastewater effluents; Snyder SA et al.; Total concentrations of several known xenobiotic estrogen receptor (ER) agonists and natural and synthetic estrogen were measured in water by use of a combination of instrumental and bioanalytical approaches . Samples from 3 municipal wastewater treatment plants (WWTPs) in south central Michigan (upstream and effluent); 4 point source locations on the Trenton Channel of the Detroit River, MI; and 5 locations in Lake Mead, NV were analyzed . Organic compounds were extracted from 5 L water samples using solid-phase extraction disks and separated into three fractions based on polarity . Whole extracts and fractions were tested for ER agonist potency using the MVLN in vitro bioassay . ER agonist potency was characterized by comparing the magnitude of induction elicited by the extract or fraction to the maximum induction caused by 17beta-estradiol (E2) . The greatest concentrations of ER agonists were associated with the most polar fraction (F3) . Instrumental analyses and further fractionation were used to identify specific ER agonists associated with bioassay responses . Bioassay data were compared to extract concentrations in order minimize variability associated with the extraction procedure . Concentrations of endogenous estrogen, E2, and the synthetic estrogen ethynylestradiol (EE2) ranged from nondetectable to 14.6 ng/mL extract (nondetectable to 3.66 ng/L water) and represented from 88 to 99.5% of the total estrogen equivalents in the water samples analyzed . Concentrations of alkylphenols (APs) ranged from nondetectable to 148 microg/mL extract (nondetectable to 37,000 ng/L water) . In general, alkylphenols contributed less than 0.5% of the total estrogen equivalents in the water samples . Both bioassay-directed fractionation results and comparison of ER agonist concentrations, adjusted for their known relative potencies, support the conclusion that E2 and EE2 were the dominant environmental estrogens in water samples from mid-Michigan and Lake Mead, NV. J Hazard Mater, 2002 Feb 14, 90(1), 51 - 62 Decomposition of aniline in supercritical water; Qi XH et al.; The decomposition of aniline in supercritical water (SCW) was studied . Experiments were performed at various temperatures, pressures, residence times, dosage of oxidant H2O2 and initial aniline concentrations to investigate their effect on the destruction efficiency . Manganous sulfate and ferrous sulfate were screened out during the experiment to study the effect of the homogenous catalysts on destruction efficiency . The effect of pH was also studied . The experiments showed that the dosage of oxidant H2O2, experimental temperature, pressure, reaction residence time and even initial concentration of the aniline in wastewater have a significant affect on the TOC removal; manganous sulfate and ferrous sulfate improve the oxidation; TOC removal improves slightly with a decrease in the initial pH value . At a system temperature 450 degrees C, pressure 28 MPa, initial pH 4.0, residence time 46 s and K value 1.1, TOC removal can reach 100%. Environ Sci Technol, 2001 Dec 15, 35(24), 4916 - 21 Flocculation/flotation/ultrafiltration integrated process for the treatment of cork processing wastewaters; Minhalma M et al.; Membrane fouling is the major problem in the treatment by ultrafiltration (UF) of the cork processing wastewaters . This problem leads to drastic reduction on the permeate fluxes and has been associated with wastewaters phenolic/tannic colloidal matter . The present work proposes a flocculation/flotation/ultrafiltration integrated process for the treatment of these wastewaters . A flocculation study was carried out in jar-test equipment with chitosan . The zeta-potential and the particle size were monitored at different pH values and for different chitosan concentrations . The results showed an increase of the zeta-potential when chitosan is added and a significant increase of the effluent particle size with the decrease of the pH . A dissolved-air flotation study was performed with the flocculated wastewater . The parameters varied were the operating pressure and the recycle ratio . It was observed that for higher pressures and at a recycle ratio of 0.19 the polyphenols removal was higher . The UF experiments were carried out in flat-sheet cells of 13.2 cm2 of membrane surface area at transmembrane pressures of 1-3 bar . A commercial membrane (Ropur-TS60) and four cellulose acetate membranes with molecular weight cutoff (MWCO) ranging from 4.5 to 86 kDa were used . The flocculation/flotation pretreatment led to the enhancement of the UF permeate fluxes . For the membrane with higher MWCO, the permeate flux enhancement reached 130%. Environ Sci Technol, 2001 Dec 15, 35(24), 4805 - 16 Nature and transformation of dissolved organic matter in treatment wetlands; Barber LB et al.; This investigation into the occurrence, character, and transformation of dissolved organic matter (DOM) in treatment wetlands in the western United States shows that (i) the nature of DOM in the source water has a major influence on transformations that occur during treatment, (ii) the climate factors have a secondary effect on transformations, (iii) the wetlands receiving treated wastewater can produce a net increase in DOM, and (iv) the hierarchical analytical approach used in this study can measure the subtle DOM transformations that occur . As wastewater treatment plant effluent passes through treatment wetlands, the DOM undergoes transformation to become more aromatic and oxygenated . Autochthonous sources are contributed to the DOM, the nature of which is governed by the developmental stage of the wetland system as well as vegetation patterns . Concentrations of specific wastewater-derived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading. Environ Sci Technol, 2001 Dec 15, 35(24), 4798 - 804 Alkylphenol ethoxylate degradation products in land-applied sewage sludge (biosolids); La Guardia MJ et al.; Alkylphenol ethoxylates, widely used in commercial and household detergents in the United States, can degrade during the wastewater treatment process to more toxic, estrogenic, and lipophilic compounds . These include octylphenol (OP), nonylphenols (NPs), nonylphenol monoethoxylates (NP1EOs), and nonylphenol diethoxylates (NP2EOs) . These compounds have received considerable attention due to their acute toxicity and ability to disrupt the endocrine system . In Europe, regulations have been established to control their impact on the environment . In this study, biosolids derived from all 11 U.S . wastewater treatment plants examined contained detectable levels of OP, NPs, NP1EOs, and NP2EOs . Nine exceeded the current Danish land application limit (30 mg/kg; sum of NPs, NP1EOs, and NP2EOs) by 6-33x . NPs were the major component, and their concentrations therein ranged from 5.4 to 887 mg/kg (dry weight) . OP, reportedly 10-20x more estrogenic than NP, was detected in these same nine biosolids at levels up to 12.6 mg/kg . Three biosolids were also subjected to the U.S . Environmental Protection Agency Toxicity Characteristic Leaching Procedure Method 1311 . NPs and NP1EOs were both detected in the leachate; the former at concentrations from 9.4 to 309 microg/L . On the basis of effect levels published in the literature, alkylphenol ethoxylate degradates in U.S . biosolids may cause adverse environmental impacts. Environ Sci Technol, 2001 Dec 15, 35(24), 4726 - 30 Biohydrogen production as a function of pH and substrate concentration; Ginkel SV et al.; The conversion of organics in wastewaters into hydrogen gas could serve the dual role of renewable energy production and waste reduction . The chemical energy in a sucrose rich synthetic wastewater was recovered as hydrogen gas in this study . Using fractional factorial design batch experiments, the effect of varying pH (4.5-7.5) and substrate concentration (1.5-44.8 g COD/L) and their interaction on hydrogen gas production were tested . Mixed bacterial cultures obtained from a compost pile, a potato field, and a soybean field were heated to inhibit hydrogen-consuming methanogens and to enrich sporeforming, hydrogen-producing acidogens . It was determined that the highest rate (74.7 mL H2/(L*h)) of hydrogen production occurred at a pH of 5.5 and a substrate concentration of 7.5 g COD/Lwith a conversion efficiency of 38.9 mL H2/(g COD/L) . The highest conversion efficiency was 46.6 mL H2/(g COD/L). J Chromatogr A, 2001 Dec 14, 938(1-2), 79 - 91 Analysis of nonylphenol and nonylphenol ethoxylates in environmental samples by mixed-mode high-performance liquid chromatography-electrospray mass spectrometry; Ferguson PL et al.; A new method is described based on mixed-mode high-performance liquid chromatography with electrospray mass spectrometry detection for comprehensive quantitative analysis of nonylphenol (NP) and nonylphenol ethoxylates (NPEOs) in wastewater and sediment . Efficient separation, reduced band broadening, and high sensitivity were achieved by employing a methanol-water gradient on a mixed-solvent gel filtration column designed for MS interfacing . Quantitative accuracy and precision of the method were improved by the use of custom-synthesized {13C6}NPEO analogs as isotope-dilution surrogate standards . Method detection limits for NP and individual NPEOs ranged from I to 55 pg injected on column. J Chromatogr A, 2001 Dec 14, 938(1-2), 57 - 65 Quantitative analysis of polycyclic aromatic hydrocarbons in sewage sludge from wastewater treatment plants; Perez S et al.; Polycyclic aromatic hydrocarbons (PAHs) are an important group of organic contaminants present in sewage sludge . Due to their persistence and toxic potential, information about their presence in sewage sludge is needed in order to assess applicability on agricultural land . A method for the gas chromatographic-mass spectrometric (GC-MS) determination was developed and applied to the trace determination of PAHs present in sewage sludge samples from six wastewater treatment plants (WWTPs) differing in the type of treatment and the origin of wastewater . PAHs were extracted from freeze-dried samples by a dichloromethane-methanol (2:1) mixture in a sonication bath . The sludge extracts were cleaned-up by an alumina column . The method showed recovery values varying from 60 to 98% . Four surrogate standards ({2H8}naphthalene, {2H10}anthracene, {2H12}benzo{a}anthracene, and {2H12}benzo{ghi}perylene) were used for quantitation by GC-MS . A reference sludge sample was analysed in order to validate the method . The sum of the 16 US Environmental Protection Agency PAHs analysed in the sewage sludge samples varied from 1.13 to 5.52 mg/kg . No significant difference between the different WWTPs was found. J Chromatogr A, 2001 Dec 14, 938(1-2), 175 - 85 Determination of neutral pharmaceuticals in wastewater and rivers by liquid chromatography-electrospray tandem mass spectrometry; Ternes T et al.; An analytical method is presented enabling the determination of nine neutral pharmaceuticals in groundwater, and for most of the compounds, in rivers and wastewater down to the lower ng/l range . The analytes belong to different medicinal groups such as antiphlogistics, psychiatric drugs and antidiabetics . Samples are enriched using solid-phase extraction (SPE) with RP-C18ec material . Analysis is performed by liquid chromatography with detection by electrospray tandem MS . Mean recoveries generally exceed 80% in groundwater, and the quantification limits are down to 50 ng/l in wastewater and down to 10 ng/l in groundwater . Losses were observed to occur either from ion suppression in the electrospray ionisation or SPE . Losses for all compounds could not be compensated for by the surrogate standard dihydrocarbamazepine . In raw municipal wastewater, concentration levels were detected for caffeine up to 147 microg/l and for propyphenazone up to 1.3 microg/l. Environ Sci Technol, 2001 Dec 1, 35(23), 4691 - 6 Salinity effect on mechanical dewatering of sludge with and without chemical conditioning; Lo IMC et al.; The salinity levels of wastewater and sludge are relatively high in some coastal cities as they may use saline water for toilet flushing, and as such,the sludge dewaterability can be affected by it . The salinity effect on sludge dewaterability was therefore investigated through experimental testing of specific resistance in filtration (SRF), time to filter (TTF), and final solid content of sludge . SRF and TTF were determined using Buchner funnel tests . The final solid content was estimated by centrifuging the sludge at four levels of rotational speed . Sludge with three salinity levels (5,000, 10,000 and 20,000 ppm) were considered in this study . Coagulants such as alum, iron(II) sulfate, and organic polyelectrolytes were added to the sludgetostudythe dewaterability of such sludge with chemical conditioning . Experimental results show that doubling the salinity level of the sludge from 10,000 to 20,000 ppm shows not much change in SRF and TTF . Compared with the sludge without chemical conditioning, the addition of the coagulants to the sludge at a salinity level of 5,000 ppm drastically reduces its SRF and TTF . However, sludge with and without chemical conditioning at a salinity of 20,000 ppm has similar SRF and TTF . The final solid content of sludge increases almost linearly with salinity . Among the coagulants used in this study, the cationic polyelectrolyte is found to be better in improving sludge dewaterability, while iron(II) sulfate performs slightly better in enhancing the final solid content of the sludge. Huan Jing Ke Xue, 2001 Sep, 22(5), 99 - 101 {Degradation of nitrobenzene in water by electrohydrodynamic DC discharge}; Li J et al.; In this paper, the experimental results with respect to the degradation of nitrobenzene in water using electrohydrodynamic DC discharge were presented . The DC voltage was 40 kV, the degradation efficiency in the first discharge process reached 50%, the total degradation efficiency in the second discharge process reached 80% . The products contained acetone . At the same time, the degradation efficiency variation with the voltage polarity, flux, and concentration were studied . These studies will be helpful to the treatment of organic wastewater. Huan Jing Ke Xue, 2001 Sep, 22(5), 87 - 90 {Sulfa-drug wastewater treatment with anaerobic/aerobic process}; Wu L et al.; Sulfa drug wastewater was treated with anaerobic/aerobic process . The removal ratios of TOC reached about 50% in anaerobic phase and about 70% in aerobic phase respectively, while volume loading rate of TOC was about 1.2 kg/(m3.d) in anaerobic phase and about 0.6 kg/(m3.d) in aerobic phase . Removal of TOC in anaerobic phase was attributed to the reduction of sulfate. Huan Jing Ke Xue, 2001 Sep, 22(5), 83 - 6 {The application of air-lift loop column filling with porous carrier in wastewater treatment}; Fan Y et al.; An air lift loop reactor filling with porous carrier particles was utilized as aeration column . Experiments were carried out in wide operating conditions . The experimental results showed that in the range of gas flow rate from 0.117 to 0.156 m3/(min.m3), a higher efficiency of removal of ammonium-N was achieved, and when the gas flow rate was above 0.039 m3/(min.m3), the COD was completely degraded in about 1 h . The filling ratio of the porous carriers in the column was an important factor for the removal of C and N compounds, and a filling ratio of 15% was proved to be most suitable in the operation ranges . The experimental results also indicated that the effect of aeration temperature on the removal efficiency was significant and the highest efficiency was obtained at around 25 degrees C. Huan Jing Ke Xue, 2001 Sep, 22(5), 79 - 82 {Pretreatment of benzoic acid wastewater}; Li Z et al.; The benzoic acid wastewater produced from toluene by liquid-phase oxidation is one of the difficult wastewater to treat because of multi-component, high CODcr value (20,000-100,000 mg/L) and nonbiodegradability . A pretreatment way of this wastewater by extraction based on chemical complexation was carried out, and tributyl phosphate (TBP), trialkylamine (7301) and trialkyphosphine oxide (TRPO) were used as complexing agent with n-octanol, kerosene as cosolvent and diluent respectively . Results showed that benzoic acid was recovery successfully and the CODcr value of wastewater was reduced to 1/6 of the initial value through multi-stages cross-flow extraction . Back-extraction was quite easy and the solvent could be reused. Huan Jing Ke Xue, 2001 Sep, 22(5), 74 - 8 {Recovery of zinc ion and cadmium ion with hollow fiber membrane extraction}; Wang Y et al.; The efficiency of hollow fiber membrane solvent extraction for the system of Meaq/bis(2-ethylhexyl) phosphate in heptane(Me = Cd2+, Zn2+) was studied for wastewater treatment and hydrometallurgy . It was found that the two phases velocity, the initial concentration and the pH value of the aqueous phase greatly influenced the extraction ratio . For very dilute solution with concentration lower than 500 mg/L, the mass transfer resistance was mainly in aqueous phase . When the aqueous phase concentration was relative higher than that of dilute solution, all the individual mass transfer resistances would not be ignored . For the concentrated solution, the mass transfer in the organic phase and the diffusion in membrane pores controlled the transport process . In the back extraction, the mass transfer resistance lied in the organic phase and the diffusion in membrane pores . The experimental results showed that it was possible that the extraction percentage achieved 90% when the metal ion concentration was lower than 400 mg/L . When the cadmium concentration was lower than 200 mg/L, its concentration can decrease 2 orders by extraction in a single-pass flow mode . The values of (HTU)w were between 15 cm and 30 cm, which was much lower than those of traditional extraction columns . The results indicated that membrane extraction with hollow fiber modules could efficiently remove or recover metal ions in the aqueous phases. Huan Jing Ke Xue, 2001 Sep, 22(5), 65 - 9 {Adsorption of weak deep blue GR on hydroxy-aluminum montmorillonite}; Zeng X et al.; Hydroxy-alumium montmorillonite may serve as potential adsorbents for organic pollutants from wastewater . It was synthesized by titrating Na-montmorillonite with hydroxy-aluminum solution (OH-/Al3+ molar ratio was 2.4) . From powder XRD data, it was shown that the interlayer(d001) of montmorillonite was increased greatly from 12.58A to 18.63A . Seven modified montmorillonite samples, including hydroxy-aluminum montmorillonite, were used to remove the dye of weak deep blue GR from water . The results showed that hydroxy-alumium montmorillonite had very high adsorption ability, only 0.0200 g could treat 25 ml weak deep GR with 95% removal . The different adsorption mechanisms of weak deep blue GR on modified montmorillonite: surface adsorption, ion-exchanging and partion, were suggested. Huan Jing Ke Xue, 2001 Sep, 22(5), 60 - 4 {Characteristics of nitrobenzene containing wastewater catalytic oxidation degradation by Fenton reagent}; Wei C et al.; Through the alteration of the concentration of catalyst and oxidant, the rulers and dynamics of nitrobenzene oxidized by Fenton reagent in different concentrations were studied . The correlativity of the reaction time and relatively remain nitrobenzene was analyzed by the unitary linear regress equation . The result of the analysis proves that the coefficient was over the critical constant . The oxidation of nitrobenzene by Fenton reagent was in conformity with first-order dynamics model and the reaction rate constant was got at the same time . The idea, using the complex of Fe as the catalyst replacing Fe2+ in the Fenton Reaction, not only got a higher reaction velocity and efficiency, but also had a distinct exclusive to the degradation of nitrobenzene . The remove velocity of nitrobenzene was improved from 17.48 mg/(L.min) to 71.22 mg/(L.min), the remove rate in 5 minutes was from 9.74% to 91.79% . The nonhomogeneous catalyst made by the artificial zeolite with Fe-complex adsorbed had the same catalyzing behavior . In addition, ultraviolet radiation can also improves the Fenton reaction to some degree . These research works could demonstrate the good application potentiality of Fenton reagent in treating wastewater. Huan Jing Ke Xue, 2001 Sep, 22(5), 45 - 9 {The influence of hydraulic characteristics on wastewater purifying efficiency in vertical flow constructed wetlands}; Wu Z et al.; The hydraulic characteristics of vertical flow constructed wetlands was investigated, and the influence of these characteristics on wastewater purifying efficiency was studied as an emphasis . The results of the experiments in small scale plots and medium scale plots showed the plant roots, with the physical and biological effects, play a significant role in hydraulics and the wastewater purifying efficiency . The other characteristics such as retention time, effluent velocity and influent load also directly affect the wastewater purifying efficiency of constructed wetland . To get a better understanding of the hydraulics will be crucial to the improvement of purifying efficiency and facilitate the practical use of constructed wetland. Fresenius J Anal Chem, 2001 Nov, 371(6), 849 - 54 Multi-element sewer slime impact pattern--a quantitative characteristic enabling identification of the source of heavy metal discharges into sewer systems; Kintrup J et al.; The capability of sewer slime to accumulate heavy metals from municipal wastewater can be exploited to identify the sources of sewage sludge pollution . Former investigations of sewer slime looked for a few elements only and could, therefore, not account for deviations of the enrichment efficiency of the slime or for irregularities from sampling . Results of ICP-MS multi element determinations were analyzed by multivariate statistical methods . A new dimensionless characteristic "sewer slime impact" is proposed, which is zero for unloaded samples . Patterns expressed in this data format specifically extract the information required to identify the type of pollution and polluter quicker and with less effort and cost than hitherto. Water Res, 2002 Jan, 36(1), 95 - 104 Oilfield wastewater treatment by combined microfiltration and biological processes; Campos JC et al.; This work deals with the treatment of offshore oilfield wastewater from the Campos Basin (Rio de Janeiro State, Brazil) . After coarse filtration, this high saline wastewater was microfiltrated through mixed cellulose ester (MCE) membranes, resulting in average removals of COD, TOC, O&G and phenols of 35%, 25%, 92% and 35%, respectively . The permeate effluent was fed into a 1-L air-lift reactor containing polystyrene particles of 2mm diameter, used as support material . This reactor was operated for 210 days, at three hydraulic retention times (HRT): 48, 24 and 12h . Even when operated at the lowest HRT (12 h), removal efficiencies of 65% COD, 80% TOC, 65% phenols and 40% ammonium were attained . The final effluent presented COD and TOC values of 230 and 55 mg/L, respectively . Results obtained by gas chromatography analyses and toxicity tests with Artemia salina showed that a significant improvement in the effluent's quality was achieved after treatment by the combined (microfiltration/biological) process. Water Res, 2002 Jan, 36(1), 257 - 65 A mathematical model of a high sulphate wastewater anaerobic treatment system; Knobel AN et al.; As an aid to the design and operation of anaerobic digesters treating high sulphate waste waters, a mathematical model describing this treatment process has been developed . Apart from sulphate reduction, the model includes those reactions which occur either prior to sulphate reduction or in competition with it . These include, hydrolysis of solid substrates, acidogenesis . beta oxidation of long chain fatty acids, acetogenesis and methanogenesis . By incorporating terms for these reactions the model is able to simulate sulphate reduction using a wide range of carbon sources . Acid/base equilibrium chemistry is included in order to predict the pH and unionized component concentrations, needed for calculating inhibition . An activity based model is used, with the activity coefficients calculated using Debye-Huckle theory . The mass transfer rates of hydrogen, methane, carbon dioxide and hydrogen sulphide from the liquid to the vapour phase are also included . A number of different reactor types may be simulated, including a dynamic batch . steady state CSTR and dynamic CSTR . By separating the hydraulic and solids residence times, high rate reactors such as UASB and packed bed reactors may also be simulated . The model has been used to successfully predict the dynamic and steady state behaviour of a number of different reactor types, utilizing both simple and complex carbon sources. Water Res, 2002 Jan, 36(1), 212 - 8 On-line titration of volatile fatty acids for the process control of anaerobic digestion plants; Feitkenhauer H et al.; The on-line titration of volatile fatty acids (VFA) was found to be a reliable method to measure the substrate (metabolite) concentration without the use of expensive analytical devices . A measurement cell was designed that ensures stable long-term operation, high throughputs and copes with both very low and very high VFA concentrations . Using synthetic textile wastewater, a recalibration of the pH probe was necessary only twice a week . A good reproducibility of the VFA concentrations was determined and standard deviations were below +/- 1% of the measured concentration . Changing salt concentrations of the wastewater in the range of 2.5-150 gl(-1) NaCl did not influence the determined VFA concentration significantly . The method was suitable to control the hydraulic retention time in an acidic phase reactor and to determine the acidification rates of wastewater compounds in batch experiments. Water Res, 2002 Jan, 36(1), 201 - 11 State detection and control of overloads in the anaerobic wastewater treatment using fuzzy logic; Murnleitner E et al.; The two-stage anaerobic wastewater pre-treatment was modelled and controlled . The biological state of the reactors could be predicted using a fuzzy logic system and based upon this, proper control actions were taken automatically in order to avoid an overload . The system was designed to handle very strong fluctuations in the concentration of the substrate and the volumetric loading rate . Hydrogen concentration together with methane concentration, gas production rate . pH and the filling level of the acidification buffer tank were used as input variables for the fuzzy logic system . The manipulated variables were the flow rate from the acidification buffer tank into the methane reactor, the temperature and pH of both reactors, the circulation rate of the fixed bed reactor, back flow from the methane reactor into the acidification, and the control of the feed into the acidification buffer tank . The developed control system was successfully tested on a fully automated lab scale two-stage anaerobic digester . Different types of wastewater from food processing industries were successfully applied . Even a restart of feeding with very high COD concentrations (100 gl(-1) after several days of stand by was handled successfully . Effluent concentrations could be kept low without using TOC, COD or equivalent measurements. Water Res, 2002 Jan, 36(1), 123 - 30 Rejection of organic compounds by ultra-low pressure reverse osmosis membrane; Ozaki H et al.; The introduction of ultra-low pressure reverse osmosis (ULPRO) membrane has widened the horizon of reverse osmosis (RO) in purification of surface water and wastewater as well as desalination of brackish water . The ULPRO membrane chemistry can provide a high water flux at low operating pressure, while maintaining a very good salt and organics rejection . This paper deals with the investigation on the rejection of low molecular weight organic compounds by ULPRO membrane . Laboratory scale experiments were carried out at a pressure of 3 kg/cm2 with a feed flow rate of 1.20 l/min . The rejection of undissociated organic compounds did not show a close relationship with the feed pH . The percentage removal of undissociated organic compounds increased linearly with the molecular weight as well as with the molecular width . The removal efficiency can be predicted by these relationships . But neither molecular weight nor molecular width can be considered as an absolute factor for rejection . The feed pH also influenced the removal efficiency of dissociated organic compounds . The efficiency decreased linearly with the increase in the dissociation constant. Ying Yong Sheng Tai Xue Bao, 2000 Feb, 11(1), 141 - 5 {Biological purification of saline chemical wastewater and variation of algological indicatiors}; Gao Y; Simulation pond experiment shows that from the entrance to the exit of the pond, the concentration of pollutants was decreased, while the species, diversity index and primary productivity of algae were gradually increased with increasing purification duration . The dominant algae species changed from high tolerance species to medium tolerant species . Algae quantity and chlorophyll-a concentration remarkably increased . Through 32 days, the purified water flowed out from the third grade pond . The relationships between algae quantity, biomass and chlorophyll-a concentration and the contents of BOD5, COD, NH3-N and PO4-P could be described with the second order equation . Temperature had an obvious effect on the algae growth and purification effectiveness . The optimum temperature condition for algae growth and wastewater purification was in the range of 20-25 degrees C. Environ Technol, 2001 Oct, 22(10), 1137 - 46 Kinetics of oxidation of odorous sulfur compounds in aqueous alkaline solution with H2O2; Feliers C et al.; Sulfur species oxidation is a crucial issue wastewater treatment . The production of sulfur compounds like H2S,CH3SH, C2H5SH, disulfides and dimethyle sulfide generates odorous nuisances for the neighborhood . The oxidation of these species by H2O2 in alkaline solution has been investigated . The results showed that thiols CH3SH and C2H5SH react with H202 only in their dissociated form RS- with rate constants respectively k = 8.81 +/- 0.48 M-1s-1 and 8.37 +/- 0.63 M-1.s-1 . Mercaptans oxidation produces 100 % of dimethyldisulfide or diethyldisulfide . The oxidation of disulfides shows a difference of reactivity between H2O2 and HO2- towards sulfur species . Increasing the pH accelerates significantly the reactions in the case of CH3SSCH3 . The oxidation rate can be described as: r = k{RSSR}{H2O2}{RSSR}{H2O2} + k{RSSR}{HO2-} {RSSR}{HO2-} with k{RSSR}{H2O2} = 1.2 x 10(-4) +/- 0.2 x 10(-4) M-1s-1 and k{RSSR}{HO2-} = 3.4 x 10(-4) +/- 0.6 x 10(-4) M-1.s-1 for CH3SSCH3 . Dimethyl sulfide presents a reactivity different from disulfides . The oxidation rate can also be described as: r = k{CH3SCH3}{H2O21}{CH3SCH3}{H2O2} + k{CH3SCH3}{HO-} {CH3SCH3}{HO2-}, however, oxidation rate decreases with pH increase . k{CH3SCH3}{H2O2} = 12.8 x 10(-3) +/- 0.96 x 10(-3) M-1.s-1 and k{CH3SCH3}{HO2-} = 4 x 10(-3) +/- 0.3 x 10(-3) M-1.s-1. Water Environ Res, 2001 Sep-Oct, 73(5), 622 - 32 Upflow anaerobic sludge blanket treatment of starch wastewater containing cyanide; Annachhatre AP et al.; Treatment of tapioca starch wastewater containing cyanide using an upflow anaerobic sludge blanket (UASB) process was investigated . Sludge from an anaerobic lagoon treating tapioca starch wastewater was used as seed . Performance of the UASB reactor with influent cyanide concentrations up to 25 mg/L was assessed . The inhibitory effects of cyanide were temporary and reversible . The process required longer recovery period for higher cyanide dosage . For 25 mg/L of cyanide concentration in the feed, the reactor required 15 days for complete recovery . Process performance was sensitive to operating parameters such as upflow velocity, cyanide loading rate, and chemical oxygen demand (COD) loading rate . A maximum cyanide loading rate of 0.38 kg/m3 x d was achieved in the process at a COD loading rate of 50 kg COD/m3 x d . Experiments with tapioca starch wastewater containing up to 10 mg/L of cyanide yielded satisfactory cyanide removal of approximately 93 to 98% and gas productivity of 7.5 m3/m3 x d with a COD loading rate of 30 to 40 kg COD/m3 x d. Water Environ Res, 2001 Sep-Oct, 73(5), 597 - 606 Time-dependent retardation model for chemical oxygen demand removal in a subsurface-flow constructed wetland for winery wastewater treatment; Shepherd HL et al.; The relative success of chemical oxygen demand (COD) removal models to describe measured rates of COD removal in a pilot-scale constructed wetland designed for treatment of high-strength winery wastewater are evaluated using retention times determined from tracer studies . Not surprisingly, two-parameter residual and retardation models better fit the measured removal data than single-parameter, first-order decay models for wastewater at average COD loadings up to nearly 5000 mg/L . The residual and retardation models yielded nearly equivalent fits to the measured data . However, the retardation model had more consistent parameters for COD removal data across different depth levels in the constructed wetland and at different loadings, and a slightly smaller sum of least-squared errors . The retardation model seems to be appropriate for constructed wetland design because it allows a steady decrease in COD with increased treatment time rather than a constant residual COD (C*) value . From the least-squares optimization procedure used to estimate model parameters (a volumetric rate constant, Kv, range of 3 to 12 d(-1)), nonrealistic, or physically meaningless, large C* values (C* range of 23 to 450 mg COD/L) that were dependent on COD loading were obtained, potentially underestimating the constructed wetland system's actual winery wastewater treatment potential . The optimal parameters for the retardation model applied to the pilot-scale constructed wetland ranged from 9 to 12 d(-1) for the initial degradation rate constant, Ko, and 2 to 5 d(-1) for the time-based retardation coefficient, b . These values should be verified for full-scale field systems based on field measurements currently underway. Water Environ Res, 2001 Sep-Oct, 73(5), 567 - 74 Anaerobic migrating blanket reactor treatment of low-strength wastewater at low temperatures; Angenent LT et al.; The feasibility of the compartmentalized anaerobic migrating blanket reactor (AMBR) was studied for the treatment of low-strength soluble wastewater under low-temperature conditions . During an operating period of 186 days, a 20-L AMBR was fed nonfat dry milk substrate as a synthetic wastewater at low temperatures (15 and 20 degrees C) . The concentration of the influent was constant at chemical oxygen demand (COD) and 5-day biological oxygen demand (BOD5) concentrations of 600 and 285 mg/L, respectively . The soluble COD (SCOD) removal efficiency was 73% at the end of the operating period (15 degrees C) at a 4-hour hydraulic retention time (HRT), while the total COD (TCOD) removal efficiency was 59% . At a 4-hour HRT, staged conditions promoted complete removal of propionic acid in the final compartments of the reactor . The specific methanogenic activity of granules increased slowly until the end of the operating time, improving the removal rate . Biomass was retained effectively, as evidenced by the solids retention time (SRT) that was always greater than 50 days even during step decreases of the reactor HRT from 12 hours to 4 hours . A long SRT also promoted system stability during changes in flow, which was observed by SCOD removal efficiencies staving greater than 70% . During a hydraulic stress test, the HRT was reduced from 4 hours to 1 hour for one day (24 HRTs) in which volatile suspended solids (VSS) in the effluent increased from an average background level of 8.7 g/d to 35 g/d and the SRT decreased from 50.5 days to 12.6 days . However, mixed liquor volatile suspended solids concentration decreased only by 1 g/L, and hence a similar COD removal efficiency and biogas production was found one day after the hydraulic stress (as compared to one day before the hydraulic stress). Space Med Med Eng (Beijing), 1999 Feb, 12(1), 46 - 50 {Biological effects of space flight on purple nonsulfur photosynthetic bacteria}; Yang HF et al.; Objective: To study biological effects of space flight on purple nonsulfur photosynthetic bacteria . Methods: Two purple nonsulfur photosynthetic bacteria, Rhodopseudomonas palustris H3 and Rhodobacter sphaeroides ZGY, were carried on satellite for 15 days and some of their biological effects were studied after recovery . Results: In space condition, survival rate of bacteria was promoted . The purification of organic wastewater, removal of nitrite, degradation of phenol and decolorization of acid red B were enhanced, and the resistance of both strains to medicine was stable . Conclusion: The major morphological and physiological characteristics of loaded strains H3-S and ZGY-S were not changed after space flight. J Chromatogr A, 2001 Dec 7, 937(1-2), 21 - 9 Use of porous graphitic carbon coupled with mass detection for the analysis of polar phenolic compounds by liquid chromatography; Vial J et al.; Phenolic compounds present in olive mill wastewater (OMW) need to be quantified because of their pollution capacity toward the environment . In the present study, six representative phenolic compounds of OMW were chosen to develop a LC-MS method . The high polarity of the compounds caused problems when using traditional reversed-phase liquid chromatography (RPLC) . Consequently, a method was developed on another kind of chromatographic phase: Porous Graphitic Carbon (PGC) involving the use of a tetrahydrofuran (THF) gradient . The influence of THF as mobile phase in LC-MS coupling, which is not common practice, was evaluated . In Atmosperic Pressure Chemical Ionisation (APCI) in the negative ion mode, the presence of THF in the mobile phase did not degrade the MS signal of the target compounds in the conditions studied . On the contrary, an improvement was even observed when the percentage of THF increased . The proposed PGC-LC-MS method was selective and linear for the six phenolic compounds analysed with limits of quantification lower than 5 ppm in all cases . The precision was satisfactory (pooled RSD around 6%) . The analyses of OMW matrix spiked sample confirmed the good performance of the proposed method. Mar Pollut Bull, 2001 Nov, 42(11), 1133 - 8 Oxygen, sulphide and nutrient uptake of the mangrove mud clam Anodontia edentula (Family: Lucinidae); Lebata MJ; Oxygen, sulphide and nutrient (ammonia, nitrite and phosphate) uptake of Anodontia edentula was measured . Oxygen and sulphide were measured from sealed containers provided with 1 l fresh mangrove mud (sulphide source) and seawater (oxygen source) with two treatments (with and without clam) at 16 replicates each . Oxygen, sulphide and other parameters were measured at days 1 (initial), 3 and 5 (final) . Nutrients were measured from containers filled with 1.5 l wastewater from a milkfish broodstock tank with two treatments (with and without clam) at eight replicates each . Ammonia, NO2 and P04 were measured at days 0 (initial) 3, 6, 9 and 12 (final) . Results showed significantly decreasing oxygen and sulphide concentrations in treatment with clams (ANOVA, p < 0.001) . A significantly higher ammonia concentration (ANOVA, p < 0.05) was observed in treatment with clams while no significant difference was observed in nitrite and phosphate between the two treatments . A decreasing ammonia and an increasing nitrite trend was also observed in both treatments starting at day 3. Mar Environ Res, 2001 Dec, 52(5), 397 - 411 Recent trends in organochlorine residues in mussels (Mytilus edulis) from the Mersey Estuary; Connor L et al.; Blue mussels (Mytilus edulis) taken from several sites in the Mersey Estuary, an urban-industrial water body in NW England, have been analyzed for residues of the persistent organochlorines, DDT, PCB congeners nos . 