Wastewater

Fresenius J Anal Chem, 2000 Jan, 366(1), 89 - 94
Application of ion-chromatography for the determination of the organic-group parameters AOCl, AOBr and AOI in water; Oleksy-Frenzel J et al.; A method of differential AOX-analysis, i.e . the simultaneous determination of AOCl, AOBr and AOI is described . Individual steps of the method including enrichment at activated carbon, combustion in an oxygen stream and ion-chromatographic detection were optimized . In most cases quantitative recoveries of various organic Cl, Br and I containing substances of different polarity and structure were obtained . The method was applied to the determination of AOX-fractions in municipal and hospital wastewater . A good agreement between conventional coulometric and the described ion-chromatographic determination was found . High concentrations up to 130 microg/L I of organic iodine compounds were measured in the influent and effluent of a municipal treatment plant in Berlin and up to 10 mg/L I in a hospital waste-water.

Biosens Bioelectron, 2000 Oct, 15(7-8), 371 - 6
Optical fiber biosensor for the determination of low biochemical oxygen demand; Chee GJ et al.; An optical fiber biosensor was developed for the evaluation of low Biochemical Oxygen Demand (BOD) values in river waters . Artificial wastewater (AWW) solution was employed as standards for the calibration of the BOD sensor . The response time of the sensor was 15 min, and the optimal BOD response was observed at 30 degrees C, pH 7.0 . A linear relationship was obtained between the output voltage and BOD5 values, and the range of determination was 1-10 mg l(-1) BOD . The sensor response was almost not influenced by chloride ion up to 1000 mg l(-1), and also not affected by heavy metal ions (Fe3+, Cu2+, Mn2+, Cr3+, Zn2+) . The BOD of river waters was estimated by using the optical fiber biosensor, and good correlation between the sensor and BOD5 test was obtained (r2 = 0.971).

Biosens Bioelectron, 2000 Oct, 15(7-8), 343 - 53
Designing an amperometric thick-film microbial BOD sensor; Chan C et al.; Thick film oxygen electrodes manufactured by screen print method have been used as a transducer for a biochemical oxygen demand (BOD) sensor . The kinetics of the immobilized yeast, Arxula adeninivorans (Arxula) has been studied . The apparent KM of immobilized Arxula (> 100 microM) is higher than free cells of Arxula (70 microM) . The increase in KM caused by the effect of immobilization extends the linear range of the sensor . End-point measurement and quasi-kinetic measurement have been studied comparatively as measurement procedures with a good correlation . The Vmax for end-point measurement is 790.7 microM/s and that for quasi-kinetic measurement is 537.3 microM/s . The limit of detection is calculated 1.24 mg/l BOD . Using the quasi-kinetic measurement, instead of end-point measurements, the measuring time can be reduced from 5-30 min to 100 s . The sensor layer thickness or increase in the layer of covering gel can increase the KM that is accompanied with the extension of the linear range of the sensor . Nevertheless, increase in the layer of covering gel will not increase the saturation signal . Domestic wastewater was checked by the thick film BOD sensor and the results are satisfactory.

Ann Chim, 2000 Nov-Dec, 90(11-12), 677 - 86
Assessment of ground water quality in a fractured aquifer under continue wastewater injection; Carrieri C et al.; Experimental studies have been carried out in a fractured coastal aquifer of the Salento Region (Nardo (Le), Italy), subject since 1991 to injection of 12,000 m3/d of treated municipal wastewater in a natural sink . The analytical parameters of ground water sampled in monitoring wells, have been compared before and after the injection started . The mound of water table (1.5 m), the reduction of seawater extent of 2 km and the spreading of pollutants injected were evaluated by means of mathematical model results . After ten years operation, the volume of the available resource for agricultural and drinking use has been increased, without notable decrease of the preexistent ground water quality . Moreover for preserving such resource from pollution, the mathematical model allowed the standards of wastewater quality for recharge to be identified . Around the sink, a restricted area was also defined with prohibition of withdrawals, to avoid infection and other risks on human health.

Anal Chem, 2001 Feb 1, 73(3), 589 - 95
Exact mass measurements on-line with high-performance liquid chromatography on a quadrupole mass spectrometer; Storm T et al.; Exact mass measurements were performed on-line with high-performance liquid chromatography on a quadrupole mass spectrometer . Compounds with molecular weights from 98 to 797, mainly aromatic sulfonates and sulfonamides, were analyzed with electrospray ionization in positive or negative mode . Internal mass calibration compounds were continuously added after separation . A Gaussian fit of the mass errors of 808 individual measurements (concentrations of 1-10 mg/L, 20-200 ng absolute on column) resulted in a mean error of 0.1 mmu (0.45 ppm) and a standard deviation sigma of 1.5 mmu (5.4 ppm) . The 99.7% confidence intervals (3sigma) were +/-4.5 mmu (+/-16.2 ppm) for single mass measurements . Averaging 10 measurements further reduced the errors to less than +/-1.5 mmu (+/-5 ppm) . Isobaric interferences with ions resulting from the mass calibrants were avoided by the use of complementary mass calibrants . The results were verified (differences below +/-4.5 mmu) with a LC/ oa-TOFMS . Limited mass range chromatograms were used to enhance selectivity in the analysis of mixtures . The method was applied to determine the elemental composition of a potential dye metabolite detected in anaerobically treated textile wastewater.

J Environ Qual, 2001 Jan-Feb, 30(1), 238 - 45
Transport of Escherichia coli in sand columns with constant and changing water contents; Powelson DK et al.; Understanding how changes in volumetric water content (theta) affect bacterial adsorption could help reduce transport of pathogenic and indicator bacteria that may be present in infiltrating wastewater . Three flow regimes that simulated infiltration from a household septic system were evaluated: saturated, unsaturated with a constant volumetric water content theta (constant unsaturated flow), and unsaturated with cyclic changes in theta (variable unsaturated flow) . Escherichia coli was suspended in artificial sewage (AS) and applied as step inputs to sand columns, with regular interruptions in input for variable unsaturated flow . A transport model was fit to the saturated and constant unsaturated flow breakthrough curves to determine retardation (R), the first-order filtration coefficient (mu), and the maximum outflow relative concentration (Cmax) . The total cells transported as a fraction of input (tau) in all three flow regimes was calculated . Constant unsaturated flow resulted in a significantly lower Cmax (0.633) in comparison with saturated flow (0.803, P < or = 0.05), although unsaturated mu (0.0693 h(-1)) was not significantly different from saturated mu (0.0259 h(-1)) . Constant unsaturated flow also resulted in a significantly smaller tau (0.617) than saturated (0.806) or variable unsaturated flow (0.734) . In variable unsaturated flow, cell concentrations were out of phase with theta--as the column drained, cell concentrations in the outflow increased; and when a pulse of suspension was applied, cell concentrations decreased . Constant unsaturated flow is probably the best for removal of pathogenic bacteria because this regime resulted in lower maximum concentrations of E . coli and greater cell removal, in comparison with saturated and variable unsaturated flow.

Poult Sci, 2001 Jan, 80(1), 57 - 65
Recovery and characterization of by-products from egg processing plant wastewater using coagulants; Xu LJ et al.; The effectiveness of precipitation or coagulation technology to treat commercial egg processing plant wastewater, using such coagulants as lignosulfonate, bentonite, carboxymethylcellulose, and ferric chloride, was evaluated . For simulated and industrial waste-water, chemical oxygen demand, turbidity, and total solids were reduced over 90, 97, and 95%, respectively, for all coagulants tested . Protein and fat recoveries were over 95% for all coagulants . The optimal coagulant concentration for maximum by-product recovery depended on initial wastewater concentrations of protein, total solids, and fat . The dried by-products contained high concentrations of protein (30 to 50%) and fat (30 to 40%) and had similar essential amino acid profiles as standard proteins from the United Nations Food and Agricultural Organization (FAO) . The relative protein digestibilities of each recovered solid (carboxymethycellulose, lignosulfonate, bentonite, and ferric chloride) and corn meal relative to a liquid whole egg standard were approximately 80, 90, 60, 30, and 56%, respectively . These compositional and in vitro digestibility studies suggest that the recovered by-products could be useful as livestock feed ingredients or for other applications.

J Chromatogr A, 2001 Jan 5, 905(1-2), 157 - 62
Determination of metal complexes of ethylenediaminetetraacetate in the presence of organic matter by high-performance liquid chromatography; Bedsworth WW et al.; A high-performance liquid chromatography method is described here for the determination of the Cd(II), Co(II), Cu(II), Pb(II), and Zn(II) complexes of ethylenediaminetetraacetate (EDTA) in municipal wastewaters and surface waters . The method involves separation by ion-exchange chromatography on a reversed-phase C18 column coated with ion-pair reagent, followed by post-column conversion to FeEDTA and subsequent detection by UV absorbance . Although Co(II) and Cu(II) coelute, they can be quantified by analyzing absorbance by CuEDTA2- prior to post-column conversion . The method detection limit of 6-8 x 10(-8) M (5-7 ng) is an order of magnitude improvement over previous UV absorbance post-column reaction methods . The technique can be used in the presence of organic matter encountered in matrices such as untreated wastewater without pre-concentration or sample cleanup.

Bioresour Technol, 2001 Feb, 76(3), 191 - 7
The role of HRT and low temperature on the acid-phase anaerobic digestion of municipal and industrial wastewaters; Maharaj I et al.; Two identical 31 completely mixed reactors with solids recycling capabilities were used to investigate the effects of hydraulic retention time (HRT) and low temperatures on volatile fatty acid (VFA) production . One reactor was fed with a 1:1 ratio of diluted primary sludge and a starch-rich industrial wastewater, while the other was fed with diluted primary sludge alone . The VFA and soluble COD concentrations and specific production rates reached their highest values at 30 h HRT and at 25 degrees C . Further increase in HRT (at 25 degrees C) or decrease in temperature (at an HRT of 30 h) resulted in lower amounts of VFA and COD produced . All parameters related to VFA and COD production were significantly higher in the industrial-municipal reactor than in the municipal-only reactor . The VFA:COD ratios were very high, with values ranging from about 0.8 to 1.0 indicating that hydrolysis was the rate-limiting step . Degradation of proteins (measured by ammonia production) was inhibited by the starch-rich wastewater in the industrial-municipal reactor, while no evidence of inhibition was found in the municipal-only reactor . This study revealed that VFA production was feasible at low temperatures (down to 8 degrees C), particularly in the presence of the industrial waste . Ultimately, the amount VFA produced was adequate, in most cases, to support subsequent biological nutrient removal (BNR) processes.

Rev Bras Biol, 2000 Aug, 60(3), 373 - 9
Influence of photoperiod on the uptake of nitrogen and phosphorus in the water by Eichhornia crassipes and Salvinia auriculata; Petrucio MM et al.; The main goal of this research was to quantify the concentrations of total and ammonium N, nitrate, total and soluble P in the water in the presence of Eichhornia crassipes and Salvinia auriculata, which were submitted to two different photoperiods in a 24 hours incubation period in the laboratory . The macrophytes were incubated in plastic vials of approximately 1.5 litters, with a previously prepared solution with NH4NO3, NH4Cl, and KH2PO4 . Eichhornia crassipes showed the highest average rate of reduction of all the nutrients analysed in relation to Salvinia auriculata . The largest photoperiod reflected in a higher average rate of reduction of nutrients, in both plants . Therefore, we may expect that in some periods of the year (e.g . summer), the aquatic macrophytes would show higher growth rates and higher rates of nitrogen and phosphorus absorption . These results are important for the implementation and management of wastewater treatment systems in tropical areas using aquatic macrophytes.

Ecotoxicol Environ Saf, 2001 Jan, 48(1), 56 - 61
Determination of wastewater LC50 of the different process stages of the textile industry; Villegas-Navarro A et al.; Textile plants are very important sources of toxic discharges . The purpose of the research described in this paper was to use bioassays with daphnids to determine the LC50 values of textile wastewater samples taken from different stages of the finishing textile industry . Toxicity due to dyeing, chlorination, and the absence of adequate physicochemical conditions for daphnid survival were considered . Wastewater samples corresponding to each process stage were collected at five finishing textile industries and assayed according to previously published procedures . The sensitivity of daphnids to chemicals was assayed using sodium dodecyl sulfate and was similar to other reports (14.6+/-6.8 vs 14.5+/-2.3 mg/L) . All effluents from the five company samples were toxic in terms of LC50 and exhibited very high toxicity with acute toxicity unit (ATU) levels between 2.2 and 960, indicating that the five textile industries produced toxic water . The sensory characteristics indicated that the dyes contributed to overall sample toxicity at all process stages . The most toxic contaminant seemed to be ClO- at levels between 0.2 and 6.8 mg/L, suggesting that further research is needed on the economic costs of stage-by-stage and total effluent treatments.

Bioresour Technol, 2001 Jan, 76(2), 91 - 8
The effect of temperature on slaughterhouse wastewater treatment in anaerobic sequencing batch reactors; Masse DI et al.; High strength slaughterhouse wastewater was treated in four 42 l anaerobic sequencing batch reactors (ASBRs) operated at 30 degrees C, 25 degrees C and 20 degrees C . The wastewater contained between 30% and 53% of its chemical oxygen demand (COD) as suspended solids (SS) . The ASBRs could easily support volumetric organic loading rates (OLRs) of 4.93, 2.94 and 2.75 kg/m3/d (biomass OLRs of 0.44, 0.42 and 0.14 g/g volatile SS (VSS)/d) at 30 degrees C, 25 degrees C, and 20 degrees C, respectively . At all operating temperatures, the total COD (TCOD) and soluble COD (SCOD) were reduced by over 92%, while average SS removal varied between 80% and 96% . Over the experimental period, 90.8%, 88.7% and 84.2% of the COD removed was transformed into methane at 30 degrees C, 25 degrees C and 20 degrees C, respectively . The decrease in the conversion of the COD removed into methane as operating temperature was lowered, may be partly explained by a lower degradation of influent SS as temperature was reduced . The reactors showed a high average methanogenic activity of 0.37, 0.34 and 0.12 g CH4-COD/gVSS/d (22.4, 12.7 and 11.8 l/d) at 30 degrees C, 25 degrees C and 20 degrees C, respectively . The average methane content in the biogas increased from 74.7% to 78.2% as temperature was lowered from 30 degrees C to 20 degrees C.

Bioresour Technol, 2001 Jan, 76(2), 151 - 9
Decolorization of azo-reactive dye by polyphosphate- and glycogen-accumulating organisms in an anaerobic-aerobic sequencing batch reactor; Panswad T et al.; An anaerobic-aerobic sequencing batch reactor with a sludge age of 8 days and anaerobic + aerobic + settling times of 18 + 5 + 1 h, was used to decolorize an azo-reactive dye wastewater . The nutrient broth (NB) and sodium acetate (SA) solution at 500 + 0, 350 + 150, 250 + 250 and 0 + 500 mg/l as COD was fed to the system to promote the polyphosphate-accumulating organisms (PAOs), while only glucose (500 mg/l COD) was used as a glycogen-accumulating organisms (GAOs) promoting substrate . The decolorization capability of the process was about 73-77 and 59-64% in terms of ADMI for the systems which the PAOs and GAOs proliferated, respectively . The color reduction was mainly achieved within the first 2 h of the anaerobic stage.

Appl Microbiol Biotechnol, 2000 Dec, 54(6), 844 - 9
Evaluation of parameters for monitoring an anaerobic co-digestion process; Bjornsson L et al.; The system investigated in this study is an anaerobic digester at a municipal wastewater treatment plant operating on sludge from the wastewater treatment, co-digested with carbohydrate-rich food-processing waste . The digester is run below maximum capacity to prevent overload . Process monitoring at present is not extensive, even for the measurement of on-line gas production rate and off-line pH . Much could be gained if a better program for monitoring and control was developed, so that the full capacity of the system could be utilised without the risk of overload . The only limit presently set for correct process operation is that the pH should be above 6.8 . In the present investigation, the pH was compared with alkalinity, gas production rate, gas composition and the concentration of volatile fatty acids (VFA) . Changes in organic load were monitored in the full-scale anaerobic digester and in laboratory-scale models of the plant . Gas-phase parameters showed a slow response to changes in load . The VFA concentrations were superior for indicating overload of the microbial system, but alkalinity and pH also proved to be good monitoring parameters . The possibility of using pH as a process indicator is, however, strongly dependent on the buffering capacity . In this study, a minor change in the amount of carbohydrates in the substrate had drastic effects on the buffering effect of the system.

Waste Manag, 2001, 21(1), 33 - 40
Treatment of effluent containing micropollutants by means of activated carbon; Solisio C et al.; Different amounts of granular activated carbon (GAC) have been tested for the removal of aliphatic and aromatic micropollutants contained in a liquid stream coming from an industrial plant . Tests have been carried out in a JAR-Test apparatus, using plugged flasks, in order to eliminate the oxygen influence on the adsorption process and to obtain information for studying the process in a pilot plant . The removal of aliphatic compounds resulted better than aromatic ones, probably because these substances are enveloped by water molecules which make adsorption on the GAC surface easier; in contrast, aromatic compounds show a lower affinity for the GAC, owing to their steric conformation . The good results obtained confirm that the proposed system is applicable to the examined effluent, even when the concentration of the pollutant load varies . In the latest part of this work, a plan for the construction of a full-scale plant to treat the examined wastewater has been developed.

Environ Manage, 2001 Mar, 27(3), 463 - 76
Analysis of socioeconomic and environmental impacts of waste stabilization pond and unrestricted wastewater irrigation: interface with maintenance; Agunwamba JC; The effluent from the waste stabilization ponds (WSPs) of the University of Nigeria, Nsukka Campus, is used for irrigation by poor rural farmers . There has been fear that the poorly maintained WSPs and the reuse practices are contributing to environmental degradation and health hazards . In this study the environmental and socioeconomic impacts of the WSPs and reuse were evaluated based on data collected from questionnaires and the literature . The engineering and agricultural properties of soil in the irrigated and nonirrigated areas were compared . Comparison of the health status of the farmers and nonfarmers, of consumers of crops irrigated with wastewater and nonconsumers was performed using Student's t test and the z-score test . The occurrences of diarrhea, typhoid fever, and malaria among the various groups were used as indices . Analyses show that the health status of the farmers and consumers is poorer than those of nonfarmers and nonconsumers at the 5% level of significance . Vegetable cultivation using WSP effluent is a means of sustenance to the farmers and provides an affordable means of satisfying their nutritional deficiencies . However, the poorly maintained WSPs create odor and mosquito nuisances, trap and destroy livestock, and flood nearby compounds with waste debris . At both 1% and 5% levels of significance, communities around the ponds (< 300 m) suffer malaria more frequently than those who live far away (> or = 300 m) . Cost-benefit analysis argues in favor of improvement of WSP management and irrigation reuse of wastewater . Dredging of the ponds, training workers and farmers, and adopting appropriate maintenance and monitoring strategies will greatly enhance the socioeconomic status of the urban poor farmers.