28, 52, 101, 118, 138, 153 and 180 (ICES7), and alpha-MHCH (alpha-methyl hexachlorocyclohexane) . The concentration range for sigmaPCB (ICES7) was 13.9-34.9 microg kg(-1) in 1994 compared with 9.6-31.9 microg kg(-1) in 1998, whilst the equivalent concentrations of sigmaDDT were 8.9-32.4 microg kg(-1) and 4.5-16.8 microg kg(-1), respectively . The concentration of alpha-MHCH, an organochlorine largely restricted to the Mersey Estuary, was 1.2-11 microg kg(-1) in 1994 and 0.3-1.3 microg kg(-1) in 1998 . At both sampling dates the inner estuary sites of Rock Ferry and Egremont were more contaminated than the outer estuary sites of New Brighton . Dove Point and Caldy Blacks . The lower concentrations of organochlorines in mussels in 1998 compared with 1994 are thought to be early evidence of significant improvements in water quality derived from major capital investment in the treatment of industrial effluents and sewage wastewater, linked to a combination of stricter legislative controls and the environmental benefits from the adoption of new, clean technologies in manufacturing. Analyst, 2001 Nov, 126(11), 2078 - 81 X-ray fluorescence spectrometric determination of sulfur-containing anionic surfactants in water after their enrichment on a membrane filter as an ion-pair complex with a cationic surfactant; Taguchi S et al.; Anionic surfactants containing sulfur in their structure were enriched on a mixed cellulose ester membrane filter (MF) by filtration as an ion-pair complex with a cationic surfactant . After their enrichment, the anionic surfactants were determined by X-ray fluorescence spectrometry of the sulfur enriched on the MF . A linear calibration was obtained over a concentration range from 0.05 to 0.8 mg L(-1) of sodium dodecyl sulfate as a standard material with less than 6% RSD . The detection limit based on 3s for the reagent blank was 2 microg L(-1) . This method is very simple, rapid and highly selective for sulfur-containing surfactants, and does not require any organic solvent extraction . This method was applied to the determination of anionic surfactant in some urban river waters where domestic wastewater was discharged . The results were compared with those obtained by conventional solvent extraction-spectrophotometry . The distribution of the analyte complexes within the MF where the ion-pair was retained is also discussed. Water Res, 2001 Dec, 35(18), 4359 - 69 Transport and fate of Cryptosporidium parvum oocysts in intermittent sand filters; Logan AJ et al.; The transport potential of Cryptosporidiim parvum (C . parvum) through intermittent . unsaturated, sand filters used for water and wastewater treatment was investigated using a duplicated . 2(3) factorial design experiment performed in bench-scale, sand columns . Sixteen columns (dia = 15 cm, L = 61 cm) were dosed eight times daily for up to 61 days with 65,000 C . parvum oocysts per liter at 15 degrees C . The effects of water quality, media grain size, and hydraulic loading rates were examined . Effluent samples were tested for pH, turbidity, and oocyst content . C . parvum effluent concentrations were determined by staining oocysts on polycarbonate filters and enumerating using epifluorescent microscopy . At completion, the columns were dismantled and sand samples were taken at discrete depths within the columns . These samples were washed in a surfactant solution and the oocysts were enumerated using immunomagnetic separation techniques . The fine-grained sand columns (d50 = 0.31 mm) effectively removed oocysts under the variety of conditions examined with low concentrations of oocysts infrequently detected in the effluent . Coarse-grained media columns (d = 1.40 mm) yielded larger numbers of oocysts which were commonly observed in the effluent regardless of operating conditions . Factorial design analysis indicated that grain size was the variable which most affected the oocyst effluent concentrations in these intermittent filters . Loading rate had a significant effect when coarse-grained media was used and lesser effect with fine-grained media while the effect of feed composition was inconclusive . No correlations between turbidity, pH, and effluent oocyst concentrations were found . Pore-sizc calculations indicated that adequate space for oocyst transport existed in the filters . It was therefore concluded that processes other than physical straining mechanisms are mainly responsible for the removal of C . pavum oocysts from aqueous fluids in intermittent sand filters used under the conditions Studied in this research. Water Res, 2001 Dec, 35(18), 4307 - 16 Modelling the sewage discharge and dispersion of Cryptosporidium and Giardia in surface water; Medema GJ et al.; Modelling the discharge of parasitic protozoa into surface water and the dispersion in rivers and streams gives insight into the contribution of the different sources of environmental contamination and in the transmission of these organisms from the point of discharge to drinking water abstraction points and bathing sites . We tested the applicability of emission (PROMISE) and dispersion (WATNAT) models developed for chemical pollutants to describe the environmental behaviour of Cryptosporidium and Giardia in the Netherlands . The annual load of Cryptosporidium and Giardia in domestic wastewater was 3.2 x 10(13) and 3.8 x 10(14) respectively . The majority (85%) of the Cryptosporidium oocysts was discharged with effluent of wastewater treatment plants . while the majority (82%) of the Giardia cysts was discharged with untreated wastewater discharges and sewer overflows . The estimated annual import through the river Rhine and Meuse was 3.2 x 1014 Cryptosporidium oocysts and 2.1 x 10(15) Giardia cysts, of which the river Rhine contributed 87 and 66%, respectively . This outweighed the total load of the discharges of treated and untreated wastewater in the Netherlands . The combination of PROMISE and WATNAT predicted concentrations of Cryptosporidium and Giardia in surface water that were in the same order of magnitude as the concentrations that were observed at 5 of the 6 sites compared . At a site with primarily agricultural contamination, the models predicted concentrations that were 1 10log-unit lower than the observed concentrations . This is a first step in the direction of a quantitative description of the transmission cycle of Cryptosporidum and Giardia through water . The use of these models combines observational occurrence data and experimental data from laboratory survival studies into a single integrated description . The description needs further improvement by incorporation of agricultural run-off and increasing the number and time frame of input monitoring data. Water Res, 2001 Dec, 35(18), 4267 - 76 Pre-acidification in anaerobic sludge bed process treating brewery wastewater; Ahn YH et al.; The effect of pre-acidification on anaerobic granule bed processes treating brewery wastewater was the focus of a comparison study employing two configurations, (a) a single stage upflow anaerobic sludge bed (UASB) and (b) an upflow acidification reactor in series with a methanogenic UASB . The pre-acidification reactor achieved 20 +/- 4% SCOD removal and 0.08 +/- 0.003 L of methane produced per gram of SCOD removal at a hydraulic retention time (HRT) of 0.75-4 h . Butyric acid was not detected and short chain fatty acids (SCFAs) were mainly acetic and propionic acids . The acidification ratio was about 0.42 +/- 0.02g SCFAs as COD,g of influent COD . Both systems' critical loading rate to achieve 80% COD removal was established at 34-39kgCOD/nm3 of total sludge bed volume per day . SCOD removal efficiency of 90 +/- 3% was achieved by both systems at an organic loading rate of 25 +/- 1 kg COD/m3 of total sludge bed volume per day, indicating that the installation of an acidification reactor had no effect in terms of the maximum granular activity, biomass granulation and the settleability of granules . At an organic loading rate of 67 kg COD/m3 of total sludge bed volume per day at an HRT of 1 h, the series system outperformed the single UASB by a removal of 62 compared to 57%. Toxicol Ind Health, 2000 Nov, 16(9-10), 335 - 438 Determination of a site-specific reference dose for methylmercury for fish-eating populations; Shipp AM et al.; Environmental risk-management decisions in the U.S . involving potential exposures to methylmercury currently use a reference dose (RfD) developed by the U.S . Environmental Protection Agency (USEPA) . This RfD is based on retrospective studies of an acute poisoning incident in Iraq in which grain contaminated with a methylmercury fungicide was inadvertently used in the baking of bread . The exposures, which were relatively high but lasted only a few months, were associated with neurological effects in both adults (primarily paresthesia) and infants (late walking, late talking, etc.) . It is generally believed that the developing fetus represents a particularly sensitive subpopulation for the neurological effects of methylmercury . The USEPA derived an RfD of 0.1 microg/kg/day based on benchmark dose (BMD) modeling of the combined neurological endpoints reported for children exposed in utero . This RfD included an uncertainty factor of 10 to consider human pharmacokinetic variability and database limitations (lack of data on multigeneration effects or possible long-term sequelae of perinatal exposure) . Alcoa signed an Administrative Order of Consent for the conduct of a remedial investigation/feasibility study (RI/FS) at their Point Comfort Operations and the adjacent Lavaca Bay in Texas to address the effects of historical discharges of mercury-containing wastewater . In cooperation with the Texas Natural Resource Conservation Commission and USEPA Region VI, Alcoa conducted a baseline risk assessment to assess potential risk to human health and the environment . As a part of this assessment . Alcoa pursued the development of a site-specific RfD for methylmercury to specifically address the potential human health effects associated with the ingestion of contaminated finfish and shellfish from Lavaca Bay . Application of the published USEPA RfD to this site is problematic; while the study underlying the RfD represented acute exposure to relatively high concentrations of methylmercury, the exposures of concern for the Point Comfort site are from the chronic consumption of relatively low concentrations of methylmercury in fish . Since the publication of the USEPA RfD, several analyses of chronic exposure to methylmercury in fish-eating populations have been reported . The purpose of the analysis reported here was to evaluate the possibility of deriving an RfD for methylmercury, specifically for the case of fish ingestion, on the basis of these new studies . In order to better support the risk-management decisions associated with developing a remediation approach for the site in question, the analysis was designed to provide information on the distribution of acceptable ingestion rates across a population, which could reasonably be expected to be consistent with the results of the epidemiological studies of other fish-eating populations . Based on a review of the available literature on the effects of methylmercury, a study conducted with a population in the Seychelles Islands was selected as the critical study for this analysis . The exposures to methylmercury in this population result from chronic, multigenerational ingestion of contaminated fish . This prospective study was carefully conducted and analyzed, included a large cohort of mother-infant pairs, and was relatively free of confounding factors . The results of this study are essentially negative, and a no-observed-adverse-effect level (NOAEL) derived from the estimated exposures has recently been used by the Agency for Toxic Substances and Disease Registry (ATSDR) as the basis for a chronic oral minimal risk level (MRL) for methylmercury . In spite of the fact that no statistically significant effects were observed in this study, the data as reported are suitable for dose-response analysis using the BMD method . Evaluation of the BMD method used in this analysis, as well as in the current USEPA RfD, has demonstrated that the resulting 95% lower bound on the 10% benchmark dose (BMDL) represents a conservative estimate of the traditional NOAEL, and that it is superior to the use of "average" or "grouped" exposure estimates when dose-response information is available, as is the case for the Seychelles study . A more recent study in the Faroe Islands, which did report statistically significant associations between methylmercury exposure and neurological effects, could not be used for dose-response modeling due to inadequate reporting of the data and confounding from co-exposure to polychlorinated biphenyls (PCBs) . BMD modeling over the wide range of neurological endpoints reported in the Seychelles study yielded a lowest BMDL for methylmercury in maternal hair of 21 ppm . This BMDL was then converted to an expected distribution of daily ingestion rates across a population using Monte Carlo analysis with a physiologically based pharmacokinetic (PBPK) model to evaluate the impact of interindividual variability . The resulting distribution of ingestion rates at the BMDL had a geometric mean of 1.60 microg/kg/day with a geometric standard deviation of 1.33; the 1st, 5th, and 10th percentiles of the distribution were 0.86, 1.04, and 1.15 microg/kg/day . In place of the use of an uncertainty factor of 3 for pharmacokinetic variability, as is done in the current RfD, one of these lower percentiles of the daily ingestion rate distribution provides a scientifically based, conservative basis for taking into consideration the impact of pharmacokinetic variability across the population . On the other hand, it was felt that an uncertainty factor of 3 for database limitations should be used in the current analysis . Although there can be high confidence in the benchmark-estimated NOAEL of 21 ppm in the Seychelles study, some results in the New Zealand and Faroe Islands studies could be construed to suggest the possibility of effects at maternal hair concentrations below 10 ppm . In addition, while concerns regarding the possibility of chronic sequelae are not supported by the available data, neither can they be absolutely ruled out . The use of an uncertainty factor of 3 is equivalent to using a NOAEL of 7 ppm in maternal hair, which provides additional protection against the possibility that effects could occur at lower concentrations in some populations . Based on the analysis described above, the distribution of acceptable daily ingestion rates (RfDs) recommended to serve as the basis for site-specific risk-management decisions at Alcoa's Point Comfort Operations ranges from approximately 0.3 to 1.1 microg/kg/day, with a population median (50th percentile) of 0.5 microg/kg/day . By analogy with USEPA guidelines for the use of percentiles in applications of distributions in exposure assessments, the 10th percentile provides a reasonably conservative measure . On this basis, a site-specific RfD of 0.4 microg/kg/day is recommended. J Chromatogr A, 2001 Nov 16, 934(1-2), 51 - 7 Solid-phase microextraction of monocyclic aromatic amines using novel fibers coated with crown ether; Zeng Z et al.; Three solid-phase microextraction (SPME) fibers prepared by the sol-gel method, containing hydroxydibenzo-14-crown-4 (OH-DB14C4), dihydroxy-substituted saturated urushiol crown ether (DHSU14C4) and 3,5-dibutyl-unsymmetry-dibenzo-14-crown-4-dihydroxy crown ether (DBUD14C4), respectively, were evaluated for the determination of aromatic amine (aniline, m-toluidine, N,N-diethylaniline, N-ethyl-m-toluidine, 3,4-dimethylaniline) . The sol-gel-derived hydroxy-dibenzo14-crown-4-coated fiber has the best affinity for several aniline derivatives . Optimization was carried out for the determination of aromatic amines with SPME fibers . The linearity was from 0.11 to 29 microg/ml and detection limits varied from 0.17 to 0.98 ng/ml . Relative standard deviation (n=5) was found to be 3.23-6.20% . The coating proved to be very stable at high temperature (to 340 degrees C) and in different solvents (organic and inorganic) . The method was applied to the determination of aromatic amines in wastewater samples from a pharmaceutical factory. Water Sci Technol, 2001, 44(9), 53 - 8 Sensor arrays: an inspired idea or an objective measurement of environmental odours? Stuetz RM, Nicolas J. The measure of annoyance odours from sewage tratment, landfill and agricultural practise has become highly significant in the control and prevention of dorous emissions from existing facilities and its crucial for new planning applications . Current methods (such as GC-MS analysis, H2S and NH3 measurements) provide an accurate description of chemical compositions or act as surrogates for odour strength, but tell us very little about the perceived effect, whereas olfactometry gives the right human response but is very subjective and expensive . The use of non-specific sensor arrays may offer an objective and on-line instrument for assessing olfactive annoyance . Results have shown that sensor array systems can discriminate between different odour sources (wastewater, livestock and landfill) . The response patterns from these sources can be significantly different and that the intensity of sensor responses is proportional to the concentration of the volatiles . The correlation of the sensors responses against odour strengths have also shown that reasonable fits can be obtained for a range of odour concentrations (100-800,000 ou/m3) . However, the influence of environmental fluctuations (humidity and temperature) on sensor baselines still remains an obstacle, as well as the need for periodic calibration of the sensory system and the choice of a suitable gas for different environmental odours. Water Sci Technol, 2001, 44(9), 309 - 16 Odor control of an anaerobic lagoon with a biological cover: floating peat beds; Picot B et al.; The use of a biological cover for in situ control of gaseous sulfide emission from an anaerobic pond was investigated by a laboratory-scale experiment . The biological cover, constituting by a peat bed floating on the wastewater, caused a reduction of the H2S emission rate by 84.6% . The addition of Fe3+ (with FeCl3) and plants (Juncus effusus L.) to the peat bed significantly improved the performance to reach a H2S removal of 95.5% . Despite the fluctuations in the sulfide concentration in the wastewater, the performance of the biological covers remained constant during the entire period of the study . The analysis of the different forms of sulfur accumulated in the peat beds allowed the understanding of the mechanisms involved in H2S removal . The high amount of sulfate demonstrated that the conditions were favorable to the biological oxidation of H2S . The addition of Fe3+ increased the formation of insoluble ferrous monosulfide (FeS) and pyrite (FeS2) . The plants seemed to convert sulfate into elemental and organic sulfur. Water Sci Technol, 2001, 44(9), 295 - 9 A pilot study of a biotrickling filter for the treatment of odorous sewage air; Wu L et al.; The nuisance impact of air pollutant emissions from wastewater treatment plants (WWTPs) is a major issue of concern to Singapore and to many developing cities worldwide . Existing chemical and physical treatment methods are efficient but costly, and may generate secondary pollutants . Biotreatment, on the other hand, is a proven control technology for effectively removing hydrogen sulphide (H2S), the principal odour component of sewage air . The biotechnology is cost-effective to remove low-concentrations of biodegradable compounds from a large flow of waste gases . A pilot-scale biotrickling filter, packed with pall rings, was set up at a WWTP in Singapore to investigate its effectiveness for treatment of odorous sewage air . A series of experiments were conducted to assess the performance of the biotrickling filter under various operating scenarios . Results indicated that even at 5 second gas retention time, the biotrickling filter could remove 95% of the inlet H2S . The behaviour of the biotrickling filter under various operating scenarios are presented and discussed in this paper. Water Sci Technol, 2001, 44(9), 135 - 42 Direct molecular hydrogen sulphide scrubbing with hollowfibre membranes; Boucif N et al.; The emission of hydrogen sulphide is a major problem associated with anaerobic treatment of sulphate and sulphite containing wastewaters . Conventional absorbing processes, such as packed towers, spray towers or bubble columns, are all constrained by factors such as flooding and foaming . Membrane systems, on the other hand, enable independent control of the liquid and gas flow rate and a step change order of magnitude increase in the specific surface area of the contact process . The membrane acts as a gas absorber with a design similar to a shell and tube heat exchanger . On the other hand, they are limited by facets of the membrane such as its resistance to mass transfer and permselectivity, as well as its cost . The work presented in this paper refers to an absorption process based on a non-wetted hollow fibre membrane for the scrubbing of hydrogen sulphide from air, with water as the contact solvent . Results presented describe the performance of the unit in terms of overall transfer and outlet liquid concentration as a function of circulation regime, gas flow rate, liquid flow rate and specific surface area . In particular, results are presented using traditional plots of Sherwood number (Sh) against Graetz (Gr) number for the liquid flowing in the lumens, such that experimental and available empirical descriptions of the process performance are directly compared . Results suggest that, as expected, very efficient mass transfer is obtained . However, the mass transfer was found to reach a maximum value against Gr, contrary to available empirical models. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(10), 2069 - 82 Synergic degradation of reactive brilliant red X-3B using three dimension electrode-photocatalytic reactor; An T et al.; A new reactor, three dimension electrode-photocatalytic reactor, was designed and used to investigate the photoelectrochemical degradation of reactive brilliant red X-3B (RBRX) in simulated wastewater . The reactor was characterized by a series of parameters, the current change, decolorization ratio, COD removal and degradation ratio . It was found that the three dimensional electrode-photocatalytic reactor could effectively destroy the RBRX within a reaction time of 30 min . The results also showed that the photoelectrochemical process is more efficient than the single application of electrochemical oxidation or photocatalytic degradation . The degradation reactions of RBRX conformed to pseudo first order kinetics in the three processes, and an apparent synergic effect in the increase of the photocurrent and the disappearance of RBRX was observed by combining the electrochemistry with photocatalytic process in the three dimension electrode-photocatalytic reactor. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(10), 1997 - 2010 Electrochemical oxidation of resorcinol for wastewater treatment using Ti/TiO2-RuO2-IrO2 electrode; Rajkumar D et al.; Electrochemical oxidation of resorcinol for wastewater treatment in the presence of chloride was investigated . Titanium Substrate Insoluble Anode (TSIA) coated with TiO2-RuO2-IrO2 was used as an anode and graphite carbon sheet was used as a cathode . The extent of resorcinol electrochemical oxidation was determined in terms of COD removal . The Box-Behnken second order composite design was used to study the effect of operating parameters such as initial pH, chloride concentration, initial concentration of resorcinol and charge input . The experimental values were in good correlation with predicted values, and the correlation coefficient was found to be good . The effect of current density on resorcinol oxidation, the AOX level during the electrochemical treatment and TOC removal were also studied for selected conditions . It has been observed that the extended electrolysis brings down the AOX concentration to lower levels . The maximum current efficiency was observed at higher resorcinol concentration, higher chloride concentration and increasing current density. Anal Sci, 2001 Nov, 17(11), 1291 - 4 Extraction and separation of cationic surfactants from river sediments: application to a spectrophotometric determination of cationic surfactant in an aquatic environment using membrane filters; Sun HF et al.; The quantitative extraction of cationic surfactant (CS+) in river sediments was studied . Further, the developed method was applied to the spectrophotometric determination of CS+ in urban river sediment samples by solid-phase extraction with membranes . A mixture of methanol and hydrochloric acid was proposed as an eluent . Dried sediment was digested in the eluent under ultrasonic irradiation . After elution, the eluent was evaporated to almost dryness . The residue was dissolved in a small volume of methanol and diluted to a certain volume with water . The pH of the solution was adjusted to 4-5 to separate iron and some other metals as precipitates of hydroxides . The solution was passed through two-piled membranes: first glass-fiber and then polytetrafluoroethylene (PTFE) membranes . A small volume of methanol was passed through the membranes to elute any CS+ retaining on the membranes . After passing the methanol solution through a cationic exchange resin column, the retained CS+ was eluted with methanol containing a high concentration of sodium chloride . Water, Bromophenol Blue (BPB) and hydrochloric acid were added to the solution . The solution was passed through a mixed cellulose ester membrane filter to retain an ion associate of CS+.BPB- . The retained ion associate was dissolved in a small volume of N,N-dimethylformamide together with the membrane filter, followed by the addition of triethanolamine to make the solution alkaline . The absorbance due to BPB2- was measured at 603 nm against a reagent blank . This method was applied to the determination of CS+ in river water and sediment . A cationic surfactant in sediments at 10(-5) mol kg-1 levels was detected with satisfactory precision . It was found that CS+ was about 500-fold enriched in the sediment from water at the place where domestic wastewater was discharged. Environ Int, 2001 Nov, 27(5), 373 - 80 Toxicity evaluation of sewage sludges in Hong Kong; Wong JW et al.; Anaerobically digested sewage sludges collected from four wastewater treatment plants located in Sha Tin, Tai Po, Yuen Long, and Shek Wu Hui in Hong Kong were subjected to chemical characterization and toxicity testing to provide preliminary assessment of their suitability for land application . All sewage sludges were slightly alkaline with pH range of 8.3-8.7 . Electrical conductivity (EC; 0.69 dS m(-1)) and soluble NH4-N content (996 mg kg(-1)) of sewage sludge from Yuen Long were lower than that of other plants . Concentrations of heavy metals were determined as total, extractable, and water-soluble fraction using mixed acid digestion, DTPA (pH 7.3), and distilled water, respectively . Yuen Long sludge was most polluted with Zn and Cr higher than the pollutant concentration limits listed in Part 503 of USEPA, owing to the effluent coming from the tannery industry . High concentration of Ni was found in sludge from Sha Tin that originated mainly from the electroplating industry . DTPA-extractable Zn contents were high in sludges from Yuen Long (1247 mg kg(-1)) and Shek Wu Hui (892 mg kg(-1)), while 3.7 mg kg(-1) of DTPA-extractable Cr was found in Yuen Long sludge . Metal speciation of sludges showed that Pb was major in residual phase while Cu, Cr, and Ni in organic and residual phases, and Zn did not show any dominant chemical phase . The sludge extracts did not exert significant adverse effect on seed germination of Brassica chinensis (Chinese cabbage), but Yuen Long sludge caused a reduction in root growth . In view of its lower EC and soluble ammonia contents, the high concentration of Zn and Cr in Yuen Long sludge would likely be responsible for this adverse effect on root growth . Therefore, Yuen Long sludge would likely have a more serious impact on soil quality and plant growth as compared to other sludges . This would require further verification from greenhouse and field experiments. Biotechnol Bioeng, 2001 Dec 5, 75(5), 521 - 9 Maximization of acetic acid production in partial acidogenesis of swine wastewater; Hwang S et al.; Swine wastewater was biologically treated to produce short-chain volatile organic acids (VOAs) in laboratory-scale continuously stirred tank reactors . The maximum production rates of acetic and butyric acids associated with simultaneous changes in pH and hydraulic retention time (HRT) were investigated, in which the degree of acidification of swine wastewater to the short-chain VOAs was <25% of influent chemical oxygen demand (COD) concentration . A constant inoculum system was used to minimize the experimental error due to the use of inconsistent inoculum . The inoculum system was operated with synthetic wastewater at 6000 mg soluble chemical oxygen demand per liter (pH 6.0) and 35 degrees C at 0.5 day hydraulic retention time . Response surface methodology was applied successfully to determine the optimum physiological condition for which the maximum rate of acetic acid production occurred, which was pH 5.90 and 0.88 day hydraulic retention time at 35 degrees C . The partial acidification process to manage swine waste should be operated in the optimum condition for acetic acid production because the optimum operating condition for butyric acid production approached the washout point . J Hazard Mater, 2002 Jan 28, 89(2-3), 303 - 17 Solar/UV-induced photocatalytic degradation of three commercial textile dyes; Neppolian B et al.; The photocatalytic degradation of three commercial textile dyes with different structure has been investigated using TiO(2) (Degussa P25) photocatalyst in aqueous solution under solar irradiation . Experiments were conducted to optimise various parameters viz . amount of catalyst, concentration of dye, pH and solar light intensity . Degradation of all the dyes were examined by using chemical oxygen demand (COD) method . The degradation efficiency of the three dyes is as follows: Reactive Yellow 17(RY17) > Reactive Red 2(RR2) > Reactive Blue 4 (RB4), respectively . The experimental results indicate that TiO(2) (Degussa P25) is the best catalyst in comparison with other commercial photocatalysts such as, TiO(2) (Merck), ZnO, ZrO(2), WO(3) and CdS . Though the UV irradiation can efficiently degrade the dyes, naturally abundant solar irradiation is also very effective in the mineralisation of dyes . The comparison between thin-film coating and aqueous slurry method reveals that slurry method is more efficient than coating but the problems of leaching and the requirement of separation can be avoided by using coating technique . These observations indicate that all the three dyes could be degraded completely at different time intervals . Hence, it may be a viable technique for the safe disposal of textile wastewater into the water streams. J Hazard Mater, 2002 Jan 28, 89(2-3), 267 - 77 Development of photoreactor design equation for the treatment of dye wastewater by UV/H(2)O(2) process; Shen YS et al.; The treatment of Direct Yellow 86 dye wastewater by the UV/H(2)O(2) process in continuous annular photoreactors was studied under various UV light intensities, influx concentrations of dye, dosages of H(2)O(2) and dimensions of photoreactor . A photoreactor design equation combined the UV light distribution profile in the reactor and the empirical rate expressions for the decomposition of dye and H(2)O(2) was used to predict the destruction of dye within photoreactors of different geometries at various operating conditions . Experimentally observed removal of the dye pollutant in the plug flow annular reactor agreed well with the theoretical solutions modeled by the developed photoreactor design equation. J Hazard Mater, 2002 Jan 28, 89(2-3), 185 - 96 Removal of phenol from aqueous solution and resin manufacturing industry wastewater using an agricultural waste: rubber seed coat; Rengaraj S et al.; Activated carbon prepared from rubber seed coat (RSCC), an agricultural waste by-product, has been used for the adsorption of phenol from aqueous solution . In this work, adsorption of phenol on rubber seed coat activated carbon has been studied by using batch and column studies . The equilibrium adsorption level was determined to be a function of the solution pH, adsorbent dosage and contact time . The equilibrium adsorption capacity of rubber seed coat activated carbon for phenol removal was obtained by using linear Freundlich isotherm . The adsorption of phenol on rubber seed coat activated carbon follows first order reversible kinetics . The suitability of RSCC for treating phenol based resin manufacturing industry wastewater was also tested . A comparative study with a commercial activated carbon (CAC) showed that RSCC is 2.25 times more efficient compared to CAC based on column adsorption study for phenolic wastewater treatment. J Biotechnol, 2002 Feb 14, 93(2), 99 - 108 Mesophilic acidification of gelatinaceous wastewater; Fang HH et al.; The influence of hydraulic retention time (HRT) and gelatin concentration on the acidification of gelatinaceous wastewater in an upflow anaerobic reactor was investigated at pH 5.5 and 37 degrees C . The degree of gelatin degradation increased with the HRT, from 84.1% at 4 h to 89.6% at 24 h, but decreased with the increase of the gelatin concentration in the influent from 65.2% at 2 g-CODl(-1) to 51.9% at 30 g-CODl(-1) . The degradation of gelatin followed the Monod kinetics with a maximum rate of 1.10 g (g-VSS x d)(-1) and a half-rate constant of 0.23 gl(-1) . The overall production rate of VFA and alcohols decreased with HRT, from 0.33 g (g-VSS x d)(-1) at 4 h to 0.15 g (g-VSS x d)(-1) at 24 h, but increased with gelatin concentration in the influent, from 0.10 g (g-VSS x d)(-1) at 4 g-CODl(-1) to 0.58 g (g-VSS x d)(-1) at 30 g-CODl(-1) . The key acidification products were acetate, propionate and butyrate, plus i-butyrate, valerate, i-valerate, caproate and ethanol in smaller quantities . Formate, methanol, propanol and butanol were found only in certain runs . Only 4.5-7.8% of COD in wastewater was converted to hydrogen and methane . The sludge yield was estimated as 0.320+/-0.014 g-VSS (g-COD)(-1). Water Sci Technol, 2001, 44(8), 85 - 90 Industrial applications of new sulphur biotechnology; Janssen AJ et al.; The emission of sulphur compounds into the environment is undesirable because of their acidifying characteristics . The processing of sulphidic ores, oil refining and sulphuric acid production are major sources of SO2 emissions . Hydrogen sulphide is emitted into the environment as dissolved sulphide in wastewater or as H2S in natural gas, biogas, syngas or refinery gases . Waste streams containing sulphate are generated by many industries, including mining, metallurgical, pulp and paper and petrochemical industries . Applying process technologies that rely on the biological sulphur cycle can prevent environmental pollution . In nature sulphur compounds may cycle through a series of oxidation states (-2, 0, +2, +4, +6) . Bacteria of a wide range of genera gain metabolic energy from either oxidising or reducing sulphur compounds . Paques B.V . develops and constructs reactor systems to remove sulphur compounds from aqueous and gaseous streams by utilising naturally occurring bacteria from the sulphur cycle . Due to the presence of sulphide, heavy metal removal is also achieved with very high removal efficiencies . Ten years of extensive laboratory and pilot plant research has, to date, resulted in the construction of over 30 full-scale installations . This paper presents key processes from the sulphur cycle and discusses recent developments about their application in industry. Water Sci Technol, 2001, 44(8), 77 - 84 Combining the biological nitrogen and sulfur cycles in anaerobic conditions; Fdz-Polanco F et al.; The biochemical processes involved in the anaerobic degradation of carbon, nitrogen and sulfur compounds can be represented by an oxidation-reduction or electron donor-acceptor scheme . The theoretic values of Gibbs free energy (deltaG0) calculated from thermodynamic data indicate the feasibility of the reactions . The interactions C-S and C-N are well known but there is a lack of information about the interaction N-S . The anaerobic transformation of nitrates using reduced sulfur compounds can be explained considering that nitrate acts as electron acceptor while reduced sulfur compounds are the electron donors . A new N-S interaction in anaerobic conditions (ORP = -425 mV) has been experimentally observed when treating industrial wastewater rich in organic nitrogen and sulfate . The mass balances of the different nitrogenous and sulfur compounds in the liquid and gas phases clearly indicated an uncommon evolution . An important percentage of the nitrogen entering the reactor as TKN was removed from the liquid phase appearing as N2 in the gas phase . Simultaneously, only part of the sulfate initially present in the influent appeared as sulfide in the effluent or as hydrogen sulfide in the gas . These experimental observations may suggest a new anaerobic N-S biological interaction involving simultaneous anaerobic ammonium oxidation and sulfate reduction, ammonium being the electron donor and sulfate the electron acceptor. Water Sci Technol, 2001, 44(8), 149 - 56 The development of anaerobic treatment and its future; McCarty PL; Anaerobic treatment is well over 100 years old . Its initial development was for the treatment of domestic wastewaters, using anaerobic filters and hybrid processes that are still of interest today . It then progressed in application to separate sludge digestion, then to treatment of dilute industrial wastewaters . Several processes have been developed that accomplish efficient treatment of wastewaters at short detention times . Major contributions to the broad application of anaerobic treatment and the better understanding of this process has come from efforts by G . Lettinga and his colleagues . They have emphasized its importance for meeting the need for sustainable development in the future . Greater efforts are now needed for broad application of anaerobic treatment for ridding the environment of unwanted organic materials by converting them into methane, a renewable energy source. Water Sci Technol, 2001, 44(8), 133 - 40 Anaerobic treatment: a key technology for a sustainable management of wastes in Europe; Lema JM et al.; Environmental regulations in the European Union, based on the concept of integrated prevention and control of pollution, are oriented towards the sustainability of the production processes, and this leads to better recovery of resources from raw materials, energy saving, etc . This philosophy introduces a new framework to Environmental Engineers, who have to make efforts concerning waste minimisation . During the last few decades technologies based on the anaerobic treatment of wastewaters and organic wastes have been applied successfully to a wide variety of problems . A case study on the impact of applying anaerobic technology to the treatment of wastewaters from the sugar industry in Spain is presented . Nowadays, processes based on anaerobic treatment appear to be an excellent option as the core of an integrated process for waste and wastewater treatment. Water Sci Technol, 2001, 44(8), 115 - 22 Potential of anaerobic digestion of complex waste(water); Zeeman G et al.; Although they differ greatly in origin complex waste(water)s mainly consist of proteins, lipids, carbohydrates and sometimes lignin in addition . Hydrolysis is the first and generally rate-limiting step in the process of anaerobic digestion of particulate organic substrates . Hydrolysis of particulate polymers can be described by Surface Based Kinetics, but for use in practice the empirical first order relation is advised . Unlike the hydrolysis of protein and carbohydrate, lipid hydrolysis is hardly occurring in the absence of methanogenesis . The latter is probably a physical rather than a biological process and affects the choice for either a one- or a two-step (phase) anaerobic reactor . In the chain of collection and transport, complex wastes often become complex wastewaters simply because of dilution . Dilution not only changes the reactor technology to be applied but also complicates the post-treatment and possibilities for resource recovery . Combining concentrated with diluted waste streams will almost always end up in much more complicated treatment technologies. Water Sci Technol, 2001, 44(8), 107 - 13 Experiences and potential of anaerobic wastewater treatment in tropical regions; Wiegant WM; In this article an overview is given on the experience with anaerobic treatment of domestic wastewater in the tropics, with emphasis on the situation in India . Some design criteria and their impact on the costs of UASB reactors are discussed . The operational results of a number of full-scale reactors are presented . The applicability of the UASB, in combination with different post-treatment units to comply with a variety of effluent standards is compared with other systems . From the available data it is concluded that, if nitrogen removal is not required, a UASB system, followed by a polishing pond, is a relatively simple, affordable, and manageable wastewater treatment system . Trickling filters may follow UASB treatment if effluent standards require removal of TKN . The inclusion of UASB reactors in wastewater treatment schemes allowing for total nitrogen removal still needs further study. Water Sci Technol, 2001, 44(8), 1 - 6 Full-scale experiences with anaerobic treatment of industrial wastewater; Frankin RJ; High rate anaerobic treatment for industrial wastewater was first applied on a commercial scale in the sugar industry in the mid 70's . Since that time the technology has developed into a standard method of wastewater treatment for a wide variety of industries . The technology is now functional in over 65 countries and a total of approximately 1,400 plants were build by the 16 leading vendors of such systems . These plants account for approximately 65% of the total number of anaerobic treatment plants for industrial applications, which is estimated to be ca . 2,000 . From the analysis from a database consisting of 1,215 plants it appears that the UASB technology as originally developed in the Netherlands is the most predominant process . It is also seen that the higher loaded EGSB type systems are gradually replacing at least some of the UASB applications. Water Sci Technol, 2001, 44(7), 23 - 34 Catch basin inserts to reduce pollution from stormwater; Lau SL et al.; Stormwater contamination represents the largest source of contaminants to many receiving waters in the United States, such as Santa Monica Bay in Los Angeles, California . Point sources to these same waters generally receive secondary or better treatment before they are released, and they are usually discharged through outfalls that diffuse the wastewater plume to prevent it from contacting the shoreline . Stormwaters receive no treatment and reach the receiving waters through a variety of ways, but most enter through catch basins or inserts to storm drains that terminate at the beach or in shallow coastal areas . Under these conditions, the stormwater discharge may have greater impact on the quality and utility of the receiving water than the treated wastewater discharges . One method of reducing pollution is to equip catch basins with an insert that can capture pollutants . A number of commercially available devices exist but few have been evaluated by independent parties in full-scale applications . A series of tests using bench and full-scale devices under both laboratory and field conditions were conducted to evaluate their ability to remove trash and debris, suspended solids and oil and grease in stormwaters . The results presented in the paper should provide a basis for future insert development and application. Water Sci Technol, 2001, 44(7), 145 - 50 Nitrogen leaching from soil treated with sludge; Sukreeyapongse O et al.; The amount of sludge generated from urban centers is increasing more and more, so wastewater treatment plants are being constructed . Recycling of sludge by application to agricultural land can alleviate the disposal pressure, and, at the same time, utilize the plant nutrients in the waste . Organic nitrogen in sludge is mineralized to inorganic forms such as nitrate and ammonium that can be taken up by plants . The inorganic forms of nitrogen, especially nitrates, can easily be leached because of its negative charge . Not only do nitrates cause eutrophication, but, at high concentration in drinking water, can also cause chemical suffocation disease in babies . This work is meant to quantify nitrate and ammonium nitrogen leached from soil treated with sludge . In order to obtain information on the composition of leachate from sludge, Kandiustults and a lysimeter study were used . Municipal and industrial sludge were applied to completely random design plots at different rates: 125, 250 and 375 kg N/ha . Each control lysimeter was treated with chemical fertilizer (N-P2O5-K2O: 20-10-10) at the rate of 125 kg N/ha . After the Chinese kale (Brassica oleracea L.) was planted in each lysimeter, leachate was collected every week and analyzed for NO3- and NH4+ . The experiment was conducted at Kasetsart University, Bangkhen Campus, Bangkok, Thailand . Average nitrogen leach in the form of NO3- was 25 times more concentrated than the NH4+ . Nitrate concentrations in the leachate exceeded the drinking water standard . Nitrate and ammonium leaching were measured to be between 1.50-3.00% and 0.03-0.14% of the total treated nitrogen, respectively . Total nitrogen losses found in this study were 44.88%, 77.24% and 77.91% of the total nitrogen applied by chemical fertilizer, Huay Kwang sludge and Bangpa In sludge, respectively. J Environ Sci (China), 2001 Oct, 13(4), 485 - 90 Impact of industrial wastewater disposal on surface water bodies in Mostord area, north greater Cairo; Abdel-Sabour MF et al.; The studied area (Shoubra El-Khima, Bahteem and Mostorod) lies in the industrial area north of Greater Cairo . The area suffers from several environmental problems such as sewage and disposal of pollutants from the surrounding factories into the surface water pathways in the area . Water samples were collected seasonally from different waterways found in the area, domestic and or industrial liquid wastes from 12 discharge tubes of different factories (as a point source of pollution) . Chemical characteristics of different water samples and its heavy metals content were determined using ion coupled plasma technique (ICP) . Results indicate that industrial and domestic wastewater samples contain several toxic levels of tested heavy metals (Cd, Co, Pb and Ni) which have a serious impact on surface waterways in the area . Shebin El-Qanater collector drain samples exhibited the highest levels of Cd, Co, Pb and Ni compared to other tested water bodies . Mostorod collector drain samples showed the highest levels of Zn and Cu . Industrial effluent samples collected from Cairo Company for Fabric industry had the highest amounts of total Zn Cu, Cd, Co and Pb, while Delta steel company discharges the highest amounts of total Fe and Mn . Al-Ahleya Plastic Company discharges the highest amounts of total-Ni . Generally, it is necessary to impose the environmental laws and its regulation regarding the industrial wastewater treatments and disposals to minimize the risk of the adverse effects of these pollutants. Appl Environ Microbiol, 2001 Dec, 67(12), 5453 - 9 Inactivation of viable Ascaris eggs by reagents during enumeration; Nelson KL et al.; Various reagents commonly used to enumerate viable helminth eggs from wastewater and sludge were evaluated for their potential to inactivate Ascaris eggs under typical laboratory conditions . Two methods were used to enumerate indigenous Ascaris eggs from sludge samples . All steps in the methods were the same except that in method I a phase extraction step with acid-alcohol (35% ethanol in 0.1 N H(2)SO(4)) and diethyl ether was used whereas in method II the extraction step was avoided by pouring the sample through a 38-microm-mesh stainless steel sieve that retained the eggs . The concentration of eggs and their viability were lower in the samples processed by method I than in the samples processed by method II by an average of 48 and 70%, respectively . A second set of experiments was performed using pure solutions of Ascaris suum eggs to elucidate the effect of the individual reagents and relevant combination of reagents on the eggs . The percentages of viable eggs in samples treated with acid-alcohol alone and in combination with diethyl ether or ethyl acetate were 52, 27, and 4%, respectively, whereas in the rest of the samples the viability was about 80% . Neither the acid nor the diethyl ether alone caused any decrease in egg viability . Thus, the observed inactivation was attributed primarily to the 35% ethanol content of the acid-alcohol solution . Inactivation of the eggs was prevented by limiting the direct exposure to the extraction reagents to 30 min and diluting the residual concentration of acid-alcohol in the sample by a factor of 100 before incubation . Also, the viability of the eggs was maintained if the acid-alcohol solution was replaced with an acetoacetic buffer . None of the reagents used for the flotation step of the sample cleaning procedure (ZnSO(4), MgSO(4), and NaCl) or during incubation (0.1 N H(2)SO(4) and 0.5% formalin) inactivated the Ascaris eggs under the conditions studied. Environ Sci Technol, 2001 Nov 1, 35(21), 4353 - 8 Biosorption of trivalent chromium on the brown seaweed biomass; Yun YS et al.; Biosorption has attracted attention as a cost-effective means for the treatment of metal-bearing wastewater . However, the mechanism of metal binding is not clearly understood, and consequently, modeling of the biosorption performance is still raising debates . In this study, the biosorption of trivalent chromium was investigated with protonated brown alga Ecklonia biomass as a model system . Titration of the biomass revealed that it contains at least three types of functional groups . The Fourier transform infrared spectrometry showed that the carboxyl group was the chromium-binding site within the pH range (pH 1-5) used in this study, where chromium does not precipitate . The pK value and the number of carboxyl groups were estimated to be 4.6 +/- 0.1 and 2.2 +/- 0.1 mmol/g, respectively . The equilibrium sorption isotherms determined at different solution pH indicated that the uptake of chromium increased significantly with increasing pH . A model for the description of chromium biosorption was developed incorporating the hydrolysis reactions that chromium undergoes in the aquatic phase . The model was able to predict the equilibrium sorption experimental data at different pH values and chromium concentrations . In addition, the speciation of the binding site as a function of the solution pH was predicted using the model in order to visualize the distribution of chromium ionic species on the binding site. Environ Sci Technol, 2001 Nov 1, 35(21), 4260 - 4 Sorption of nonpolar aromatic contaminants by chlorosilane surface modified natural minerals; Huttenloch P et al.; The efficacy of the surface modification of natural diatomite and zeolite material by chlorosilanes is demonstrated . Chlorosilanes used were trimethylchlorosilane (TMSCI), tert-butyldimethylchlorosilane (TBDMSCI), dimethyloctadecylchlorosilane (DMODSCI), and diphenyldichlorosilane (DPDSCI) possessing different headgroups and chemical properties . Silanol groups of the diatomite and zeolite were modified by chemical reaction with the chlorosilanes resulting in a stable covalent attachment of the organosilanes to the mineral surface . The alteration of surface properties of the modified material was proved by measurements of water adsorption capacity, total organic carbon (TOC) content, and thermoanalytical data . The surface modified material showed great stability even when exposed to extremes in ionic strength, pH, and to pure organic solvents . Sorption of toluene, o-xylene, and naphthalene from water was greatly enhanced by the surface modification compared to the untreated materials which showed no measurable sorption of these compounds . The enhanced sorption was dependent on the organic carbon content as well as on chemical characteristics of the chlorosilanes used . Batch sorption experiments showed that the phenyl headgroups of DPDSCI have the best affinity for aromatic compounds . Removal from an aqueous solution of 10 mg/L of naphthalene, o-xylene, and toluene was 71%, 60%, and 30% for surface modified diatomite and 51%, 30%, and 16% for modified clinoptilolite, respectively . Sorption data were well described by the Freundlich isotherm equation, which indicated physical adsorption onto the lipophilic surface rather than partitioning into the surface organic phase . The chlorosilane modified materials have an apparent potential for application in environmental technologies such as permeable reactive barriers (PRB) or wastewater treatment. Sci Total Environ, 2001 Nov 12, 279(1-3), 207 - 14 Characterisation and evolution of a soil affected by olive oil mill wastewater disposal; Sierra J et al.; A location used for 10 years as an uncontrolled olive oil mill wastewater disposal site is studied in this work . Once it was closed the sedimented solid waste on the soil surface was removed . In order to evaluate the influence upon soil characteristics, morphological aspects and analytical parameters of a soil profile from the affected zone are compared to those of a control soil located near the landfill . The residual contamination levels in the underlying soil are determined . The results show that the wastewater infiltration in the soil has caused carbonate dissolution and redistribution and modifications in pH values, electrical conductivity, nutrient contents, phenolic compounds and biological activity of the horizons . Removal of waste, natural leaching and biological activity, in time, led to an effective decrease in electrical conductivity and phenolic compounds, although residual levels can be important even 2 years later. Bioresour Technol, 2002 Jan, 81(1), 61 - 9 Slaughterhouse wastewater treatment: evaluation of a new three-phase separation system in a UASB reactor; Caixeta CE et al.; The anaerobic treatment of the wastewater from the meat processing industry was studied using a 7.2 1 UASB reactor . The reactor was equipped with an unconventional configuration of the three-phase separation system . The effluent was characterized in terms of pH (6.3-6.6), chemical oxygen demand (COD) (2,000-6,000 mg l(-1)), biochemical oxygen demand BOD5 (1,300-2,300 mg 1(-1)), fats (40-600 mg l(-1)) and total suspended solids (TSS) (850-6,300 mg l(-1)) The reactor operated continuously throughout 80 days with hydraulic retention time of 14, 18 and 22 h . The wastewater from Rezende Industrial was collected after it had gone through pretreatment (screening, flotation and equalization) . COD, BOD and TSS reductions and the biogas production rate were the parameters considered in analyzing the efficiency of the process . The average production of biogas was 111 day(-1) (STP) for the three experimental runs . COD removal varied from 77% to 91% while BOD removal was 95% . The removal of total suspended solids varied from 81% to 86% . This fact supports optimal efficiency of the proposed three-phase separation system as well as the possibility of applying it to the treatment of industrial effluents. Water Sci Technol, 2001, 44(6), 81 - 8 On-site wastewater technologies in Australia; Ho G et al.; Domestic wastewater reuse is currently not permitted anywhere in Australia but is widely supported by the community, promoted by researchers, and improvised by up to 20% of householders . Its widespread implementation will make an enormous contribution to the sustainability of water resources . Integrated with other strategies in the outdoor living environment of settlements in arid lands, great benefit will be derived . This paper describes six options for wastewater reuse under research by the Remote Area Developments Group (RADG) at Murdoch University and case studies are given where productive use is being made for revegetation and food production strategies at household and community scales . Pollution control techniques, public health precautions and maintenance requirements are described . The special case of remote Aboriginal communities is explained where prototype systems have been installed by RADG to generate windbreaks and orchards . New Australian design standards and draft guidelines for domestic greywater reuse produced by the Western Australian State government agencies for mainstream communities are evaluated . It is recommended that dry composting toilets be coupled with domestic greywater reuse and the various types available in Australia are described . For situations where only the flushing toilet will suffice the unique 'wet composting' system can be used and this also is described . A vision for household and community-scale on-site application is presented. Water Sci Technol, 2001, 44(6), 67 - 72 Degradation kinetics of reactive dye by UV/H2O2/US process under continuous mode operation; Fung PC et al.; Degradation of a dye, C . I . Reactive Red 120, in dyeing waatewater by the process o UV/H2O2/US was studied with a bench-scale reactor under the continuous mode of operation . The effects of dyeing wastewater flow rate and the feeding rate of an oxidant, H2O2, on the color removal efficiency of the process were investigated . The significance of ultrasonic (US) combined with UV irradiation was also investigated and the performances of the process on color removal were evaluated . The results showed that the decoloration process followed a pseudo first-order kinetic model and the UV light is the most significant factor on dye removal . Besides, at higher flow rates, incomplete color removal was observed due to relatively insufficient irradiation time (low degradation rate) . In order to achieve a higher degradation rate, the feeding rate of H2O2 should be increased. Water Sci Technol, 2001, 44(6), 55 - 62 Evaluation of total nitrogen pollution reduction strategies in a river basin: a case study; Drolc A et al.; The enrichment of groundwater and rivers by nutrients (nitrogen and phosphorus compounds) and their consequences is one of the most severe problems across Europe as well in Slovenia . Transfer of nutrients from different sources into the environment causes eutrophication of surface waters, nitrate accumulation in groundwater, and others . In this paper, the methodology of the material flow analysis is presented and applied to develop a nitrogen balance in a river basin and to evaluate different scenarios for total nitrogen pollution reduction . Application of the methodology is illustrated by means of a case study on the Krka river, Slovenia . Different scenarios are to be considered: the present level of sewerage and treatment capacities, different stages of wastewater treatment and management of agricultural activities on land . The results show that beside effluents from wastewater treatment plants, agriculture contributes significantly to the total annual nitrogen load . Beside reduction of point sources by means of wastewater collection and implementation of nutrient removal technology, managing agricultural nitrogen in order to protect river water quality and drinking water supply should become a major challenge in the Krka river basin. Water Sci Technol, 2001, 44(6), 47 - 54 Study of impacts of treated wastewater to the Krka river, Slovenia; Cotman M et al.; Surface waters are used for disposal of treated effluents from wastewater treatment plants . These effluents usually contain only small amounts of various contaminants but these harmful components accumulate over time in the river, especially in sediments . An integrated approach for the evaluation of the impact of treated effluents was used to predict an ecological risk assessment to the Krka river beside Novo Mesto . The effluents from pharmaceutical and municipal wastewater treatment plants were discharged too closely into the receiving stream, so that separate impacts could not be distinguished . Biologically treated industrial effluents contained great amounts of barely biodegradable organic pollution, organic nitrogen, ammonia and phosphorus, and sometimes zinc . The toxicity of effluents was mostly dependent on their chemical composition . The municipal discharge contained greater amounts of organic pollution that was completely biodegraded but still had a great nutrient pollution load . The effluents were nontoxic . The harmful substances from the effluents were traced in the river . In the downstream site slightly higher concentration of organic pollutants, organic nitrogen, phosphorus, and zinc were detected due to discharges . The river water was over-saturated with oxygen, especially in the summer . In toxicity tests, samples of the river water were nontoxic . Sediments at the downstream site accumulated from discharged organic nitrogen, phosphorus, or zinc . The results of our study show that the main problem is eutrophication of the river Krka, so it is obvious we must reduce the quantity of nutrients in the effluents from wastewater treatment plants . In both effluents it will be necessary to reduce the polluting load of phosphorus, the limiting element for growth of algae and macrophytes in the receiving stream . In the industrial effluent it will be necessary to reduce substances which cause toxicity, such as zinc and nonbiodegradable organic compounds that may be accumulatec the water ecosystem over time. Water Sci Technol, 2001, 44(6), 181 - 8 Sustainable development in pollution control and the role of anaerobic treatment; Lettinga G et al.; The increasing scarcity of clean water sets the need for appropriate management of available water resources . Particularly regions suffering from a lack of water urgently need integrated environmental protection and resource conservation (EP and RC) technologies in order to enable effective management of the available water resources . EP and RC-concepts focus on pollution prevention and on a minimum of consumptive use of energy, chemicals, and water in pollution abatement and a maximum of re-use of treated wastewater, by-products and residues produced in the treatment of waste and wastewater . Consequently, by implementing these concepts, waste(water)s like sewage and industrial effluents become an important source of water, fertilisers, soil conditioners and (frequently) energy instead of a social threat . In addition, a bridge is made between environmental protection and agriculture practice, stimulating (urban) agriculture in the neighbourhood of large cities . Anaerobic treatment is considered as the core technology for mineralising organic compounds in waste(water) streams . Additional technologies are required to comply with the reuse criteria . Some examples of possible EP and RC concepts, using the anaerobic treatment technology for the reclamation of domestic sewage are discussed. Water Sci Technol, 2001, 44(6), 163 - 72 Wastewater management in Greece: experience and lessons for developing countries; Tsagarakis KP et al.; Technologies to treat wastewater are now well established and are capable of producing almost any degree of purification . The main issue surrounding the selection of a given process lies in deciding which is the most appropriate and applicable technology for the particular social, political and economic environment . This paper concentrates on the development of the municipal wastewater treatment sector in Greece . It examines the deficiencies and problems arising from the implementation of wastewater management policies and makes a number of suggestions and recommendations . The areas considered include, among others, historical development, economic development and pollution control, key issues for wastewater treatment policies and lessons applicable to developing countries . It is hoped that this study will be a valuable source of information for countries embarking on nationwide sanitation projects. Water Sci Technol, 2001, 44(6), 141 - 6 Anaerobic treatment and biogas recovery for sago wastewater management using a fluidized bed reactor; Saravanane R et al.; Starch manufacturing industrial units, such as sago mills, both at medium and large scale, suffer from inadequate treatment and disposal problems due to high concentration of suspended solid