J Chromatogr A, 2000 Nov 3, 897(1-2), 205 - 14
Ion chromatographic analysis of tetracyclines using polymeric column and acidic eluent; Ding X et al.; High-performance ion chromatography (HPIC) is first successfully used to analyze tetracycline antibiotics (TCs) in this work . The TCs are well separated on a solvent compatible polymeric cation-exchange column within 12 min . Isocratic elution with acetonitrile-hydrochloride is very advantageous for routine analysis . HPIC may be seen as a specific variant of the more common high-performance liquid chromatography (HPLC) for water-soluble and polar pharmaceuticals with low hydrophobicity . The detection limits (signal-to-noise ratio=3:1) of oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), doxycycline (DC) are 10, 10, 20 and 20 microg l(-1), respectively . Samples are prepared by vortex mixing with an ethylenediaminetetraacetic acid disodium salt (Na2EDTA)-McIlvaine buffer (pH 4.0) solution and the mixture filtrates through a molecular weight cut-off filter . The method has been successfully applied to monitor the OTC removal rate through every reactor in the process of OTC manufacturing wastewater treatment by bio-chemical technology . It is also applicable to determine the TCs residues in milk and milk powder with satisfying results.

J Air Waste Manag Assoc, 2000 Nov, 50(11), 1920 - 8
Characterization of products from fluidized-bed combustion of coal; Bednarik V et al.; The technology of fluidized-bed combustion (FBC) of coal generates byproducts that have a series of unique characteristics and potential uses in technological practice . In this study, the products of fluidized-bed combustion (FBC-P) of coal derived from Moravian heat stations, a.s . Zlin, Cinergy Global Resources, Czech Republic, were characterized . Particular attention was paid to determining the chemical composition of FBC-P, the content of polycyclic aromatic hydrocarbons (PAHs) and toxic metals in the water leachates of these FBC-P, the content of unburned carbon, the capability of FBC-P to solidify with water and form a solid matrix, and the method for discovering optimum mixing water content for FBC-P solidification . The results suggest that one of the qualitatively more important means of utilizing FBC-P could be their application during solidification/stabilization (S/S) of wastes, particularly wastewater treatment sludges.

Risk Anal, 2000 Oct, 20(5), 613 - 25
Exposure assessment of heavy metals resulting from farmland application of wastewater sludge in Tianjin, China: the examination of two existing national standards for soil and farmland-used sludge; Cao H et al.; Land application is one of the major methods of managing municipal sludge in China . The sludge is used for fertilizing and conditioning soil, but due to the high concentration of heavy metals and other chemicals that it contains, improper use of sludge will lead to the contamination of farmland soil . To provide guidance on the application of sludge in China, the Control Standards for Pollutants in Sludge for Agricultural Use (CSPSAU) were enacted, and implemented in 1985 . Afterwards, the National Environment Quality Standards for Soil (NEQSS) were also formulated and put into effect in 1996 . In this article, these two national standards were examined by means of exposure assessment . The main exposure pathway to humans that was considered was dietary intake of crops grown on the sludge-applied farmland . Five major types of agricultural crops (rice, wheat, tuber roots, vegetables, and fruits) and three groups of exposure population (the urban individual group, the rural sludge-applying individual group, and the rural sludge nonapplying individual group) were assessed . This case study in Tianjin, China, shows the necessity of reexamining the national standards of the CSPSAU and the NEQSS in the context of risk assessment . More comprehensive surveys and monitoring programs assessing heavy metals contained in farmland soils and crop tissues will be necessary for examining the risks to human health.

Occup Med, 2001 Jan-Mar, 16(1), 23 - 38
Sewage workers: toxic hazards and health effects; Mulloy KB; Municipal sewage workers provide an essential service in the protection of public health . The wastewater treatment process brings the worker in contact with multiple pathogens, toxic gases, chemicals, and physical hazards . Issues such as the prevalence of hepatitis A among wastewater treatment workers in the U.S . have not been well studied . There remains a controversy on the need to offer hepatitis A pre-exposure immunization . Health effects to some exposures, such as gram-negative bacteria and endotoxins, have been well studied among other workers, and preventive measures, such as permissible endotoxin levels, that have been established for these workers should be adopted for the wastewater treatment environment . Further study into mortality and morbidity rates among sewage workers and the relationship to exposures and the development of preventive measures is needed.

Folia Microbiol (Praha), 1999, 44(6), 673 - 6
Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi; Kahraman S et al.; Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungi Coriolus versicolor, Funalia trogii, Phanerochaete chrysosporium and Pleurotus sajor-caju . The effect of cotton stalk on decolorizing and COD removing capability was demonstrated . P . chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%, F . trogii (in 30% medium with cotton stalk)) by 51 and 55%, respectively.

J Chromatogr A, 2000 Oct 27, 896(1-2), 149 - 58
Improved routine speciation of organotin compounds in environmental samples by pulsed flame photometric detection; Bancon-Montigny C et al.; The high toxicity of the organotin species requires sensitive analytical methods in order to understand the origins of pollution and perform monitoring programs in the water cycle . The optimisation of a new detection method, pulsed flame photometric detection (PFPD), is reported for the simultaneous determination of butyl-, phenyl- and octyltins . The methodology of the experimental designs at two levels was used . It allows the evaluation of the influence of the three gas flow-rates on the peak heights and resolution between the closest peaks obtained using two different wavelengths of detection (390 and 611 nm) . The modelling of these two responses, according to second-order polynomials, leads to the precise adjustment of the operating conditions . PFPD has shown two significant improvements over conventional flame photometric detection: increased sensitivity (absolute detection limits: 0.07 to 2 pg as Sn) and greater selectivity, whatever the wavelength used . This new analytical process was validated by the analysis of certified reference material and spiked river water . It was used in routine analysis of environmental samples (wastewater, sludge, sand and oyster).

J Chromatogr A, 2000 Oct 27, 896(1-2), 95 - 104
Highly selective and efficient determination of US Environmental Protection Agency priority phenols employing solid-phase extraction and non-aqueous capillary electrophoresis; Morales S et al.; Non-aqueous capillary electrophoresis has been used in the separation of a complete list of 26 priority phenols included in the 8041 US Environmental Protection Agency method and the 76/464/EEC European Union directive . A highly selective and efficient separation was obtained when the background electrolyte used was 150 mM ammonium acetate dissolved in N-methylformamide-acetonitrile (75:25) . Solid-phase extraction was successfully assayed as an enrichment strategy for the analysis of low-concentration samples . A styrene-divinylbenzene functionalized cartridge provided excellent recoveries of phenols from water samples at neutral pH . The limits of quantification obtained permit the application of the proposed method to the determination of priority phenols in wastewater samples.

Environ Manage, 2001 Jan, 27(1), 37 - 46
A simple stream monitoring technique based on measurements of semiconservative properties of water; Stewart AJ; Correlative relationships exist among conductivity, alkalinity, and hardness in streams due to natural geological and climatological controls, but the relationships among these three water-quality factors can be altered strongly by inputs of ion-rich wastewaters . The degree of alteration can be monitored conveniently by use of a simple chemical perturbation index, computed by subtracting the sum of rank pairwise correlations among the conductivity, alkalinity, and hardness (for observations on each of these variables, measured through time) from 3.0 . The chemical perturbation index can be used to document or characterize spatiotemporal changes in stream water quality . This study explains the development of the index's concept and provides examples of its application in an extensive stream monitoring program used to assess ecological conditions in streams on the Department of Energy's Oak Ridge Reservation in east Tennessee, USA . The chemical perturbation index technique may be particularly useful in community-based stream monitoring programs because to its simplicity and low cost.

J Hazard Mater, 2000 Dec 30, 80(1-3), 33 - 42
The removal of heavy metal from aqueous solutions by sawdust adsorption - removal of copper; Yu B et al.; Locally available sawdust, a byproduct of the world industry, was found to be a low cost and promising adsorbent for the removal of copper(II) from wastewater . In this work, adsorption of copper on sawdust has been studied by using batch techniques . The equilibrium adsorption level was determined to be a function of the solution pH, contact time, and sorbate concentration . The equilibrium adsorption capacity of sawdust for copper was obtained by using linear Freundlich and Langmuir isotherms . Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the maple sawdust . The results provide strong evidence to support the hypothesis of adsorption mechanism . It also supplies significant sawdust operation capacity data for engineering design.

Anal Chem, 2000 Nov 1, 72(21), 5280 - 4
Immunologic trapping in supported liquid membrane extraction
Thordarson E, Jonsson JA, Emneus J.
To obtain a high degree of selectivity in sample preparation, supported liquid membrane (SLM) extraction was combined with immunologic recognition . The SLM employs a hydrophobic polymer for supporting the immobilization of an organic solvent, thus forming a nonporous membrane . Said membrane separates the aqueous sample on one side (donor) from a receiving aqueous phase on the other (acceptor) . The extraction involves the partitioning of neutral compounds between the sample solution, continuously pumped alongside the membrane, and the membrane . From the membrane, reextraction takes place into a second aqueous phase containing antibodies specific for the target compound(s) . Hence, there is a formation of an antibody-antigen complex at the heart of the sample preparation (ImmunoSLM) . When the immunocomplex forms, the antigen can no longer redissolve in the organic membrane, thus being trapped in the acceptor . Consequently, the concentration gradient of free antigen over the membrane is ideally unaffected, this being the driving force for the process . With a surplus of antibody, the concentration of analyte in the receiving phase will easily exceed the initial sample concentration . In this work, the so formed immunocomplex was quantified on-line, using a fluorescein flow immunoassay in a sequential injection analysis (SIA) setup . The outlined ImmunoSLM-SIA scheme was successfully applied for the extraction of 4-nitrophenol from spiked water solutions as well as from a spiked wastewater sample, indicating that the immunoextraction can be suitable when dealing with difficult matrixes.

Ultrason Sonochem, 2000 Oct, 7(4), 255 - 9
Sonochemical and photochemical oxidation of organic matter; Naffrechoux E et al.; Recent developments in sonochemistry have led us to study its use to treat water and wastewater . The effects of ultrasound wave in hydrophilic chemical oxidations are mainly due to hydroxyl radical production during the cavitation-induced water decomposition . Currently, the sonochemical destruction of aromatic compounds in water solution is obtained with low rates . The aim of this work is to evaluate the efficiency of the sonochemical effect in conjunction with a photochemical irradiation . Taking phenol as an example, the combined action of sonochemistry and photochemistry has been considered in a 'sonuv' reactor . An important enhancement of the degradation rate of phenol has been observed . It may be the result of three different oxidative processes: direct photochemical action, high frequency sonochemistry and reaction with ozone (produced by UV irradiation of air) . The process has been successfully tested to lower the chemical oxygen demand of a municipal wastewater.

Chemosphere, 2000 Nov, 41(10), 1611 - 20
Toxicity and detoxification of Swedish detergents and softener products; Pettersson A et al.; Detergents and softeners are used in large quantities and some of their ingredients are highly toxic to aquatic organisms . In the present study the acute toxicity to Daphnia magna was determined for 26 detergents and five softener Swedish products . Only one of the detergents had a 48-h EC50 > 100 mg/l . The 48-h EC50 for the other 25 detergents ranged from 4 to 85 mg/l . The 48-h EC50 for the five softeners ranged from 15 to 166 mg/l . Detoxification tests, with and without inoculum of sewage organisms, showed that all tested products were detoxified to some extent after 16 days and that the rate of detoxification was considerably higher with addition of sewage organisms . Toxicity to D . magna of the detergents and softeners, and the biotic detoxification rate was correlated with the concentration of surfactants used in formulating the products (more surfactants increased toxicity and a slower rate of detoxification) . These results emphasize the importance of biological purification of domestic wastewater containing detergents and a suggested development of less toxic and more easily degradable surfactants.

Chemosphere, 2000 Nov, 41(10), 1519 - 27
The cytotoxic effect of wastewater from the phosphoric gypsum depot on common oak (Quercus robur L.) and shallot (Allium cepa var . ascalonicum); Pavlica M et al.; The effect of wastewater from a phosphoric gypsum depot on common oak, Quercus robur L., at cytogenetical level was studied . Allium-test was used as a control . The treatment of common oak seedlings with wastewater under laboratory conditions caused mitodepressive effect . Chromosome aberrations and mitotic irregularities were found . Cytogenetic analysis of common oak seedlings grown from acorns collected near the depot did not show changes in mitotic activity in comparison to control but the number of aberrations was higher than in control . In comparison to Alliumtest common oak was found to be more tolerant to wastewater from the phosphoric gypsum depot.

Chemosphere, 2000 Dec, 41(11), 1733 - 40
EOX and organochlorine compounds in fish and ringed seal samples from Lake Ladoga, Russia; Kostamo A et al.; Information about the pollution of Lake Ladoga, the largest lake in Europe, has been controversial . Various effluents and drainage waters affect the quality of the lake water . Wastewaters have caused eutrophication of parts of Lake Ladoga, but concentrations of persistent organic pollutants in the lake's food webs are poorly understood . In this study, concentrations of some organochlorine compounds, chlorophenols (CPs), and extractable organic halogen (EOX) were determined in smelt (Osmerus eperlanus), vendace (Coregonus albula), pikeperch (Lucioperca lucioperca), whitefish (Coregonus lavaretus), and the Ladoga seal (Phoca hispida ladogensis) from the northern part of the lake . The concentrations of organochlorine compounds in fish were low . Concentrations were between 0.07 and 0.15, 0.65 and 1.0, and 0.29 and 0.48 mg/kg lipids for hexachlorobenzene, total polychlorinated biphenyl (PCB) and p,p'-DDE, respectively . The results indicated biomagnification from smelt and vendace to pikeperch and ringed seal . In ringed seals, concentrations of PCB and DDT were 12 and 29 times higher than in fish used by ringed seals as major food sources.

Chemosphere, 2000 Aug, 41(3), 311 - 21
An approach for assessment of water quality using semipermeable membrane devices (SPMDs) and bioindicator tests; Petty JD et al.; As an integral part of our continued development of water quality assessment approaches, we combined integrative sampling, instrumental analysis of widely occurring anthropogenic contaminants, and the application of a suite of bioindicator tests as a specific part of a broader survey of ecological conditions, species diversity, and habitat quality in the Santa Cruz River in Arizona, USA . Lipid-containing semipermeable membrane devices (SPMDs) were employed to sequester waterborne hydrophobic chemicals . Instrumental analysis and a suite of bioindicator tests were used to determine the presence and potential toxicological relevance of mixtures of bioavailable chemicals in two major water sources of the Santa Cruz River . The SPMDs were deployed at two sites; the effluent weir of the International Wastewater Treatment Plant (IWWTP) and the Nogales Wash . Both of these systems empty into the Santa Cruz River and the IWWTP effluent is a potential source of water for a constructed wetland complex . Analysis of the SPMD sample extracts revealed the presence of organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) . The bioindicator tests demonstrated increased liver enzyme activity, perturbation of neurotransmitter systems and potential endocrine disrupting effects (vitellogenin induction) in fish exposed to the extracts . With increasing global demands on limited water resources, the approach described herein provides an assessment paradigm applicable to determining the quality of water in a broad range of aquatic systems.

Appl Environ Microbiol, 2000 Nov, 66(11), 5092 - 8
Heavy metal coprecipitation with hydrozincite {Zn(5)(CO(3))(2)(OH)(6)} from mine waters caused by photosynthetic microorganisms; Podda F et al.; An iron-poor stream of nearly neutral pH polluted by mine tailings has been investigated for a natural phenomenon responsible for the polishing of heavy metals in mine wastewaters . A white mineralized mat, which was determined to be hydrozincite {Zn(5)(CO(3))(2)(OH)(6)} by X-ray diffraction analysis, was observed in the stream sediments mainly in spring . The precipitate shows a total organic matter residue of 10% dry weight and contains high concentrations of Pb, Cd, Ni, Cu, and other metals . Scanning electron microscopy analysis suggests that hydrozincite is mainly of biological origin . Dormant photosynthetic microorganisms have been retrieved from 1-year-old dry hydrozincite . The autofluorescent microorganisms were imaged by a scanning confocal laser microscope . A photosynthetic filamentous bacterium, classified as Scytonema sp . strain ING-1, was found associated with microalga Chlorella sp . strain SA1 . This microbial community is responsible for the natural polishing of heavy metals in the water stream by coprecipitation with hydrozincite.

Anal Chem, 2000 Oct 15, 72(20), 4979 - 84
Room temperature sonolysis-based advanced oxidation process for degradation of organomercurials: application to determination of inorganic and total mercury in waters by flow injection-cold vapor atomic absorption spectrometry
Capelo JL, Lavilla I I, Bendicho C.
A new oxidation method based on room-temperature ultrasonic irradiation (sonolysis) is proposed for conversion of organomercurials into inorganic mercury and subsequent determination by flow injection-cold vapor atomic absorption spectrometry . This advanced oxidation process eliminates the need for chemical oxidants, high temperature, and pressure for degradation of organomercurials so that total mercury can be determined with sodium tetrahydroborate(III) or tin(II) chloride as reducing agents . Complete oxidations can be accomplished within 3 min, using a 40% sonication amplitude (100 W nominal power) provided by a probe ultrasonic device (20 kHz frequency) and a 1 mol L(-1) HCl liquid medium . The presence of HCl was seen to be necessary for fast oxidation of organomercurials, in contrast to other chemical oxidants such as H2O2 or HNO3 which yielded incomplete oxidation . Further advantages of the proposed method over existing methods which are currently employed for oxidation prior to total Hg determination are the removal of hazardous wastes and the decreased risk of Hg losses by volatilization . Oxidation kinetics indicated a pseudofirst-order reaction with apparent rate constants (k) of 3.2 x 10(-2) and 1.6 x 10(-2) s(-1) for methylmercury and phenylmercury, respectively . Oxidation experiments in the presence of foreign substances acting as OH radical scavengers showed a tolerance at least up to a concentration of 1000 mg L(-1) . Likewise, model wastewaters with chemical oxygen demand of up to 1000 mg L(-1) could be processed without diminishing the oxidation efficiency . The method was applied to determination of inorganic and total mercury in simulated wastewaters and spiked environmental waters in combination with selective reduction.

J Agric Food Chem, 2000 Oct, 48(10), 5061 - 7
Decreased superoxide anion production in cultured human promonocyte cells (THP-1) due to polyphenol mixtures from olive oil processing wastewaters; Leger CL et al.; The purpose of this study was to examine whether human monocytic line THP-1 after differentiation into adherent macrophages, taken as a model of human macrophages implicated in atheroma, is able to produce lower quantities of O(2)(*)(-) either in the presence of polyphenol-rich olive oil wastewater (OWW) fractions or after OWW preincubation and withdrawal from the medium . In these respective conditions, the purpose was to examine the scavenging activity and the cell action of OWW toward O(2)(*)(-) production . It was clearly seen that OWW fractions lowered the O(2)(*)(-) production in both conditions, leading to the conclusion that they were able to scavenge O(2)(*)(-) and to depress O(2)(*)(-) production in the cell . Given the role of O(2)(*)(-) in LDL oxidation and oxidized LDL in atheroma, these results support an antiatherogenic role of OWW and its potential utilization as a food complement.