content present in the effluent . In order to investigate the viability of treatment of sago effluent, a laboratory scale study was conducted . The treatment of sago effluent was studied in a continuous flow anaerobic fluidized bed reactor . The start-up of the reactor was carried out using a mixture of digested supernatant sewage sludge and cow dung slurry in different proportions . The effect of operating variables such as COD of the effluent, bed expansion, minimum fluidization velocity on efficiency of treatment and recovery of biogas was investigated . The treated wastewater was analysed for recycling and reuse to ensure an alternative for sustainable water resourse management . The maximum efficiency of treatment was found to be 82% and the nitrogen enriched digested sludge was recommended for agricultural use. Water Sci Technol, 2001, 44(6), 1 - 10 Evapotranspiration for domestic wastewater reuse in remote indigenous communities of Australia; Anda M et al.; In the past sewage ponding in indigenous settlements was commonplace as a result of overcrowding combined with inappropriate septic tank and leach drain design, installation and operation . The response over the past 10 years has been to develop reticulated sewerage systems to lagoons when the funds become available . These are often successful in terms of operation, improved public health and low maintenance but are expensive and wasteful of limited water supplies . Evapotranspiration (ET) is an effective method for on-site domestic effluent disposal in areas of Western Australia with soils of low permeability . Evapotranspiration systems have been established in a number of communities both for research/demonstration and as specified by architects . The systems usually follow two septic tanks for the disposal of all domestic effluent . A case study will be presented for a remote indigenous community where the ET systems installed for greywater only have been monitored over the last two years since installation . The use of evapotranspiration has enabled reuse of effluent for successful examples of revegetation and food production and points to the need for a holistic approach to design and service delivery in these communities that includes a total environmental management plan. Environ Toxicol Chem, 2001 Nov, 20(11), 2456 - 61 A novel toxicity fingerprinting method for pollutant identification with lux-marked biosensors; Turner NL et al.; A novel technique is described for the identification and quantification of environmental pollutants based on toxicity fingerprinting with a metabolic lux-marked bacterial biosensor . This method involved characterizing the toxicity-based responses of the biosensor to seven calibration pollutants as acute temporal-dose response fingerprints . An algorithm is described to allow comparisons of responses of an unknown pollutant to be made against the calibration data . This is based on predicting pollutant concentration at each of six different time points over the course of a 5-min assay . If the prediction is consistent between the unknown pollutant and a calibration pollutant at the 95% test level, this is considered to be a positive identification . All seven calibration pollutants could be successfully distinguished from each other with this technique . Environmental samples, individually spiked with single concentrations of pollutants, were compared in this way against the calibration pollutants . An 83% identification success was achieved, with no false positives at the 95% test level . This is a simple and rapid technique that potentially can be applied to monitoring of industrial wastewater or as a screening tool for regulators. Ambio, 2001 Aug, 30(4-5), 306 - 14 Water-quality changes in Latvia and Riga 1980-2000: possibilities and problems; Juhna T et al.; Long-term changes in the environmental quality of water in Latvia (chemical composition of inland waters, wastewater treatment, and drinking-water treatment practices and quality) as a response to socioeconomic changes have been studied . Water composition, the major factors influencing water chemistry, and human impacts (wastewater loading) were studied to determine changes that occurred after recent reductions in pollution emissions, particularly nutrient loading, to surface waters . After 1991, (Latvia regained independence in 1991) inland water quality has begun to improve mainly as a result of decreases in nutrient loads from point and nonpoint sources and substantial efforts in the area of environmental protection . The situation differs, however, for drinking-water treatment, where practices have also changed during the whole period from 1980 till 2000 . More stringent drinking-water-quality standards and novel insights regarding changes in water quality in the distribution network, necessitate further improvements in public water supply, and place this particular water issue among Latvia's main priorities. Ambio, 2001 Aug, 30(4-5), 297 - 305 Water-quality control, monitoring and wastewater treatment in Lithuania 1950 to 1999; Cetkauskaite A et al.; The Lithuanian water-management system developed on the basis of Soviet regulations in 1950-1990 . Surface-water quality monitoring started in the 1950s, and the system was improved in the 1960s . Today, 48 rivers are being monitored using up to 70 parameters . Statutory monitoring of discharges started in 1962, wastewater standards were issued in 1957 and 1966, and then revised in 1996 . Wastewater-treatment plants were built first in rural areas, in factories since the 1950s, and later in towns . Since 1991, large capacity municipal plants have been constructed with foreign assistance . Water quality has improved in some rivers since 1970, but Lithuania's main river, Nemunas, remains moderately polluted . The lower Nemunas is especially affected by discharges of municipal and industrial wastewater from Sovietsk and Neman (Russia), which account for half of the total loading . Hydrobiological data of 1994-1998 indicated the eutrophication of the Curonian Lagoon, and bacteriological pollution and blue-green algae blooms in the Baltic Sea north of Klaipeda. Ambio, 2001 Aug, 30(4-5), 287 - 91 The struggle for a cleaner urban environment: water pollution in Malmö 1850-1911; Olsson G; This article focuses on the emergence of water pollution problems in the city of Malmo and on how they were discussed and solved . Various countermeasures were proposed and considered, but finally the discharge of wastewater into the Sound of Oresund was regarded as the best solution . As a result, a local pollution problem was transformed into a regional issue . The solutions adopted in Malmo are briefly compared with decisions made in Gothenburg and Stockholm. Ambio, 2001 Aug, 30(4-5), 277 - 81 Urban impact in the history of water quality in the Stockholm archipelago; Johansson L et al.; From the historical perspective, the increasing number of inhabitants in the city of Stockholm has had a negative effect on water quality in the surrounding lakes and coastal region . Government control and measures taken to improve water quality have been in progress since the mid-19th century . Water conditions in the 19th century, compared to later years is difficult to assess from the first chemical and biological investigations, due to infrequent sampling and the different parameters and methods used . However, a retrospective evaluation of water quality can be made on the basis of results from plankton investigations, which began in the early 20th century . The occurrence of the cyanobacteria Planktothrix agardhii, which indicates nutrient-rich conditions, was surveyed during summers with similar temperature conditions throughout the 20th century . The results show that eutrophied conditions probably prevailed in the Stockholm archipelago from the beginning of 20th century until the early 1990s . In the last decade of the 20th century, water quality appeared to be better than 100 years earlier . Today's better water conditions are most probably an effect of proper measures taken in wastewater treatment. Ambio, 2001 Aug, 30(4-5), 272 - 6 Stages of municipal water protection in Vaasa during the 20th century; Katajamaki H et al.; Vaasa, located on the Gulf of Bothnia, is representative of medium-sized cities on the coast of the Baltic Sea . This article discusses Vaasa's impact on the surrounding sea area and the city's reactions to the pollution of the sea . The history of wastewater treatment in Vaasa strongly suggests that first-generation environmental problems, e.g . the pollution problems caused by municipal wastewater discharges, were solved only as a last resort after a prolonged development process . The first wastewater treatment plant was completed in 1953 . In the long run, municipal policies became more costly for the environment and for the town itself than would have been the case if the option of constructing a central treatment plant had been accepted in the first instance . In Vaasa, the environment itself did not provide the incentive, the change was motivated by health risks, noxious odors and poor outdoor-bathing possibilities that resulted from municipal wastewater discharges . No action was taken until ultimately forced by necessity . This article also discusses social science approaches to environmental studies. Ambio, 2001 Aug, 30(4-5), 264 - 71 The history of eutrophication in the sea area of Helsinki in the 20th century . Long-term analysis of plankton assemblages; Finni T et al.; The aim of this study is to present a historical continuum of nearly 100 years of environmental investigations and changes in trophic levels in the sea area of Helsinki . The survey is based on a re-examination of original planktological and meteorological data; the principle being that eutrophication can be detected in plankton assemblages despite changes in methodology . The bays around Helsinki were found to be moderately eutrophic to hypereutrophic at the beginning of the 20th century . There were considerable differences in the development of the bays both in terms of degradation and recovery . The efficiency of wastewater treatment and especially the introduction of sea outfall have played an important role in decreasing eutrophication in the bay area of Helsinki. Chemosphere, 2001 Nov, 45(6-7), 1023 - 31 Alkaline hydrolysis of humic substances--spectroscopic and chromatographic investigations; Kumke MU et al.; To find out more on the structure of humic substances (HS), isolated dissolved organic carbon (DOC) samples from a brown water lake and a wastewater effluent were fractionated and subjected to alkaline hydrolysis . UV/Vis and fluorescence spectroscopy, as well as size-exclusion chromatography with on-line detection of UV absorption, fluorescence and DOC concentration were used to investigate the structural changes caused by the hydrolysis reaction . Following hydrolysis, the fluorescence intensity increased considerably despite a decrease in the UV absorption . The UV absorption and the DOC data from the SEC experiments revealed a strong shift to smaller molecular sizes after hydrolysis . The spectra of the hydrolysed samples, as well as the size-exclusion chromatograms, were compared to spectra of hydroxybenzoic acids and hydroxycinnamic acids . From this comparison, it can be concluded that the hydrolysis products have a structure similar to these organic acids. Water Sci Technol, 2001, 44(5), 93 - 101 Photochemical-biological treatment of a real industrial biorecalcitrant wastewater containing 5-amino-6-methyl-2-benzimidazolone; Sarria V et al.; 5-amino-6-methyl-2-benzimidazolone (AMBI), used in the manufacture of dyes, was characterised as a biorecalcitrant compound by means of different biodegradability tests . In order to enhance the biodegradability of this important pollutant, the application of Advanced Oxidation Process (AOPs) as a pretreatment was explored . Some experiments were addressed to find the most efficient AOP . The systems H2O2/hv, TiO2/H2O2/hv, Fe3+/hv, Fe3+/H2O2 and Fe3+/H2O2/hv were compared . The photo-Fenton system was the most efficient and the optimal conditions (AMBI, Fe3+, H2O2 concentrations) for the degradation of AMBI were found . During the photo-Fenton degradation, experiments were also made to obtain information concerning the evolution of: (a) organic carbon and initial compound concentration; (b) the oxidation state; (c) the toxicity; (d) the biodegradability; and (e) the chemical nature of the intermediates . These analyses show that the solution resulting from the treatment of AMBI is biologically compatible and complete mineralisation can be performed by biological means . A combined photochemical (Fenton) and biological flow reactor for the degradation of AMBI was successfully operated in continuous mode at laboratory scale . 100% of the initial concentration of AMBI and 80.3% of Dissolved Organic Carbon (DOC) were removed in 3.5 hours of total residence time . Finally, some field experiments under direct sunlight carried out at the Plataforma Solar de Almeria, Spain, demonstrated that this solar catalytic system is an effective treatment for this kind of industrial wastewater. Water Sci Technol, 2001, 44(5), 75 - 83 Integration of chemical and biological treatments for textile industry wastewater: a possible zero-discharge system; Lee HH et al.; Theoretical and experimental studies have established that integrated treatment systems (mostly chemical and biological) for various industrial wastewaters can achieve better quality of treatment and can be cost-effective . In the present study, the objective is to minimize the use of process water in the textile industry by an economical recycle and reuse scheme . The textile wastewater was first characterized in terms of COD, BOD5, salinity and color . In order to recycle such wastewater, the contaminants should be mineralized and/or removed according to the reusable textile water quality standards . Typical results show that this is achievable . An economic analysis has been conducted on the proposed integrated system . The economic analysis shows that the integrated system is economically more attractive than any of the single treatment technologies for achieving the same target of treatment . The information presented in this paper provides a feasible option for the reduction of effluent discharges in the textile industry. Water Sci Technol, 2001, 44(5), 61 - 7 Ozone treatment of textile wastewaters for reuse; Ciardelli G et al.; Treatment of textile wastewaters by means of an ozonation pilot plant are described . Wastewaters used were produced by a dyeing and finishing factory and were first treated in an active sludge plant and filtrated through sand . In the appropriate conditions very high colour removal (95-99%) was achieved and the effluent could be reused in production processes requiring water of high quality as dyeing yarns or light colorations . Even if the chemical oxygen demand of treated waters was still in a range (75-120 mg/l, a decrease of up to 60%) that was usually considered to be too high for recycling purposes, recycling experiments were successful . The economical viability of the techniques implementation was also demonstrated and the industrial plant is currently under realisation under an EU financed project . The paper considers also the possible improvement of ozone diffusion by means of membrane contactors realised in a second pilot plant, in order to further reduce operating costs of the technique . With respect to traditional systems, the gas/liquid contact surface is much higher being that of the membrane . Ozone at the interface is therefore immediately solubilized and potentially consumed with no additional resistance to the mass transfer. Water Sci Technol, 2001, 44(5), 339 - 45 Optimal experimental design and artificial neural networks applied to the photochemically enhanced Fenton reaction; Gob S et al.; Among advanced oxidation processes (AOPs), the photochemically enhanced Fenton reaction may be considered as one of the most efficient for the degradation of contaminants in industrial wastewater . This process involves a series of complex reactions . Therefore, an empirical model based on artificial neural networks has been developed for fitting the experimental data obtained in a laboratory batch reactor for the degradation of 2,4-dimethyl aniline (2,4-xylidine), chosen as a model pollutant . The model describes the evolution of the pollutant concentration during irradiation time as a function of the process conditions . It has been used for simulating the behavior of the reaction system in sensitivity studies aimed at optimizing the amounts of reactants employed in the process, an iron(III) salt and hydrogen peroxide, as well as the temperature . The results show that the process is most sensitive to the concentration of iron(III) salt and temperature, whereas the concentration of hydrogen peroxide has a minor effect. Water Sci Technol, 2001, 44(5), 325 - 30 Abatement of the major contaminants present in olive oil industry wastewaters by different oxidation methods: ozone and/or UV radiation versus solar light; Miranda et al.; Four different cinnamic acids (caffeic acid, ferulic acid, p-coumaric acid and cinnamic acid) present in olive oil wastewaters, were treated with advanced oxidation methods: ozone and/or UV radiation . Basic and acid media were tested . Differences between all four acids were found, both in the reaction times and the intermediates formed . Based on a careful study of these intermediates and the variation of their concentrations all along the reaction time, a general mechanism for the degradative oxidation of cinnamic acids is proposed . These results are compared with those obtained with solar light, using a pyrylium salt as a catalyst. Water Sci Technol, 2001, 44(5), 317 - 23 Photochemical oxidation of iodized X-ray contrast media (XRC) in hospital wastewater; Sprehe M et al.; Iodized X-ray contrast media (XRC) for medical applications are responsible for the high concentration of AOX (halogenated organic compounds adsorbable on activated carbon) in hospital wastewater exceeding the legal German discharge limit . The refractory properties of these substances lead to an accumulation in the natural waterbody . The elimination of contrast media from hospital wastewater by photochemical oxidation with hydrogen peroxide was investigated . The mechanism and the kinetics of the degradation of XRC were examined . These experiments demonstrate that a complete removal of the organically bonded iodine and a partial mineralization is feasible . The degradation in the UV reactor could be enhanced by adding hydrogen peroxide and by using a bubble column to remove the formed elemental iodine from the solution by stripping . Furthermore, the influence of various operating parameters such as gas flowrate, H2O2 input, XRC concentration and kind of XRC were investigated . Experiments showed that a recycling of elemental iodine from the exhaust gas is technically and economically possible. Water Sci Technol, 2001, 44(5), 287 - 93 Treatment of diglyme containing wastewater by advanced oxidation--process design and optimisation; Grossmann D et al.; Diglyme (CAS No . 111-96-6), a biorefractive ether with teratogenic properties is of considerable importance as a solvent in the synthetic chemical industry . Results of lab-scale investigations into the optimal conditions for the oxidative mineralisation of 0.05 to 1 g/L of diglyme in synthetic process waters by hydrogen peroxide and ozone based advanced oxidation processes are presented . Fenton, photo-assisted Fenton and UV/H2O2 oxidation processes show acceptable TOC removals . At 50 degrees C the initial TOC removal rates varies between 0.07 and 6g TOC/L*h . The rates increase with the initial diglyme and hydrogen peroxide concentration as well as with the UV irradiation energy intensity . For example at a 1 g/l diglyme concentration a stoichiometric H2O2 addition resulted in TOC degradation of 60% to 70% after 30 minutes under the investigated conditions . Treatment with ozone/H2O2 at a pH of 8 and 25 degrees C required at least 100 minutes to achieve comparable mineralisation results . Biodegradability can be reached in far shorter times . Ozone on its own cannot be recommended for diglyme treatment . If complete mineralisation of diglyme is the objective, the UV/H2O2 oxidation process should be favoured . The ozone/H2O2 process might offer a viable alternative in cases where the oxidation step is followed by biological wastewater treatment, so that biodegradability is aimed at. Water Sci Technol, 2001, 44(5), 245 - 9 Comparison of suspended and fixed photocatalytic reactor systems; Geissen SU et al.; Photocatalysis is a promising technology for the purification of pretreated wastewaters in sun-rich countries if an economically applicable reactor system is available . Within this project the catalyst separation as an essential process step of suspended reactor systems was investigated . For the separation of suspended catalyst a sedimentation basin with and without lamella and a membrane filtration were investigated . The sedimentation was found to be very sensitive to the kind of the ion background of wastewater, the pH, the TiO2 influent concentration as well as the hydrodynamics in the clarifier . Under optimized conditions effluent concentrations of less than 5 mg SS/L and a clear water without turbidity could be reached with a specific flow rate of up to 0.7 m3/m2/h . The best performance for P25 was achieved with a TiO2 influent concentration of 5 g/L . Membrane filtration was the only method to guarantee a complete retention of the TiO2 as well as a rejection of microorganisms and high molecular compounds . With cross-flow velocities of 3 m/s and a transmembrane pressure of 100 kPa flux rates up to 1,200 L/m2/h were achieved . A flow-film-reactor (FFR) was operated with the model compound DCA under identical conditions with fixed and suspended TiO2 . Whereas the fixed system has the advantage that no separation step is necessary and a simple construction can be used, suspended systems offer a three times higher reaction velocity for a catalyst concentration of 10 g/L, but are also characterized by higher investment costs. Water Sci Technol, 2001, 44(5), 237 - 44 Solar detoxification of wastewater in a novel aerated cascade photoreactor (ACP); Xi W et al.; A newly developed aerated cascade photoreactor (ACP), based on a non-concentrating suspension photoreactor, combines the advantages of a cascade with the increased mass-transfer and the use of oxygen from air as an oxidizing agent in a bubble column . Systematic studies of the limiting hydrodynamic conditions in the ACP and the solid/liquid-separation of the photocatalyst from the treated wastewater have shown that the ACP is technically and commercially attractive . The ACP outperforms the thin-film fixed-bed reactor (TFFBR) with respect to a 3-13 times higher degradation efficiency for the model compound dichloroacetic acid (DCA) . The treatment of two biologically pretreated real wastewaters, one from a textile factory and one from car-washing, have been successfully carried out under artificial light and sunlight. Water Sci Technol, 2001, 44(5), 229 - 36 Highly concentrated phenolic wastewater treatment by heterogeneous and homogeneous photocatalysis: mechanism study by FTIR-ATR; Arana J et al.; The degradation of high phenol concentrations (1 g/L) in water solutions by TiO2 photocatalysis and the photo-Fenton reaction has been studied . From the obtained data it may be suggested that degradation of phenol by TiO2-UV takes place onto the catalyst surface by means of peroxo-compounds formation . At low phenol concentrations other mechanism, the insertion of OH . radicals, may be favored . On the other hand, highly concentrated phenol aqueous solutions treatment by the photo-Fenton reaction gives rise to the formation of polyphenolic polymers . These seem to reduce the process rate . Degradation intermediates have been identified by HPLC and FTIR . The FTIR study of the catalyst surface has shown infrared bands attributable to different chemisorbed peroxo-compounds, formates, ortho-formates and carboxylates that can inactivate the catalyst. Water Sci Technol, 2001, 44(5), 187 - 95 Photocatalytic thin film cascade reactor for treatment of organic compounds in wastewater; Chan AH et al.; The photocatalytic oxidation of benzoic acid was investigated in a pilot scale-cascade photoreactor . The photoreactor consists of an array of UV lamps (40 W, 365 nm) illuminating a cascade of three inclined 316 stainless steel plates, on which titanium dioxide (TiO2) was immobilized by electrophoretic deposition . The percentage removal of total organic carbon (TOC) of liquid samples was determined . The photocatalytic process was affected by several operating parameters . Increasing the solution temperature was found to reduce the dissolved oxygen (DO) level and to decrease the rate of the degradation process . The Langmuir-Hinshelwood equation was found to be accurate for modeling the degradation of benzoic acid with initial concentrations of 50 ppm, 75 ppm and 100 ppm . The rate of removal of TOC was positively affected by UV light intensity, but appeared to be independent of solution flowrate in the range examined . Control experiments confirmed that the effects of adsorption of the solute onto the TiO2 catalysts and photolytic degradation were negligible. Water Sci Technol, 2001, 44(5), 15 - 21 Investigation of the reaction pathway of OH radicals produced by Fenton oxidation in the conditions of wastewater treatment; Yoon J et al.; Abstract Fenton reaction has been often used to treat industrial wastewater or landfill leachate . However, most mechanistic research into the Fenton reaction has been confined to low concentration conditions (usually the concentration of iron is less than 1 mM) . These conditions are removed from the circumstances of real application . This is especially true in the treatment of landfill leachate in Korea . Therefore, we investigated the characteristics of the Fenton system using high concentrations of iron (mostly {Fe2+} = 1 approximately 10 mM, {H2O2} = 5 mM, {Organic (t-BuOH or methanol)} = 0 or 30 mM) and interpreted the results from the known reaction mechanisms of the Fenton system . As a result, the use of high ferrous ion (> or = 1 mM) is believed to be appropriate for producing large quantities of OH . within a short period of time, causing fast consumption of hydrogen peroxide . However, OH . scavenging by the ferrous ion, the changes of oxidation products due to the oxygen depleted conditions, and the precipitation effect of ferric ion must be considered for the successful application of Fenton reaction . On the other hand, in low ferrous ion (<1 mM), it is important to utilize the redox cycles of iron in an effective manner. Water Sci Technol, 2001, 44(5), 145 - 52 Combination of coagulation and catalytic wet oxidation for the treatment of pulp and paper mill effluents; Verenich et al.; Wet oxidation (WO) is a well established process for purification of concentrated municipal and industrial wastewaters . Many attempts have been made to modify the WO process or to create a suitable combination of processes . This work was undertaken to investigate wet oxidation integrated with coagulation, i.e . to treat the sludge remaining after coagulation with a WO process . The possibility of regeneration of the used coagulant was also considered . Two waters from paper mills were used: TMP (thermomechanical pulp) circulation water and membrane concentrate . About 50% of the COD in the original water can be removed by coagulation using Fe2(SO4)3 . The results from the wet oxidation experiments show the positive effect of iron in the chemical sludge as a catalyst . The efficiency of the WO process was enhanced almost by 100% . The remaining dissolved organic matter can be easily removed biologically. Water Sci Technol, 2001, 44(5), 139 - 44 Ethers as pollutants in groundwater: the role of reaction parameters during the aquasonolysis; Lifka J et al.; Abstract Methyl tertiary butyl ether (MTBE) is one of the most used fuel oxygenates . Oxygenates improve combustion, thereby reducing CO and hydrocarbon emissions in motor vehicle exhaust . MTBE is highly soluble in water and poorly sorbed to carbon based substrates such as soil . An important property of MTBE is its poor biodegradability . The treatment of contaminated groundwater and wastewater by means of conventional biological, chemical and physical techniques turned out to be inefficient . As a matter of principle the degradation of organic compounds by ultrasound in water (aquasonolysis) is practicable as an advanced technology for remediation of waters contaminated with MTBE . The degradation reactions mainly occur in the cavitation bubbles as pyrolytical processes . Under the test conditions, the frequency range between 300 and 800 kHz leads to acceptable degradation values at a power density of 5 W/cm2 . The degradation was not suppressed by radical scavenger (n-butanol) . With concentrations above 25 mg/L MTBE in water, significantly influence of concentration on degradation could be observed. Water Sci Technol, 2001, 44(5), 131 - 8 Mechanism of radiation purification of polluted water and wastewater; Pikaev AK; The paper summarizes the results of the studies on radiation purification of polluted water and wastewater conducted in the author's laboratory in cooperation with other institutions . The removal of heavy metals (cadmium, lead, chromium and mercury) from water and wastewater, the purification of wastewater from surfactant and petroleum products, molasses distillery slops, municipal wastewater in the aerosol flow, river water from colored natural organic pollutants, wastewater of dyeing complex and paper mill, the decomposition of some dyes, hydrogen peroxide, chlorine-containing organic compounds, formic acid, etc . were investigated in detail . As a rule, electron-beam treatment in combination with ordinary methods (biological, coagulation, adsorption, flotation, etc.) was used . The main attention is paid to the mechanism of purification of the studied systems . The role of redox reactions of primary products of water radiolysis and secondary short-lived species formed from pollutants, formation of precipitates capturing the pollutants etc . is discussed. Water Sci Technol, 2001, 44(5), 117 - 23 On the need for engineering models of integrated chemical and biological oxidation of wastewaters; Ollis DF; Experimental examples of sequential chemical and biological oxidation treatment have been previously reviewed by Scott and Ollis, and economic estimates proposed by Esplugas and Ollis . Despite the prevalence of examples evident in these reviews and in recent conferences, very little use of kinetic models to codify and rationalize results on complex or simulated wastewaters has appeared . In consequence, models are not widely available nor have they yet received widespread acceptance as a method of analysis and reporting . To ameliorate this situation we here report a summary of important kinetic behaviors characteristic of individual chemical and biological kinetics, and provide experimental examples from recent works which illustrate the utility of such simple kinetic forms to construct two step treatment engineering models for complex wastewater and waters. Water Sci Technol, 2001, 44(5), 109 - 16 The role of chemical oxidation in combined chemical-physical and biological processes: experiences of industrial wastewater treatment; Bertanza G et al.; In this work, some experiences are described concerning the application of chemical oxidation in the treatment of industrial wastewaters in combination with other chemical-physical and/or biological processes . In the first case, two different wastewaters from saturated and unsaturated polyester resin production were considered . In a second case, optimal process conditions were assessed for the treatment of a wastewater deriving from polystyrene production . A third experience dealt with a comparison among different processes (flocculation, Fenton process, ozonisation, oxidation by means of ozone and hydrogen peroxide, oxidation by means of hydrogen peroxide and UV radiation), for the pretreatment of two industrial wastewaters (the first one being produced in a textile factory, the second one coming from detergent manufacturing) . The evaluation of different processes was carried out by means of laboratory scale tests, considering treatment efficiency (organic substance removal, changes in wastewater biodegradability) and parameters (chemicals and energy consumption, sludge production) which play an important role in cost determination. J Environ Monit, 2001 Oct, 3(5), 548 - 51 Destruction of helminth eggs by photosensitized porphyrin; Alouini Z et al.; Tunisian untreated wastewater exhibits an average of 30 human helminth eggs per litre . After treatment, the concentration decreases to one egg per litre, or more in some cases . The percentage removal cited for wastewater processes provides no real indication of the destruction of the organisms, but merely of their transfer to another medium . In this study, we report the use of an environmentally friendly photoactive compound for wastewater disinfection . Photosensitization involves the generation of very toxic short-lived species on absorption of light by porphyrin . Microorganism photosensitization is potentially useful for sterilization and for the treatment of certain bacterial diseases . Gram-positive bacteria can be photoinactivated by a range of photosensitizers, but Gram-negative bacteria are not usually susceptible to photosensitized destruction . Our findings clearly demonstrate that the cationic meso-substituted porphyrin, tetra-(4-N-methylpyridyl) porphin tetra-tosylate (T4MPYP), is an efficient photosensitizer of helminth eggs on visible light illumination . The microscopic observation of helminth eggs shows that many types of ultrastructural alterations are potentially associated with exposure to T4MPYP and an adequate intensity of light: morphological changes without breakage; small alterations of eggshells; complete destruction . The degree of egg alteration increases with both increasing T4MPYP concentration and irradiation time . Moreover, the dissolved oxygen concentration, water quality and the type of eggs can influence the sensitivity of helminth eggs to photosensitization . Indeed, suspended solids (turbidity) were the most influential solution parameter on the efficiency of the photochemical process. Parassitologia, 2000 Dec, 42(3-4), 205 - 9 Giardia and Cryptosporidium in water: evaluation of two concentration methods and occurrence in wastewater; Brandonisio O et al.; Giardia and Cryptosporidium are important agents of water-borne parasitic diseases . In this work we have examined the recovery efficiency of two methods for concentrating Giardia cysts and Cryptosporidium oocysts from water: a membrane filtration method and a crossflow filtration method . Results demonstrated a higher recovery efficiency for crossflow filtration method in comparison to the membrane filtration method . In addition, Giardia cysts and Cryptosporidium oocysts concentration was evaluated in wastewater samples submitted to chemical flocculation or chemical flocculation followed by slow sand filtration . Results showed that slow sand filtration was capable of reducing the number of Giardia cysts, but not of Cryptosporidium oocysts in wastewater. J Chromatogr A, 2001 Sep 28, 930(1-2), 119 - 25 On-line microdialysis-high-performance liquid chromatographic determination of aniline and 2-chloroaniline in polymer industrial wastewater; Jen JF et al.; Determination of aniline and 2-chloroaniline in polymer industrial wastewater was examined using high-performance liquid chromatography with on-line microdialysis . After dilution, aniline and 2-chloroaniline in the sample were diffused through a cellular dialysis membrane into the perfusion stream under controlled conditions . Conditions for obtaining optimum dialysis efficiency such as flow-rate and polarity modifier in the perfusion stream, pH and added salt in the sample solution, as well as chromatographic conditions were investigated . The results indicate that the dialysis achieved at a sample matrix pH value of 9.5 with 0.1 M NaCl addition, and the perfusate at 10-microl/min flow-rate offered optimum dialysis efficiency . The aniline and 2-chloroaniline were well separated in an acceptable time on a reversed-phase C18 column eluted with 40% aqueous methanol solution at pH 7.0 and 1.0 ml/min flow-rate . The proposed method provided a very simple procedure to determine aniline and 2-chloroaniline in wastewater . Application was illustrated by the analysis of aniline and 2-chloroaniline in wastewater released from a polymer factory. Chemosphere, 2001 Nov, 45(4-5), 625 - 34 Effects of sludge-amendment on mineralization of pyrene and microorganisms in sludge and soil; Klinge C et al.; Hydrophobic contaminants sorb to sludge in wastewater treatment plants and enter the soil environment when the sludge is applied to agricultural fields . The mineralization of pyrene was examined in soil, in sludge mixed homogeneously into soil, and in sludge-soil systems containing a lump of sludge . Sludge-amendment enhanced the mineralization of pyrene in the soil compared to soil without sludge, and the most extensive mineralization was observed when the sludge was kept in a lump . The number of protozoa, heterotrophic bacteria and pyrene-mineralizing bacteria was much higher in the sludge compared to the soil . The amendment of sludge did not affect the number of protozoa and bacteria in the surrounding soil, which indicated that organic contaminants in the sludge had a little effect on the number of protozoa and bacteria in the surrounding soil. Biosens Bioelectron, 2001 Dec, 16(9-12), 661 - 6 A multi-channel continuous toxicity monitoring system using recombinant bioluminescent bacteria for classification of toxicity; Gu MB et al.; A multi-channel system for continuous toxicity monitoring and classification of toxicity was developed based upon a previously developed two-stage minibioreactor system . The multi-channel system consists of a series of a two-stage minibioreactor systems connected by a fiber optic probe to a luminometer . Each channel was used for cultivating different recombinant bacterial strains, such as TV1061 (grpE::luxCDABE), DPD2794 (recA::luxCDABE), and DPD2540 (fabA::luxCDABE), which are induced by protein-, DNA-, and cell membrane damaging-agents, respectively . GC2 (lac::luxCDABE) is a bacterium expressing bioluminescence constitutively, which shows a reduction in its light level as cellular toxicity increases . Artificial wastewater samples were made by combining toxic chemicals, including Mitomycin C (a representative DNA damaging agent), phenol (a representative protein damaging agent), and cerulenin (a representative cell membrane damaging agent), and injecting this sample into each channel in order to simulate the detection of toxicity for mixed chemical samples . Each channel showed a specific bioluminescent response due to the toxic chemicals contained in the sample wastewater, while GC2 showed a general response to cellular toxicity . By using this multi-channel continuous toxicity monitoring system, classification of toxicity in field samples was found to be possible. Life Support Biosph Sci, 2000, 7(3), 273 - 82 Artificial biospheres as a model for global ecology on planet Earth; Allen J; Artificial biospheres of the scale and complexity of Biosphere 2 can only work with coordinated rigorous design at each level of ecology: biospheres, biomes, bioregions, ecosystems, communities, patches, phases, physical-chemical functions, guilds, populations, organisms, and cells (both eucaryotic and procaryotic) . This article reviews these theoretical concepts and provides examples of how this structure was applied to the design and development of Biosphere 2 . In addition to this ecological engineering design, the addition of humans as inhabitants in the closed system required design of ethnological patterns and of technical and cybernetic systems for meeting specifically human requirements of labor efficiency, climate, nutrition, wastewater recycle, and pure air and water . Ecological levels of biospheric complexity can be directly applied to studies of the Earth's biosphere and, in fact, must be used to understand complex biospheric processes. Life Support Biosph Sci, 2000, 7(3), 251 - 61 Toward a reverse osmosis membrane system for recycling space mission wastewater; Lee S et al.; Essential to extended human exploration and utilization of space is providing a clean supply of potable water as well as water for washing . Recycling of space mission wastewater is necessary for long-term space missions due to the limited capacity of water storage . In this study, initial measurements toward a wastewater reclamation system that provides a clean water supply using reverse osmosis (RO) membranes have been made using stirred cell filtration experiments . Low-pressure reverse osmosis (LPRO) membranes were used to obtain high flux of permeate as well as high rejection . Detergent removal was above 99%, and dissolved salt removal was above 90% in single-pass treatment, while total organic carbon (TOC) removal was nearly 80% . Most problematic is nitrogen rejection, which was 74% at best . Comparison of feed water before and after urea hydrolysis shows that the rejection of nitrogen compounds can be increased to 95% by allowing urea hydrolysis to occur . The removal efficiency for nitrogen compounds was also improved by increasing the shear rate near membrane surface . As a result, the product water in two passes could meet the hygiene water requirements for human space missions, and the product water in three passes could meet potable water regulations with overall recovery of 77% . This study also suggests that dynamic rotating membrane filtration, which can produce a high shear rate, will be useful to increase the system recovery as well as pollutant rejection . Grant numbers: NAG9-1053 Environ Sci Technol, 2001 Oct 1, 35(19), 3869 - 76 Nature and chlorine reactivity of organic constituents from reclaimed water in groundwater, Los Angeles County, California; Leenheer JA et al.; The nature and chlorine reactivity of organic constituents in reclaimed water (tertiary-treated municipal wastewater) before, during, and after recharge into groundwater at the Montebello Forebay in Los Angeles County, CA, was the focus of this study . Dissolved organic matter (DOM) in reclaimed water from this site is primarily a mixture of aromatic sulfonates from anionic surfactant degradation, N-acetyl amino sugars and proteins from bacterial activity, and natural fulvic acid, whereas DOM from native groundwaters in the aquifer to which reclaimed water was recharged consists of natural fulvic acids . The hydrophilic neutral N-acetyl amino sugars that constitute 40% of the DOM in reclaimed water are removed during the first 3 m of vertical infiltration in the recharge basin . Groundwater age dating with 3H and 3He isotopes, and determinations of organic and inorganic C isotopes, enabled clear differentiation of recent recharged water from older native groundwater . Phenol structures in natural fulvic acids in DOM isolated from groundwater produced significant trihalomethanes (THM) and total organic halogen (TOX) yields upon chlorination, and these structures also were responsible for the enhanced SUVA and specific fluorescence characteristics relative to DOM in reclaimed water . Aromatic sulfonates and fulvic acids in reclaimed water DOM produced minimal THM and TOX yields. Res Microbiol, 2001 Sep, 152(7), 621 - 30 Trends in the use of protozoa in the assessment of wastewater treatment; Nicolau A et al.; Increasing environmental pollution and the continuous development of new chemicals and drugs has led to ever growing concern about the potential effects of these compounds directly or indirectly on human health . As concerns water pollution, protozoa seem to be an excellent tool to assess both toxicity and pollution: they are regarded as biological indicators of pollution when their presence or absence can be related to particular environmental conditions, and they are considered test organisms when a species or population is used to evaluate the toxicity of relevant toxic compounds . Thus, an integrated approach is being developed to assess how toxic compounds affect the different biological levels of organisation--from the community level to the species level--of ciliated protozoa . The present paper reports and discusses the current state of the art of this approach. Appl Microbiol Biotechnol, 2001 Sep, 56(5-6), 809 - 15 Development of a rapid pH-based biosensor to monitor and control the hygienic quality of reclaimed domestic wastewater; Dewettinck T et al.; The re-use of treated domestic wastewater necessitates a rigorous control and rapid monitoring of the hygienic quality of the reclaimed water . For this purpose, a new pH-based biosensor was developed . The essence of the methodology of the sensor is the monitoring of the acidification due to bacterial metabolism of added glucose . To improve the sensitivity, the alkalinity of the water sample is reduced prior to monitoring the acidification . This is done by stripping CO2 at a neutral or acidic pH value . The hygienic aspect of the sensor lies in the applied temperature (37 degrees C) and the use of N2 as decarbonizing gas, thus creating conditions favorable for enteric bacteria . The developed sensor could be used onsite at an advanced stage of treatment, as an endpoint or intake quality control device . For both applications, a useful correlation was obtained between log total plate count and lag time or acidification rate, respectively . Absolute detection limits lay in the ranges of either 10(3) colony-forming units (CFU)/ml in 6 h (endpoint quality control), or less than 10(5) CFU/ml in 1 h (intake quality control). J Memb Sci, 2001 Feb, 182(1-2), 77 - 90 Reverse osmosis filtration for space mission wastewater: membrane properties and operating conditions; Lee S et al.; Reverse osmosis (RO) is a compact process that has potential for the removal of ionic and organic pollutants for recycling space mission wastewater . Seven candidate RO membranes were compared using a batch stirred cell to determine the membrane flux and the solute rejection for synthetic space mission wastewaters . Even though the urea molecule is larger than ions such as Na+, Cl-, and NH4+, the rejection of urea is lower . This indicates that the chemical interaction between solutes and the membrane is more important than the size exclusion effect . Low pressure reverse osmosis (LPRO) membranes appear to be most desirable because of their high permeate flux and rejection . Solute rejection is dependent on the shear rate, indicating the importance of concentration polarization . A simple transport model based on the solution-diffusion model incorporating concentration polarization is used to interpret the experimental results and predict rejection over a range of operating conditions . Grant numbers: NAG 9-1053. J Environ Sci (China), 2001 Jul, 13(3), 365 - 7 Cleaning method of the oil field wastewater treatment by UF process; Wang JR et al.; This article introduces experiments and researches of polysulphone ultrafiltration membrane's effect on oil field polluted water and approaches renewing oil field polluted water and approaches renewing of membrane's flux by different detergents and cleaning method . Good result has been achieved by doing experiments and the renewal rate of membrane is over 90%. J Environ Sci (China), 2001 Apr, 13(2), 237 - 46 Effect and mechanism of coking residual ammonia water treating by flue gas; Cheng ZJ et al.; The treatment of coking residual ammonia water has been a big difficult problem at home and abroad, and there is no breakthrough research achievement in the past . The invention patent "The method of treating all coking wastewater or treating coking residual ammonia water by flue gas" has been successfully used in Huaian Steel Works for high concentration and organic industry wastewater treatment . Not only can it realize the wastewater zero discharge, but also the wastewater treatment has an effect of de-sulfur and de-nitrogen for flue gas . So that the flue gas exhaust can meet the requirement of emission standard . The mass transfer and heat transfer, fly ash absorption and coagulation, acid and alkali neutralization reaction, catalysis oxidation and reduction reaction in flue gas would be the major factors. J Environ Sci (China), 2001 Apr, 13(2), 198 - 200 A new technology for harnessing the dye polluted water and dye collection in a chemical factory; Pu JP et al.; A new technology for harnessing the dye polluted water and dye collection was developed . It is based on the enhanced evaporation by using solar, wind and air temperature energy and additional heat-electric energy . It consists of four parts: (1) evaporation carrier system (evaporation carrier and frame for evaporation carrier) for polluted water; (2) polluted water circulating system (pumping-spraying-collecting); (3) heating system; (4) workshop with polluted water reservoir-tanks and rainfall prevention roof . The polluted water was (heated in case necessary) sprayed to the evaporation carrier system and the water was evaporated when it moved in the space and downward along the carrier mainly by using natural (solar, wind and air temperature energy) . In case, when there is no roof for the carrier system, the polluted water can be stored in the reservoirs (storage volume for about 20 days) . The first 10-25 mm rainfall also need to be stored in the reservoirs to meet the state standard for discharging wastewater . The dye may be collected at the surface in the reservoir-tanks and the crystallized salt may be collected at the bottom plate . The black-color wastewater released by the factory is no more discharged to the surface water system of Taihu Lake Basin . About 2 kg dye and 200 kg industrial salt may be collected from each tone of the polluted water . The non-pollution production of dye may be realized by using this technology with environmental, economical and social benefits. Sci Total Environ, 2001 Sep 28, 277(1-3), 87 - 94 Catalyzed UV oxidation of organic pollutants in biologically treated wastewater effluents; Wang GS et al.; A batch reactor was used to evaluate the efficiency of advanced oxidation process of the organic pollutants in biologically treated wastewater effluents with UV/H2O2 . A 450-W high-pressure mercury vapor lamp was used as the light source . During the degradation process, the concentration of the dissolved organic compounds could be increased by more than twofold due to the decomposition of microorganisms . This increase of the dissolved organic compounds was eliminated if the water was filtered before the photodegradation experiments . It is observed that the UV alone could play a role for the oxidation of the organic pollutants; however, the addition of a small amount of hydrogen peroxide promotes the degradation efficiency of organic compounds in wastewater . The best oxidation efficiency was obtained when the water samples were under acidic conditions (pH 5), and the rate of degradation was not enhanced with the increasing H2O2 dosages . The optimum H2O2 dose was between 0.01% and 0.1% for the oxidation processes in this study . The presence of the carbonate/bicarbonate ions in water inhibits the degradation of the organic compounds. J Contam Hydrol, 2001 Oct, 51(3-4), 163 - 78 Transport and fate of organic wastes in groundwater at the Stringfellow hazardous waste disposal site, southern California; Leenheer JA et al.; In January 1999, wastewater influent and effluent from the pretreatment plant at the Stringfellow hazardous waste disposal site were sampled along with groundwater at six locations along the groundwater contaminant plume . The objectives of this sampling and study were to identify at the compound class level the unidentified 40-60% of wastewater organic contaminants, and to determine what organic compound classes were being removed by the wastewater pretreatment plant, and what organic compound classes persisted during subsurface waste migration . The unidentified organic wastes are primarily chlorinated aromatic sulfonic acids derived from wastes from DDT manufacture . Trace amounts of EDTA and NTA organic complexing agents were discovered along with carboxylate metabolites of the common alkylphenolpolyethoxylate plasticizers and nonionic surfactants . The wastewater pretreatment plant removed most of the aromatic chlorinated sulfonic acids that have hydrophobic neutral properties, but the p-chlorobenzene-sulfonic acid which is the primary waste constituent passed through the pretreatment plant and was discharged in the treated wastewaters transported to an industrial sewer . During migration in groundwater, p-chlorobenzenesulfonic acid is removed by natural remediation processes . Wastewater organic contaminants have decreased 3- to 45-fold in the groundwater from 1985 to 1999 as a result of site remediation and natural remediation processes . The chlorinated aromatic sulfonic acids with hydrophobic neutral properties persist and have migrated into groundwater that underlies the adjacent residential community. Biodegradation, 2000, 11(6), 401 - 5 Anaerobic treatability and biogas production potential studies of different agro-industrial wastewaters in Turkey; Demirer GN et al.; The anaerobic treatability and methane generation potential of the wastewaters of the three important agro-industries in Turkey, namely, cheese-making, poultry breeding and the olive-oil mill industries were studied . Biochemical methane potential (BMP) experiments were conducted for different initial chemical oxygen demand (COD) concentrations . The results indicate that anaerobic treatment was possible for all the wastewaters studied and the biogas produced had a high methane content. Environ Pollut, 2001, 115(1), 97 - 106 Evidence of coprostanol estrogenicity to the freshwater mussel Elliptio complanata; Gagne F et al.; Coprostanol (5 beta (H)-cholestan-3 beta ol) is a reduced metabolite of cholesterol produced by micro-organisms found in the intestinal tract of mammals . This substance abounds in urban effluents and is accumulated by organisms living in the vicinity of municipal effluent outfalls . In an earlier study, freshwater mussels exposed to contaminated river water for 62 days accumulated large quantities of coprostanol (Cop) in their soft tissues (16 micrograms/g dry wt.) . Moreover, these mussels were found to have elevated levels of vitellin in their hemolymphs, suggesting estrogenic effects . Although municipal wastewaters are known to contain other estrogenic compounds capable of inducing Vn synthesis in mussels, the estrogenic potential of coprostanol was singled out for examination . To this end, mussels were first injected with concentrations of coprostanol via the abductor muscle route, and allowed to stand in aerated water for 72 h at 15 degrees C . The levels of Vn in mussel hemolymph were assayed using the organic alkali-labile phosphate method . A competitive estradiol-binding assay was then devised to measure the ability of coprostanol to compete in the binding of fluorescein-labeled estradiol-albumin to cytosolic proteins . Coprostanol partially reversed the binding of labeled estradiol-albumin to cytosolic proteins with an EC50 of 1 mM . In addition, injections of coprostanol and estradiol-17 beta led to increased levels of vitellins in the hemolymph of treated mussels . Moreover, incubation of cop in gonad homogenate extracts in the presence of NADPH led to the formation of two compounds, as determined by high-performance thin-layer chromatography . One of these compounds appears to be the C17 oxidation product of coprostanol, whose polarity is similar to that of estradiol . The results present evidence that coprostanol is estrogenic to freshwater mussels. J Med Entomol, 2001 Sep, 38(5), 760 - 2 Failure of a permethrin treatment regime to protect cattle against bluetongue virus; Mullens BA et al.; Holstein heifers in a confined feedlot setting on a southern California dairy were either sprayed individually along the ventral midline using 0.2% permethrin (250 ml/animal) (two pens) or were not treated (two pens) . Treatments (n = 6 dates) were applied every 2 wk during the peak fall bluetongue virus transmission season (22 August-29 October) . Animals seronegative for bluetongue virus antibodies at the initial bleeding on 15-18 September (n - 106 in the treatment pens and n = 117 in the control pens) were bled again for testing 2 mo later (12-13 November) . Seroconversion rates were not significantly different: 56% for the treated animals and 48% for the controls (P > 0.2) . The area has many essentially contiguous, confinement dairies with wastewater ponds that produce large numbers of Culicoides sonorensis Wirth & Jones, the primary bluetongue virus vector . Further, these dairies presumably provided a large reservoir of virus-infected cattle to infect vectors in the immediate area . Under these severe virus challenge conditions, permethrin applied at 2-wk intervals failed to reduce exposure to bluetongue virus. Water Sci Technol, 2001, 44(4), 23 - 31 Psychrophilic one- and two-step systems for pre-treatment of winery waste water; Kalyuzhnyi SV et al.; The operation performance of a single and two (in series) laboratory UASB reactors (working volume of 2.7 l, recycle ratio varied from 1:1 to 1:18) treating diluted wine vinasse was investigated under psychrophilic conditions (4-10 degrees C) . For a single UASB reactor seeded with granular sludge, the average organic loading rates (OLR) applied were 4.7, 3.7 and 1.7 g COD/l/d (hydraulic retention times (HRTs) were around 1 d) at 9-11, 6-7 and 4-5 degrees C, respectively . The average total COD removal for preacidified vinasse wastewater was around 60% for all the temperature regimes tested . For two UASB reactors in series, the average total COD removal for treatment of non-preacidified wastewater exceeded 70% (the average OLRs for a whole system were 2.2, 1.8 and 1.3 g COD/l/d under HRTs of 2 days at 10, 7 and 4 degrees C, respectively) . In situ determinations of kinetic sludge characteristics (Vm and Km) revealed the existence of substantial mass-transfer limitations for the soluble substrates inside the reactor sludge bed . Therefore an application of higher recycle rations is essential for enhancement of UASB pre-treatment under psychrophilic conditions . The produced anaerobic effluents were shown to be efficiently post-treated aerobically--final effluent COD concentrations were around 0.1 g/l. J Environ Qual, 2001 Sep-Oct, 30(5), 1710 - 9 Trace element removal from coal ash leachate by a 10-year-old constructed wetland; Ye ZH et al.; This study investigated the ability of a 10-yr-old constructed wetland to treat metal-contaminated leachate emanating from a coal ash pile at the Widows Creek electric utility, Alabama (USA) . The two vegetated cells, which were dominated by cattail (Typha latifolia L.) and soft rush (Juncus effusus L.), were very effective at removing Fe and Cd from the wastewater, but less efficient for Zn, S, B, and Mn . The concentrations were decreased by up to 99% for Fe, 91% for Cd, 63% for Zn, 61% for S, 58% for Mn, and 50% for B . Higher pH levels (>6) in standing water substantially improved the removing efficiency of the wetland for Mn only . The belowground tissues of both cattail and soft rush had high concentrations of all elements; only for Mn, however, did the concentration in the shoots exceed those in the belowground tissues . The concentrations of trace elements in fallen litter were higher than in the living shoots, but lower than in the belowground tissues . The trace element accumulation in the plants accounted for less than 2.5% of the annual loading of each trace element into the wetland . The sediments were the primary sinks for the elements removed from the wastewater . Except for Mn, the concentrations of trace elements in the upper layer (0-5 cm) of the sediment profile tended to be higher than the lower layers (5-10 and 10-15 cm) . We conclude that constructed wetlands are still able to efficiently remove metals in the long term (i.e.,>10 yr after construction). J Environ Qual, 2001 Sep-Oct, 30(5), 1528 - 32 Biosolids applications affect runoff water quality following forest fire; Meyer VF et al.; Soil erosion and nutrient losses are great concerns following forest wildfires . Biosolids application might enhance revegetation efforts while reducing soil erodibility . Consequently, we applied Denver Metro Wastewater District composted biosolids at rates of 0, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to increase plant cover and growth . Soils were classified as Ustorthents, Ustochrepts, and Haploborols . Simulated rainfall was applied for 30 min at a rate of 100 mm h(-1) to 3- x 10-m paired plots . Biosolids application rates did not significantly affect mean total runoff (p < 0.05) . Sediment concentrations were significantly greater (p < 0.05) from the control plots compared with the plots that had received the 80 Mg biosolids ha(-1) rate . Biosolids application rate had mixed effects on water-quality constituents; however, concentrations of all runoff constituents for all treatment rates were below levels recommended for drinking water standards, except Pb . Biosolids application to this site increased plant cover, which should provide erosion control. J Air Waste Manag Assoc, 2001 Sep, 51(9), 1351 - 8 Removal of hydrocarbons from wastewater using treated bark; Haussard M et al.; This paper explores the possibility of removing hydrocarbons (HCs) and trace elements from synthetic and industrial effluents using treated bark as biosorbent . Coniferous bark was treated either chemically (Tc) or biologically (Tb) to eliminate soluble organic compounds of bark . The removal efficiency (RE) of the HCs from a synthetic oil-water mixture containing spent diesel motor oil exceeds 95% using 2 g/L of treated bark mixed with a synthetic oil-water mixture containing 2 g/L of spent oil . Under these conditions, the retention capacity (RC) was approximately 1 g HC/g dry substrate . The sorption reaction seems to be quasi-instantaneous, and the retention capacity of spent oil on treated bark increases as the temperature augments . This implies that the retention mechanism is related to the capillary action . Results of Fourier transform infrared (FTIR) spectroscopy indicate that spent oil is mainly composed of alkanes . They also suggest that no chemical bonds between Tc and spent oil were established . Measurement of the surface tension of spent oil and the wetting index of the bark suggests that only spent oil will be retained by the substrate . Treatment of an industrial effluent containing 14.4 g/L of total HCs was performed using Tc . It was possible to remove 97% of HCs and retain some trace elements such as Al, Ca, Fe, Mg, S, and so on. Anal Chem, 2001 Sep 15, 73(18), 4522 - 9 Organic chloramine analysis and free chlorine quantification by electrospray and atmospheric pressure chemical ionization tandem mass spectrometry; Takats Z et al.; Atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI), together with tandem mass spectrometry (MSn), are used to study the mechanism of chlorination of amines and to develop a method for qualitative and quantitative determination of organic chloramines . Cyclohexylamine and 1,4-butanediamine (putrescine) are used as model compounds to investigate the mechanisms of the reactions between primary aliphatic amines and hypochlorous acid (aqueous Cl2) . The chlorination products are identified and characterized by collision-induced dissociation (CID) and H/D exchange . Chlorination occurs by electrophilic addition of Cl+ and may be followed by HCl elimination, hydrolysis, or, in the case of diamines, amine elimination by intramolecular nucleophilic substitution . The relative rates of chlorination at amine and chloramine nitrogens are a function of pH and depend on the basicity of the amine . A novel method for active chlorine quantification using ESI or APCI mass spectrometry is suggested on the basis of the extent of chlorination of a sacrifical amine standard . This measurement has a limit of detection for N-chlorocyclohexylamine in the range of 0.1-10 microM, a linear dynamic range of 10(2)-10(3), and an accuracy of +/-10%, as determined for wastewater samples. Water Sci Technol, 2001, 44(4), 83 - 8 The use of upflow anaerobic sludge blanket reactors in the treatment of poultry slaughterhouse wastewater; Del Nery V et al.; This work studied the performance of the dissolved air flotation (DAF) system and the start-up and the operation of two 450 m3 UASB reactors in a poultry slaughterhouse in Sorocaba, Brazil . The DAF presented reduction efficiency of grease and fats, suspended solids and COD 50% higher . The reactors were seeded with non-adapted sludge . The average COD of the reactor influent was 2,695 mg/L; and the initial organic loading rate (OLR) and the initial sludge loading rate at the start-up were 0.51 kg COD/m3.day and 0.04 kg COD/kg VTS.day, respectively . The start-up period was 144 days . During this time the reactor flow rate and OLR were gradually increased . At the reactor start-up, the maximum OLR value was 2.1 kg COD/m3.day, the COD reduction was higher than 80%, and the concentration of volatile fatty acids (VFA) was below 100 mg/L . The COD reductions, considering the reactor effluent raw COD and soluble COD were similar throughout the period studied in both reactors . The reactor effluent raw COD was approximately 10% higher than the soluble COD until the 225th day of operation . From the 225th day of operation this value increased 20%-30% due to the sludge washout . The effluent soluble COD reduction, the effluent VFA concentration and the operational stability attested the good performance of UASB reactors in poultry slaughterhouse wastewater treatment. Water Sci Technol, 2001, 44(4), 7 - 14 Influence of HRT (hydraulic retention time) and SRT (solid retention time) on the hydrolytic pre-treatment of urban wastewater; Ligero P et al.; This work presents the results obtained from a study on the pretreatment of urban wastewater using a digester that acted as a system for the retention of solids (sedimentation-filtration), hydrolysis of the retained solids and acidification of the dissolved substances . After start-up (Phase I), the digester was operated at hydraulic retention times (HRT) of 4.4, 3.4 and 2.2 h and at solid retention times (SRT) of 24, 16 and 14 d, during Phases II, III and IV, respectively . The retention and removal of suspended solids (SS) was maintained slightly above 60%, independently of HRT and SRT . Conversely, eliminated chemical oxygen demand (COD) decreased slightly upon reducing HRT and SRT . The influence of these two parameters on the generation of volatile fatty acids (VFA) is more notable, reaching effluent VFA concentration of 29 (Phase II), 96 (Phase III), and 107 (Phase IV) mg COD/I . VFA to SS generation ratios were 0.13 (II), 0.35 (III), and 0.48 (IV) g VFACOD/g SS added . Optimum values were reached at an HRT of 2.2 h . Taking 100 kg influent COD as a base, the conversion of different kinds of COD was as follows (in kg influent: kg effluent): VFACOD(4:17), non-VFA soluble COD (45:23), VSSCOD (51:23) . Simultaneously to these conversions, 2 kg VSSCOD are generated as purge stream and 35 kg COD are eliminated during the process. Water Sci Technol, 2001, 44(4), 57 - 62 Blanket development in a malting wastewater anerobic treatment; Martinez J et al.; A 3 m3 pilot UASB reactor was operated with malting wastewater . In order to find the aggregation characteristics, the sludge concentration profile was determined throughout time . Reactor behaviour concerning the physical properties of the sludge can be evaluated using this procedure . Moreover, organic load per VSS can be calculated from this profile . The organic load based per VSS is more accurate as a design parameter than the volumetric load . Under the study conditions imposed the COD removal efficiencies achieved were about 85% . Organic loads of 0.6-0.7 kg COD/(kgVSS.d) were reached . After operating at 30 degrees C, temperatures of 28 degrees C and 15 degrees C were tested, showing no decrease in COD removal efficiency . At week 15 the presence of granules was verified, and after that, sludge concentrations of 30-35 kg VSS/m3 were measured at the bottom of the reactor . The SVI of the granular sludge decreased to values below 20 mL/gVSS . The settlement velocity was 10 m/h, which is much greater than the recommended values for the settlement zone; therefore, no problems are to be expected in the settler regarding the sludge sedimentation . The biomass yield coefficient obtained was 0.10 gVSS/gCOD in agreement with literature values for brewering effluent. Water Sci Technol, 2001, 44(4), 41 - 7 An integrated anaerobic--physico-chemical treatment concept for wool scouring wastewater; Pelaez H et al.; The strong flow wastewater from a wool scouring industry is treated by a combination of anaerobic digestion and physico-chemical postreatment . Based on previous laboratory results (Gutierrez et al., 1999), three anaerobic baffled reactors (ABR) of 300 m3 each were built, processing 60% of the strong flow of a wool scouring mill for about two years . COD and grease removal in the anaerobic reactors were 47-50% and 50-55% respectively, with an organic load between 8.9 and 6.7 kg COD/m3 d . The effluent of the anaerobic reactors was assayed with additives in an industrial decanter centrifuge . As results of these assays, all the effluent of the three reactors was sent to the decanter centrifuge after dosing additives . Overall COD and grease removal of the integrated system were 87% and 93% respectively . Dosage of coagulation-flocculation additives was optimized in a continuous flocculation device . The