J Agric Food Chem, 2000 Oct, 48(10), 4839 - 43
Development and characterization of a flavoring agent from oyster cooker effluent; Kim DS et al.; The general composition of concentrated oyster cooker effluent (OCE) was 80% moisture, 6.7% total nitrogen, 2.4% glycogen, and 8.5% ash . Optimum conditions for enzymatic hydrolysis of OCE were 50 degrees C, 2 h of reaction time, 0.1% amylase mixture (alpha-amylase plus glucoamylase), and 0.2% protease NP . Hydrolysis of OCE led to an increase in free amino acids, with taurine comprising approximately 20% of the total . Inosine monophosphate was predominant (456 mg/100 g) among nucleotides and related compounds . Enzyme hydrolysis increased extractable nitrogen by approximately 2-fold . Trimethylamine, trimethylamine oxide, and total creatinine levels were not affected by enzyme treatment . Predominant aroma-active components of enzyme-hydrolyzed OCE included 2-acetyl-1-pyrroline and 3-(methylthio)propanal . Results of this study may help alleviate the wastewater disposal problem currently caused by OCE.

J Hazard Mater, 2000 Dec 1, 79(1-2), 117 - 31
Adsorption studies on Citrus reticulata (fruit peel of orange): removal and recovery of Ni(II) from electroplating wastewater; Ajmal M et al.; The ability of fruit peel of orange to remove Zn, Ni, Cu, Pb and Cr from aqueous solution by adsorption was studied . The adsorption was in the order of Ni(II)>Cu(II)>Pb(II)>Zn(II)>Cr(II) . The extent of removal of Ni(II) was found to be dependent on sorbent dose, initial concentration, pH and temperature . The adsorption follows first-order kinetics . The process is endothermic showing monolayer adsorption of Ni(II), with a maximum adsorption of 96% at 50 degrees C for an initial concentration of 50 mg l(-1) at pH 6 . Thermodynamic parameters were also evaluated . Desorption was possible with 0.05 M HCl and was found to be 95.83% in column and 76% in batch process, respectively . The spent adsorbent was regenerated and recycled thrice . The removal and recovery was also done in wastewater and was found to be 89% and 93.33%, respectively.

Sci Total Environ, 2000 Oct 16, 261(1-3), 75 - 89
Detection of localized methylmercury contamination by use of the mussel adductor muscle in Minamata Bay and Kagoshima Bay, Japan; Haraguchi K et al.; Based on our previous finding that the concentrations of total mercury in mussel adductor muscle approximated those of methylmercury, we compared concentrations of total mercury in the adductor muscle of the mussel Mytilus galloprovincialis, collected from four sites around Minamata City from 1993 to 1995 and four sites in Kagoshima Bay from 1997 to 1998, to assess the level of localized methylmercury contamination . Though the input of mercury from the chemical plant had stopped by around 1970, concentrations of total mercury in the mussel adductor muscle were higher at two sites (26-121 ng/g, n = 135) near the main fallout of wastewater from the chemical plant in Minamata Bay than at the other sites, i.e . two sites 1-5 km from the former sites in Minamata City (6-28 ng/g, n = 52), and all sites in Kagoshima Bay (2-30 ng/g, n = 287) . The localized methylmercury contamination around the chemical plant in Minamata Bay was documented also by our sensitive analysis of mercury concentrations in seawater and sediment samples . The survey of concentrations of total mercury in the mussel adductor muscle seems to be useful for monitoring the methylmercury contamination in coastal areas.

Int J Syst Evol Microbiol, 2000 Sep, 50 Pt 5, 1821 - 7
Janibacter terrae sp . nov., a bacterium isolated from soil around a wastewater treatment plant; Yoon JH et al.; A bacterial strain, CS12T, which was isolated from soil around a wastewater treatment plant, was subjected to a polyphasic taxonomic study using phenotypic characterizations and genetic methods . The cell wall of strain CS12T contains meso-diaminopimelic acid as the diamino acid but no arabinose and galactose . The predominant menaquinone is MK-8(H4) . Mycolic acids are absent . Strain CS12T has a cellular fatty acid profile containing saturated, unsaturated, branched and 10-methyl fatty acids . The major fatty acids are iso-C16:0, C18:1 omega9c and anteiso-C17:0, The G+C content is 69 mol% . A phylogenetic tree based on 16S rDNA sequences showed that strain CS12T forms an evolutionary lineage within the radiation enclosing the members of the family Intrasporangiaceae and, in particular, a coherent cluster with Janibacter limosus DSM 11140T . The level of 16S rDNA similarity between strain CS12T and J . limosus DSM 11140T is 98.7% . The phenotypic characteristics and DNA-DNA relatedness data indicate that strain CS12T should be distinguished from J . limosus DSM 11140T . Therefore, on the basis of the data presented, a new species of the genus Janibacter, Janibacter terrae, is proposed . The type strain of the new species is strain CS12T (= KCCM 80001T = JCM 10705T).

Sci Total Environ, 2000 Oct 9, 260(1-3), 45 - 55
Mercury in the River Nura and its floodplain, Central Kazakhstan: II . Floodplain soils and riverbank silt deposits; Heaven S et al.; A unique and serious case of mercury pollution has occurred in the River Nura and its floodplain in Central Kazakhstan, where mercury-rich wastewater from an acetaldehyde plant was discharged largely without treatment for several decades . In the river, the mercury became associated with millions of tonnes of power station fly ash, forming a new type of deposit known as 'technogenic silt' . During spring floods these highly contaminated silts are transported downstream and are dispersed over the floodplain, leading to widespread contamination of the land . A detailed survey of the floodplain was carried out to investigate the extent of pollution and to assess the need for remediation . Total mercury concentrations in the topsoils of the floodplain ranged from near background levels to over 100 mg/kg . Mercury concentrations in river bank deposits were found to range from a mean of 73.3 mg/kg Hg in the most contaminated section of the river to a mean of 13.4 mg/kg Hg at a distance of 70 km downstream . Concentrations were lower than corresponding concentrations in the riverbed within the first 25 km from the source of the pollution, but thereafter they were significantly higher . The results show that over the past 30-40 years a large proportion of the contaminated sediments from the river was deposited on the 70 km of banks and in the floodplain below the pollution source . Topsoils of the floodplain and silt deposits located on or close to the river banks contain an estimated 53 t and 65 t of mercury respectively, with an additional 62 t in a small natural swamp which was formerly used as a waste disposal area . The contamination is serious but relatively localized, with > 70% of the total amount of mercury in topsoils and > 90% of mercury in river bank deposits located within 25 km from the source.

Arch Environ Contam Toxicol, 2000 Nov, 39(4), 469 - 79
A comparison of selected diversity, similarity, and biotic indices for detecting changes in benthic-invertebrate community structure and stream quality; Lydy MJ et al.; Implementation of advanced wastewater treatment at the two municipal wastewater-treatment plants for Indianapolis, Indiana, resulted in substantial improvement in the quality of the receiving stream and significant changes in the benthic-invertebrate community . Diversity, similarity, and biotic indices were compared to determine which indices best reflected changes in the composition of the biota in the river . None of the indices perfectly reflected the changes in river quality or community structure . Similarity indices, especially percentage similarity, exhibit the most promise of the three classes of indices . Diversity indices were least useful, wrongly indicating that water quality deteriorated after the upgrade of the wastewater-treatment plants . The most descriptive tool in analyzing the data was the percentage of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa present . Using a mixture of indices and other analytical tools, such as EPT, in the analysis of biological data will ensure the most effective investigations of water quality.

J Colloid Interface Sci, 2000 Oct 15, 230(2), 367 - 376
Preparation and Characterization of Ceramic Hollow Microspheres for Heavy Metal Ion Removal in Wastewater; Bae E et al.; Ceramic hollow microspheres (CHMSs) were prepared to use as supports for the removal of heavy metal ions from industrial waste-water . A water extraction sol-gel technique was used to prepare porous CHMS by extracting water from an emulsion of LUDOX (silica colloid; SiO(2), Aldrich Co.) and 2-ethyl-1-hexanol . Experiments were conducted to control pore size, wall thickness, and separation yield by examining the ratio of precursors (LUDOX and 2-ethyl-1-hexanol), catalyst (NH(4)OH), sintering temperature, surfactant (SPAN 80), extractant (n-butanol), stirring speed, and concentration of precursor (LUDOX) . The results revealed that the optimum conditions were 20 ml of a 10 wt% solution of LUDOX, 10 ml of NH(4)OH, a sintering temperature of 500 degrees C, 0.4 ml of SPAN 80, 200 ml of n-butanol, and a stirring speed of 730 rpm/100 ml of 2-ethyl-1-hexanol . CHMSs were impregnated in Cyanex 272 and examined for their ability to remove heavy metal ions from a solution . Based on an experiment involving the removal of metal ions using CHMSs that were prepared under optimum conditions, Zn ion was removed at a level of 0.354 mmol/g at pH 4, which was about twice the adsorption capacity of CHMSs prepared by Wilcox (Mater . Res . Soc . Symp . Proc . 346, 201 (1994)) .

Sci Total Environ, 2000 Aug 21, 258(1-2), 5 - 19
Cost-benefit analysis of the use of TBT: the case for a treatment approach; Abbott A et al.; The current climate of hostility towards the use of tributyltin (TBT) as an active ingredient in ship anti-fouling paint appears to be based on a very biased assessment of its environmental impact . While many national and international regulatory agencies are moving towards further restriction, and a complete ban is under active discussion, a number of factors appear to have been ignored . The economic impact of a ban on TBT when no adequate substitute exists could be substantial . Environmentally, consequences would include a substantial increase in the consumption of fossil fuel, with corresponding increases in carbon dioxide and sulphur dioxide emissions; the construction of more vessels; the transfer of ship-building, ship-repairing and ship-breaking activities from well-regulated to unregulated or under-regulated areas in the developing world; and a shift from sea transport to less environmentally acceptable forms of transport . Experience in Europe and other parts of the developed world shows that existing restrictions, where they are properly enforced, are probably adequate to alleviate the environmental damage associated with TBT . Some existing legislation acts to inhibit the search for effective substitutes . The environmental benefits of TBT have been ignored . Little thought has been given to a technical, rather than a legislative solution to controlling TBT inputs to the environment . A method is described for treating TBT-contaminated wastewaters, which has been successfully tested in prototype at full scale . Legislative measures against TBT will do nothing to address the problem of the existing backlog of contaminated material, nor even to permit the IMO proposal for the removal of TBT from all ships by 2008 to be successfully concluded in an environmentally safe manner, since no provision has been made for the disposal of the existing TBT; most probably it will be dumped in environmentally sensitive, unregulated areas in the developing world.

Mem Inst Oswaldo Cruz, 2000 Sep-Oct, 95(5), 713 - 6
Factors that can interfere with virus concentration from wastewater when using Zeta Plus 60S filter membranes; Queiroz AP et al.; Zeta plus filter membranes (ZP60S) have been shown to be efficient for rotavirus concentration from wastewater and for the reduction of cytotoxicity for cell cultures . Recently a variability in both properties was observed . In view of the low costs and the high virus recovery rates obtained in the past, we re-evaluated the application of ZP60S filter membranes for virus concentration from environmental samples . Some factors that could interfere with the concentration strategy using ZP60S were also considered and assessed including the type of water to be filtered and the possible release of toxic substances from the membrane matrix during filtration.

Anal Chem, 2000 Sep 1, 72(17), 3995 - 4002
Electrochemical study of chemically modified and screen-printed graphite electrodes with
Prodromidis MI, Veltsistas PG, Karayannis MI.
The preparation and electrochemical characterization of graphite electrodes modified with hexadecylpyridinium-bis(chlorilato)-antimonyl(V), {SbVO(CHL)2}Hex, (CMEs) as well as their behavior as electrocatalysts toward the oxidation of sulfide are described . The self-exchange rate constant ko of immobilized {SbVO(CHL)2}Hex and the effect of the surface coverage were evaluated . {SbVO(CHL)2}Hex is a new compound . Synthesis protocol and some identification studies are given . The fabrication of screen-printed electrodes (SPEs) with a mixture of 5% (w/ w) {SbVO(CHL)2}Hex/graphite powder in 1.5% (w/v) ethyl cellulose in 2-butoxyethyl acetate is also described . SPEs, poised at +0.08 mV versus Ag/AgCl, at pH 6.5 were utilized for the determination of sulfide in simulated wastewater samples . Interference of various compounds was also tested . The proposed method correlates well with a colorimetric method . Calibration graphs were linear over the range 0.01-0.7 mM sodium sulfide and the CV was 2.8% (n = 8) for 0.1 mM sodium sulfide . Recovery ranged from 94 to 102% . Both {SbVO(CHL)2}Hex CMEs and SPE showed very good storage stability . {SbVO(CHL)2}Hex CMEs showed poor working stability in contrast to printed electrodes, which operated with no remarkable loss of their initial activity for more than 100 runs.

J Chromatogr A, 2000 Aug 11, 889(1-2), 195 - 209
Inter-laboratory comparison of liquid chromatographic techniques and enzyme-linked immunosorbent assay for the determination of surfactants in wastewaters; Castillo M et al.; Seven laboratories participated in an inter-laboratory comparison exercise within the framework of the PRISTINE, SANDRINE and INEXsPORT European Union Projects . Solid-phase extraction (SPE) methodologies were used for the extraction of target analytes from wastewaters . The analytical strategies were based on liquid chromatography (LC) coupled to mass spectrometric (MS) or to fluorescent (FL) detection in all cases with the exception of one laboratory using a test-tube enzyme-linked immunosorbent assay kit . Samples were spiked with the surfactants nonylphenolpolyglycol ether, coconut diethanolamide, linear alkylbenzene sulfonate, nonylphenolpolyglycol ether sulfate, alkylpolyglycol ether and secondary alkane sulfonate . After enrichment on previously conditioned SPE cartridges, the SPE cartridges were distributed among the participating laboratories without the information about the amount of spiked surfactants . In addition, SPE cartridges loaded with a real-world environmental sample containing a tannery wastewater were also analyzed . The results of the programme showed that SPE followed by LC-MS techniques are reliable for the surfactants determination at submicrogram to microgram per liter levels in wastewaters . Inter-laboratory precision values were calculated as the reproducibility relative standard deviation (RSD(R)) which was determined from the reproducibility standard deviation (sR) and the average concentration at a particular concentration level . When data from all laboratories were pooled, the RSD(R) values ranged from 5.1 to 28.3% for the determination of target analytes . The most accurate result corresponded to that given for linear alkylbenzene sulfonates . Taking into account that different methodologies were used (including non-chromatographic techniques) and the complexity of the samples analyzed, it can be considered that acceptable reproducibility values were obtained in this inter-laboratory study.

East Mediterr Health J, 1999 Sep, 5(5), 912 - 21
Helminthic infections associated with the use of raw wastewater for agricultural purposes in Beni Mellal, Morocco; Habbari K et al.; We aimed to determine the possible risks associated with raw wastewater use for agricultural purposes, particularly the transmission of helminthic infections among children . In a randomly-selected sample of 1343 children, 740 of them were from five regions using raw wastewater for agriculture, while 603 were from four control regions that do not use such water . The prevalence of helminthic infection was found to be significantly higher among children in regions using wastewater, compared to control regions . Behavioural characteristics and public water supply were found to be associated with higher infection rates . Adequate treatment of wastewater as well as public health education are highly recommended.

Environ Manage, 2000 Nov, 26(5), 577 - 584
Nonpoint-Source Agricultural Hazard Index: A Case Study of the Province of Cremona, Italy; TREVISAN M et al.; This paper reports the results of a study aimed at the evaluation of the hazard level of farming activities in the province of Cremona, Italy, with particular reference to groundwater . The applied methodology employs a parametric approach based on the definition of potential hazard indexes (nonpoint-source agricultural hazard indexes, NPSAHI) . Two categories of parameters were considered: the hazard factors (HF), which represent all farming activities that cause or might cause an impact on groundwater (use of fertilizers and pesticides, application of livestock and poultry manure, food industry wastewater, and urban sludge), and the control factors (CF), which adapt the hazard factor to the characteristics of the site (geographical location, slope, agronomic practices, and type of irrigation) . The hazard index (HI) can be calculated multiplying the hazard factors by the control factors and, finally, the NPSAHI are obtained dividing HI into classes on a percentile basis using a scale ranging from 1 to 10 . Organization, processing, and display of all data layers were performed using the geographical information system (GIS) ArcView and its Spatial Analyst extension . Results show that the potential hazard of groundwater pollution by farming activities in the province of Cremona falls mainly in the fifth class (very low hazard).

Lett Appl Microbiol, 2000 Aug, 31(2), 157 - 62
Effect of disinfection upon dissolved organic carbon (DOC) in wastewater: bacterial bioassays; Arana I et al.; Quantitative and qualitative changes in organic matter content of wastewater effluents attributable to chlorination and ozonation have been analysed using bioassays as well as organic carbon direct measures . Bioassays were carried out using the bacterial populations of wastewater and two Escherichia coli strains as test micro-organisms . Our results indicate that pure strains present some advantages over indigenous bacteria . Although wastewater bacterial populations are better adapted to growth in wastewater, E . coli strains are more sensitive to changes in dissolved organic carbon (DOC) content . Moreover, the use of pure cultures allows estimation of the portion of DOC which can be converted in cell biomass, the assimilable organic carbon (AOC) . Finally, the results obtained using prototrophic and the auxotrophic strains of E . coli suggested that ozonation alters the amino acid composition of wastewater while chlorination does not change the quantity nor the quality of the DOC present in effluents.

J Environ Sci Health B, 2000 Sep, 35(5), 623 - 43
Phytoavailability and extractability of potassium, magnesium and manganese in calcareous soil amended with olive oil wastewater; Gallardo-Lara F et al.; Land disposal of olive oil wastewater using it as a soil amendment requires a knowledge of the effects that its application may produce on the status of the mineral nutrients in the plant-soil system . A pot experiment using calcareous soil was performed in a growth chamber to examine the effects of olive oil wastewater on the availability and postharvest soil extractability of K, Mg and Mn . The experiment included 6 treatments: two rates of olive oil wastewater, two mineral fertilizer treatments containing K (which supplied K in amounts equivalent to the K supplied by the olive oil wastewater treatments), a K-free mineral fertilizer treatment, and a control . The pots were sown with ryegrass as the test plant, harvesting 3 times at intervals of one month . Olive oil wastewater has demonstrated a considerable capacity for supplying K that can be assimilated by the plant, tending in fact to surpass the mineral potassium fertilizer tested . The application of olive oil wastewater tends to reduce the concentration of Mg in the plant, similarly to the effect of adding mineral potassium fertilizer . An enhancement of Mn availability takes place in the soil amended with olive oil wastewater, which on occasion has produced Mn concentrations in plant that could be considered phytotoxic or at least excessive . After harvesting, we observed an increase in the amount of exchangeable K in soil with added industrial wastewater . However, these increases are lower than those in soil treated with mineral potassium fertilizer . The levels of exchangeable, carbonate-bound, organic-bound and residual Mg in soil were higher in treatments incorporating olive oil wastewater than in those with added mineral K, with the opposite tendency occurring in the amount of Fe-Mn oxides-bound Mg in soil . Treatments based on olive oil wastewater, especially in high doses, increased the amount of exchangeable and carbonate-bound Mn in soil, in comparison with treatments adding mineral fertilizers with or without K . In contrast, the addition of industrial wastewater caused a drop in the amount of Fe-Mn oxides-bound and organic-bound Mn in soil.