proposed treatment is cheaper and easier to control than others alternatives with COD removal higher than 93%. Water Sci Technol, 2001, 44(4), 305 - 12 Influence of agitation rate on the performance of a stirred anaerobic sequencing batch reactor containing immobilized biomass; Ratusznei SM et al.; The present work reports on the influence of the mechanical agitation rates on the performance of a stirred anaerobic sequencing batch reactor containing immobilized biomass on polyurethane foam, as inert support, treating synthetic domestic wastewater . The reactor was operated at 30 degrees C and an 8-hour cycle was used to treat approximately 0.5 L of the synthetic substrate with a COD concentration of nearly 500 mg/L . The studied agitation rates ranged from no agitation to 750 rpm . The system attained non-filtered substrate removal efficiency greater than 83% when agitation was employed . A very short start-up period and good solid retention could be observed . The use of agitation increased the efficiency of the reactor and enabled reduction of the total cycle time . An empirical equation and a first-order kinetic model are proposed to analyze the influence of agitation rates on the reactor's performance. Water Sci Technol, 2001, 44(4), 205 - 12 Flotation technique with coagulant and polymer application applied to the post-treatment of effluents from anaerobic reactor treating sewage; Reali AP et al.; This paper presents the results of a study performed with a lab-scale batch DAF unit fed with previously coagulated (with FeCl3 and/or cationic polymer) effluent from a pilot-scale expanded bed anaerobic reactor treating domestic sewage . The association between ferric chloride and polymers was studied, aimed at sludge reduction . Ferric chloride dosages ranging from 15 to 65 mg.l-1, and polymer dosages from 0.25 to 7.0 mg.l-1 were investigated . Flocculation conditions were kept constant: 20 min of time (Tf) and 80 s-1 of mean velocity gradient (Gf) . Air requirement was kept to 19.0 g of air.m-3 wastewater, using 20% recycle ratio and saturation pressure at 450 kPa . When the anaerobic reactor was operating at steady state conditions, it was possible to reduce the FeCl3 dosage from 65 to 30 mg.l-1 after applying 0.4 mg.l-1 of non-ionic polymer, before the DAF process . For these dosages, 79% COD removal (residual of 23 mg.l-1), 86% total phosphate removal (residual of 0.9 mg.l-1) and 98% turbidity removal (residual of 2.6 NTU) were observed . Furthermore, the use of adequate polymer together with 30 mgFeCl3.l-1 leads to the production of high rising rate flocs. Chemosphere, 2001 Oct, 45(1), 85 - 90 Kinetic model for phenolic compound oxidation by Fenton's reagent; De Heredia JB et al.; A kinetic model is developed for the oxidation of phenolic compounds by Fenton's reagent . In the first stage a rigorous kinetic model is applied to calculate the different kinetic rate constants for the oxidation process of p-hydroxybenzoic acid . In a second phase a competitive method is applied to calculate these kinetic constants for another 10 phenolic compounds present in agroindustrial and pulp paper wastewaters . These 10 phenolic compounds were: beta-resorcylic acid, 3-(4-hydroxyphenyl)-propionic acid, ferulic acid, protocatechuic acid, caffeic acid, p-coumaric acid, vanillic acid, syringic acid, veratric acid and 3,4,5-trimethoxybenzoic acid. Chemosphere, 2001 Oct, 45(1), 77 - 83 Solar photocatalytic decolorization of methylene blue in water; Kuo WS et al.; In this study, a photocatalytic decolorization system equipped with immobilized TiO2 and illuminated by solar light was used to remove the color of wastewater . To examine the decoloring efficiency of this system, photocatalytic decolorization of an organic dye such as methylene blue was studied as an example . The effects of light source, pH, as well as the initial concentration of dye were also investigated . It was observed that the solution of methylene blue could be almost completely decolorized by the solar light/TiO2 film process while there was about 50% color remaining with solar irradiation only . In addition, it was found that the decoloring efficiency of solution was higher with solar light irradiation than with artificial UV light irradiation, even though the artificial UV light source supplied higher UV intensity at 254 nm . The color removal rate of methylene blue with solar light irradiation was almost twice that of artificial UV light irradiation . This phenomena was mainly attributed to that some visible light range of solar light was useful for exciting the methylene blue molecules adsorbed on TiO2 film, leading to a photosensitization process undergoing and decoloring efficiency promoted . This solar-assisted photocatalytic device showed potential application for decoloring organic dyes in wastewater. J Chromatogr A, 2001 Aug 24, 927(1-2), 103 - 10 Routine analysis of alcohol and nonylphenol polyethoxylates in wastewater and sludge using liquid chromatography-electrospray mass spectrometry; Cohen A et al.; A wide range of alcohol and nonylphenol polyethoxylates was determined by separation on a reversed-phase liquid chromatographic column, followed by electrospray ionisation-mass spectral analysis . The compounds were separated chromatographically according to their aliphatic chain length . The mass spectral analysis functioned as a second separation step during which homologues of the ethoxylates were separated according to their polyethoxylate chain length . In this manner a truly orthogonal separation was obtained . The compounds were detected as ammonium complexes . The analysis presented is capable of qualitative and quantitative determination of a large number of ethoxylates as well as their metabolites in a single run . The method was applied to many different sample types, ranging from primary and treated wastewater to sludge . Batches of 50 real samples were routinely analysed without the need for cleaning the mass spectrometer or regeneration of the column . By utilising the extracted mass chromatograms, detection limits of 1 to 10 microg/l could be obtained for individual compounds in water samples, while the detection limits were around 100 microg/kg in sludge, depending on the degree of pollution. Huan Jing Ke Xue, 2001 Jul, 22(4), 42 - 5 {Bioaccumulation mechanism of red tide alga Prorocentrum micans for heavy metal ions}; Zhao L et al.; Pollution of heavy metal from industrial wastewater is a worldwide environmental problem . Biosorption is an effective technology for the treatment of low concentration industrial wastewater . The purpose of this study was to evaluate the heavy metal uptake capacities of the biomass of marine red tide Prorocentrum micans . All red tide biomass used in this study were obtained from cultivation in our lab . Batch experimental results showed that living and non-living biomass of P . micans killed by CH2O were similar setting property for Cu2+, Pb2+, Ni2+, Zn2+, Ag+ and Cd2+ . This study indicated that biomass of P . micans has a high capacities for above six heavy metal and the kinetics under the conditions studied were relatively fast . About 90% of the biosorption occurred within 10 min and an equilibrium was reached in 30 min . The Biosorption capacities for heavy metal ions were strongly dependent on pH of the solution, and higher capacities were obtained at pH around 5 and higher . Bonding and FIR of P . micans polysaccharide obtained by the hot water method for Cu2+, Pb2+, Ni2+, Zn2+, Ag+ and Cd2+ was also studied . The study indicated that -OH and -CONH2 groups were active center of biosorption. Huan Jing Ke Xue, 2001 Jul, 22(4), 37 - 41 {Degradation of methamidophos by Saccharomyces rouxii WY-3}; Liu B et al.; A strain of Yeast WY-3 was isolated from wastewater sample . It is capable of utilizing methamidophos as sole nitrogen and phosphorus sources, and also capable of utilizing methylamine, ethylamine and ammonium sulfate as nitrogen sources except nitrate and hydroxylamine . The yeast could grow in medinm containing 60% glucose and was identified as Saccharomyces rouxii WY-3 . The strain contains a high active acid phosphatase . The crude enzyme was applied to a plate of polyacrylanide gel for electrophoresis, then activity was detected as white single band . Inhibiting test showed that sodium fluoride could seriously inhibit the activity of acid phosphatase to release phosphorus from methamidophos, wherease it make no effect on deamination of the strain WY-3 from methamidophos . After methamidophos was degraded by strain WY-3, toxity of the pesiticide reduced obviously, and its portion intermediate, methanol and inorganic phosphorus, were deteted. Huan Jing Ke Xue, 2001 Jul, 22(4), 117 - 9 {Removing the nitrogen from the ammonium sulfite method paper mill wastewater by anoxic/aerobic SBR}; Sun J et al.; The experiment results showed that the best technology of removing the nitrogen was anoxic time to aerobic time of 1:1.5, a cycle of 8 hours; the SRT should be more than 12 d and the loading of NH3-N should be less than 0.063 g/(g.d); when the concentration of CODCr, NH3-N and NOx-N was 1200-1800 mg/L, 135-200 mg/L and 7-10 mg/L respectively, without external carbon sources, the removal rate of NH3-N and TN could respectively achieve 95% and 66%; after adding sodium acetate the removal rate of TN could get to 85% . The addition of sodium acetate at the concentration equivalent to theoretical CODCr values of 125 mg/L appeared to be the most economical and reliable option. Toxicol In Vitro, 2001 Aug-Oct, 15(4-5), 531 - 7 Effect of linear alkylbenzene sulfonate (LAS) on ion transport and intracellular calcium in kidney distal epithelial cells (A6); Bjerregaard HF et al.; Linear alkylbenzene sulfonate (LAS) is found in near-shore environments receiving wastewater from urban treatment plants in a concentration reported to have physiological and toxic effect on aquatic organisms . The aim of this study was to investigate the effect LAS on ion transport and homeostasis in epithelia cells . A6 cells form a polarised epithelium when grown on permeable supports, actively absorb sodium and secrete chloride . Only the addition of LAS (100 microM) to the apical solution of A6 epithelia resulted in an increase in the active ion transport measured as short circuit current (SCC) and transepithelial conductance (G(t)) . This increase could not be affected by the sodium channel inhibitor amiloride (100 microM), indicating that LAS stimulated the chloride secretion . Change in the intracellular calcium concentration (Ca(2+))(i) was measured in fura-2 loaded A6 cells, since it known that increase in (Ca(2+))(i) stimulate chloride secretion . LAS induced a concentration-dependent increase in (Ca(2+))(i) from 5 to 200 microM, where the half-maximal stimulating concentration on 100 mM resulted in an increase in (Ca(2+))(i) from 108+/-15 to 570+/-26 nM (n=4; P<0.01) . The increase in (Ca(2+))(i) could be blocked by the calcium chelator ethylenebis(5-oxyethylenenitrilo)tetraacetic acid (EGTA), showing that the effect of LAS was due to influx of extracellular calcium . Furthermore, it was shown that the calcium channel inhibitor verapamil (0.2 mM) abolished the LAS induced increase in (Ca(2+))(i) and Gt when applied to the apical solution . However, verapamil has no inhibitory effect on these parameters when the non-ionic detergent Triton X-100 (100 microM) was added to A6 cells . These results indicate that LAS induced a specific activation of calcium channels in the apical membrane of A6 epithelia, leading to increase in (Ca(2+))(i) and thereby increased chloride secretion as a result of stimulation of calcium-dependent chloride channels in the apical membrane . The change in ion homeostasis is thought to be the fundamental reason to the physiological and toxic effects induced by LAS in marine organism. J Hazard Mater, 2001 Oct 12, 87(1-3), 273 - 87 Removal of chromium from water and wastewater by ion exchange resins; Rengaraj S et al.; Removal of chromium from water and wastewater is obligatory in order to avoid water pollution . Batch shaking adsorption experiments were carried out to evaluate the performance of IRN77 and SKN1 cation exchange resins in the removal of chromium from aqueous solutions . The percentage removal of chromium was examined by varying experimental conditions viz., dosage of adsorbent, pH of the solution and contact time . It was found that more than 95% removal was achieved under optimal conditions . The adsorption capacity (k) for chromium calculated from the Freundlich adsorption isotherm was found to be 35.38 and 46.34 mg/g for IRN77 and SKN1 resins, respectively . The adsorption of chromium on these cation exchange resins follows the first-order reversible kinetics . The ion exchange resins investigated in this study showed reversible uptake of chromium and, thus, have good application potential for the removal/recovery of chromium from aqueous solutions. J Hazard Mater, 2001 Oct 12, 87(1-3), 199 - 212 Non-passivating polymeric structures in electrochemical conversion of phenol in the presence of NaCl; Zareie MH et al.; The formation of non-passivating polymeric structures was investigated during electrochemical conversion of phenol using carbon electrodes and NaCl as electrolyte . The influence of initial phenol concentration, current density and reaction temperature on phenol conversion and polymer morphology was studied by FTIR and STM, while the fate of intermediate compounds was analyzed by GC/MS . Unlike previous work, non-passivating solid polymer was produced at high voltage and current density values in the presence of NaCl . The most orderly polymer formed at 912 mg l(-1) initial phenol concentration, current density 32.9 mA cm(-2), NaCl concentration 120 g l(-1) and temperature 25 degrees C . Higher operational parameters yielded disorderly formed aggregates of the polymer in decreasing surface density on STM images . Along with the polymer, only toxic mono-, di- and tri-chlorophenols were formed as intermediate compounds during the electrochemical conversion, which eventually were polymerized and/or oxidized to final products . FTIR analysis and enlarged STM image implied the repeating phenol units in the polymer structure . The results may lead to appropriate techniques for the removal of phenol from wastewater in the form of a solid polymer. J Hazard Mater, 2001 Oct 12, 87(1-3), 127 - 37 Removal and recovery of heavy metals from electroplating wastewater by using Kyanite as an adsorbent; Ajmal M et al.; Kyanite, a commercial mineral has been utilized as an adsorbent for the removal of heavy metals, such as Ni(II), Zn(II), Cr(VI) and Cu(II) from electroplating wastewater . The effect of contact time, pH, concentration, adsorbent doses, particle size of the adsorbent, salinity and hardness, both in natural and wastewater on the adsorption of Cu(II) have been studied in detail . The adsorption of metal ions seems to be an ion exchange process . The adsorbed metals ions from electroplating wastewater were recovered by batch as well as column operation using dilute HCl solution . The column operation was found to be more effective compared to batch process. J Hazard Mater, 2001 Oct 12, 87(1-3), 73 - 98 Development of adsorptive removal process for treatment of explosives contaminated wastewater using activated carbon; Rajagopal C et al.; The adsorption characteristics of nitro-organics such as trinitro-toluene (TNT), dinitro-toluene (DNT) and nitrobenzene (NB) on granular activated carbon (GAC) were studied to understand their dynamic adsorption behaviour for dilute aqueous solutions . A model was developed to predict the dynamics of the adsorption process and the effect of various design and operating parameters on adsorption characteristics . The model predictions would provide inputs to design of bench scale and pilot plant scale experiments.Section 2 of the paper describes the assumptions, predictions, development of the model and its validation with experimental data generated during bench scale and pilot plant trials . Section 3 presents the breakthrough characteristics obtained by conducting experimental runs for GAC of different surface areas from 650 to 1500 m(2)/g, hydraulic loading rates (HLR) ranging between 12 and 24 m(3)/h/m(2), feed concentrations from 50 to 130 mg/l and bed heights between 300 and 1000 mm for TNT, DNT and NB solutions . The effect of these independent parameters on the breakthrough time, adsorption capacity and the minimum concentration achieved in the effluent was studied and the results obtained are presented in this paper . These indicate that the adsorption capacity goes though a maximum when studied as a function of HLR and feed concentration . The adsorption capacity per unit surface area also shows a maximum around 1000 m(2)/g . The minimum bed height required for meeting environmental effluent discharge limit of 1 ppm was experimentally found to be about 800 mm . These results compare well with the predictions based on the model developed for column adsorption process . Data from these experimental runs and the model predictions have been used to optimise various parameters for the design of a pilot plant unit with 200 l per hour capacity. Bioresour Technol, 2001 Nov, 80(2), 121 - 9 Entrapment of white-rot fungus Trametes versicolor in Ca-alginate beads: preparation and biosorption kinetic analysis for cadmium removal from an aqueous solution; Arica MY et al.; The biosorption of cadmium ions onto entrapped Trametes versicolor mycelia has been studied in a batch system . The maximum experimental biosorption capacities for entrapped live and dead fungal mycelia of T . versicolor were found as 102.3 +/- 3.2 mg Cd(II) g(-1) and 120.6 +/- 3.8 mg Cd(II) g(-1), respectively . Biosorption equilibrium was established in about 1 h and biosorption was well described by the Langmuir and Freundlich biosorption isotherms . The change in the biosorption capacity with time was found to fit the pseudo-second-order equation . Since the biosorption capacities were relatively high for both entrapped live and dead forms, those fungal forms could be considered as suitable biosorbents for the removal of cadmium in wastewater-treatment systems . The biosorbents were reused in three consecutive adsorption/desorption cycles without a significant loss in the biosorption capacity. Environ Sci Technol, 2001 Sep 1, 35(17), 3584 - 8 A dynamic study and modeling of the formation of polyhydroxyalkanoates combined with treatment of high strength wastewater; Yu J et al.; Production of biodegradable thermoplastics, polyhydroxyalkanoates (PHAs), from organic wastes may provide multiple benefits to environmental conservation efforts . In this study, microfiltration-coupled reactors were set up to study the dynamic behavior of a typical PHA-producing bacteria, Ralstonia eutropha, fed with a real acidic solution from starch acidogenesis in a continuous flow system . The majorfermentation acids (butyric and acetic acids) were utilized by the PHA producers at a high conversion rate (>95%) when the cells were suspended in a small volume of mineral solution (pH 7), but at a low conversion rate (<10%) when the cells were suspended in an acidic solution (pH 4) . The acids were consumed mainly for PHA synthesis and maintenance energy, which resulted in slow growth of PHA-producing cells and a washout of the cells in the continuous flow system . PHAs, however, were continuously synthesized and accumulated during the washout . A simple dynamic model is proposed for estimation of specific growth rates and PHA formation rates during the washout at two hydraulic retention times (HRT) or dilution rates . The net specific growth rate of PHA-producing cells was near zero at a hydraulic retention time (HRT) of around 30 h, but it increased to 0.01 h(-1) when the HRT was reduced to 18 h . The model also reveals that PHA was synthesized faster based on the active biomass (ABM) during the short HRT (10.3 mg PHA/g ABM.h) than during the long HRT (3.4 mg PHA/g ABM.h). Water Environ Res, 2001 Mar-Apr, 73(2), 233 - 6 Particle effects on ultraviolet disinfection of coliform bacteria in recycled water; Jolis D et al.; Pilot- and bench-scale coliform inactivation tests with UV irradiation were used to show how suspended solids remaining in filtered secondary effluent affect the efficiency of the UV disinfection process . Observed kinetic inactivation rates decreased with increasing suspended particle sizes of 7 microm or larger present in tertiary effluent . First-order inactivation rates estimated from collimated beam dose-response curves for discrete ranges of UV doses were substantially different, which should caution researchers not to compare inactivation data obtained with largely dissimilar UV doses or suspended particle distributions . A dose of approximately 800 J/m2 was identified as the minimum dose that will consistently meet the California wastewater reclamation coliform criterion when applied to in-line filtration effluent. Water Environ Res, 2001 Mar-Apr, 73(2), 165 - 72 Enzyme-catalyzed removal of phenol from refinery wastewater: feasibility studies; Ibrahim MS et al.; Phenols are present in petroleum refining wastewater . An enzymatic method for removing phenols from industrial aqueous effluent has been developed in the past several years . In this method, a peroxidase enzyme catalyzes the oxidation of phenol by hydrogen peroxide generation of phenoxyl radicals . These radicals diffuse from the active center of the enzyme into solution and react nonenzymatically to eventually form higher oligomers and polymers, which can be removed from wastewater by conventional coagulation and sedimentation or filtration . In this study, Arthromyces ramosus peroxidase (ARP) was applied to treat a petroleum refining wastewater containing 2 mM (188 mg/L) phenol in a batch and continuous-flow system . The latter consisted of a plug-flow reactor (PFR) where the reaction took place between phenol and hydrogen peroxide catalyzed by the enzyme in the presence of polyethylene glycol (PEG) . A flocculation tank followed the PFR where alum and sodium hydroxide were added and then the polymers formed were settled in a sedimentation tank and removed from the system . Most (95 to 99%) of the phenol was removed by the same dose of ARP required for the treatment of synthetic wastewater containing an equal amount of phenol . Polyethylene glycol, as an additive, reduced enzyme inactivation and consequently reduced the enzyme dose and the cost of the treatment process . Step feeding of hydrogen peroxide was not effective in reducing the enzyme requirement . A significant removal of chemical oxygen demand was achieved when using PEG to reduce the enzyme dose. Environ Technol, 2001 Aug, 22(8), 979 - 90 Treatment of alloy-electroplating wastewater by an automated solvent extraction technique; Sze YK et al.; Electroplating with highly toxic metals is being gradually replaced by alloy or mixed-metal electroplating . We developed a solvent extraction method for the treatment of waste rinsewater generated in Zn-Co alloy electroplating, based on the studies of the extraction properties . An alkyl ester of an alkylphosphonic acid (PC-88A) or a dialky phosphinic acid (Cyanex 272) was used as the extractant . The two metals were co-extracted into the organic solvent and then separately recovered in a simple process . The feasibility of the process was demonstrated with automated mixer-settler solvent extraction units. Water Res, 2001 Oct, 35(15), 3754 - 7 Effect of age on the susceptibility of zebrafish eggs to industrial wastewater; Gellert G et al.; Toxic effects of 40% (v/v) and 60% (v/v) concentrations of wastewater from the industrial sector of chemical production on eggs of the zebrafish (Danio rerio) were investigated . Significant poisonous effects could be registered in test solutions containing 40% wastewater for eggs up to 0.5 h of age . Solutions containing 60% wastewater affected the mortality of the exposed eggs up to 1 h of age . Earlier stages were more sensitive to industrial wastewater than later stages . The differences in susceptibility must be ascribed to the ontogenetic stage of the eggs at which the experiment was started and to differences in the chorion permeability . The chorion is less permeable after hardening and works as a barrier to detrimental wastewater contents . This circumstance explains the higher viability of zebrafish eggs at the age of > 1 h . When using early stages of the zebrafish for ecological risk estimations, the eggs should, at best, not exceed the age of 0.5 h. Water Res, 2001 Oct, 35(15), 3697 - 705 Acidification of mid- and high-strength dairy wastewaters; Yu HQ et al.; Batch and continuous experiments were conducted to study the influence of dairy wastewater strength (2-30g-COD/L) on acidification at pH 5.5 and 37 degrees C . Results of batch experiments showed that carbohydrate was preferentially acidified as compared to protein and lipid . Production of VFAs (mainly acetate, propionate and butyrate) and hydrogen corresponded to carbohydrate acidification, whereas production of alcohols (mainly ethanol, propanol and butanol), plus i-butyrate and higher molecular-weight VFAs, corresponded to protein acidification . In treating high-strength wastewaters (8-30 g-COD/ L), acetate, butyrate and P(H2) decreased after reaching their peak levels before leveling off . Results of continuous experiments with 12h of hydraulic retention showed that acidification decreased with the increase of wastewater COD, from 57.1% at 2 g-COD/L to 28.8% at 30 g-COD/L; among the constituents in dairy wastewater, 92-99% of carbohydrates, 59-85% of protein and 12-42% of lipid were acidified . High-strength wastewater favored production of hydrogen and alcohols, especially propanol and butanol . The biomass yield was 0.258g-VSS/g-COD. Water Res, 2001 Oct, 35(15), 3679 - 87 Origin and distribution of polyaromatic hydrocarbons and polychlorobiphenyls in urban effluents to wastewater treatment plants of the Paris area (France); Blanchard M et al.; Polyaromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs), were investigated in urban effluents to wastewater treatment plants in the Paris area (France), under different meteorological conditions . The Acheres plant was considered with special attention because of its particular features . Wastewater PAH concentration level was 6 fold higher than that of PCBs . In March, PCB concentrations did not vary whatever the meteorological conditions whereas, for PAHs, they were markedly higher during rainy episodes . In September, concentrations of both pollutants increased due to rainy weather . The rise was 30 fold stronger for PAHs . Daily fluxes displayed the same trends . This suggests that the contribution of atmospheric wet deposition to wastewater contamination prevails for PCBs . In contrast, PAHs appeared to originate mainly from urban runoff processes. Water Res, 2001 Oct, 35(15), 3665 - 9 Purification of oily wastewater by hybrid UF/MD; Gryta M et al.; Investigations on the treatment of oily wastewater by a combination of ultrafiltration (UF) and membrane distillation (MD) as a final purification method have been performed . A tubular UF module equipped with polyvinylidene fluoride (PVDF) membranes and a capillary MD module with polypropylene membranes were tested using a typical bilge water collected from a harbour without pretreatment . The permeate obtained from the UF process generally contains less than 5 ppm of oil . A further purification of the UF permeate by membrane distillation results in a complete removal of oil from wastewater and a very high reduction of the total organic carbon (99.5%) and total dissolved solids (99.9%). Water Res, 2001 Oct, 35(15), 3649 - 55 Aqueous leaching properties and environmental implications of cadmium, lead and zinc trimercaptotriazine (TMT) compounds; Matlock MM et al.; 2,4,6-Trimercaptotriazine, trisodium salt nonahydrate (TMT-55) is a commercial product that is widely used to chemically precipitate cadmium, lead, zinc and other heavy metals from wastewaters and contaminated natural waters . When mixed with aqueous solutions of TMT-55, aqueous solutions of either reagent-grade zinc, cadmium, or lead salts precipitate crystalline "Zn-TMT", amorphous or crystalline "Cd-TMT" or amorphous "Pb-TMT" (M3{S3C3N3}2.nH2O, where M=Cd2+, Pb2+, and Zn2+ and n> or = 0) that may eventually crystallize if stored in air . Laboratory aqueous leaching studies over 78-106 days using pH 3 HCl, distilled water (pH 6) and pH 9-10 NaOH evaluated the stability of the Cd-, Pb-, and Zn-TMT precipitates . Under pH 3 conditions, the amorphous Cd- and Pb-TMT compounds converted to their crystalline forms and amorphous Cd-TMT also crystallized in distilled water . Otherwise, no decomposition products were detected in the leached solid residues . When compared with the aqueous solubilities of corresponding sulfides and most hydroxides, the TMT compounds were significantly more soluble in distilled water and pH 3 HCl. Water Res, 2001 Oct, 35(15), 3579 - 86 Optimal decolorization and kinetic modeling of synthetic dyes by Pseudomonas strains; Yu J et al.; Pseudomonas spp were isolated from an anaerobic-aerobic dyeing house wastewater treatment facility as the most active azo-dye degraders . Decolorization of azo dyes and non-azo dyes including anthraquinone, metal complex and indigo was compared with individual strains and a bacterial consortium consisting of the individual strain and municipal sludge (50 50wt) . The consortium showed a significant improvement on decolorization of two recalcitrant non-azo dyes, but little effect on the dyes that the individual strains could degrade to a great or moderate extent . Decolorization of Acid violet 7 (monoazo) by a Pseudomonas strain GM3 was studied in detail under various conditions . The optimum decolorization activity was observed in a narrow pH range (7-8), a narrow temperature range (35-40 degrees C), and at the presence of organic and ammonium nitrogen . Nitrate had a severe inhibitory effect on azo dye decolorization: 10 mg/L led to 50% drop in decolorization activity and 1000 mg/L to complete activity depression . A kinetic model is established giving the dependence of decolorization rate on cell mass concentration (first-order) and dye concentration (half order) . The rate increased with temperature from 10 to 35 C, which can be predicted by Arrhenius equation with the activation energy of 16.87 kcal/mol and the frequency factor of 1.49 x 10(11) (mg L)1/2/g DCM min. Water Environ Res, 2001 May-Jun, 73(3), 374 - 82 A biological phosphorus removal potential test for wastewaters; Park JK et al.; A simple test was proposed to assess whether phosphorus in a wastewater can be removed using a biological phosphorus removal (BPR) process . The test includes the measurement of phosphorus release during 2 hours of the anaerobic stage in a batch reactor containing phosphorus-accumulating organisms (PAOs) and estimation of the effluent phosphorus concentration using biochemical relationships . The BPR potential test developed allowed for the successful evaluation of BPR feasibility for five wastewater samples . The BPR potential test was validated by comparing the test results with the effluent phosphorus concentrations measured in a sequencing batch reactor (SBR) . An effluent phosphorus concentration of 1.9 mg P/L predicted for the BPR potential test performed was close to the effluent phosphorus concentration of 1.8 mg P/L obtained from an SBR on the same day . During the anaerobic stage, phosphorus release was significantly affected by the sludge concentration initially, but became insignificant after 2 hours . The initial sludge concentration affected the phosphorus release rate; thus, it is recommended that the BPR potential test be conducted at a target mixed liquor volatile suspended solids concentration . It is also recommended that the BPR potential test be conducted at the site where the PAO-containing sludge is available and the wastewater sample can be delivered at 4 degrees C in less than 24 hours . The PAOs in different sludges had almost identical phosphorus release after 2 hours; however, the characteristics of facultative bacteria in sludges affected the phosphorus release . If the wastewater is prefermented for at least 3 days before the BPR potential test, the amount of phosphorus released by various PAO-containing sludges is expected to be identical. Water Environ Res, 2001 May-Jun, 73(3), 363 - 7 Wastewater dewatering polymer affect on biosolids odor emissions and microbial activity; Rosenfeld PE et al.; Odor emissions and microbial activity associated with biosolids dewatered using seven different polyacrylamide cationic polymers were investigated . Nitrogen, sulfur, ketone, and odor unit emissions, and biosolids microbial community metabolic profiles were measured for biosolids containing each polymer . Ammonia represented more than 98% of total nitrogen flux for all polymers, with small concentrations of trimethyl amine . Dimethyl disulfide and carbon disulfide fluxes summed represented 87 to 97% of the sulfur flux for all polymers, with lesser quantities of dimethyl sulfide . Maximum dimethyl disulfide, ammonia, and trimethyl amine concentrations were estimated to be 3.4, 3.2, and 13.5 times greater than published detection limits, respectively . Maximum dimethyl sulfide, carbon disulfide, acetone, and methyl ethyl ketone concentrations were estimated to be 0.028, 0.007, 0.002, and 0.0006 times less than published detection limits, respectively . All treatments were found to volatilize equal odor unit emissions (with the exception of one polymer), and polymers were not found to dramatically affect odor emission from biosolids application . Metabolic fingerprints revealed differences in the ability of microbial communities from certain polymer treatments to degrade amino acids as a sole carbon substrate . In addition, odor unit emissions were significantly correlated with potential for amino acid decomposition. Water Environ Res, 2001 May-Jun, 73(3), 314 - 21 Comparison of temperature-phased and two-phase anaerobic co-digestion of primary sludge and municipal solid waste; Schmit KH et al.; Characterization of the similarities and differences between two-phase and temperature-phased systems treating primary wastewater sludge (PS) and the organic fraction of municipal solid waste (OFMSW) as substrate was performed by comparing the rates of key steps, including hydrolysis and methanogenesis . Aceticlastic methanogenic rates were determined using batch respirometric tests with inocula from operating two-phase and temperature-phased systems . The initial methane production rates ranged from 0.32 to 0.93 mL methane/g volatile solids (VS)h for all systems, with the greatest rates observed from the first stage of the temperature-phased system . Hydrolysis rates were determined from particulate chemical oxygen demand destruction . The first stage of the temperature-phased system had greater specific hydrolysis rates than the first stage of the two-phase system at each operating condition . The temperature-phased system