J Occup Environ Med, 2000 Aug, 42(8), 821 - 6
Prevalence of antibody to hepatitis A virus in drinking water workers and wastewater workers in Texas from 1996 to 1997; Weldon M et al.; To determine if wastewater workers had a higher prevalence of antibody to hepatitis A virus (anti-HAV) than drinking water workers, a convenience sample of Texas wastewater and drinking water workers was evaluated for risk factors by questionnaire and tested for anti-HAV . A total of 359 wastewater and 89 drinking water workers participated . Anti-HAV positivity was 28.4% for wastewater and 23.6% for drinking water workers . After adjustment for age, educational attainment, and Hispanic ethnicity, the odds ratio for the association between anti-HAV positivity and wastewater industry employment was 2.0 (95% confidence interval, 1.0 to 3.8) . Among wastewater workers, never eating in a lunchroom, > or = 8 years in the wastewater industry, never wearing face protection, and skin contact with sewage at least once per day were all significantly associated with anti-HAV positivity in a model that adjusted for age and educational attainment . Wastewater workers in this study had a higher prevalence of anti-HAV than drinking water workers, which suggested that wastewater workers may have been at increased risk of occupationally acquired hepatitis A . Work practices that expose workers to wastewater may increase their risk.

J Chromatogr A, 2000 Jul 21, 886(1-2), 271 - 82
Identification of reactive dyes in spent dyebaths and wastewater by capillary electrophoresis-mass spectrometry; Poiger T et al.; Capillary electrophoresis with diode array detection and mass spectrometry combined with solid-phase extraction were employed for the identification of reactive vinylsulfone and chlorotriazine dyes and their hydrolysis products in spent dyebaths and raw and treated wastewater . Recoveries of dyes from treated wastewater as their tetrabutylammonium ion-pairs using C18 reversed-phase cartridges ranged from 81 to 121% . Detection limits in sewage effluent of the different dyes and hydrolysis products ranged from 23 to 42 microg/l . The method was successfully applied to the detection of the hydrolysis products of five reactive dyes in influents and effluents of a municipal wastewater treatment plant receiving dyehouse effluents.

Cent Eur J Public Health, 2000 Jul, 8 Suppl, 88 - 9
H2O2/UV/air oxidation of organic contaminants in the gas-sparged cyclone reactor; Artuna E et al.; In the last decade advanced oxidation processes (AOPs) have been gaining importance for destruction of waste as cleaner methods enabling conversion of organic contaminants to harmless species . Photodegradation processes in the presence of hydrogen peroxide (H2O2), ozone (O3) and titanium dioxide (TiO2) are most frequently offered for wastewater treatment . The novel gas-sparged reactor equipped with UV lamp proved to be an efficient system for photochemical degradation . In this investigation 80 ppm aqueous solution of phenol was treated for 40 minutes . 13% of phenol was eliminated in the UV/air system and 73% in the UV/H2 O2/air system at 80 l/min air flowrate . Air sparging did not result in phenol removal with the gas phase.

Can J Microbiol, 2000 Aug, 46(8), 736 - 40
Identification and characterization of nuclease activities in anaerobic environmental samples; Ruiz TR et al.; DNA-degrading activity from anaerobic samples of bovine ruminal fluid, primary anaerobic digestor wastewater, freshwater sediments, and marine sediments was observed in the presence of 5 mM EDTA . Nuclease activity experiments involved exposing salmon chromosomal DNA to the environmental samples in 50 mM pH 7.2 buffer, incubating at 37 degrees C, and subjecting the products to electrophoresis . The same stock and concentration of EDTA used in these assays (5 mM) completely inhibited commercial grade DNase . Nuclease activity in two of the samples, ruminal fluid and wastewater, was further characterized . DNA degradation in the ruminal sample was significantly reduced when EDTA or citrate concentrations were increased to 50 mM or above . DNA degradation activity in ruminal fluid was associated with material that passed through a 0.22-micron filter, but wastewater activity was associated with material retained by a 3-micron filter . Degradation activity in the wastewater was resistant to heat pretreatment, whereas the rumen activity was heat-labile (70 degrees C, 60 min) . These results demonstrated the biochemical complexity of these two environments and that high molecular weight DNA has a short half-life in these anaerobic environments.

Anal Chem, 2000 Jul 15, 72(14), 3379 - 82
Photocatalytic sensor for chemical oxygen demand determination based on oxygen electrode; Kim YC et al.; The construction and performance evaluation of a novel Chemical Oxygen Demand (COD) sensor is described . The sensor measures, using an oxygen electrode, a decrease of dissolved oxygen of a given sample resulting from photocatalytic oxidation of the organic compounds therein . As the photocatalyst, titanium dioxide (TiO2) fine particles adsorbed on a translucent poly(tetrafluoroethylene) (PTFE) membrane was used . The oxygen electrode with the membrane attached on its tip was used as the sensor probe . The operation characteristics of the sensor are demonstrated using an artificial wastewater and real water samples from lakes in Japan . This method is considered to be reliable, in that the observed parameter is close to the theoretical definition of chemical oxygen demand (COD), the amount of oxygen consumed for oxidation of organic compounds.

J Hazard Mater, 2000 Sep 15, 76(2-3), 237 - 49
Removal of chlorophenols from aqueous solution by fly ash; Kao PC et al.; Fly ash from coal-fired thermal power plants can be used for the removal of 2-chlorophenol (2-CP) and 2,4-dichlorophenol (2,4-DCP) with enthalpy changes of about -3 kcal/mol . The amounts of 2-CP and 2,4-DCP removed are affected by the pH value of the solution . The efficiency of removal improves when the pH value is less than the pK(a) values of 2-CP and 2,4-DCP, respectively . The adsorbed amount of chlorophenol by fly ash is also affected by particle diameter, carbon content, and the specific surface area of the ash used in this study . As expected, more adsorption takes place with fly ash of higher carbon content and larger specific surface area . Moreover, the adsorbed amount of chlorophenol is not influenced by the matrix in the wastewater, as shown by studying the removal of 2-CP and 2, 4-DCP in wastewater from a synthetic fiber plant . Chlorophenols in the wastewater were also removed efficiently through a fly ash column, with breakthrough times being inversely proportional to flow rates.

Can J Microbiol, 2000 Jul, 46(7), 653 - 9
Changes in the metabolism of the microalga Chlorella vulgaris when coimmobilized in alginate with the nitrogen-fixing Phyllobacterium myrsinacearum; Gonzalez-Bashan LE et al.; In an agroindustrial wastewater pond, a naturally occurring unicellular microalga, Chlorella vulgaris, was closely associated with the terrestrial plant-associative N2-fixing bacterium Phyllobacterium myrsinacearum . When the two microorganisms were artificially coimmobilized in alginate beads, they shared the same internal bead cavities, and the production of five microalgal pigments increased, but there were no effects on the number of the cells or the biomass of the microalga . The association, however, reduces the ability of C . vulgaris to remove ammonium ions and phosphorus from water . The bacterium produced nitrate from ammonium in synthetic wastewater with or without the presence of the microalga, and fixed nitrogen in two culture media . Our results suggest that interactions between microalgae and associative bacteria should be considered when cultivating microalgae for wastewater treatment.

Int J Occup Environ Health, 2000 Jul-Sep, 6(3), 177 - 82
Predictors of blood lead levels in agricultural villages practicing wastewater irrigation in Central Mexico; Cifuentes E et al.; To investigate whether the agricultural use of untreated wastewater (i.e . crop irrigation) was associated with elevated blood lead levels in a farming population in the Mezquital Valley and which risk factors, other than exposure to untreated wastewater, were associated with elevated blood lead levels, lead levels were measured in venous blood obtained from 735 individuals . Blood samples were analyzed by atomic absorption spectrophotometry . Food habits and dietary intake were gathered by interview, using a semi-quantitative food-frequency questionnaire . The average blood lead level was 7.8 microg/dL (SD 4.66 microg/dL; range 1.2-36.7 microg/dL) . 23% of the study population had blood lead levels exceeding 10 microg/dL . The use of lead-glazed ceramics (LGC) was significantly associated with elevated lead levels (p = < 0.001) . Other significant variables included age, gender (males), and non-farming-related occupations (e.g., technicians, factory workers) . p = 0.005, 0.08, and 0.001, respectively . When the analysis was stratified by the use of LGC for food preparation, an inverse relationship between higher daily calcium intake and blood lead level was detected (beta = - 0.040, p = < 0.05) . Thus, blood lead levels were positively associated with the use of LGC . Calcium intake showed a protective effect, maybe by decreasing absorption of lead in the gastrointestinal tract . No association between occupational exposure to untreated wastewater or crop consumption and blood lead levels was detected . Further environmental and health surveillance is recommended.

Emerg Infect Dis, 2000 Jul-Aug, 6(4), 358 - 62
Seroprevalence of West Nile, Rift Valley, and sandfly arboviruses in Hashimiah, Jordan; Batieha A et al.; We conducted a serosurvey among patients of a health center in Hashimiah, a Jordanian town of 30,000 inhabitants located near a wastewater treatment plant and its effluent channel . Serum samples from 261 patients >/=5 years of age were assessed for immunoglobulin G (IgG) and IgM antibodies against West Nile, sandfly Sicilian, sandfly Naples, and Rift Valley viruses; the seroprevalence of IgG antibodies was 8%, 47%, 30%, and 0%, respectively . Female participants were more likely to have been infected than male . Persons living within 2 km of the treatment plant were more likely to have been infected with West Nile (p=0.016) and sandfly Sicilian (p=0.010) viruses . Raising domestic animals within the house was a risk factor for sandfly Sicilian (p=0.003) but not for sandfly Naples virus (p=0.148) . All serum samples were negative for IgM antibodies against the tested viruses . Our study is the first documentation of West Nile and sandfly viruses in Jordan and calls attention to the possible health hazards of living close to wastewater treatment plants and their effluent channels.

Environ Health Perspect, 2000 Jul, 108(7), A308 - 15
Bordering on environmental disaster; Schmidt CW; Millions of people live on the U.S.-Mexico border, drawn by employment opportunities from industry and agriculture, and booming growth is expected to continue in the coming decades . But the influx of people has long outstripped the capacity of border towns and cities to provide for their citizens, and a large percentage of the population lives in sprawling, underserviced shantytowns . Although investment in environmental infrastructure on both sides has led to improvements, shortages among necessities such as drinking water, wastewater treatment, and solid waste disposal are at crisis levels . In addition, a host of diseases including gastrointestinal infections, asthma, tuberculosis, multiple myeloma, systemic lupus erythematosus, hepatitis A, neural tube defects, and lead poisoning have been linked to environmental conditions on the border . Ongoing binational studies are attempting to define the breadth of the public and environmental health crisis and find ways to help make the border a healthier place.

Chemosphere, 1999 Feb, 38(4), 823 - 34
Analysis of volatile fatty acids in wastewater collected from a pig farm by a solid phase microextraction method; Yo SP; The main purpose of this study is to develop a reliable Solid Phase Microextraction (SPME) method for monitoring the concentration of volatile fatty acid (VFA) in the wastewater collected from pig farms . Ten volatile fatty acid species were spiked in 2 ml of swine wastewater and extracted with a carbowax coated extraction fiber to evaluate the accuracy and precision of the method . The fiber was introduced into a gas chromatography system by thermal desorption and detected by a mass spectrometer detector . The estimated method detection limits ranged from 11.5 mM/L for formic acid to 0.03 mM/L for heptanoic acid . The method is more sensitive than the sample direct injection method . The percentage recovery of analytes ranged from 77.3 for propanoic acid to 114.1 for formic acid at the spike level of 19.09 mM/L . The compound absorption rate varied significantly with the fiber absorption time for n-Valeric, isocaproic, n-caproic and heptanoic acids . An SPME method with twenty minutes fiber absorption and three minutes thermal desorption was tested in this study and resulted in good reproducibility for analyzing VFAs in swine wastewater . The method may be applied for scanning a wide spectrum of polar organic compounds in environmental samples.

Chemosphere, 2000 Oct, 41(8), 1287 - 94
Decolorization of textile wastewater by photo-fenton oxidation technology; Kang SF et al.; This paper describes the use of photo-fenton process for color removal from textile wastewater stream . The wastewater sample to be treated was simulated by using colorless polyvinyl alcohol (PVA) and reactive dyestuff of R94H . As a result, the hydroxyl radical (HO*) oxidation can effectively remove color, but the chemical oxygen demand (COD) was removed in a slight degree . The color removal is markedly related with the amount of HO* formed . The optimum pH for both the OH* formation and color removal occurs at pH 3-5 . Up to 96% of color can be removed within 30 min under the studied conditions . Due to the photoreduction of ferric ion into ferrous ion, color resurgence was observed after 30 min . The ferrous dosage and UV power affect the color removal in a positive way, however, the marginal benefit is less significant in the higher range of both . PVA as the major background COD of a textile wastewater stream inhibits the color removal insignificantly as its concentration increases.

Chemosphere, 2000 Oct, 41(8), 1155 - 60
Ground discarded tires remove naphthalene, toluene, and mercury from water; Gunasekara AS et al.; Ground discarded tires adsorb naphthalene, toluene, and mercury ions (Hg2+) from aqueous solutions . Their sorption properties and kinetics were determined by batch equilibration techniques at 20 degrees C . The isotherms were linear for naphthalene and toluene and their sorption coefficients were about 1340 and 255 (ml/g), respectively . Sorption of the organic compounds by the ground rubber particles was relatively fast (within 30 min) . However, the mercury isotherms were non-linear, and its sorption was slow as compared to the sorption of the organics . The rubber particles had a strong affinity for Hg2+ . These results show that ground discarded tires are effective in removing organic compounds and Hg2+ from wastewater and other contaminated environments . In addition it would be a useful, environmentally friendly use of discarded tires (one tire per year per capita is discarded in the United States).

Chemosphere, 2000 Oct, 41(8), 1137 - 47
Photochemistry of hydrolytic iron (III) species and photoinduced degradation of organic compounds . A minireview; Feng W et al.; On the basis of the research literature of the last fifty years, we have reviewed the photochemical properties of different hydrolytic Fe(III) species and the photodegradation of organic compounds in aqueous solutions initiated by them (mainly including low-molecular-weight Fe(III)-OH complexes, Fe(III) oxides (Fe2O3) and Fe(III) hydroxides (FeOOH)) . Furthermore, the feasibility and prospects of the novel photochemical methods of using Fe(III) salts and oxides in wastewater treatments are being discussed in this paper.

Sci Total Environ, 2000 Jun 22, 256(1), 39 - 57
An inventory of historical mercury emissions in maritime canada: implications for present and future contamination; Sunderlan EM et al.; Mercury is a longstanding concern in Maritime Canada due to high levels of contamination in a number of fish and bird species . The recycled component of past releases of anthropogenic mercury may be a significant source of ongoing pollution in many areas . Historical information on mercury releases can be used to quantify past and present anthropogenic contamination . We present an inventory of historical mercury emissions from anthropogenic sources in Maritime Canada for the years 1800-1995 . Long-term trends in mercury emissions and the significance of the cumulative burden of mercury released from local sources are discussed . Emissions are calculated using both historical monitoring data and the application of emission factors . The nature of current anthropogenic sources of mercury is quite different than it was several decades ago when many of the existing policies governing mercury pollution were created . Our inventory illustrates that many of the most significant sources in the past such as the chlor-alkali industry, paint containing mercury additives, and pharmaceuticals, have been largely phased out with fossil fuel combustion and waste disposal remaining as the most significant modern sources . Atmospheric emissions in Maritime Canada peaked in 1945 (> 1,750 kg year-1), and again between 1965 and 1970 (> 2,600 kg year-1) . Cumulative releases of mercury from anthropogenic sources for the years 1800-1995 were between 115 and 259 t to the atmosphere alone, and 327-448 t when discharges to wastewater and effluents were included . Assuming that only 0.2% (Nriagu, 1994.) of these releases become part of the recycled fraction of current fluxes, we estimate that between 570 and 900 kg Hg year-1 is deposited in Maritime Canada from past anthropogenic sources . Modern sources within Maritime Canada contribute at least 405 kg year-1 to the total annual deposition of 1.71 t over the provinces of New Brunswick, Nova Scotia and Prince Edward Island, leaving approximately 735 kg year-1 from natural sources and long-range contamination . Further study is needed to verify these estimates and clarify the significance of natural and long-range sources of mercury in Maritime Canada.

J Chromatogr A, 2000 Jun 16, 882(1-2), 321 - 8
On-line microdialysis-ion chromatographic determination of inorganic anions in olive-oil mill wastewater; Buldini PL et al.; A fully automated method is presented for the determination of inorganic anions in olive-oil mill effluents using on-line dialysis-ion chromatography . The wastewater is first of all sonicated at room temperature to make it homogeneous, then diluted and microdialized . Most of the organic load of the effluents is removed in a few minutes without using reagents, while soluble anion quantitation remains unaffected . The clear solution is analyzed for the inorganic anions content by direct injection on to an ion chromatograph equipped with a conductivity detector . In the absence of standards, the separation efficiency of microdialysis has been investigated by spiking wastewater samples as well as standard oil emulsions with varying amounts of inorganic anions and subjecting them to microdialysis for different periods of time prior to performing instrumental analysis . Excellent spike recoveries and low relative standard deviations are obtained for all the anions if a 10 min microdialysis time is overcame . Chloride, nitrite, nitrate, phosphate and sulphate are not affected by the microdialysis procedure and their recovery is between 96 and 104% in wastewater as well as in standard oil emulsion . Calibration plots are linear over about two orders of magnitude . The dialysis membrane has been replaced after more than 100 analyses . The UV photolysis pre-treatment of the same sample evidences the different information that can be obtained by the two sample pre-treatment procedures.

Tunis Med, 2000 Feb, 78(2), 109 - 14
{Intestinal parasitosis and environmental pollution: 1343 pediatric cases in Beni-Mellal, Morocco}; Habbari K et al.; This study was undertaken to determine the possible health risk associated with raw wastewater use in agricultural purposes, particularly, the transmission of parasite infections among children of five regions in Beni-Mellal, Morocco . In a randomly-selected sample of 1343 children, 740 of them were from five regions using raw wastewater for agriculture, and 603 were from 4 control regions that do not practice wastewater irrigation . One or more parasite infections were identified in 50.8% of the children living in the wastewater re-use regions and in 8.2% only of the others . The seven parasites identified were Entamoeba histolytica, Giardia intestinalis, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Hymenolepis nana, Taenia saginata, which infected 34.3%, 5.1%, 20.5%, 0.4%, 5.2%, 7.2%, 0.5% in the exposed population and 4.3%, 0.3%, 3.8%, 0.3%, 1.0%, 0.6% and 0.0% in the control population respectively . In conclusion, raw wastewater use in Beni-Mellal lead to a high risk of parasite infections . Adequate treatment of wastewater is highly recommended.