outperformed the two-phase system in terms of methane production and VS destruction when treating a mixed OFMSW-PS stream at OFMSW-to-PS ratios of 0:100, 20:80, and 40:60 . When the feed ratios were 60:40 and 80:20 OFMSW-PS, there was no significant difference in the performance of the two systems . The overall methane yield and VS destruction of the temperature-phased system ranged from 0.299 to 0.418 L/g VS fed and 47.5 to 71.6%, respectively . The overall methane yield and VS destruction of the two-phase system ranged from 0.281 to 0.332 L/g VS fed and 39.6 to 69.3%, respectively. Lett Appl Microbiol, 2001 Oct, 33(4), 264 - 8 Growth and production of biomass of Rhodovulum sulfidophilum in sardine processing wastewater; Azad SA et al.; AIMS: Rhodovulum sulfidophilum was grown in sardine processing wastewater to assess growth characteristics for the production of bacterial biomass with simultaneous reduction of chemical oxygen demand . METHODS AND RESULTS: Growth characteristics were compared in diluted and undiluted, settled and non-settled wastewater growing in anaerobic light and aerobic dark conditions; and also at different agitation speeds . The highest biomass (8.75 g l(-1)) and a reduction in chemical oxygen demand of 71% were obtained in unsettled, undiluted wastewater after 120 h culture with 15% inoculum . In settled wastewater, highest biomass (7.64 g l(-1)) and a COD reduction of 77% was also obtained after 120 h . Total biomass was higher (4.34 g l(-1)) after 120 h culture in anaerobic light compared to (3.23 g l(-1)) in aerobic dark growth . CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: Better performance, mean of total biomass (6.97 g l(-1) after 96 h), total carotenoids (4.24 mg g(-1) dry cell from 24 h) and soluble protein (431 microg ml(-1) after 96 h) were obtained from aerobic dark culture at 300 rev min(-1) . The COD reduction, however, was lower (69%) after 96 h culture . Thus, the benefits in the production of bacterial biomass in non-sterilized sardine processing wastewater with the reduction of chemical oxygen demand could be achieved. Water Environ Res, 2001 Jan-Feb, 73(1), 72 - 9 Fate and toxicity of aircraft deicing fluid additives through anaerobic digestion; Gruden CL et al.; Benzotriazole derivatives are widely used corrosion inhibitors and their fate during wastewater treatment processes is unknown . The purpose of this research was to study the toxic effects and fate of the two commercially significant benzotriazole isomers used in aircraft deicing fluids (4-, and 5-, methylbenzotriazole {MeBT}) during anaerobic digestion . Experiments were executed in microcosms using mesophilic anaerobic biomass co-digesting wastewater sludge and propylene glycol . Sorption of MeBT to digesting solids could be approximated with a Freundlich model, and no anaerobic breakdown of either MeBT isomer was detected . Digesters fed more than 300 mg/L MeBT responded with a significant decrease in methanogenic microbial activity and volatile solids production and a concomitant increase in accumulation of volatile fatty acids . Direct microscopic measurements using fluorescent phylogenetic probes applied to digesting biomass revealed that members of both Archaea and Bacteria domains were sensitive to MeBT . Granular activated carbon (GAC) (volatile solids: GAC = 10%) reduced the apparent toxic effects of MeBT; GAC addition nearly restored the baseline activity of digesters fed MeBT (500 to 1000 mg/L). Water Environ Res, 2001 Jan-Feb, 73(1), 63 - 71 Chemical oxygen demand analysis of wastewater using trivalent manganese oxidant with chloride removal by sodium bismuthate pretreatment; Miller DG et al.; Current chemical oxygen demand (COD) analyses generate wastes containing hexavalent and trivalent chromium, mercury, and silver . Waste disposal is difficult, expensive, and poses environmental hazards . A new COD test is proposed that eliminates these metals and shortens analysis time, where trivalent manganese oxidant replaces hexavalent chromium (dichromate) . A silver catalyst is not required . Optional pretreatment removes chloride via oxidation to chlorine using sodium bismuthate, eliminating the need for mercury . Sample aqueous and solid components are separated for chloride removal, then recombined for total COD measurement . Soluble and nonsoluble COD can be determined separately . Digestion at 150 degrees C is complete in 1 hour . Results are determined by titration or by spectrophotometric reading . Test wastes contain none of the metals regulated for disposal under the Resource Conservation and Recovery Act . Results are shown for selected organic compounds and various wastewaters . Statistical comparisons are made with dichromate COD and biochemical oxygen demand (BOD5) test values. Water Environ Res, 2001 Jan-Feb, 73(1), 58 - 62 Oxygen mass-transfer coefficients for different sample containers used in the headspace biochemical oxygen demand test; Logan BE et al.; To accurately measure the oxygen demand of a wastewater sample in a headspace biochemical oxygen demand (HBOD) or other respirometric test, the rate of oxygen transfer to the aqueous phase must be greater than the oxygen exertion rate by the sample . Oxygen mass-transfer coefficients (Kawa) measured for 28-, 55-, and 160-mL, partially full (18 to 89%) containers placed on their sides on a shaker table and mixed at 200 r/min averaged 8.0 h-1 (range 5.4 to 9.9 h-1) . For this mass-transfer coefficient, HBOD values as great as 1340 mg/L.d are possible at the start of an HBOD test, although the maximum daily HBOD declines to 192 mg/L.d at the end of the test because of oxygen depletion in the sample headspace . Mass-transfer coefficients for shaken samples decreased only at low shaking speeds (< 50 r/min) . Oxygen mass-transfer coefficients for shaken samples were always larger than those (average of 1.8 h-1) measured for samples in a 250-mL bottle mixed with a stir bar on a stir plate . These mass-transfer coefficients indicate that the oxygen demand of typical full-strength municipal wastewaters can be measured in HBOD tests without oxygen transfer limiting the reaction rate. Water Environ Res, 2001 Jan-Feb, 73(1), 37 - 44 Lead and zinc removal by laboratory-scale constructed wetlands; Song Y et al.; Constructed wetlands have the potential to trap and remove metals in mine wastewater . To determine the effectiveness of constructed wetlands for treating selected heavy metals in neutral mine effluent typical of lead mines, eight laboratory-scale constructed wetlands were set up to treat a synthetic, slightly alkaline, mine water containing 34.2 mg/L sulfate (SO4(2-)), 50 micrograms/L lead (Pb), and 300 micrograms/L zinc (Zn) . After 45 days, one of the wetlands was switched to treat a synthetic smelter effluent with a much greater load of SO4(2-), sodium (Na+), and Pb . Temperature, hydraulic loading, and substrate composition typically did not affect treatment efficiency . The pH of the effluent was reduced from 8.0 to 8.5 to near neutral . The average removal in the eight wetlands was 90% for Pb and 72% for Zn . In wetlands operating on synthetic mine water, SO4(2-) was completely removed, likely by conversion to sulfide by sulfate-reducing bacteria . In the wetland operating on synthetic smelter effluent, only approximately 25% of 6 g/L influent sulfate was removed, and a breakthrough period of 4 days for Na+ was observed . Whole effluent toxicity assays on undiluted wetland effluent from wetlands treating mine and smelter water had 100% survival of fathead minnows and Daphnia magnia . Survival of Ceriodaphnia dubia was zero in undiluted effluent, but 75 to 100% survival was observed when the effluent was diluted to one-half strength. Bioresour Technol, 2001 Oct, 80(1), 37 - 43 Influence of different natural zeolite concentrations on the anaerobic digestion of piggery waste; Milan Z et al.; The effect of different natural zeolite concentrations on the anaerobic digestion of piggery waste was studied . Natural zeolite doses in the range 0.2-10 g/l of wastewater were used in batch experiments, which were carried out at temperatures between 27 degrees C and 30 degrees C . Total chemical oxygen demand (COD), total and volatile solids, ammonia and organic nitrogen, pH, total volatile fatty acids (TVFA), alkalinity (Alk) and accumulative methane production were determined during 30 days of digestion . The anaerobic digestion process was favored by the addition of natural zeolite at doses between 2 and 4 g/l and increasingly inhibited at doses beyond 6 g/l . A first-order kinetic model of COD removal was used to determine the apparent kinetic constants of the process . The kinetic constant values increased with the zeolite amount up to a concentration of 4 g/l . The values of the maximum accumulative methane production (Gm) increased until zeolite concentrations of 2-4 g/l . The addition of zeolite reduced the values of the TVFA/ Alk ratio while increasing the pH values, and these facts could contribute to the process failure at zeolite doses of 10 g/l. Ann Chim, 2001 Jul-Aug, 91(7-8), 401 - 8 Metal contents in tench otoliths: relationships to the aquatic environment; Adami G et al.; A monitoring of the quality of waters was attempted determining metal accumulation in target organs as otoliths of freshwater fish . Tenchs of age ranging between 2 and 10 years were sampled in three different canals receiving wastewater from industrial, agricultural and urban activities . Metal contents were determined in both lapilli and asterisci otoliths, using inductively coupled plasma-atomic emission spectroscopy (ICP-AES) . Analytical data are reported for minor metals and for some trace metals . Al, Fe and Zn have contents depending on the environment where the fish has lived, while Na, K, Ca and Sr contents are insensitive to the different aquatic habitat . Considering the two types of otolith separately, lapilli display a different affinity for trace metals (Al, Fe and Zn), while in asterisci this affinity is matched only for zinc . The high affinity of zinc for both types of otoliths suggests using this metal for discriminating the fresh waters by checking its accumulation in otoliths, as well as correlating this accumulation with age of the fish: a negative power curve equation is proposed . Since highest concentrations are found in individuals of 2-3 yr., it is advisable to use this fish for such environmental studies. Appl Microbiol Biotechnol, 2001 Aug, 56(3-4), 550 - 4 Mediated microbial biosensor using a novel yeast strain for wastewater BOD measurement; Trosok SP et al.; Two new yeast strains (SPT1 and SPT2) were isolated and immobilized on glassy carbon electrodes to form microbial biosensors for estimation of biochemical oxygen demand (BOD) . Ferricyanide was proven to be the most efficient mediator to shuttle electrons from the redox center of reduced microbial enzymes to the electrode in the presence of excess glucose/glutamic acid (GGA) . With a 3-fold greater metabolic assimilation capability and greater responses to various effluent samples, SPT1 was selected for sensor-BOD measurements . BOD estimations for the GGA standard resulted in an extended linear range: 2-100 mg/l . Response reproducibility was +/-10% for a GGA standard containing 10 mg BOD/l . For analysis of pulp mill effluents, the BOD detection limit was 2 mg/l with a response time of 5 min. Water Sci Technol, 2001, 44(2-3), 9 - 15 A model-based approach to predicting BOD5 in settled sewage; Brydon DA et al.; Rapid, accurate and reliable measurements of BOD are a very desirable basis for monitoring and controlling wastewater treatment works . Unfortunately, however, producing satisfactory measurements using hardware instrumentation has proved difficult . This paper addresses the issue of BOD estimation using a model-based approach . Two models are developed from historical data using neural network methods . The first model estimates the five-day BOD of the settled sewage using flow, solids, chloride and ammonia data and produces accurate predictions . The second model uses only flow and solids data as inputs yet still produces acceptable (although less accurate) predictions . It was concluded from this that satisfactory estimates of five day BOD can be produced using information that is relatively common to most works . The models are straightforward to apply on-line and offer a method of estimating five day BOD in real-time that is likely to be cheaper, more reliable and easier to maintain than hardware instrumentation. Water Sci Technol, 2001, 44(2-3), 85 - 93 International product cost comparison in the field of water management; Bode H et al.; Comparing international costs in the field of water management is difficult . The frame conditions in the various countries are very different . They influence the costs and particularly the sewage charges in a complex way . Some of these conditions are outlined by analyzing the situation in Germany as a "case study" . An objective comparison should deal with the in situ arising product costs as annual costs . The product costs consist of both the operating and the capital costs . The annual product costs of 34 wastewater treatment plants in six different European countries are presented . The observed differences in the quality of the construction and of the mechanical equipment of the plants were taken into account with different depreciation periods . The product costs in four of six countries, including Germany, were found to be nearly at the same level . Although the German frame conditions are demanding and difficult the expectation of outstanding high product costs was not confirmed. Water Sci Technol, 2001, 44(2-3), 57 - 62 Performance of the full-scale biological nutrient removal plant at Noosa in Queensland, Australia: nutrient removal and disinfection; Urbain V et al.; Stringent effluent quality guidelines are progressively implemented in coastal and sensitive areas in Australia . Biological Nutrient Removal (BNR) plants are becoming a standard often including a tertiary treatment for disinfection . The BNR plant in Noosa - Queensland is designed to produce a treated effluent with less than 5 mg/l of BOD5, 5 mg/l of total nitrogen, 1 mg/l of total phosphorus, 5 mg/l of suspended solids and total coliforms of less than 10/100 ml . A flexible multi-stage biological process with a prefermentation stage, followed by sand filtration and UV disinfection was implemented to achieve this level of treatment . Acetic acid is added for phosphorus removal because: i) the volatile fatty acids (VFA) concentration in raw wastewater varies a lot, and ii) the prefermenter had to be turned off due to odor problems on the primary sedimentation tanks . An endogenous anoxic zone was added to the process to further reduce the nitrate concentration . This resulted in some secondary P-release events, a situation that happens when low nitrate and low phosphorus objectives are targeted . Long-term performance data and specific results on nitrogen removal and disinfection are presented in this paper. Water Sci Technol, 2001, 44(2-3), 399 - 407 Chemical characteristics and leachability of organically contaminated heavy metal sludge solidified by silica fume and cement; Jun KS et al.; This paper discusses the development of mixtures with silica fume as a stabilization/solidification agent and binder for industrial wastewater residue containing organic and heavy metal contaminants . The UCS (Unconfined Compressive Strength) gradually increased to 66.7% as the silica fume content increased to 15% . The leaching of TOC and chromium decreased as more OPC was substituted with silica fume . When the mix had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution . Also, microstructural studies on the solidified wastes through the scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contribute to setting, but coated the cement particles and retarded the setting reactions . The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and contaminant leachability. Water Sci Technol, 2001, 44(2-3), 381 - 7 The influence of biosolids treatment files on the mobility of metal trace elements; Maisonnave V et al.; The production of sludge in France is estimated to be about 900,000 metric tons dry matter per year and 60% of this is recycled onto agricultural land . At present, the long term future of this procedure is open to question and among the different arguments being put forward are the levels of metallic trace elements and the risk of accumulation in soils . This study presents the behaviour of metallic trace elements in sludges from three different treatment procedures: thickened liquid sludges, dewatered sludges and dried sludges . These biosolids are mixed with a clay soil and then placed in a temperature and humidity controlled glasshouse . Several containers are seeded with ryegrass and compared with controls . For the three harvests, covering all the amendments studied (including non-amended soil), the differences are not really representative . Absorption by the ryegrass is low in all cases . For the cadmium, the chromium, the nickel and the lead, the roots are 5 to 10 times more concentrated than the leaves . The majority of these elements stay absorbed in the roots, regardless of the amendment used . The addition of the sludges has considerably reduced the uptake of water in ryegrass throughout its growth cycle . Quite apart from their fertilizing qualities, wastewater treatment plant sludges could offer important implications for irrigation. Water Sci Technol, 2001, 44(2-3), 321 - 7 Annual nutrients export modelling by analysis of landuse and topographic information: case of a small Mediterranean catchment; Payraudeau S et al.; The preservation of water bodies from eutrophication implies accurate estimation of phosphorus and nitrogen loads and the control of nutrient production on a catchment scale . In this paper, a simple tool for the modelling of annual nutrient loads is presented . It is implemented in ARC/INFO GIS using Arc Macro Language (AML) . The use of a GIS is justified as the spatial characteristics of the catchment area (land use, industrial wastewater location) dictate water quality . The annual nutrient loads are worked out on the catchment scale, using existing GIS routines together with specific routines developed in AML for hydrological and water quality modelling purposes . The catchment area is divided into hydrological subcatchments with relatively homogeneous spatial characteristics . Each subcatchment is linked to a specific nutrient export potential . These nutrient loads, calculated on a subcatchment-by-subcatchment basis, are conveyed to the outlet of the catchment and allow annual nutrient load estimation . A comparison with a water monitoring study is conducted to verify the adequation of modelling results for phosphorus and nitrogen loads. Water Sci Technol, 2001, 44(2-3), 31 - 8 Planning of wastewater treatment and disposal systems of Istanbul metropolitan area; Eroglu V et al.; Current and future wastewater treatment and disposal strategies of Istanbul city are presented . Istanbul is the largest city of Turkey and has a population of 10 million that may reach about 20 million in 2032 . The city is divided into Asian and European sides by the Bosphorus Strait . The Sea of Marmara is an enclosed sea, connected to the Black Sea and Aegean Sea by the straits of Bosphorus and Dardanelles . Therefore, there is very strong and permanent stratification in the Sea of Marmara throughout the year, lower layers carrying Mediterranean and the upper layers carrying Black Sea water . This unique coastal structure of Istanbul necessitated a detailed study to determine the level of wastewater treatment and the location and depth of marine outfalls . A comprehensive three-dimensional water quality modelling study concluded that tertiary treatment including nitrogen and phosphorus removal is required for the effluent discharges into the Marmara Sea . However, enhanced primary or even primary treatment has been found satisfactory for discharges into the lower layers of the Bosphorus and into the Black Sea . Provisions for upgrading to secondary treatment were recommended . The status of existing and planned wastewater treatment plants and sea outfalls of Istanbul city are also presented . Although the amount of treated wastewater was only 63 percent in 1998, a target of 95 percent treatment level by the end of 2000 has been adopted in implementation plans . All treatment plants are located at or close to the coast except Pasakoy WWTP which is in the catchment area of Omerli Reservoir, the major source of drinking water for Istanbul city . The Pasakoy WWTP has been designed to treat wastewaters collected from the catchment area of Omerli Reservoir to tertiary level before ultimate disposal . The implementation programme together with the cost estimates are given . Total investment on water, wastewater and stormwater projects up to year 2032 is estimated at about 10 billion US Dollars . The share of the wastewater projects in this total is increasing with time . The financial analysis concluded that investments for a Higher Demand Scenario can be realised by raising the water tariffs to 1.0 $/m3 for Phase 1 and 0.9 $/m3 for Phase 2. Water Sci Technol, 2001, 44(2-3), 261 - 8 Use of real time control modelling on the urban sewage system of Nancy; Zug M et al.; Since 1991, European Legislation on the urban treatment of wastewater requires local authorities to take into account the treatment of polluted water transported by the sewerage system and this during dry and wet weather conditions . In the seventies, the urban Community of Grand Nancy constructed storage tanks in its sewerage system in order to prevent flooding and wish today to use them to reduce and control the pollution discharges into the receiving water . This action is a part of a European LIFE project 1996-2000 . The main aim of this project was to assess the effectiveness of reducing pollution of one particular retention basin, the 12,000 m3 Gentilly tank . This one has two operating modes: protection against floods during heavy rain and reduction of pollutant overflows during lighter rain . To assess its effect on the pollutant discharge, the HYDROWORKS DM software and its Real Time Control Module have been used, calibrated and validated . As this study is still in progress, this paper describes the studied site and the modelling results under different weather conditions and shows that the mathematical model can be used to simulate the operation of the catchment area and its associated sewerage system realistically. Water Sci Technol, 2001, 44(2-3), 25 - 30 Environmental accounting--a decision support tool in WWTP operation and management; Clauson-Kaas J et al.; The various emissions to water, air and soil from the municipal wastewater treatment plant of Avedore Wastewater Service Company are accounted for and quantified in terms of the environmental impacts to which they contribute: global warming, acidification, eutrophication, space demand for controlled deposition of residues, as well as persistent toxicity, human toxicity and eco-toxicity . The impacts are expressed on the same scale, namely as fraction of the total per capita loads in a national scenario 1990, also called the person equivalent or PE1990 . This provides a compact and informative overview of the environmental impacts and allows for a holistic prioritisation in the operation and management of the plant . The accounting shows that the resulting emissions per person in the catchment area of the plant correspond to 0.5-5.0% of the average Danish PE1990 for the impacts in question. Water Sci Technol, 2001, 44(2-3), 235 - 41 Predicting the sound power and impact of a wastewater treatment plant; De Heyder B et al.; Several process units at a wastewater treatment plant (WWTP) can produce a significant level of sound and thus induce sound nuisance for nearby residents . The risk for sound nuisance should be considered by making a prognosis of sound impact in an early project phase (planning, design) . A prognosis requires information with respect to the sound characteristics of the different process units . This paper reports the development of empirical models for the sound power of relevant process units in the water line at Aquafin WWTPs . The used methodology for model derivation and validation allowed us to minimize the required number of measurements . Besides the methodology, the paper describes in detail the derivation and validation of the empirical model for the splashing water of screw pumps . Also the use of all the derived empirical models to determine the sound impact of a wastewater treatment plant at close distance is illustrated with a case-study. Water Sci Technol, 2001, 44(2-3), 211 - 8 The effect of acid cleaning on a fine pore ceramic diffuser aeration system; Hung CH et al.; Fine pore ceramic diffuser aeration, a very competitive high efficiency system, is widely used in aerobic biological processes for providing dissolved oxygen and mixing . Concern has been registered regarding the maintenance of these systems and their susceptibility to diffuser fouling . Selected ceramic diffusers, removed from the Madison Metropolitan Sewage District (MMSD) Nine Springs Wastewater Treatment Plant, Wisconsin, U.S.A., were fractured and analyzed in an attempt to identify the elemental components of the internal foulants and to evaluate the effect of acid cleaning on diffuser performance . The fouling condition of diffusers were initially characterized by dynamic wet pressure (DWP) measurements . Microimages taken from the non acid-treated diffuser profile using scanning electronic microscopy revealed the structural difference of internal foulants which may correspond to the stage of foulant formation . For diffuser samples from the MMSD facility, calcium phosphate minerals were predominant foulants, although some calcium carbonate and organic carbon have also accumulated . The clogging of diffuser internal void space was verified by observing thin sections of diffuser cross-sections . Selected diffusers were then treated with strong acid to study its effectiveness in removing internal foulant by acid soaking . Even though the acid treated diffusers showed significant reduced DWP values, acid treatment, the common diffuser cleaning technique, does not completely remove these internal foulants . This may be the reason why the acid-treated diffusers never reached like-new conditions . Furthermore, once these acid-treated diffusers are installed back to the aeration tank, these dewatered foulant sections may very well behave as seed for future clogging. Water Sci Technol, 2001, 44(2-3), 189 - 96 Choice of the sand for sand filters used for secondary treatment of wastewater; Lienard A et al.; In a range from 100 to about 1,000 People Equivalent (PE), Secondary Wastewater Sand Filters (SWSF) are used by a lot of rural communities in France . A series of case studies however point out that several criteria concerning global and detailed design and implementation of these systems have to be approached scientifically, in order to obtain the expected results on a long-term basis . The choice of the sand constituting the infiltration bed, core of the biological reactor, is of course one of the key elements and is the main subject of this article . It must have a sufficient initial permeability in order to ensure an adapted infiltration speed, after colonisation by the purifying biomass . The d10 fines content and degree of uniformity mainly control this permeability . The quarry or the aggregate extractor, who masters his production this way, usually gives these elements, based on granulometric analysis . However the adjustment of an infiltration test with clear water is essential to check on site the conformity of the deliveries. Water Sci Technol, 2001, 44(2-3), 145 - 53 Validation and implementation of model based control strategies at an industrial wastewater treatment plant; Demey D et al.; In this paper, the practical implementation and validation of advanced control strategies, designed using model based techniques, at an industrial wastewater treatment plant is demonstrated . The plant under study is treating the wastewater of a large pharmaceutical production facility . The process characteristics of the wastewater treatment were quantified by means of tracer tests, intensive measurement campaigns and the use of on-line sensors . In parallel, a dynamical model of the complete wastewater plant was developed according to the specific kinetic characteristics of the sludge and the highly varying composition of the industrial wastewater . Based on real-time data and dynamic models, control strategies for the equalisation system, the polymer dosing and phosphorus addition were established . The control strategies are being integrated in the existing SCADA system combining traditional PLC technology with robust PC based control calculations . The use of intelligent control in wastewater treatment offers a wide spectrum of possibilities to upgrade existing plants, to increase the capacity of the plant and to eliminate peaks . This can result in a more stable and secure overall performance and, finally, in cost savings . The use of on-line sensors has a potential not only for monitoring concentrations, but also for manipulating flows and concentrations . This way the performance of the plant can be secured. Water Sci Technol, 2001, 44(2-3), 127 - 34 Using the World Wide Web to revolutionise technology transfer and training in the water and wastewater industries; Lant PA et al.; Industry professionals of the near future will be supported by an IT infrastructure that enables them to complete a task by drawing on resources and people with expertise anywhere in the world, and access to knowledge through specific training programs that address the task requirements . The increasing uptake of new technologies enables information to reach a diverse population and to provide flexible learning environments 24 hours a day, 7 days a week . This paper examines one of the key areas where the World Wide Web will impact on the water and wastewater industries, namely technology transfer and training . The authors will present their experiences of developing online training courses for wastewater industry professionals over the last two years . The perspective is that of two people working at the "coalface". Water Sci Technol, 2001, 44(2-3), 111 - 7 Benchmarking--an approach to efficiency enhancement in planning, construction and operation of wastewater treatment plants; Stemplewski J et al.; In the following paper the technique of benchmarking was transferred to the field of wastewater treatment . The method was developed within a pilot project, in which 4 wastewater treatment plants (WVTP) (size category: 10,000-100,000 p . e.) of the Emschergenossenschaft/Lippeverband and the Aggerverband were involved . Meanwhile this method is applied to more than 100 WWTP . Specific technical and economic parameters were determined for the whole treatment plant and afterwards assigned to the different treatment steps . With these numbers differences between the examined plants and the respective benchmarks were visible . On the basis of the following cause analysis a schedule could be developed containing at first measures, which could be translated into action immediately . The less obvious reasons for differences between individual numbers required a deeper cause analysis . Because of external influences not all the plants can reach the benchmarks. Water Sci Technol, 2001, 44(2-3), 1 - 8 New simulators for the optimum management and operation of wastewater treatment plant; Ayesa E et al.; This paper presents the basic description and the first full-scale implementation of a new kind of simulator specially designed to facilitate and improve the management and operation of modern wastewater treatment plants (WWTP) . This new kind of simulator for plant operation is specifically adapted to every WWTP and the software is developed considering the common needs of the operators in plant exploitation . The internal structure of the plant operation simulator is based on a complete connection between the real data and the mathematical model of the plant . The software is then able to perform the processing, storage and management of the plant data and to predict the evolution of the process reading the required inputs from its stored files . The results obtained with the first application recommend the implementation of this new kind of simulators for plant operation in other treatment plants . However, it is important to note that the application of this technology implies a systematic and rigorous methodology in the acquisition and processing of the most significant plant data. Water Res, 2001 Oct, 35(14), 3457 - 61 Monitoring of organochlorine and organophosphorus pesticides in the water of the Reconquista River (Buenos Aires, Argentina); Rovedatti MF et al.; The Reconquista river is a typical example of the adverse impact of human activity on a watercourse . Approximately 10% of the population of the country is settled on its basin and it receives wastewater discharges from residences and industries . This paper describes the results of the first systematic data for measurement of pesticides in surface water of the river, based on a monthly monitoring program over two-year span . The analyses were performed, in three sampling stations (S1, S2 and S3), along 46 km of its course, following the AOAC methods . Screening included the following pesticides: (a) Organochlorines: alpha, beta and gamma HCH; heptachlor, heptachlor epoxide; aldrin; endrin; dieldrin; op' and pp' DDT; op' and pp' DDE; alpha and gamma chlordane and endosulphan II; (b) Organophosphates: ethyl and methyl parathion; chlorpyrifos and fenitrothion . From the 60 samples analyzed, 35% contained organochlorine pesticides in a concentration higher than the detection limit . Organophosphates were found in no case . Throughout the studied period, DDT and its metabolite DDE were only found in S1 and gamma chlordane in S3; heptachlor was present in 50% of the samples of S2 and in 35% of S3, while HCH isomers were detected in 38% of S2 and 45% of S3 samples . Neither temporal nor spatial trends were found . There was not a relationship between the time of samplings and the fumigation season for farming purposes . At all locations, pesticides levels were found to be between 40 and 400 times higher than the legal limits established for protection of aquatic life. Water Res, 2001 Oct, 35(14), 3418 - 28 Modified inorganic polymer flocculant-PFSi: its preparation, characterization and coagulation behavior; Wang D et al.; As a new kind of water and wastewater treatment reagents, inorganic polymer flocculants (IPFs) are in a trend of rapid development . Among them, iron-based IPF without any toxic problems is greatly expected . In this paper, a new protocol for preparation of iron-based IPF is investigated . Three kinds of silica, named silicaA, silicaB and silicaC, are prepared and used as modifiers to tailor-make polyferric silicate (PFSi), denoted PFSiA . PFSiB and PFSiC, respectively, in accordance to the above silica . Based on several direct and indirect speciation methods, the species distribution and characteristic of three kinds of PFSi are investigated in detail . The experiment results show that the species distribution of PFSi is mainly decided by the kinds of silica introduced and Si/Fe ratio adopted . SilicaA and silicaB function as precipitation preventing reagents during the hydrolysis of Fe(III) . At certain amount of basicity, Fe(a) (monomers) increases with increase of Si, Fe ratio, while Fe(c) (colloidal species) decreases markedly . Although the formation of Fe(c) is inhibited, the stabilization of Fe(b) (oligomers or polymers) can still not be achieved . SilicaC on the other hand exhibits little effect on the species distribution of modified Fe(III) solutions . The coagulation behavior of above PFSi is also examined . The different effect of silica is then discussed with respect to the chemical species. Water Res, 2001 Oct, 35(14), 3402 - 10 Multivariate and multiscale monitoring of wastewater treatment operation; Rosen C et al.; In this work extensions to principal component analysis (PCA) for wastewater treatment (WWT) process monitoring are discussed . Conventional PCA has some limitations when used for WWT monitoring . Firstly, PCA assumes that data are stationary, which is normally not the case in WWT monitoring . Secondly, PCA is most suitable for monitoring data that display events in one time-scale . However, in WWT operation . disturbances and events occur in different time-scales . These two limitations make conventional PCA unsuitable for WWT monitoring . The first limitation can be overcome by use of adaptive PCA . In adaptive PCA . the PCA model is continuously updated using an exponential memory function . Variable mean, variance and co-variance are thus adapted to the changing conditions . The second problem can be solved by time-scale decomposition of data prior to analysis . The time-scale decomposition methodology involves wavelets and multiresolution analysis (MRA) in combination with PCA . MRA provides a tool for investigation and monitoring of process measurement at different time-scales by decomposing measurement data into separate frequency bands . Time-scale decomposition increases the sensitivity of the monitoring, which makes it possible to detect small but significant events in data displaying large variations . Moreover, time-scale information is sometimes important in the interpretation of a disturbance to determine its physical cause . Also, by decomposing data, the problem of changing process conditions is partly solved . All the presented methods are illustrated with examples using real WWT process data. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(7), 1335 - 47 Effects of some water-quality and operating parameters on the decolorization of reactive dye solutions by ozone; Wu J et al.; The ozonation of reactive dye solutions has been investigated . Results of studies on ozone mass transfer indicated that the volumetric mass transfer coefficient of ozone increased with the following water-quality and operating parameters: pH, initial dye concentration, applied ozone dose, and temperature . A model was developed to predict the volumetric mass transfer coefficient of ozone from the above parameters . The results of kinetic studies showed that ozonation of the aqueous reactive dye was a pseudo-first-order reaction with respect to the dye . The apparent rate constant increased with the pH, applied ozone dose and temperature, however, it declined logarithmically with the initial dye concentration . Meanwhile, Ozonation enhanced the biodegradability and reduced the COD of the reactive dye wastewater effectively. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(7), 1237 - 43 Treatment of wastewater sludge by liquid state bioconversion process; Alam MZ et al.; This study was conducted to evaluate the effect of an eminent decay fungus, Phanerocheate chrysosporium of organic residues on wastewater sludge for its improvement through decomposition and separation of waste particles by Liquid State Bioconversion (LSB) . The effect of fungal treatment was compared to uninoculated (Control) at three different harvests 7, 14 and 21 days after inoculation (DAI) . The observed results showed that the weight loss and solid content of wastewater sludge were significantly influenced by Phanerocheate chrysosporium . Both parameters were highly influenced at 7 DAI . The COD and pH of wastewater sludge were also highly influenced by fungal treatment. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(7), 1227 - 36 The effects of hydraulic retention time and loading rate on brewery wastewater treatment using sequencing batch reactors; Ling L et al.; Four laboratory-scale suspended-growth aerobic sequencing batch reactors (SBR) were used to study the effects of hydraulic retention time (HRT) and loading rate on the treatment of brewery wastewater . Factorial experiments and response surface analysis were carried out to explore the optimal operating conditions . A maximum total organic carbon (TOC) removal of 97% was estimated, at a HRT of 1.44 days with a loading rate of 3122 mg/L day . The maximum suspended solids removal, around 95%, would occur at values of HRT and loading rate of 1.32 days and 13.84 g/L day, respectively . TOC removal was more sensitive to the variations of HRT, however, the loading rate was more important than the HRT for suspended solids removal. Water Environ Res, 1998 Jan-Feb, 70(1), 14 - 26 A model for predicting contaminant removal by adsorption within the International Space Station water processor: 1 . Multicomponent equilibrium modeling; Bulloch JL et al.; A thermodynamic model is developed to predict adsorption equilibrium in the International Space Station water processor's multifiltration beds . The model predicts multicomponent adsorption equilibrium behavior using single-component isotherm parameters and fictitious components representing the background matrix . The fictitious components are determined by fitting total organic carbon and tracer isotherms with the ideal adsorbed solution theory . Multicomponent isotherms using a wastewater with high surfactant and organic compound concentrations are used to validate the equilibrium description on a coconut-shell-based granular activated carbon (GAC), coal-based GAC, and a polymeric adsorbent. Adv Space Res, 1997, 20(10), 1833 - 43 Integration of crop production with CELSS waste management; Wignarajah K et al.; Lettuce plants were grown utilizing water, inorganic elements, and CO2 inputs recovered from waste streams . The impact of these waste-derived inputs on the growth of lettuce was quantified and compared with results obtained when reagent grade inputs were used . Phytotoxicity was evident in both the untreated wastewater stream and the recovered CO2 stream . The toxicity of surfactants in wastewater was removed using several treatment systems . Harmful effects of gaseous products resulting from incineration of inedible biomass on crop growth were observed . No phytotoxicity was observed when inorganic elements recovered from incinerated biomass ash were used to prepare the hydroponic solution, but the balance of nutrients had to be modified to achieve near optimal growth . The results were used to evaluate closure potential of water and inorganic elemental loops for integrated plant growth and human requirements. Life Support Biosph Sci, 1997, 4(3-4), 145 - 53 Nutrient recycling systems of Biosphere 2 . Litterfall, decomposition, and wastewater recycling: results from the 1991-1993 closure experiment; Nelson M; Important aspects of nutrient recycling in Biosphere 2 were plant litterfall/leaf decomposition in the terrestrial biomes and sewage and wastewater processing by a constructed wetland system . During the second year of closure, annual litterfall ranged from 1317 +/- 283 g/m2 in the lowland rainforest to 141 +/- 58 g/m2 in the desert sand dune area . Litterfall patterns followed different seasonal regimes in the biomes . Leaf decomposition averaged 90%/year in Biosphere 2, with the smallest leaf loss in the desert biome . For maintenance of soil fertility in the agricultural area, inedible crop material and domestic animal manure was composted, and human waste products and wastewater from people, labs, and domestic animals was processed in a 41-m2 constructed wetland . The wetland produced 1200 kg of fodder and remaining nutrients were returned to the soils via irrigation water. Life Support Biosph Sci, 1998, 5(1), 31 - 4 Assessment of the viral removal capability of the International Space Station Water Recovery and Management system; Roman MC et al.; The development of the International Space Station (ISS) Water Reclamation and Management (WRM) system has been supported through integrated testing at NASA/Marshall Space Flight Center (MSFC) . Assessment of the viral removal capabilities of the ISS water processor was performed as part of the hardware performance evaluation . For the Viral Challenge Test, a known concentration of viruses was mixed with human-generated wastewater and reclaimed using the ISS Water Processor . The composition and concentrations of the different wastewaters used for this test represented the combination of contaminants expected to be found in the wastewater that will be collected and recycled on board the ISS . The results from the Viral Challenge Test clearly showed that the ISS WRM has the capacity to reduce the concentration of viruses in the wastewater by 12 log10 units. Waste Manag Res, 1991 Oct, 9(5), 373 - 7 The hygienic aspects of wastewater reuse; Cooper RC; Historically drinking water contaminated with wastewater discharged from nearby communities has been a major public health problem whose solution was directed towards the treatment of drinking water rather than of the source of contamination . The increased need for deliberate wastewater reuse has stimulated greater interest in the ability of wastewater treatment processes to produce a product in which the risk of infection, upon reuse, is reduced to an acceptable level . A brief overview of the disease agents involved, human dose-response considerations, microbial standards, and treatment plant reliability is presented . Selected experiences with the question as to how our terrestrial experience can be applicable to advanced life support systems is addressed. Water Res, 1990 Jul, 24(7), 875 - 81 Activity and adaptation of nitrilotriacetate (NTA)-degrading bacteria: field and laboratory studies; McFeters GA et al.; Adaptation of bacterial activity for the degradation of nitrilotriacetate (NTA) was studied using natural sediment samples and an NTA-degrading bacterium (strain ATCC 29600) . Sediment samples from a river with persistent levels of NTA had much higher NTA-degradative activity than comparable samples from a less contaminated control site . When sediment from the control site was exposed to high levels of NTA a 5 day lag preceded an abrupt increase in NTA degradation while strain 29600 colonized on sand and grown in the absence of NTA became induced within eight hours . The induction of strain 29600 was compared between bacteria in suspension and cells attached to sand . The sand-associated bacteria became induced 4 to 5 h before the planktonic suspension and displayed over threefold greater specific activity . Suspensions of strain 29600 became adapted within 8 h when placed in membrane diffusion chambers that were immersed within a municipal wastewater reactor containing NTA . These findings support the concept that induction is a part of the process of bacterial adaptation to degrade NTA and sand-associated bacteria can adapt more quickly to and have a greater degradative activity for NTA than planktonic cells. Anal Chem, 2001 Aug 15, 73(16), 3890 - 5 Determination of steroid estrogens in wastewater by immunoaffinity extraction coupled with HPLC-electrospray-MS; Ferguson PL et al.; A new method, based on immunoaffinity extraction coupled with liquid chromatography/electrospray mass spectrometry (LC/ESI-MS) is described for the determination of the steroid estrogens beta-estradiol (E2), estrone (E1), and alpha-ethynylestradiol (E2) in wastewater . The use of highly selective immunosorbents in sample preparation prior to analysis allows the removal of interfering sample matrix compounds present in the wastewater extracts that would otherwise cause severe ionization suppression of the estrogens during the electrospray process . In addition, immunoextraction removes much of the isobaric noise from the selected ion monitoring chromatograms, increasing the signal-to-noise ratios for analytes, and contributing to the low detection limits (0.18 and 0.07 ng/L for E2 and E1, respectively) achieved by the current method . The method was applied to analysis of estrogens in two wastewater effluents . Recoveries of E2 and E1 were excellent (>90%), while the nonimmunogen (but structurally related) analyte EE2 was not retained (recovery <2%) from effluent extracts by the immunosorbent . This illustrates the extreme selectivity of the immunoextraction purification step . Precision of the method was high, with relative standard deviations below 5% . Concentrations of E2 in wastewater varied from 0.77 to 6.4 ng/L, while concentrations of E1 were greater (1.6-18 ng/L). Analyst, 2001 Aug, 126(8), 1304 - 11 Metal fractionation in olive oil and urban sewage sludges using the three-stage BCR sequential extraction method and microwave single extractions; Perez Cid B et al.; The conventional three-stage BCR sequential extraction method was employed for the fractionation of heavy metals in sewage sludge samples from an urban wastewater treatment plant and from an olive oil factory . The results obtained for Cu, Cr, Ni, Pb and Zn in these samples were compared with those attained by a simplified extraction procedure based on microwave single extractions and using the same reagents as employed in each individual BCR fraction . The microwave operating conditions in the single extractions (heating time and power) were optimized for all the metals studied in order to achieve an extraction efficiency similar to that of the conventional BCR procedure . The measurement of metals in the extracts was carried out by flame atomic absorption spectrometry . The results obtained in the first and third fractions by the proposed procedure were, for all metals, in good agreement with those obtained using the BCR sequential method . Although in the reducible fraction the extraction efficiency of the accelerated procedure was inferior to that of the conventional method, the overall metals leached by both microwave single and sequential extractions were basically the same (recoveries between 90.09 and 103.7%), except for Zn in urban sewage sludges where an extraction efficiency of 87% was achieved . Chemometric analysis showed a good correlation between the results given by the two extraction methodologies compared . The application of the proposed approach to a certified reference material (CRM-601) also provided satisfactory results in the first and third fractions, as it was observed for the sludge samples analysed. Waste Manag, 2001, 21(7), 671 - 6 Kinetics and thermodynamics of copper ions removal from wastewater by use of zeolite; Panayotova MI; Natural Bulgarian zeolite was tested for its ability to remove Cu2+ from model wastewater . Influence of process variables was investigated . It was found that the optimum wastewater to zeolite ratio is 100:1 and the optimum pH value of water to be treated is 5.5 to 7.5 . Zeolite with finer particles shows a higher uptake capacity . The simultaneous presence of Ca2+ and Mg2+ in concentrations similar to their concentrations in Bulgarian natural water does not significantly influence the uptake of Cu2+ . Zeolite modification by treating it with NaCl, CH3COONa and NaOH increases its uptake ability . Copper ions are strongly immobilized by modified zeolite and secondary pollution of water caused by its contact with preloaded zeolite is very low (1.5-2.5% of Cu2+ preliminary immobilized have been released back into acidified water) . Contacting with 2 mol dm(-3) NaCl can easily regenerate loaded zeolite; best results were obtained for zeolite modified with NaCl . Requirements of Bulgarian standards for industrial wastewater can be met by a one-stage process for an initial Cu2+ concentration of 10 mg dm(-3), and by a two stage process for an initial Cu2+ concentration of 50 mg dm(-3) . Uptake of Cu2+ by zeolite from neutral wastewater has proved to be as effective as Cu2+ removal by precipitation of copper hydroxide . The process of Cu2+ uptake by natural zeolite is best described by the kinetic equation for adsorption . This fact, together with the correlation found between the Cu2+ uptake and the amount of Na+, Ca2+ and K+ released into solution by zeolite shows that the ion exchange sorption plays the basic role in Cu2+ uptake by natural zeolite . The value obtained for the apparent activation energy (26.112 kJ mol(-1) implies that the process can be easily carried out with a satisfactory rate . The uptake equilibrium is best described by the Langmuir adsorption isotherm, with Langmuir constants KL= 6.4 x 10(-2) dm3 mg(-1) and M = 6.74 mg g(-1) . The apparent equilibrium constant found shows moderate affinity of zeolite for Cu2+ . Values of deltaG degrees and deltaH degrees found show the spontaneous and endothermic nature of the process of Cu2+ uptake by natural zeolite. Waste Manag, 2001, 21(7), 631 - 5 Use of steel converter slag as nickel adsorber to wastewater treatment; Ortiz N et al.; Magnetite, the main component of converter slag in the steel industry, can be used for the adsorption of Ni(II) from aqueous solutions, over a range of conditions: initial metal concentration (10-100 mg 1(-1)), stirring times (2-240 min), adsorbent dosage (1 g for 0.5 1 of metal solution) and temperatures (20, 30 and 38 degrees C) . The adsorption rate increased with initial concentration but decreased with increase in temperature, due to competition of the dissolution process . The adsorption process obeyed the Freundlich isotherm model. Syst Appl Microbiol, 2001 Jul, 24(2), 294 - 302 Aeration conditions affecting growth of purple nonsulfur bacteria in an organic wastewater treatment process; Izu K et al.; Effects of aeration on purple nonsulfur bacteria (PnSB) were studied in photobioreactors . Bacterial community changes were analyzed by denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH) . DGGE band pattern change was small and only few prominent bands were obtained at non-aeration condition . Sequencing results of the prominent DGGE bands obtained at this condition revealed that they represented mainly the PnSB, Rhodobacter sphaeroides and Rhodopseudomonas palustris . On the other hand, under aerated condition, some prominent bands originated from heterotrophs appeared but no proliferation of PnSB was observed . FISH was applied to detect PnSB and their population was quantified . Maximum PnSB ratio (up to 80%) was obtained both at non-aeration condition and at constant ORPs less than -200 mV . In the presence of DO, Rps . palustris was more competitive to chemoheterotrophs than Rb . sphaeroides. Environ Monit Assess, 2001 Jul, 70(1-2), 135 - 51 Effects of land use and municipal wastewater treatment changes on stream water quality; Ha SR et al.; This study was undertaken to analyze the quantitative impact of a municipal wastewater treatment operation on the long-term water quality changes in a tributary of the Han-river, Korea from 1994 to 1999 . Changes of land use pattern in the study watershed are quantitatively analyzed on the basis of land use maps that were created by classifying Landsat TM images acquired in April 1994 and March 1999 . During this period, the average increase of land use area in terms of residence, cultivation, and barren was 5.89, 0.13, and 0.12%, respectively, and the corresponding decrease in water and forest area was 0.21 and 0.16% . The annual average reductions of BOD, T-N, and T-P by the municipal wastewater treatment operation were about 89, 11 and 27%, respectively . Spatial analysis of the pollution discharge from watershed was undertaken using a geographic information system (GIS) based model . A clear reciprocal relationship was found between the basin-wide self-purification coefficient and the watershed form ratio excepting a catchment area with water drain facilities . Due to land use changes over the five year study period, water quality change in terms of BOD, T-N, and T-P were (+)1.04 mg l(-1) (corresponding to a 13.7% increase of pollution), (+)0.58 mgl(-1) (10.0% increase), and (-)0.01 mg l(-1) (1.6% decrease) . On the other hand, the effect of water quality restoration assessed by outward appearance during the same period was about 67.6, 39, and 36.5%, respectively . Consequently, it is understood that total stream water quality recovery in terms of BOD, T-N, and T-P were 81.3, 49.0, and 38.1% respectively, and that this included a negative contribution resulting from increased land use and a positive contribution due to the wastewater treatment operation at Inchon. ISA Trans, 2001, 40(3), 267 - 81 Application of the SCADA system in wastewater treatment plants; Dieu B; The implementation of the SCADA system has a positive impact on the operations, maintenance, process improvement and savings for the City of Houston's Wastewater Operations branch . This paper will discuss the system's evolvement, the external/internal architecture, and the human-machine-interface graphical design . Finally, it will demonstrate the system's successes in monitoring the City's sewage and sludge collection/distribution systems, wet-weather facilities and wastewater treatment plants, complying with the USEPA requirements on the discharge, and effectively reducing the operations and maintenance costs. Chemosphere, 2001 Aug, 44(5), 973 - 9 Identification and quantification of chlorinated bisphenol A in wastewater from wastepaper recycling plants; Fukazawa H et al.; Chlorinated derivatives of bisphenol A were detected in the final effluents of eight paper manufacturing plants in Shizuoka, Japan, where thermal paper and/or other printed paper is used as the raw material . Their amounts were determined by gas chromatography/mass spectrometry (GC/MS) after treatment with N, O-bis(trimethylsilyl)trifluoroacetamide, and ranged from traces to 2.0 microg/l . They are likely produced by chlorination of bisphenol A, which was released into the effluents from the pulping process of wastepaper, during or after bleaching with chlorine. Chemosphere, 2001 Aug, 44(5), 1055 - 63 Regulating colored textile wastewater by 3/31 wavelength ADMI methods in Taiwan; Kao CM et al.; The wastewater from textile dyeing facilities is difficult to treat satisfactorily because of high compositional variability and high color intensity . To reduce colored effluents discharged into watercourses, the government of Taiwan adopted the Effluent True Color Standard in 1998 . The true color discharge limit is 400 American Dye Manufactures Institute (ADMI) units . The adopted analytical method is the ADMI Tristimulus Filter Method (3 wavelength (WL) method), and the 31 WL ADMI method might be also adopted as an alternative for color value measurement . The refractory nature of textile dyes and the introduction of this new regulation present an environmental challenge to the Taiwanese textile industry . The main objectives of this study were to (1) evaluate the efficacy of current wastewater treatment systems for controlling the colored textile wastewater discharges, and (2) evaluate the correlations between 3 and 31 WL ADMI methods . Ten representative textile wastewater treatment facilities employing biological and chemical coagulation treatment technologies were selected to perform a 10-consecutive-day effluent sampling and analysis . Results show that a significant difference between 3 and 31 ADMI methods was observed . These two ADMI methods cannot be substituted for each other, and the discharge standard should be determined based on the selected testing method . Investigation results also suggest that the commonly used wastewater treatment technology (biological + chemical coagulation) fails to effectively remove dye from the colored textile wastewater . Sodium hypochlorite (NaOCl) addition was applied by most facilities as the temporary post-polishment step to comply with the color discharge standard. Chemosphere, 2001 Aug, 44(5), 1017 - 23 Highly concentrated phenolic wastewater treatment by the photo-Fenton reaction, mechanism study by FTIR-ATR; Arana J et al.; Phenol degradation by Photo-Fenton reaction has been studied in highly concentrated wastewaters and most intermediate species have been identified by Fourier Transform IR-Spectroscopy with ATR device . During the photodegradation of highly concentrated phenol solutions, the formation of dissolved and precipitate tannin has been observed . The possibility of a Fe3+-Pyrogallol complex formation, previous to the tannin formation, has been proposed too . The complex formation involving Fe3+ ions could be related to the observed Photo-Fenton activity decrease . Tannin formation inhibits the complete mineralization of phenol because *OH radicals attack will produce further condensation steps and the polymer size increase . This fact limits the applicability of the process for highly concentrated phenolic wastes mineralization . However, the tannin precipitation allows its separation from the solution by conventional filtration, and reduction of the corresponding dissolved organic carbon . These observations have been proved from the identification of primary degradation products, catechol and hydroquinone . Catechol is considered to be the first step for the formation of tannins . Degradation process for phenol, catechol and hydroquinone have been monitored by total organic carbon (TOC) measurements along the reaction time span . From these results, a global mechanism for the Photo-Fenton degradation of phenol is proposed. Chemosphere, 2001 Sep, 44(6), 1455 - 62 Survey of PCDD/Fs and non-ortho PCBs in UK sewage sludges; Stevens J et al.; A survey of PCDD/F and non-ortho PCB concentrations in the mesophilic, anaerobically digested sludge of 14 UK wastewater treatment works was carried out . The range of total Cl1-Cl8DD/F concentrations in the sludges was 8880-428000 pg/g dw with a median of 23300 pg/g dw . The concentrations of the three non-ortho PCBs were in the range 272-63000 pg/g dw with a median of 695 pg/g dw . The PCDD/F I-TEQs of the sludges studied were comparable to those published in the literature with a range of 20-225 pg I-TEQ/g dw and a median of 40.4 pg/g dw . The non-ortho PCBs usually added 2-7 pg/g to the total TEQ with one notable exception which increased the TEQ value 20-fold . With three exceptions, the PCDD/F content of the sludges fell well below the draft EU limit values proposed on 27 April 2000 . The homologue group pattern of the PCDD/Fs is dominated by the HpCDDs and OCDD and is consistent with that found in most sewage sludges . There appears to be no correlation between the degree of industrial input and the PCDD/F concentration . This suggests that trade effluent is not always the most significant source of PCDD/Fs to wastewater in the UK. Huan Jing Ke Xue, 2001 May, 22(3), 108 - 12 {The granulation of PCP-degrading anaerobic sludge with industrial organic wastewater as co-substrate}; Xu X et al.; The granulation of PCP degrading anaerobic sludge in two improved UASB reactors under co-existence of two types of industrial wastewater and PCP were studied . It was found that the granulation of PCP degrading anaerobic sludge could be divided into three stages, i.e . sludge acclimation, granular pre-formation and granular maturation . The changes in biomass, sludge bioactivity, population and ecological distribution of three group bacteria involved in anaerobic digestion during the course of granulation were also examined . Anaerobic granules from two reactors showed high dechlorination activity at meta, otho and para position . Rod-shaped and filamentous shaped Methanosaeta-like spp . were found in anaerobic granules . Results of electron microscopy revealed the presence of synthophic microcolonies and non-layed microstructure in PCP-degrading granules . The types of industrial wastewater used as co-substrate had affected the course of sludge granulation, dechlorinating activity and pre-dominant methanogens in PCP-degrading anaerobic granules. Ann Chim, 2001 May-Jun, 91(5-6), 295 - 304 Role played by a natural channel on the quality of bordering environment: a chemical assessment; Lopez A et al.; Based on a rational and simple chemical approach, a field-investigation aimed to assess the role played by a natural channel "lama" on the quality of underlying groundwater and neighbouring soils has been carried out . The results have demonstrated that: (a) the stream flowing through the "lama" is mainly made up of treated effluent from a nearby municipal wastewater treatment plant; (b) the occurrence of nitrates in the "lama" is due to rain-washing of nitrogen fertilized agricultural soils bordering on the "lama"; (c) hydraulic connections exist between the lama and the underlying groundwater causing contaminants flowing through the "lama" to reach groundwater within less than one week; (d) compared with the values measured in the "lama", the concentrations of TOC, N-NH4 and N-NO3 in groundwater result: lower, far lower and greater, respectively; (e) agricultural soils bordering on the "lama" result significantly contaminated by halogenated organics. Environ Technol, 2001 Jul, 22(7), 837 - 43 Uptake of 15N by macrophytes in subsurface-flow wetlands treating domestic wastewater; Weaver RW et al.; Constructed subsurface-flow wetlands are becoming more common for on-site treatment of domestic wastewater to provide secondary quality effluent . Macrophytes are generally added to wetlands to increase treatment efficiency but their role in reducing N content is controversial . Our investigation utilized two subsurface-flow wetlands to determine the efficiency of different macrophytes in uptake of 15N labeled ammonium sulfate . Macrophytes in Wetland 1 recovered 35% of the added N in their shoots but only 5% of the added N was recovered in the shoots and roots in Wetland 2 . A major difference for the two wetlands was N and hydraulic loadings . Wetland 1 received 7.5 Kg N ha(-1)d(-1) and Wetland 2 received 16.9 Kg N ha(-1)d(-1) . Retention time for Wetland 1 based on pore volumes was 2.9 d and for Wetland 2 it was 1.2 d . The retardation factor for NH4+ was approximately 2.5 for both wetlands and the breakthrough curves indicated lack of plug flow . The importance of macrophytes in taking up NH4 appeared to dependent on N and hydraulic loadings. Environ Technol, 2001 Jul, 22(7), 823 - 30 Ultrasonication as a pre-treatment method for the enhancement of the psychrophilic anaerobic digestion of aquaculture effluents; McDermott BL et al.; The effectiveness of ultrasonication as a pre-treatment method for the psychrophilic anaerobic treatment of aquaculture effluents was assessed using a 4 l solids digester . Ultrasonication of aquaculture wastewater was found to enhance the removal of chemical oxygen demand by anaerobic digestion by almost 10% . There was also a concurrent increase in total biogas production from 0.29 l day(-1) to 0.45 l day(-1) with a corresponding 10% increase in methane concentration . Furthermore, there was an increase of 60% in effluent total ammonia nitrogen concentration as a result of sonication in comparison with a 45% increase for untreated digester waste. Environ Technol, 2001 Jul, 22(7), 791 - 801 Recent developments in chelate degradation; Sillanpaa M et al.; Chelating agents are used in various industrial processes to inactivate transition metals by forming cyclic complexes . As nitrogen containing compounds, these substances increase the nitrogen load in wastewater . Also, they increase the heavy metal concentrations in the wastewater effluent . It has been long recognised that EDTA and DTPA are relatively recalcitrant compounds and thus pass through wastewater treatment without adequate removal . A number of interesting studies on the degradability of EDTA and DTPA--either by advanced oxidation processes or biological processes--have been carried out recently . This review focuses mainly on these two compounds. Spectrochim Acta A Mol Biomol Spectrosc, 2001 Aug, 57(9), 1833 - 8 Kinetic spectrophotometric method for the determination of oxalic acid by its catalytic effect on the oxidation of safranine by dichromate; Ensafi AA et al.; A new catalytic kinetic spectrophotometric method for the determination of oxalic acid has been described based on its catalytic effect on the redox reaction between safranine and dichromate in dilute sulfuric acid media . The reaction is monitored photometrically by measuring the decrease in absorbance of safranine at the maximum wavelength of 530 nm . Under the optimum conditions, a calibration graph from 0.10 to 10.00 microg ml(-1) of oxalic acid with a detection limit of 0.08 microg ml(-1) was obtained . The relative standard deviation (R.S.D.) for ten replicate measurements of 1.0 and 5.0 microg ml(-1) oxalic acid was 2.7 and 2.5%, respectively . The purposed method is simple, sensitive, selective and inexpensive . The applicability of the proposed method was determined by the determination of oxalic acid in spinach and wastewater samples with satisfactory results. Environ Sci Technol, 2001 Aug 1, 35(15), 3231 - 6 A continuous system for Fe0 reduction of nitrobenzene in synthetic wastewater; Mantha R et al.; Nitrobenzene is a major environmental pollutant, and its degradation is difficultto achieve . Hence, a chemical reduction pretreatment is sought in this research, before the resulting aniline can be treated by enzyme-mediated oxidative polymerization . Zerovalent iron (Fe0) has been successfully employed to reduce nitrobenzene to aniline in synthetic wastewater in both batch and continuous flow reactors . The concentration of nitrobenzene studied was thatwhich would be present in industrial wastewater streams (millimolar, 123 ppm), a concentration range considerably higher than those studied previously with groundwater by other researchers . Anaerobic conditions were maintained in the reactors by including Na2SO3 as an oxygen scavenger in the presence of CoCl2.6H2O, which acted as a catalyst . Batch reactors exhibited adsorption of aniline on the Fe0, which could be described by a langmuir isotherm . A 200 g Fe0 (particle size: 1-2 mm) bed completely converted 1 mM of nitrobenzene flowing upward for about 600 pore-volumes before experiencing flow reduction due to clogging due to corrosion products . Green-black precipitates (Fe0 corrosion products) were formed at the influent end of the column which were identified as maghemite.
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