Nat Biotechnol, 2000 Jul, 18(7), 775 - 8
Aerobic degradation of tetrachloroethylene by toluene-o-xylene monooxygenase of Pseudomonas stutzeri OX1; Ryoo D et al.; Tetrachloroethylene (PCE) is thought to have no natural source, so it is one of the most difficult contaminants to degrade biologically . This common groundwater pollutant was thought completely nonbiodegradable in the presence of oxygen . Here we report that the wastewater bacterium Pseudomonas stutzeri OX1 degrades aerobically 0 . 56 micromol of 2.0 micromol PCE in 21 h (Vmax approximately 2.5 nmol min(-1) mg(-1) protein and KM approximately 34 microM) . These results were corroborated by the generation of 0.48 micromol of the degradation product, chloride ions . This degradation was confirmed to be a result of expression of toluene-o-xylene monooxygenase (ToMO) by P . stutzeri OX1, since cloning and expressing this enzyme in Escherichia coli led to the aerobic degradation of 0.19 micromol of 2.0 micromol PCE and the generation of stoichiometric amounts of chloride . In addition, PCE induces formation of ToMO, which leads to its own degradation in P . stutzeri OX1 . Degradation intermediates reduce the growth rate of this strain by 27%.

Annu Rev Public Health, 2000, 21, 223 - 45
Water reclamation and unrestricted nonpotable reuse: a new tool in urban water management; Okun DA; Growing urbanization accompanying growing population is increasing the demand for water supply in communities throughout the world . Water resources for many cities are already proving inadequate . Additional water resources are inherently more costly and are often not available because other communities and/or land owners have the water rights . Although conservation, particularly through demand management, may delay the need for additional sources for a short period, the need is inevitable . One approach that has been found to provide substantial additional water for communities is the reclamation of wastewaters produced by the communities themselves for unrestricted nonpotable purposes, such as for landscape and market crop irrigation, industry, cooling towers, air conditioning, toilet flushing, construction, vehicle washing, and environmental enhancement . This is done by providing dual distribution systems . Nonpotable reuse is already widely practiced despite the fact that the reclaimed water distribution systems needed to be installed in existing communities . Inasmuch as additional water is needed for growing populations, the costs would be substantially reduced if the two systems were to be built at the same time in the newly developing areas . Reuse of reclaimed water for potable purposes may be feasible, but it imposes added public health risks that need to be accepted only as a last resort.

J Toxicol Environ Health A, 2000 May 26, 60(2), 137 - 51
Evaluating the efficiency of toxicity abatement in a constructed wetland with Ceriodaphnia dubia; Belin JI et al.; Constructed wetlands are becoming increasingly popular as low-cost, high-efficiency means of treating agricultural and municipal wastewaters . Monitoring programs for constructed wetlands usually measure physical and chemical characteristics of wetland treatment, including hydraulic residence time and removal of nutrients (N, P), suspended solids, and biochemical oxygen demand (BOD) . However, toxicity abatement is seldom measured as evidence of wetland treatment efficiency . In this study, toxicity tests combined with chemical measurements were employed to measure the efficiency of a constructed wetland in treating swine wastes during fall and winter sampling periods . Although the wetland system operated at three wastewater loading rates, only the high-loading-rate cells were tested because of their year-round flows . Wastewater samples were collected prior to, during, and following wetland treatment to track treatment progress as effluents passed through the wetland cells . Toxicity tests with Ceriodaphnia dubia showed significant toxicity abatement of wastewater as it progressed through the constructed wetland system; however, residual toxicity was still observed in the final wetland effluent . No seasonal differences were observed in toxicity abatement between fall and winter wastewater samples, although nitrate and BOD were removed more efficiently during the fall . Results suggest that, while the constructed wetland system is effective in reducing toxicity in swine wastewater, further pre- or posttreatment or additional dilution is necessary before treated effluents are discharged into surface water.

J Hazard Mater, 2000 Aug 28, 76(1), 125 - 38
The management of arsenic wastes: problems and prospects; Leist M et al.; Arsenic has found widespread use in agriculture and industry to control a variety of insect and fungicidal pests . Most of these uses have been discontinued, but residues from such activities, together with the ongoing generation of arsenic wastes from the smelting of various ores, have left a legacy of a large number of arsenic-contaminated sites . The treatment and/or removal of arsenic is hindered by the fact that arsenic has a variety of valence states . Arsenic is most effectively removed or stabilized when it is present in the pentavalent arsenate form . For the removal of arsenic from wastewater, coagulation, normally using iron, is the preferred option . The solidification/stabilization of arsenic is not such a clear-cut process . Factors such as the waste's interaction with the additives (e.g . iron or lime), as well as any effect on the cement matrix, all impact on the efficacy of the fixation . Currently, differentiation between available solidification/stabilization processes is speculative, partly due to the large number of differing leaching tests that have been utilized . Differences in the leaching fluid, liquid-to-solid ratio, and agitation time and method all impact significantly on the arsenic leachate concentrations.This paper reviews options available for dealing with arsenic wastes, both solid and aqueous through an investigation of the methods available for the removal of arsenic from wastewater as well as possible solidification/stabilization options for a variety of waste streams.

Appl Biochem Biotechnol, 2000 Spring, 84-86, 255 - 65
N-demethylation of methylene blue by lignin peroxidase from Phanerochaete chrysosporium . Stoichiometric relation for H2O2 consumption; Ferreira VS et al.; Phanerochaete chrysosporium lignin peroxidase (LiP) can degrade synthetic dyes such as heterocyclic, azo, and triphenylmethane on its activation by H2O2 . Analysis of the reaction products indicated that N-demethylation reactions are involved in the degradation of crystal violet and methylene blue (MB) . We studied LiP oxidation of methylene blue and azure B (AB) in reaction mixtures containing different dye:H2O2 stoichiometric relations aiming at the selective formation of N-demethylated derivatives . High yields, about 70%, of the mono- and didemethylated derivatives, azure B and azure A, were obtained with the use of 1:1 and 1:2 MB:H2O2, respectively . Using azure B as substrate in reaction mixtures containing 1:1 AB:H2O2, a yield of 70% was also observed in azure A . Reaction mixtures containing 1:3 MB:H2O2 and 1:2 AB:H2O2, originated several oxidation products in similar proportions . These results indicated that the process of enzymatic degradation of methylene blue and azure B initiates via N(CH3)2 oxidation . According to the yields that were obtained for azure B and azure A, this enzymatic route can be used for the synthesis of these dyes since these data compare favorably to the chemical route that has a yield of 35% . The use of a dye:H2O2 relation of 1:10 resulted in a decoloration level of about 85%, showing the usefulness of this procedure for wastewater treatment . The reaction products were followed by spectrophotometric analysis within the wavelength of 500-700 nm . The product identifications were performed using a reverse-phase high-performance liquid chromatography (HPLC) C-18 column and thin-layer chromatography.

Int J Syst Evol Microbiol, 2000 May, 50 Pt 3, 1203 - 10
Gordonia nitida sp . nov., a bacterium that degrades 3-ethylpyridine and 3-methylpyridine; Yoon JH et al.; A bacterial strain, LE31T, which is capable of degrading 3-ethylpyridine and 3-methylpyridine, was isolated from an industrial wastewater and was taxonomically studied by using a polyphasic approach . Strain LE31T was identified as a member of the genus Gordonia on the basis of chemotaxonomic characteristics and phylogenetic inference-based 16S rDNA sequence . The cell wall contained meso-diaminopimelic acid, arabinose and galactose (wall chemotype IV) . The predominant menaquinone was MK-9(H2) . The mycolic acids contained 47-55 carbon atoms . The major fatty acids were C16:0, C18:1 omega9c, 10-methyl-C18:0 (TBSA) . The G+C content of DNA was 67 mol% . The 16S rDNA sequence of strain LE31T was most similar to that of the type strain of Gordonia rubropertincta . The differences in some phenotypic characteristics and the genetic distinctiveness distinguish strain LE31T from the Gordonia species described previously . Therefore it is proposed that strain LE31T should be placed in the genus Gordonia as a new species . The name Gordonia nitida is proposed for strain LE31T . The type strain of the new species is strain LE31T (= KCTC 0605BPT = KCCM 80004T).

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 427 - 32
New policies and measures for saving a great manmade reservoir providing drinking water for 20 million people in the Republic of Korea; Ahn KH; Water quality of the Paldang reservoir, the largest drinking water supply source in the Republic Korea provides raw water for about 20 million people living in Seoul Metropolitan area . Water quality has been deteriorating mainly due to improperly treated livestock waste and domestic wastewater discharged from motels, restaurants, and private homes . A recent survey conducted by the Ministry of Environment (MOE) showed that the water quality of this reservoir has been identified as Class III must contain less than 6 ppm of BOD, which will require advanced purification treatment before it can be used as drinking water . The MOE also announced that this water source would no longer be potable unless wastewater in the catchment is treated efficiently . To protect drinking water resources, the MOE has set up comprehensive management . These programmes include new regulations, measures, land use planning and economic incentives.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 383 - 7
Review of the wastewater situation in Morocco; Mandi L; Recent estimations of the wastewater production of Morocco amounted to 370 million m3 per year, and this is expected to increase to 900 million m3 by the year 2020 . In most cases wastewater is discharged directly into the environment, either to the sea via short outfalls or onto farmland for irrigation or infiltration . Major improvements in the quality of wastewater are needed urgently because of the strong migration of the rural population towards the towns and the very rapid demographic expansion . Studies for Sanitation Master Plans for the main towns are currently in progress and are a first step towards meeting these requirements . Development of a national master plan for liquid sewage is a way of extending this procedure over the whole territory.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 331 - 6
Sewage disinfection towards protection of drinking water resources; Kolch A; Wastewater applied in agriculture for irrigation could replace the use of natural drinking-water resources . With respect to high concentrations of human pathogens wastewater has to be disinfected prior to use . This paper introduces disinfection methods with emphasis on UV irradiation.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 325 - 9
Improved purification of water and waste-water with low-cost dead-end-ultrafiltration; Peters TA; One aspect of the increasing contamination of water sources is sewage effluent . In some countries it is generally disinfected prior to discharge to protect downstream communities, which use the water for drinking and recreation . However, serious questions have been raised regarding the efficacy of conventional treatments to remove or destroy viruses, and regarding the generation of harmful byproducts by sewage chlorination . A safe and reliable solution is the use of ultrafiltration for the purification of wastewater, as the ultrafiltration membranes form an absolute barrier for bacteria and viruses including colloids and macromolecules . However, this application also demands the use of open channel module systems that can be cleaned with high efficiency with regard to scaling, fouling and especially biofouling . The flat membrane module systems using selected membranes and a special plant design can meet these and further requirements expected in this application, including easy handling, low energy consumption and optimised operation costs . Technical details of the module system, case studies and cost aspects are presented.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 257 - 60
Carbon, nitrogen and heavy metal dynamics in long-term wastewater irrigated Mexican soils; Herre A et al.; In column experiments of Mexican wastewater irrigated soils the effects of changing water quality (untreated = UT, primary = PT and tertiary treated = TT wastewater) on carbon, nitrogen and heavy metal dynamics were investigated . In the column effluents the nitrate concentrations varied between 141-683 mg l-1 . The total amount of leached TOC decreased in the order UT > PT > TT . Outflow concentrations of Pb ranged from 31.6-166.5 micrograms l-1 and of Cu from 31.2-146.8 micrograms l-1 . Irrigation water quality influenced the Pb but not the Cu efflux . Cu seemed to be co-transported with TOC by preferential flow whereas there was no correlation of Pb and TOC concentrations in the effluents . The possibility of Pb transport through preferential flow paths is discussed.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 241 - 7
Health effect of wastewater reuse in agriculture; Bouhoum K et al.; The present study addresses the impact of wastewater reuse in agriculture on the transmission of protozoan and helminthic infections . For this purpose, an epidemiological study was carried out on two populations of children totalling 608 individuals for protozoan infections and 528 for helminthic infections . Each population comprised an exposed group living in the wastewater spreading area of Marrakech and a control group . Results showed that 72% of the exposed group had protozoan infections . This rate did not exceed 45% in the control group . The pathogenic protozoan infections observed were giardiasis and amoebiasis . Regarding helminthic infections, 73% of the exposed children were infected compared with 30% of the control group . The risk attributable to wastewater reuse in the transmission of pathogenic protozoan and helminthic infections was 41% and 43%, respectively . Children of the spreading area are therefore more exposed to detectable risks from parasitic helminths and protozoa than the control children.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 233 - 9
Reuse of wastewater in aboriginal communities in Western Australia; Mathew K et al.; Western Australia is a very arid area and freshwater is a precious resource . The wise and efficient use of this resource is essential for the establishment of communities in this region . Wastewater reuse in Aboriginal communities is a very recent development . Initially leach drains disposed of wastewater . Due to their failure most of the major communities now have the effluent from the septic tanks collected by a small diameter reticulated sewerage system and directed to oxidation ponds for treatment . The overflow from the oxidation ponds is allowed to flow over land or to a creek without any specific use . This paper discusses available reuse options as well as the options specific to Aboriginal communities in Western Australia . It is intended to demonstrate that in arid regions reuse wastewater can act as a water conservation and pollution control measure.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 227 - 32
Efficiency and sustainability of soil-aquifer treatment for indirect potable reuse of reclaimed water; Drewes JE et al.; An increasing number of municipalities are considering the indirect reuse of treated wastewater (recycled water) by groundwater recharge as a feasible option to augment potable water supplies . This planned approach offers several advantages compared to the conventional way of discharging effluents into surface waters, including the additional treatment afforded as the water percolates and co-mingles with groundwater (soil aquifer treatment) . While groundwater recharge has been used in the United States (U.S.) for several decades and has been the subject of a number of studies, limitations in methodology and testing have prevented many within the scientific and technical community from being able to fully address a number of complex public health questions related to organic chemicals, nitrogen and microorganisms . Ongoing research being conducted in Arizona and California is directed at reducing the uncertainties about the efficiency and sustainability of soil aquifer treatment for indirect potable reuse of recycled water.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 213 - 8
Wastewater reuse with groundwater safeguard; Ouazzani N et al.; In Morocco, reuse of raw wastewater for irrigation is practised around the big cities without taking into account the sanitary and environmental concerns . All national institutions involved in wastewater problems are convinced of the need for wastewater treatment with extensive systems before it can be applied for agricultural reuse . Our experimental work on wastewater treatment using lagooning, macrophytic plants, reed beds, infiltration percolation or over-land flow showed that of all these extensive systems lead to an effluent classified into category B according to WHO guidelines . However, the amount of nitrogen largely exceeded the crops' requirements and could cause serious problems for groundwater . Using the DRASTIC method, a vulnerability map was established for groundwater in the plain surrounding the city of Marrakech . The estimates of nitrogen amounts from wastewater that can reach groundwater after crop uptakes showed that only the low vulnerability zone could be safely irrigated with the treated wastewater . The second zone of moderate vulnerability covering 50% of the area in the plain could receive the treated wastewater, but a careful program of irrigation is required to avoid nitrate contamination of groundwater . The third zone at a high vulnerability level should be protected, without any further irrigation using wastewater, even after extensive treatment . This new approach integrating the results of the preliminary vulnerability study of groundwater zones could constitute a helpful tool to improve management of regional projects of wastewater reclamation and reuse.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 207 - 12
Improvements of wastewater treatment for groundwater protection in the Haertsfeld; Haakh F; Wastewater treatment in rural water protection zones is crucial for sustainable source water protection . Specific problems arise where wastewater from decentral treatment plants infiltrates towards vulnerable aquifers . Within the water protection zone of the Egau Waterworks sited on the Swabian highlands with a karstic aquifer, a concept for a central sewer system and wastewater plant went into operation in 1993 in order to solve the conflict between drinking water demands and wastewater treatment . Since then, water quality of the Buchbrunnen karst spring which is used for drinking water supply for about 400,000 inhabitants has shown improvements . The paper describes the development of typical parameters including groundwater flow time and corresponding concentration levels . The concept implemented here may serve as a model for a successful water protection initiative.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 141 - 6
Wastewater discharge and water quality standards in Brazil--implications for the selection of wastewater treatment technologies; von Sperling M; The paper describes and comments the Brazilian standards for water quality and effluent discharge (CONAMA Directive No . 20, 1986) . The emphasis of the paper is on the conventional parameters which characterise domestic wastewater (BOD, SS, NH4+, N, P and coliforms) . The wastewater treatment systems for achieving compliance are analysed with two perspectives: requirements for the discharge standards and requirements for the receiving water standards . The main treatment technologies available are listed, together with their capability to remove the major pollutants included in the Brazilian legislation . The analysis for the receiving water standards are given for different dilution ratios (river/discharge flows): 1/10, 1/1, 10/1 and 100/1 . The difficulty in complying with the receiving water standards for BOD, phosphate and coliforms is highlighted and the cost implications for the adoption of more sophisticated technologies in order to achieve compliance are also provided . Although the specific quantitative values cited in the paper are associated with the Brazilian legislation, it is believed that the major conceptual issues are applicable to a large number of urban areas in other countries.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 117 - 21
Pollution of water sources due to poor waste management--the case of Dar-es-Salaam; Makule DE; Pollution of water sources for the city of Dar-es-Salaam originates from haphazard disposal of solid wastes, discharge of untreated or inadequately treated wastewater to water sources, lack of standard sanitary facilities and poor hygienic practices . Contaminated water used for human consumption can lead to serious health problems e.g . cholera, typhoid, skin diseases, etc., which, in turn, leads to reduced working hours/manpower . This has a direct effect to production output which can lead to a deterioration of local community welfare . Having realised this as a problem, the Government of Tanzania stipulated, in its water policy of 1991, the need for protection of water sources . In achieving this goal, proper waste management was singled out to be of vital importance . Due to economic hardships, however, budget allocation by the central Government could not cover the costs needed for proper handling of waste . This left Tanzania with no alternative other than heavy reliance on donor and bilateral organisations for financial support of programmes . Nevertheless, these sources of funds proved to be unreliable for many different reasons . To deal with these problems, the Government currently emphasises involving local community and NGOs, the formation of stakeholder funds and organisations, and involvement of the private sector . Other efforts are intensification of education programmes to create more awareness to the local communities on the need for protection of water sources . Although at its infancy level, the system is showing some signs of improvement.

Schriftenr Ver Wasser Boden Lufthyg, 2000, 105, 111 - 5
New regulatory framework for wastewater quality control in Mexico; Saade Hazin L; This paper analyses the new regulatory framework for wastewater quality control developed in Mexico . It provides a description of the Mexican government strategies for water pollution control . The discussion focuses on the policy instruments used, their evolution and the main difficulties encountered in their implementation . The new regulatory framework is discussed highlighting some of the economic implications of the reforms . The paper concludes that proper institutional development and monitoring are essential factors for the success of any policy instrument for wastewater quality control.

Ecotoxicol Environ Saf, 2000 Jun, 46(2), 192 - 201
Effects of spray-irrigated wastewater effluent on temporary pond-breeding amphibians; Laposata MM et al.; Comparison was made of abiotic conditions, amphibian reproductive outputs, and the survival of embryonic and larval amphibians in wastewater effluent-irrigated and natural temporary ponds in an area in Centre County, Pennsylvania that has been spray-irrigated with secondarily treated, chlorinated wastewater effluent from The Pennsylvania State University for approximately 14 years . Three species of temporary pond-breeding amphibians were studied: wood frogs (Rana sylvatica LeConte), Jefferson salamanders (Ambystoma jeffersonianum Green), and spotted salamanders (A . maculatum Gravenhorst) . Comparisons of physico-chemical parameters in 10 wastewater-irrigated and 10 natural temporary ponds over 19 weeks in 1997 indicated that wastewater -irrigated ponds had significantly higher median conductance, pH, inverted question markNa, inverted question markK, inverted question markCa, inverted question markMg, and inverted question markN-NO(3) and lower inverted question markdissolved oxygen . Many of the wastewater-irrigated ponds supported large mats of duckweed (Lemna spp.) that completely blanketed the pond's surface by mid-May . There were significantly fewer egg masses of all three species in wastewater-irrigated ponds than in natural ponds in both 1997 and 1998 . In situ egg hatching success and larval survival (over a 6-day period) of all species was lower in wastewater-irrigated ponds than in natural ponds . Cumulatively, these studies suggest that wastewater effluent irrigation may impact amphibian populations by reducing the survival of amphibian eggs and larvae .

Int J Syst Evol Microbiol, 2000 Jan, 50 Pt 1, 259 - 64
Aminobacterium mobile sp . nov., a new anaerobic amino-acid-degrading bacterium; Baena S et al.; A novel, curved (0.3 x 4.0-5.0 microm), Gram-negative, non-sporulating, mesophilic bacterium, designated strain ILE-3T (T = type strain), was isolated from an anaerobic lagoon in a dairy wastewater treatment plant . Optimal growth occurred at 37 degrees C and pH 7.4 on a medium containing serine as an energy source and yeast extract . The strain was motile by means of one or two lateral flagella . It required yeast extract for growth on serine, glycine, threonine and pyruvate . Poor growth was obtained on cysteine, Casamino acids, biotrypcase, peptone and 2-oxoglutarate . In the presence of Methanobacterium formicicum, strain ILE-3T oxidized alanine, glutamate, leucine, isoleucine, valine and aspartate to a minor extent . The G+C content of the DNA was 44 mol% . Phylogenetic analysis of the 16S rRNA gene of strain ILE-3T indicated that it was related to Aminobacterium colombiense (95% similarity value) . On the basis of the phenotypic and phylogenetic characteristics, strain ILE-3T is designated as a new species of the genus Aminobacterium, namely Aminobacterium mobile sp . nov . (= DSM 12262T).

Bull Math Biol, 2000 Jan, 62(1), 17 - 35
On estimating the probability of aperiodic outbursts of microbial populations from their fluctuating counts; Peleg M et al.; The irregular sequence of counts of a microbial population, in the absence of observable corresponding environmental changes (e.g., temperature), can be regarded as reflecting the interplay of several unknown or random factors that favor or inhibit growth . Since these factors tend to balance one another, the fluctuations usually remain within bounds, and only by a coincidence--when all or most act in unison--does an 'outburst' occur . This situation can be represented mathematically as a sequence of independent random variables governed by a probability distribution . The concept was applied to reported microbial counts of ground meat and wastewater . It is found that the lognormal distribution could serve as a model, and that simulations from this model are indistinguishable from actual records . The parameters of the lognormal (or other) distribution can then be used to estimate the probability of a population outburst, i.e., an increase above a given threshold . Direct estimation of the outburst probability based on frequency of occurrence is also possible, but in some situations requires an impractically large number of observations . We compare the efficiency of these two methods of estimation . Such methods enable translation of irregular records of microbial counts into actual probabilities of an outburst of a given magnitude . Thus, if the environment remains 'stable' or in dynamic equilibrium, the fluctuations should not be regarded merely as noise, but as a source of information and an indicator of potential population outbursts even where obvious signs do not exist.

Chemosphere, 2000 Jul, 41(1-2), 283 - 7
Removal of heavy metals from anaerobically digested sewage sludge by isolated indigenous iron-oxidizing bacteria; Xiang L et al.; The removal of heavy metals (Cr, Cu, Zn, Ni and Pb) from anaerobically digested sludge from the Yuen Long wastewater treatment plant, Hong Kong, has been studied in a batch system using isolated indigenous iron-oxidizing bacteria . The inoculation of indigenous iron-oxidizing bacteria and the addition of FeSO4 accelerated the solubilization of Cr, Cu, Zn, Ni and Pb from the sludge . pH of the sludge decreased with an increase in Fe2+ concentrations and reached a low pH of 2-2.5 for treatments receiving both bacterial inoculation and FeSO4 . After 16 days of bioleaching, the following heavy metal removal efficiencies were obtained: Cr 55.3%, Cu 91.5%, Zn 83.3%, Ni 54.4%, and Pb 16.2% . In contrast, only 2.6% of Cr, 42.9% of Cu, 72.1% of Zn, 22.8% of Ni and 0.56% of Pb were extracted from the control without the bacterial inoculation and addition of FeSO4 . The residual heavy metal content in the leached sludge was acceptable for unrestricted use for agriculture . The experimental results confirmed the effectiveness of using the isolated iron-oxidizing bacteria for the removal of heavy metals from sewage sludge.

Chemosphere, 2000 Jul, 41(1-2), 251 - 7
Performance of different microalgal species in removing nickel and zinc from industrial wastewater; Chong AM et al.; A series of batch experiments was conducted to compare the ability of 11 microalgal species of the same cell density in removing nickel (Ni) and zinc (Zn) from synthetic wastewater . These included Chlorella vulgaris (commercially available), Chlorella sorokiniana and Scenedesmus quadricauda (isolates from polluted water of Wuhan, China), and eight different isolates from Hong Kong . The Wuhan isolate of Scenedesmus removed most Ni, probably due to its large biomass . Nickel concentration was reduced from an initial 30 to 0.9 mg/l after 5 min (97% Ni removal), and further declined to 0.4 mg/l after 90 min of treatment . In wastewater containing 30 mg/l Ni and 30 mg/l Zn, more than 98%, Ni and Zn were removed simultaneously at the end of 5 min treatment, indicating that the presence of Zn in wastewater did not affect Ni removal by this Scenedesmus isolate . The second most effective species for Ni removal was an isolate, tentatively identified as Chlorella miniata, Ni concentration was reduced to 10 mg/l after 90 min, and was only slightly interfered by the presence of Zn . In terms of metal removal per unit biomass or unit surface area of algal cells, C . miniata was the best species in removing Ni and Zn . At the other extreme, one Hong Kong isolate (Synechocystis sp.) did not remove any Ni and only achieved 40% Zn removal . Performance of the other isolates was comparable with the commercial C . vulgaris, less than 50% Ni was removed after 5 h of treatment and Ni removal was significantly reduced by the presence of Zn . All algae tested were found to be viable, showing these 11 species could tolerate a mixture of 30 mg/l Ni and 30 mg/l Zn in wastewater.

Chemosphere, 2000 Jul, 41(1-2), 149 - 53
Degradation pathway of persistent branched fatty acids in natural anaerobic ecosystem; Sin SN et al.; Branched fatty acids (BAFs) in industrial effluents are often persistent in biological wastewater treatment systems and end up as organic contaminants in the water environment . In this study, degradation of eight characteristic BAFs in a natural anaerobic ecosystem of an eutrophic river sediment was studied in vitro by enrichment culture techniques . The anaerobic consortium, comprising of BFA-degrading and methane-producing genera, degraded BFAs with a tertiary carbon through beta-oxidation followed by methanogenesis mechanisms . The consortium could not degrade BFAs with a quaternary carbon . The degree of branching at the alpha or beta position along the carbon chain interfered with the beta-oxidation mechanisms, and hence affected the degradability of the compound.

Chemosphere, 2000 Jul, 41(1-2), 3 - 6
Copper contamination in paddy soils irrigated with wastewater; Cao ZH et al.; Copper (Cu) contamination was investigated in paddy soils where Cu-rich wastewater (12 mg Cu/l) was used for irrigation . The results showed that Cu contamination increased the soil Cu content from 17.0 mg Cu/kg in the non-wastewater irrigated soils (NWIS) to 101.2 mg Cu/kg in the wastewater irrigated soils (WIS), and Cu accumulated mostly in the surface layer (0-10 cm) of the paddy soil . The average Cu contents in brown rice, rice hull and rice straw from NWIS were 1.4, 7.3 and 14.5 mg Cu/kg, while those from WIS were 15.5, 133.2, and 101.4 mg Cu/kg, respectively . Correlation analysis revealed that the relationship between the Cu content in the rice straw and the rice hull with the total Cu content of the soil could be described by an exponential function (R2 = 0.921 and 0.831, respectively; P <0.01) . Rice plants grown in the WIS showed symptoms of black roots, less effective tiller, etc . Subsequently, the rice yield decreased by 18-25%, compared with that grown in NWIS.

Anal Chem, 2000 May 1, 72(9), 2022 - 8
Multimicrobial sensor using microstructured three-dimensional electrodes based on silicon technology; Konig A et al.; Two microbial strains with different substrate spectra were immobilized separately within a single biosensor chip featuring four individually addressable platinum electrodes . These were sputtered onto the inner surface of four isolated pyramidal cavities ("containments") micromachined on a silicon wafer . The biosensor chip was integrated into a flow-through system to measure the oxygen consumption of the immobilized microorganisms in the presence of assimilable analytes . As a model system, a yeast for the determination of biochemical oxygen demand (BOD) and a strain capable of degrading polycyclic aromatic hydrocarbons (PAH) were chosen . It was shown that the simple and mass-producible containment sensor exhibits good performance data: lower detection limit 0.1 mg/L naphthalene and 1 mg/L sensor-BOD; calibration range up to 30 mg/L; precision 3-6%; response time 2-3 min; service life up to 40 days; shelf life at 4 degrees C 6 months . The versatility of the multimicrobial sensor was demonstrated by measuring ordinary municipal wastewater samples as well as various aqueous samples contaminated with PAH . The concept of a multimicrobial sensor not only enlarges the substrate spectrum for sum parameters such as BOD but leads to additional information which allows for a more differentiated and immediate knowledge of sample composition . Using chemometrical data analysis, the multimicrobial sensor lays a foundation for developing an "electronic tongue".

Sci Total Environ, 2000 Apr 24, 250(1-3), 9 - 19
Total metal concentrations and partitioning of Cd, Cr, Cu, Fe, Ni and Zn in sewage sludge; Scancar J et al.; Application of the BCR three-step sequential extraction procedure to sewage sludge samples collected at an urban wastewater treatment plant (Domzale, Slovenia) is reported . The total concentrations of Cd, Cr, Cu, Fe, Ni and Zn and their concentrations in fractions after extraction were determined by flame or electrothermal atomic absorption spectrometry (FAAS, ETAAS) under optimised measurement conditions . Total acid digestion including hydrofluoric acid (HF) treatment and aqua regia extraction were compared in order to estimate the efficiency of aqua regia extraction for determination of total metal concentrations in sewage sludge . It was found experimentally that aqua regia quantitatively leached these heavy metals from the sewage sludge and could therefore be applied in analysis of total heavy metal concentrations . The total concentrations of 856 mg kg(-1) Cr, 621 mg kg(-1) Ni and 2032 mg kg(-1) Zn were higher than those set by Slovenian legislation for sludge to be used in agriculture . Total concentrations of 2.78 mg kg(-1) Cd, 433 mg kg(-1) Cu and 126 mg kg(-1) Pb were below those permitted in the relevant legislation . CRM 146R reference material was used to follow the quality of the analytical process . The results of the BCR three-step sequential extraction procedure indicate high Ni and Zn mobility in the sludge analysed . The other heavy metals were primarily in sparingly soluble fractions and hence poorly mobile . Due to the high total Ni concentration and its high mobility the investigated sewage sludge could not be used in agriculture.

Appl Environ Microbiol, 2000 May, 66(5), 2259 - 62
Fortified sera and their use in environmental virology; Hoyt JL et al.; Four commercially available fortified sera were compared to fetal bovine serum (FBS) with regard to their ability to maintain or increase the sensitivity of the Buffalo green monkey (BGM) kidney cell line to viral infection . Nine virus strains and five wastewater samples were used . Fortified sera were comparable to FBS for the enumeration of some viruses by the plaque method and for the detection of virus in wastewater by the most-probable-number assay.

Appl Microbiol Biotechnol, 2000 Mar, 53(3), 348 - 51
Hexavalent chromium reduction by a dichromate-resistant gram-positive bacterium isolated from effluents of tanneries; Shakoori AR et al.; A gram-positive, chromium (Cr)-resistant bacterial strain (ATCC 700729) was isolated from effluent of tanneries . It was grown in media containing potassium dichromate concentration up to 80 mg ml(-1) of the medium . The dichromate reducing capability of the bacterium was checked by estimating the amount of Cr VI in the medium before and after introduction of bacterial culture . The influence of factors like pH of the medium, concentration of Cr, and the amount of the inoculum was studied to determine the ability of the bacterium to reduce Cr VI in the medium under various conditions . In a medium containing dichromate 20 mg ml(-1) more than 87% reduction of dichromate ions was achieved within 72 h . The feasibility of the use of this bacterial strain for detoxification of dichromate in the industrial wastewater has been assessed . The isolated strain can be exploited for specific environmental clean-up operations.

J AOAC Int, 2000 Mar-Apr, 83(2), 290 - 7
Determination of bisphenol A in sewage effluent and sludge by solid-phase and supercritical fluid extraction and gas chromatography/mass spectrometry; Lee HB et al.; Methods have been developed for the determination of bisphenol A (BPA) residues in municipal sewage and sludge samples . BPA in wastewater samples was enriched with a C18 solid-phase extraction cartridge, eluted with acetone, and converted to the pentafluoropropionyl derivative . For sludge samples, BPA was acetylated and extracted with supercritical carbon dioxide . In both cases, BPA-d16 was used as a surrogate to monitor extraction efficiency . Final analyses of derivatized sample extracts were performed by gas chromatography/mass spectrometry operating in the electron impact mode . For water samples, mean recoveries and standard deviations were 89 +/- 6, 94 +/- 4, and 85 +/- 7% at fortification levels of 1, 0.1, and 0.025 microg/L, respectively, with a method detection limit of 0.006 microg/L . For solid waste samples, mean recoveries and standard deviations were 93 +/- 5 and 92 +/- 6% at fortification levels of 2.5 and 0.25 microg/g, respectively, and the method detection limit was 0.05 microg/g . For the Canadian samples under investigation, concentrations of BPA ranged from 49.9 to 0.031 microg/L in sewage influent and effluent, and from 36.7 to 0.104 microg/g in sludge.

G Ital Med Lav Ergon, 1999 Jan-Mar, 21(1), 9 - 12
{Treatment plants: viruses in aerosols}; Romano M et al.; A survey was carried out on the animal virus occurrence in wastewater and aerosols, in 2 treatment plants . Forty-five samples of sewage (10 litres) and 118 aerosol (2.3 m3) were examined . Forty out of forty-five (88.9%) of sewage and four out of one hundred and eighteen of aerosol (3.4%) samples were positive for viruses . Thirty-three reovirus and nine enterovirus strains were recovered from the sewage, two reovirus and two enterovirus strains from aerosol . Among enterovirus strains 6 resulted coxsackievirus B5, 3 coxsackievirus B4, 1 poliovirus, 1 strains remained unidentified.

Enzyme Microb Technol, 2000 Apr 1, 26(7), 484 - 490
Phenol-oxidase (laccase) activity in strains of the hyphomycete Chalara paradoxa isolated from olive mill wastewater disposal ponds; Robles A et al.; Production of laccase activity by nine strains of Chalara paradoxa isolated from olive mill wastewater disposal ponds were studied . Enzyme extracts obtained from cultured broths by adsorption on hydroxyapatite showed a single band of laccase activity on ABTS after polyacrylamide gel electrophoresis (PAGE) . They showed small mobility differences, with molecular masses of 67 to 68 kDa . Enzymes from the different strains oxidized a variety of phenolic and non-phenolic substances, and they could be divided into two groups according to their relative activities on substrates . All laccases showed a dual pH dependence of activity, with a maximum in the range of pH 3.0 to 4.5 for ABTS, o-dianisidine and 2,6-dimethoxyphenol, and pH 6.0 (Group 1) or pH 6.5 (Group 2) for syringaldazine and other substrates . Optimal temperatures were in the range of 10 to 28 degrees C for two strains (maximum at 10 degrees C) and 10 to 37 degrees C for the rest . The different enzymes were partially inactivated by heating at 60 degrees C and totally inactivated at 70 degrees C . Laccases were stable in a pH range of 3.0 to 9.0 (except for strain 36A, which was partially inactivated at pH 3.0), but became inactivated at pH 2.0 . Altogether these data suggest that Ch . paradoxa strains produce different laccase isoenzymes.

Int J Syst Evol Microbiol, 2000 Mar, 50 Pt 2, 639 - 44
Desulfovirga adipica gen . nov., sp . nov., an adipate-degrading, gram-negative, sulfate-reducing bacterium; Tanaka K et al.; A novel, mesophilic, Gram-negative bacterium was isolated from an anaerobic digestor for municipal wastewater . The bacterium degraded adipate in the presence of sulfate, sulfite, thiosulfate and elemental sulfur . (E)-2-Hexenedioate accumulated transiently in the degradation of adipate . (E)-2-Hexenedioate, (E)-3-hexenedioate, pyruvate, lactate, C1-C12 straight-chain fatty acids and C2-C10 straight-chain primary alcohols were also utilized as electron donors . 3-Phenylpropionate was oxidized to benzoate . The G + C content of the DNA was 60 mol% . 16S rDNA sequence analysis revealed that the new isolate clustered with species of the genus Syntrophobacter and Desulforhabdus amnigenus . Strain TsuAS1T resembles Desulforhabdus amnigenus DSM 10338T with respect to the ability to utilize acetate as an electron donor and the inability to utilize propionate without sulfate in co-culture with Methanospirillum hungatei DSM 864 . Strains TsuAS1T and DSM 10338T form a 'non-syntrophic subcluster' within the genus Syntrophobacter . Desulfovirga adipica gen . nov., sp . nov . is proposed for the newly isolated bacterium, with strain TsuAS1T (= DSM 12016T) as the type strain.

J Chromatogr A, 2000 Mar 3, 872(1-2), 309 - 14
Analysis of steroids in environmental water samples using solid-phase extraction and ion-trap gas chromatography-mass spectrometry and gas chromatography-tandem mass spectrometry; Kelly C; This paper describes an improved method for the extraction and determination of three steroids, oestrone, 17beta-oestradiol, and the synthetic contraceptive steroid 17alpha-ethinyloestradiol in aqueous matrices . Samples of wastewater and environmental water were spiked with internal standards, comprising isotopically labelled analogues of the steroids to be determined . The samples were extracted using solid-phase extraction disks and the extracts were then derivatized to form tert.-butyldimethylsilyl derivatives . The derivatised steroids were determined in the final extracts by GC-MS or GC-MS-MS allowing an operational detection limit for each steroid in effluent samples of 1 ng l(-1).

Biochemistry (Mosc), 2000 Mar, 65(3), 324 - 31
Application of polyphosphate metabolism to environmental and biotechnological problems; Keasling JD et al.; The synthesis and degradation of polyphosphate (polyP) are influenced by the energy state of the cell and extracellular phosphate levels . The import of excess phosphate and its incorporation into polyP under phosphate- and energy-rich growth conditions allows organisms to survive when phosphate or energy are depleted . Under phosphate-starvation conditions, phosphate can be recovered from polyP by hydrolysis . When the organism is energy starved, energy can be recovered either by regenerating the high-energy phosphoanhydride bond donor (ATP in most cases) or by hydrolysis of polyP and subsequent secretion of orthophosphate to recharge the transmembrane proton gradient . Understanding how the energy state of the cell and environmental phosphate levels affect polyP metabolism is essential to improving such environmental processes as enhanced biological phosphorus removal, a treatment process that is widely used to remove excess phosphate from wastewater . Manipulation of the genes responsible for polyP metabolism can also be used to improve gene expression from phosphate-starvation promoters and to remove heavy metals from contaminated environments.

Chemosphere, 2000 May-Jun, 40(9-11), 1131 - 42
Input/output balance of estrogenic active compounds in a major municipal sewage plant in Germany; Korner W et al.; 24 h samples of untreated and treated wastewater were taken in parallel from a modern municipal sewage plant in southern Germany in March and June 1998 . After solid phase extraction, total estrogenic activity was quantitatively measured with a miniaturized E-screen assay and the levels of nine estrogenic phenolic chemicals analyzed by HRGC/LRMS . 17Beta-estradiol equivalent concentrations (EEQ) were 58 and 70 ng/l in the influent and 6 ng/l in the effluent, indicating that the load of estrogenic activity of the wastewater was reduced by about 90% in the sewage plant . Less than 3% of the estrogenic activity was found in the sludge . 4-t-octylphenol, 4-nonylphenol, bisphenol A, 2-hydroxybiphenyl, and 4-chloro-3-methylphenol were detected in the untreated wastewater at levels from 0.13 to 3.6 microg/l . 4-t-octylphenol, 4-nonylphenol, and bisphenol A were present in the effluent at concentrations from 0.16 to 0.36 microg/l, 2-hydroxybiphenyl and 4-chloro-3-methylphenol were not detectable . The contribution of the quantified levels of phenolic xenoestrogens to total estrogenic activity in the sewage was 0.7-4.3%.

Anal Chem, 2000 Mar 1, 72(5), 992 - 8
Characterization of dyes and other pollutants in the effluent of a textile company by LC/NMR and LC/MS
Preiss A, Sanger U, Karfich N, Levsen K, Mugge C.
LC/NMR and LC/MS (the latter technique in the MSn mode) were used to characterize the organic constituents of industrial wastewater with emphasis on polar, nonvolatile compounds . In the effluent of a textile company, various compounds such as anthraquinone-type dyes and their byproducts, a fluorescent brightener, a byproduct from polyester production, and auxiliaries such as anionic and nonionic surfactants and their degradation products were identified . It is shown that the combined use of both hyphenated techniques provides complementary structural information . If applied under comparable chromatographic conditions, they are well-suited for the nontarget analysis.

Appl Microbiol Biotechnol, 2000 Feb, 53(2), 249 - 54
Azo-dye degradation in an anaerobic-aerobic treatment system operating on simulated textile effluent; O'Neill C et al.; Decolorisation of azo dyes during biological effluent treatment can involve both adsorption to cell biomass and degradation by azo-bond reduction during anaerobic digestion . Degradation is expected to form aromatic amines, which may be toxic and recalcitrant to anaerobic treatment but degradable aerobically . Methods for the quantitative detection of substituted aromatic amines arising from azo-dye cleavage are complex . A simple qualitative method is suggested as a way in which to investigate whether decolorisation is actually due to degradation, and whether the amines generated are successfully removed by aerobic treatment . Samples from a combined anaerobic-aerobic system used for treating a simulated textile wastewater containing the reactive azo dye Procion Red H-E7B were analysed by high-performance liquid chromatography/ultraviolet (HPLC-UV) methods . Anaerobic treatment gave significant decolorisation, and respiration-inhibition tests showed that the anaerobic effluent had an increased toxicity, suggesting azo-dye degradation . The HPLC method showed that more polar, UV-absorbing compounds had been generated . Aerobically, these compounds were removed or converted to highly polar compounds, as shown by HPLC analysis . Since the total organic nitrogen (TON) decreased aerobically as organic N-containing compounds were mineralised, aromatic amine degradation is suggested . Although only a simple qualitative HPLC method was used, colour removal, toxicity and TON removal all support its usefulness in analysing biotreatment of azo dyes.

J Hazard Mater, 2000 Apr 3, 73(2), 161 - 78
Kinetics of p-hydroxybenzoic acid photodecomposition and ozonation in a batch reactor; Benitez FJ et al.; The decomposition of p-hydroxybenzoic acid, an important pollutant present in the wastewaters of the olive oil industry, has been carried out by a direct photolysis provided by a polychromatic UV radiation source, and by ozone . In both processes, the conversions obtained as a function of the operating variables (temperature, pH and ozone partial pressure in the ozonation process) are reported . In order to evaluate the radiation flow rate absorbed by the solutions in the photochemical process, the Line Source Spherical Emission Model is used . The application of this model to the experimental results provides the determination of the reaction quantum yields which values ranged between 8.62 and 81.43 l/einstein . In the ozonation process, the film theory allows to establish that the absorption process takes place in the fast and pseudo-first-order regime and the reaction is overall second-order, first-order with respect to both reactants, ozone and p-hydroxybenzoic acid . The rate constants are evaluated and vary between 0.18x10(5) and 29.9x10(5) l/mol s depending on the temperature and pH.

Ecotoxicol Environ Saf, 2000 Mar, 45(3), 310 - 6
Monitoring Wadi El Raiyan lakes of the egyptian desert for inorganic pollutants by ion-selective electrodes, ion chromatography, and inductively coupled plasma spectroscopy; Saleh MA et al.; Wadi El Raiyan is a great depression located southwest of Cairo in the western desert of Egypt, one of the most arid regions of the world . In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the El Faiyum province to provide a reservoir for the wastewater that exceeded the capacity of Lake Qarun north of the province . Pollutants from agricultural waste including pesticides and fertilizers as well as other effluents of industrial activities and runoffs certainly will pass into the biotic elements of the ecosystem . This report presents the status of inorganic pollutants including anions, cations, and trace metals in the two lakes and the surrounding springs of Wadi El Raiyan using ion chromatography, ion-selective electrodes, and inductively coupled plasma emission spectroscopy . The report also includes the levels of selected metals in the vegetation community of the area . The result of this investigation revealed a great improvement in water quality of the Wadi El Raiyan lakes compared to 1988 report by Saleh et al . Mercury was not detected in any of the samples and the level of lead was significantly reduced . Cadmium levels were much higher than those seen earlier . The higher level of cadmium might be used as an indicator to track the contamination of water by human waste . Concentrations of common anions were not significantly different from those reported earlier . However, an increase in the level of cyanide was observed . Levels of heavy metals in vegetation around the lakes were also found to be lower than previously reported .

Appl Environ Microbiol, 2000 Mar, 66(3), 925 - 9
Biochemical and molecular characterization of a laccase from Marasmius quercophilus; Dedeyan B et al.; The basidiomycete Marasmius quercophilus is commonly found during autumn on the decaying litter of the evergreen oak (Quercus ilex L.), a plant characteristic of Mediterranean forest . This white-rot fungus colonizes the leaf surface with rhizomorphs, causing a total bleaching of the leaf . In synthetic liquid media, this white-rot fungus has strong laccase activity . From a three-step chromatographic procedure, we purified a major isoform to homogeneity . The gene encodes a monomeric glycoprotein of approximately 63 kDa, with a 3.6 isoelectric point, that contains 12% carbohydrate . Spectroscopic analysis of the purified enzyme (UV/visible and electron paramagnetic resonance, atomic absorption) confirmed that it belongs to the "blue copper oxidase" family . With syringaldazine as the substrate, the enzyme's pH optimum was 4.5, the optimal temperature was 75 degrees C, and the K(m) was 7.1 microM . The structural gene, lac1, was cloned and sequenced . This gene encodes a 517-amino-acid protein 99% identical to a laccase produced by PM1, an unidentified basidiomycete previously isolated from wastewater from a paper factory in Spain . This similarity may be explained by the ecological distribution of the evergreen oak in Mediterranean forest.

J AOAC Int, 2000 Jan-Feb, 83(1), 231 - 6
Improved determination of mercury complex with Thiomicher's ketone by beta-correction spectrophotometry; Gao HW et al.; Determination of the mercury complex formed with Thiomicher's ketone (TMK) was improved by beta-correction spectrophotometry in the presence of a nonionic surfactant at pH 5 . The complex formed was Hg(TMK)2, and its true molar absorptivity is reported for the first time: epsilon Hg(TMK)2(560) = 1.04 x 10(5) L/mol.cm . In addition, the stability constant of Hg(TMK)2 was equal to 3.64 x 10(10) at an ion strength of 0.01 at 20 degrees C . Results from analyses of wastewater samples showed that the relative standard deviations were < or = 8.3%, and the recoveries of mercury ranged from 90 to 110%.

J Biotechnol, 2000 Feb 17, 77(2-3), 265 - 73
Oxirane-immobilized Lentinula edodes laccase: stability and phenolics removal efficiency in olive mill wastewater; D'Annibale A et al.; Immobilization of Lentinula edodes laccase on Eupergit C increased pH, thermal and proteolytic stability with slight modifications in laccase oxidation efficiency . Immobilized laccase proved to be efficiently stable in removing olive mill wastewater phenolics.

J Air Waste Manag Assoc, 2000 Feb, 50(2), 272 - 7
Pyrolysis kinetics and residue characteristics of petrochemical industrial sludge; Chiang HL et al.; This study investigated the pyrolysis characteristics of sludge from wastewater treatment plants in the petrochemical industry and focused on the pyrolysis kinetics, elemental composition of residue, and volatile organic compounds (VOCs) of exhaust gas . As pyrolysis temperature increased to 773 K, the increasing rate of crude oil production tended to a stable condition . The result indicated that the optimal temperature of crude oil and water mixed production was 773 K . When pyrolysis temperature increased from 673 to 973 K, carbon, oxygen, nitrogen, and hydrogen concentrations of residue decreased and the sulfur concentration of residue increased . The concentrations of benzene, toluene,ethylbenzene, and styrene increased by the increasing pyrolysis temperature . We found that the reaction order of sludge pyrolysis was 2.5 and the activation energy of the reaction was 11.06 kJ/mol . We believe that our pyrolysis system is transitional between devolatilization and combustion.

J Air Waste Manag Assoc, 2000 Feb, 50(2), 234 - 9
Methane emissions from domestic waste management facilities in Jordan--applicability of IPCC methodology; Abdulla FA et al.; In this paper, methane emissions from municipal wastewater treatment plants and municipal solid waste (MSW) landfills in Jordan for 1994 have been estimated using the methodology developed by the Intergovernmental Panel on Climate Change (IPCC) . For this purpose, the 14 domestic wastewater treatment plants in the country were surveyed . Generation rates and characterization of MSW components as well as dumping and landfilling practices were surveyed in order to estimate 1994 CH4 emissions from these sites . Locally available waste statistics were used in cases where those of the IPCC guidelines were not representative of Jordan's statistics . Methane emissions from domestic wastewater in Jordan were estimated at 4.66 gigagrams (Gg) . Total 1994 CH4 emissions from MSW management facilities in Jordan are estimated at 371.76 Gg--351.12 Gg (94.45%) from sanitary landfills, 19.83 Gg (5.33%) from MSW open dumps, and 0.81 Gg (0.22%) from raw sewage-water dumping ponds . Uncertainties associated with these estimations are presented.

Bull World Health Organ, 1999, 77(12), 973 - 80
Assessment of cell culture and polymerase chain reaction procedures for the detection of polioviruses in wastewater; Grabow WO et al.; WHO considers that environmental surveillance for wild-type polioviruses is potentially important for surveillance for acute flaccid paralysis as a means of confirming eradication of poliomyelitis . The present study investigated methods for detecting polioviruses in a variety of water environments in South Africa . Most polioviruses were isolated on L20B mouse cells, which, however, were not selective: 16 reoviruses and 8 enteroviruses, apparently animal strains, were also isolated on these cells . Vaccine strains of polioviruses were isolated from surface waters during and shortly after two rounds of mass vaccination of children in an informal settlement where there was no sewerage . The results demonstrated the feasibility of poliovirus surveillance in such settlements . It was also evident that neither poliovirus vaccine strains nor other viruses were likely to interfere significantly with the detection of wild-type polioviruses . Optimal isolation of polioviruses was accomplished by parallel inoculation of L20B mouse cells and at least the PLC/PRF/5 human liver and buffalo green monkey (BGM) kidney cell lines . Analysis of cell cultures using the polymerase chain reaction revealed that 319 test samples contained at least 263 human enteroviruses that failed to produce a cytopathogenic effect . This type of analysis thus significantly increased the sensitivity of enterovirus detection.

Chemosphere, 2000 Feb, 40(3), 255 - 65
New PEC definitions for river basins applicable to GIS-based environmental exposure assessment; Boeije GM et al.; By means of GREAT-ER (Geo-Referenced Regional Exposure Assessment Tool for European Rivers) aquatic chemical fate simulations can be performed for river basins . To apply the resulting digital maps with local (river stretch specific) predicted concentrations in regional aquatic exposure and risk assessment, the output has to be aggregated to a (single) value representative of exposure in the catchment . Two spatially aggregated PEC definitions are proposed for this purpose: PECinitial (unweighted aggregation of concentrations just downstream of wastewater emissions) and PECcatchment (weighted aggregation of all average stretch concentrations) . These PECs were tested using simulations for two pilot study catchments (Calder and Went, UK) . This confirmed the theoretical considerations which led to the definitions, and it illustrated the need for weighting to resolve scale-dependencies.

J Occup Environ Med, 2000 Jan, 42(1), 83 - 7
Evaluation of occupational transmission of hepatitis A virus among wastewater workers; Trout D et al.; To provide information concerning potential occupational transmission of hepatitis A virus (HAV) among wastewater workers in a large city in the United States, a cross-sectional survey was performed using a saliva test to detect antibodies to HAV (anti-HAV) . Fifty-nine (20%) of 302 participants tested positive for anti-HAV . After controlling for the confounding effects of age and race, wastewater work was not significantly associated with an increase in the prevalence of anti-HAV (prevalence ratio = 1.3; 95% confidence interval 0.7 to 2.4) . Additionally, when examining only the wastewater workers, no statistically significant occupational risk factors for anti-HAV were identified . The results of this survey are consistent with the position of the Centers for Disease Control and Prevention regarding groups at risk for HAV infection.

Sci Total Environ, 1999 Dec 15, 243-244, 323 - 8
Trace elements in children's hair, as related exposure in wastewater spreading field of Marrakesh (Morocco); Lekouch N et al.; Lead and cadmium concentration was determined in the hair of 327 school children living in a wastewater spreading field of Marrakesh (Morocco) . The influence of age, sex, food habits and family occupation on the children's hair Pb and Cd concentration was also evaluated . Girls had more metal in their hair than boys (16.5 +/- 5.4 micrograms/g and 12.5 +/- 3.5 micrograms/g, respectively) . However, for Cd the boys had more metal (2.9 +/- 0.6 and 2.2 +/- 0.4, respectively) but the difference was not statistically significant and metal levels decreased with age . Family occupation, direct contact with wastewater, customs and food habits were the most significant factors influencing the metal content of children's hair . The average Pb and Cd content were higher in the exposed children (14.8 +/- 4.5 micrograms/g and 2.5 +/- 0.5 micrograms/g, respectively) than in the non-exposed children (4.6 +/- 2.2 micrograms/g and 0.6 +/- 0.2, respectively), but the difference was not statistically significant . This study shows that in this area all the population (especially children) was extremely exposed to the danger caused by potentially toxic metals.

Biodegradation, 1999, 10(4), 297 - 305
Anaerobic transformation of 1,1,1-trichloroethane by municipal digester sludge; Chen C et al.; Anaerobic transformations of 1,1,1-trichloroethane (TCA), 1,1-dichloroethane (DCA), and chloroethane (CA) were studied with sludge from a lab-scale, municipal wastewater sludge digester . TCA was biologically transformed to DCA and CA and further to ethane by reductive dechlorination . TCA was also converted to acetic acid and 1,1-dichloroethene (11DCE) by cell-free extract . 11DCE was further biologically converted to ethene . This pathway was confirmed by transformation tests of TCA, DCA and CA, by tests with cell-free extract, and by chloride release during TCA degradation . With cell-free extract, acetic acid accounted for approximately 90% of the TCA transformed; tests with live cells indicate that the fraction of TCA transformed by this pathway decreased with lower biomass . The dechlorination of DCA to CA and CA to ethane was not stoichiometric . A high rate of TCA removal was observed under the experimental conditions . The results indicate that removal of TCA in anaerobic digestion should be complete, but DCA and CA could persist in a normally operating digester.

J Hazard Mater, 1999 Dec 31, 70(3), 157 - 70
Separation of aniline from aqueous solutions using emulsion liquid membranes; Devulapalli R et al.; An emulsion liquid membrane process is developed to separate aniline from dilute aqueous solution . Aniline (amino-benzene) is a carcinogenic chemical common in industry and industrial wastewater . Due to aniline's high boiling point (183 degrees C) and low concentration in wastewater, more traditional methods of separation such as distillation are very energy intensive . This emulsion process is offered as a low energy alternative . All separations occur in a Rushton stirred tank . The membrane phase consists of kerosene and the surfactant sorbitan monooleate (span 80) . Hydrogen chloride solution is the internal phase . This study also examines the effects of HCl concentration, aniline concentration, and the amount of emulsion on separation . Up to 99.5% of the aniline is removed from solutions containing 5000 ppm in as little as 4 min depending on process conditions . Leakage is minimal and swelling is only about 3% after 5 min of processing . Approximately 98% of the membrane phase (both kerosene and span 80) is successfully recovered and recycled by using heat and/or adding 2-propanol for demulsification.

J Hazard Mater, 1999 Dec 23, 70(1-2), 41 - 52
Electrochemical oxidation of a textile dye wastewater using a Pt/Ti electrode; Vlyssides AG et al.; Textile dye wastewater (TDW) from a reactive azo dyeing process was treated by an electrochemical oxidation method using Ti/Pt as anode and stainless steel 304 as cathode . Due to the strong oxidizing potential of the chemicals produced (chlorine, oxygen, hydroxyl radicals and other oxidants) when the wastewater was passed through the electrolytic cell the organic pollutants were oxidized to carbon dioxide and water . A number of experiments were run in a batch, laboratory-scale, pilot-plant, and the results are reported here according to residence time and initial addition of HCl in raw wastewater . When of 2 ml of HCl 36% were added and after 18 min of electrolysis at 0.89 A/cm(2), chemical oxygen demand (COD) was reduced by 86%, biochemical oxygen demand (BOD(5)) was reduced by 71%, ADMI color units were reduced by 100%, and TKN was reduced by 35% . The biodegradability of the wastewater was improved because the COD/BOD ratio decreased from 2.16 to 1.52 . At the same time the efficiency of the electrode was about 170 g h(-1) A(-1) m(-2) . and the mean energy consumption was 21 kW h/kg of COD . These results indicate that this electrolytic method could be used for effective TDW oxidation or as a feasible detoxification and color removal pretreatment stage for biological post treatment.

J Agric Food Chem, 1999 Sep, 47(9), 3911 - 8
Wine distillery wastewater degradation . 1 . Oxidative treatment using ozone and its effect on the wastewater biodegradability; Beltran FJ et al.; Laboratory-scale experiments were conducted to investigate the impact of ozonation on the degradability of wine distillery wastewaters, usually called vinasses, with the goal of developing combined chemical-biological methods for their treatment . Chemical oxygen demand (COD), biological oxygen demand (BOD), total organic carbon (TOC), and ultraviolet absorbance at 254 nm (UV(254)) were taken as reference parameters to follow the pollution level . The vinasses were treated both directly and after being mixed with domestic sewage . Ozonation of pure vinasses required high ozone doses to achieve a significant efficiency for removing the organic matter . Mixing vinasses with domestic sewage allowed higher degradation rates with ozone . Ozone was also demonstrated to be an appropriate oxidizing agent to improve vinasses's biodegradability and organic matter removal . A mathematical model of the ozonation kinetics based on the film theory concept is also presented.

J Biotechnol, 1999 Oct 8, 75(2-3), 229 - 39
Neural network modeling for on-line estimation of nutrient dynamics in a sequentially-operated batch reactor; Lee DS et al.; In monitoring and controlling wastewater treatment processes, on-line information of nutrient dynamics is very important . However, these variables are determined with a significant time delay . Although the final effluent quality can be analyzed after this delay, it is often too late to make proper adjustments . In this paper, a neural network approach, a software sensor, was proposed to overcome this problem . Software sensor refers to a modeling approach inferring hard-to-measure process variables from other on-line measurable process variables . A bench-scale sequentially-operated batch reactor (SBR) used for advanced wastewater treatment (BOD plus nutrient removal) was employed to develop the neural network model . In order to improve the network performance, the structure of neural network was arranged in such a way of reflecting the change of operational conditions within a cycle . Real-time estimation of PO3-(4), NO-3, and NH+4 concentrations was successfully carried out with the on-line information of the SBR system only.

J AOAC Int, 1999 Nov-Dec, 82(6), 1466 - 73
Analysis of interlaboratory performance in the determination of total selenium in water; Steinhoff PJ et al.; This study explored the performance of experienced laboratories in the analysis for total selenium in water by a variety of analytical methods . The goal of the study was to examine intra- and interlaboratory variability . Replicates (n = 7) of 7 sample types that included a reference material of known Se concentration, natural waters, and treated wastewaters were submitted to 7 laboratories with prequalified Se analytical experience . Results of the study indicated wide ranges in minimum and maximum results, distinct differences in laboratory precision, and routine reporting of numerical results below statistical limits of quantitation . Hydride generation as a sample introduction technique demonstrated superior performance . In general, the study supports a caution advisory about using low-level Se data, especially results lower than about 10 micrograms Se/L, without quantitating the statistical uncertainty of the data . Because this study used data from samples that were submitted in bulk to participating laboratories prequalified for Se analytical expertise and experience, it can be considered a best-case demonstration of performance.

Chemosphere, 1999 Dec, 39(14), 2459 - 66
Sorption of arsenate and arsenite anions by iron(III)-poly(hydroxamic acid) complex; Haron MJ et al.; Iron(III)-poly(hydroxamic acid) resin complex has been studied for its sorption abilities with respect to arsenate and arsenite anions from an aqueous solution . The complex was found effective in removing the arsenate anion in the pH range of 2.0 to 5.5 . The maximum sorption capacity was found to be 1.15 mmol/g . The sorption selectivity showed that arsenate sorption was not affected by chloride, nitrate and sulphate . The resin was tested and found effective for removal of arsenic ions from industrial wastewater samples.

Int J Parasitol, 1999 Sep, 29(9), 1379 - 413
Isolation, propagation and characterisation of Cryptosporidium; Gasser RB et al.; This review consists of 11 papers presented at the Consensus Conference on Cryptosporidium in Water (Parasitology Stream), held in Melbourne, Australia, from 5 to 6th October 1998 . The conference was sponsored by the Water Services Association of Australia, the Australian Water and Wastewater Association, and the Collaborative Research Centre for Water Quality and Treatment . The papers summarise the advantages and disadvantages of various contemporary technologies applicable to parasite propagation and biochemical/molecular characterisation . Studies have detected distinct genetic differences between clinical isolates from humans and animals, and it is hoped that comprehensive documentation studies will facilitate the identification of environmental isolates in the not too distant future.

J Environ Sci Health B, 1999 Nov, 34(6), 1101 - 10
Ultrafiltration tests for the reutilization of greenhouse wastewater; Liu M et al.; A lab-scale experiment was performed using two different pore-size ultrafiltration membranes to investigate the removal efficiency of Tomato Mosaic Virus (ToMV), retainability of pollutant and nutrients, and flow characteristics . From the experiment, it may be concluded that ultrafiltration can be used effectively to eliminate ToMV . Tests with a 30K pore-size ultrafiltration membrane achieved 99% virus removal efficiency and a 5K membrane practically removed 100% of the virus in greenhouse wastewater . Nutrient analysis indicated that all the essential nutrients could be retained and re-utilized.

J Environ Sci Health B, 1999 Nov, 34(6), 1009 - 21
Development of a prefabricated treatment plant for diluted pig wastewater; Chen HJ et al.; In order to develop a prefabricated treatment and reuse plant for diluted pig wastewater, an entrapped-mixed-microbial-cell (EMMC) process was evaluated for its process performance and economic analysis . At the hydraulic retention time (HRT) of 30 hrs (loading rate of 1.0 g TCOD/L/d) and intermittent aeration of 1 hr of aeration and 1 hr of non-aeration, it was found that, by using the pretreatment of the ammonium crystallization, both the medium and large carriers were able to reduce TCOD, SCOD, and T-N by 83.51, 84.11, and 95.10%, respectively . The EMMC unit and lime post-treatment followed by ammonium crystallization can reduce BOD5, TCOD, SCOD, TSS, T-N, and T-P, respectively by 99.22, 93.85, 92.67, 97.73, 96.43, and 97.27% . The treated wastewater, after disinfection, is able to meet the requirements of the standards issued by the USEPA for reuse of food crops . The economic analysis indicates that based on the process performance of the EMMC unit, a prefabricated wastewater treatment plant for 2000 pigs has comparable net present worth (NPW) comparing intermittent aerated biological systems and less operation and maintenance and land requirement than conventional biological processes for removal carbon and nitrogen . A farm operation of more than 2000 pigs meets the unit cost of US$4.91/pig/yr . This will minimize the problems pertaining to technical factors or considerations that heavily influence planning, construction and operation of a pig wastewater treatment system.

Int J Syst Bacteriol, 1999 Oct, 49 Pt 4, 1817 - 27
Phylogenetic relationships of filamentous sulfur bacteria (Thiothrix spp . and Eikelboom type 021N bacteria) isolated from wastewater-treatment plants and description of Thiothrix eikelboomii sp . nov., Thiothrix unzii sp . nov., Thiothrix fructosivorans sp . nov . and Thiothrix defluvii sp . nov; Howarth R et al.; The relationship of mixotrophic and autotrophic Thiothrix species to morphologically similar chemoorganotrophic bacteria (e.g . Leucothrix species, Eikelboom type 021N bacteria) has been a matter of debate for some years . These bacteria have alternatively been grouped together on the basis of shared morphological features or separated on the basis of their nutrition . Many of these bacteria are difficult to maintain in axenic culture and, until recently, few isolates were available to allow comprehensive phenotypic and genotypic characterization . Several isolates of Thiothrix spp . and Eikelboom type 021N strains were characterized by comparative 16S rRNA sequence analysis . This revealed that the Thiothrix spp . and Eikelboom type 021N isolates formed a monophyletic group . Furthermore, isolates of Eikelboom type 021N bacteria isolated independently from different continents were phylogenetically closely related . The 16S rRNA sequence-based phylogeny was congruent with the morphological similarities between Thiothrix and Eikelboom type 021N . However, one isolate examined in this study (Ben47) shared many morphological features with the Thiothrix spp . and Eikelboom type 021N isolates, but was not closely related to them phylogenetically . Consequently, morphology alone cannot be used to assign bacteria to the Thiothrix/type 021N group . Comparative 16S rRNA sequence analysis supports monophyly of the Thiothrix/type 021N group, and phenotypic differences between the Thiothrix spp . and Eikelboom type 021N bacteria are currently poorly defined . For example, both groups include heterotrophic organisms that deposit intracellular elemental sulfur . It is therefore proposed that the Eikelboom type 021N bacteria should be accommodated within the genus Thiothrix as a new species, Thiothrix eikelboomii sp . nov., and three further new Thiothrix species are described: Thiothrix unzii sp . nov., Thiothrix fructosivorans sp . nov . and Thiothrix defluvii sp . nov.

Int J Syst Bacteriol, 1999 Oct, 49 Pt 4, 1353 - 7
Microbacterium kitamiense sp . nov., a new polysaccharide-producing bacterium isolated from the wastewater of a sugar-beet factory; Matsuyama H et al.; Two strictly aerobic, heterotrophic and mesophilic new organisms, strains Kitami A1 and Kitami C2T, were isolated from the wastewater of a sugar-beet factory in Kitami City, Hokkaido, Japan . In batch cultures, these organisms produced both insoluble and soluble exopolysaccharides (EPSs) utilizing sucrose as the sole carbon source . The G + C contents of the strains Kitami C2T and Kitami A1 were 69.2 mol% . Both strains had anteiso-C15:0 acid, anteiso-C17:0 acid and iso-C16:0 as major components . The major isoprenoid quinones from these strains included menaquinone-11 and menaquinone-12 . Physiological and biochemical characterization, phylogenetic analysis and DNA-DNA relatedness indicated that these two organisms are new species of the genus Microbacterium, for which the name Microbacterium kitamiense is proposed . The type strain of M . kitamiense is strain Kitami C2T (= JCM 10270T).

J Hazard Mater, 1999 Sep 10, 68(3), 193 - 203
Results from the low level mercury sorbent test at the Oak Ridge Y-12 Plant in Tennessee; Hollerman W et al.; A mercury sorbent test was performed near the headwaters of the Upper East Fork Poplar Creek at the Oak Ridge Y-12 Plant in Tennessee . The sorbents SIR-200 (ResinTech), Keyle:X (SolmeteX), and GT-73 (Rohm and Haas) were the best materials tested for low level mercury removal . Each of these sorbents has a thiol-based active site . None of the tested sorbents reduced the mercury concentration to less than the existing 12 ng/l NPDES limit . For this small scale test, SIR-200, Keyle:X, and GT-73 reduced the mercury concentration to less than 51 ng/l, which is a regulatory treatment goal . The other sorbents tested, including granular activated carbon (Filtrasorb 300), did not reduce the mercury concentration below 51 ng/l at any tested flow up to 5 bed volumes per minute . Because of the cost and large volume of sorbent, a wastewater treatment plant for this stream would be prohibitively expensive to construct and maintain.

Rev Saude Publica, 1999 Aug, 33(4), 379 - 84
{Monitoring of parasites in domestic sewage}; Semenas L et al.; OBJECTIVE: The evaluation of the presence of parasites in semisolid and liquid sewage in Argentinian Patagonia in view of the fact that this is a restriction for its use . METHODS: The samples taken at 4 Domestic Sewage Plants were analyzed in accordance with Standard Methods for the Examination of Water and Wastewater, Environmental Protection Agency, World Health Organization and some other classifications . RESULTS: Only 2 of 6 semisolid samples analyzed had non-viable Ascaris lumbricoides eggs . Of the 10 liquid samples analyzed, only 2 did not contain eggs whereas the remaining ones had pathogens of categories I (Giardia sp., Hymenolepis nana and Enterobius vermicularis) and III (Ascaris lumbricoides, Ancylostoma duodenale and Trichuris trichiura) . CONCLUSIONS: All semisolid samples turned out to be satisfactory for use as fertilizer as no viable Ascaris lumbricoides eggs were found in any of them . But only 6 of the liquid samples were satisfactory for use as they had no eggs or their concentrations was equal to or less than 1 egg per litre.

J Hazard Mater, 1999 Nov 15, 69(3), 273 - 86
Recycling of lead-contaminated EDTA wastewater; Kim C et al.; Ethylene diaminetetraacetic acid (EDTA) is one of the chelating agents used in the soil washing process for the decontamination of lead-contaminated soil . Lead-EDTA complexes in the wastewater from the soil washing process must be removed before the wastewater can be safely discharged . This study outlines a method to recycle Pb-EDTA wastewater by substituting the Pb complexed with EDTA with Fe(III) ions at low pH, followed by precipitation of Pb ions with phosphate or sulfate ions . Fe(III) ions complexed with EDTA were then precipitated at high pH using sodium hydroxide . The resulting solution (Fe-precipitated solution) was tested on three lead-contaminated soils . The Fe-precipitated EDTA solution was found to have similar extraction capabilities as fresh EDTA solution . Experimental results showed that the recycled EDTA solution may be recycled several times without losing its extractive power . Recycled EDTA wastewater with phosphate precipitation was found to be slightly more effective than recycled EDTA solution using sulfate precipitation . The recycling procedure may be applied to wastewater generated during soil washing of lead-contaminated soil, resulting in a reduction in wastewater generated and savings in the amount of EDTA used.

Chemosphere, 1999 Nov, 39(11), 1853 - 60
Synergistic effects of combination of photolysis and ozonation on destruction of chlorophenols in water; Kuo WS; Synergistic effects including TOC elimination, ozone consumption and microtoxicity reduction for combination of photolysis and ozonation compared to those of direct photolysis and ozonation alone on destruction of chlorophenols including 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol were studied . It was found that the synergistic effects of combination of photolysis and ozonation increased obviously with increasing initial pH of solution to basic pH levels . Results showed that the synergistic effects of photolytic ozonation under the conditions imposed was notable with mineralization rate enlarging more than 100%, oxidation index (OI) decreasing 50%, and microtoxicity being reduced by 30%, indicating that the potentialities of photolytic ozonation compared to direct photolysis and ozonation alone was remarkable for treatment of industrial wastewater containing chlorophenols.

Chemosphere, 1999 Nov, 39(11), 1781 - 94
Occurrence and behavior of wastewater indicators in the Santa Ana River and the underlying aquifers; Ding WH et al.; The occurrence and behavior of wastewater indicator compounds in the Santa Ana River (SAR) water and the underlying aquifer recharged by the SAR has been studied . The SAR contains a high proportion of tertiary treated wastewater effluents, up to 100% during summer and fall . The following water quality parameters were quantified: four specific wastewater indicator compounds, ethylene diaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), a naphthalene dicarboxylate (NDC) isomer, alkylphenol polyethoxy carboxylates (APECs), and selected haloacetic acids (HAAs), nitrate, dissolved oxygen (DO), DOC, total carbohydrate, and phenolic substances . Statistical analysis indicated that normal distribution was adequate to describe the probability distribution of the constituents in most cases . In the river, the concentrations of wastewater indicator compounds decreased as the fraction of storm runoff increased . EDTA and NDC were detected in a monitoring well near the river and in two production wells 1.8 and 2.7 km down gradient with little apparent attenuation . By contrast, NTA, APECs, bromochloro- and dibromoacetic acids appeared to be attenuated significantly during infiltration of river water and groundwater transport.

FEMS Microbiol Ecol, 1999 Nov 1, 30(3), 209 - 216
Physiological responses of Tetrahymena pyriformis to copper, zinc, cycloheximide and Triton X-100; Nicolau A et al.; Protozoa, and particularly ciliates, are essential in aerobic purification processes of wastewaters and have proved to be very sensitive to environmental changes . The physiological response of the ciliate Tetrahymena pyriformis was assessed in terms of mortality, growth and grazing capacity after exposure to four toxicants: copper, zinc, cycloheximide and Triton X-100 . In the ranges of concentrations used, mortality, inhibition of growth and inhibition of grazing were observed with all toxicants employed, but in different ways . Copper and zinc showed lower toxicity than observed in other studies with protozoa, though some of the present results are in accordance with those reported by other authors . This supports the importance of the organism tested and the experimental conditions of the bioassays.

J Colloid Interface Sci, 1999 Oct 15, 218(2), 359 - 368
Ultrafiltration of Micellar Solutions Containing Phenols; Adamczak H et al.; Micellar-enhanced ultrafiltration represents a potentially attractive tool for the removal of different contaminants from wastewaters . The ultrafiltration of micellar solutions containing phenol or 4-nitrophenol was studied . Sodium dodecyl sulfate (SDS), hexadecyltrimethyl ammonium sulfate, alkyl polyglucoside Glucopon 215 SC UP, and oxyethylated methyl dodecanoates with the average degree of oxyethylation equal to 5 and 9 were used as surfactants and NaHCO(3) as an electrolyte and alkalizing agent . Filtration and phenol rejection depends on the presence of NaHCO(3) and the type of surfactant . NaHCO(3) depresses to the filtration rate, especially in the case of SDS and hydrophobic oxyethylated methyl dodecanoate . The highest filtration rates are obtained for hexadecyltrimethyl ammonium bromide (CTAB) and alkyl polyglucoside micellar solutions . The best separations, both of phenol and 4-nitrophenol (almost 100% rejection), are obtained for CTAB micellar solutions at the pH range from 3 to 11 . Nonionic surfactants are not effective enough for the separation of phenol and 4-nitrophenol . SDS solutions permit only the separation of phenol .

Environ Manage, 1999 Nov, 24(4), 497 - 507
RESEARCH: Comparison of Temporal Trends in Ambient and Compliance Trace Element and PCB Data in Pool 2 of the Mississippi River, USA, 1985-1995; Anderson J et al.; / The Intergovernmental Task Force on Monitoring has suggested studies on ambient (in-stream) and compliance (wastewater) data to determine if monitoring can be reduced locally or nationally . The similarity in temporal trends between retrospective ambient and compliance water-quality data collected from Pool 2 of the Mississippi River, USA, was determined for 1985-1995 . Constituents studied included the following trace elements: arsenic (As), cadmium (Cd), chromium (Cr), hexavalent chromium (Cr(6+)), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), zinc (Zn), and polychlorinated biphenyls (PCBs) . Water-column, bed-sediment, and fish-tissue (fillets) data collected by five government agencies comprised the ambient data set; effluent data from five registered facilities comprised the compliance data set . The nonparametric Mann-Kendall trend test indicated that 33% of temporal trends in all data were statistically significant (P < 0.05) . Possible reasons for this were low sample sizes, and a high percentage of samples below the analytical detection limit . Trends in compliance data were more distinct; most trace elements decreased significantly, probably due to improvements in wastewater treatment . Seven trace elements (Cr, Cd, Cu, Pb, Hg, Ni, and Zn) had statistically significant decreases in wastewater and portions of either or both ambient water and bed sediment . No trends were found in fish tissue . Inconsistency in trends between ambient and compliance data were often found for individual constituents, making overall similarity between the data sets difficult to determine . Logistical differences in monitoring programs, such as varying field and laboratory methods among agencies, made it difficult to assess ambient temporal trends.KEY WORDS: Mann-Kendall trend test; Ambient data; Compliance data; Trace elements; PCBs, Mississippi Riverhttp://link.springer-ny.com/link/service/journals/00267/bibs/24n4p497.html</HEA

Public Health Rep, 1999 Jul-Aug, 114(4), 353 - 8
Eliminating mercury use in hospital laboratories: a step toward zero discharge; Harvie J; In 1996, the Western Lake Superior Sanitary District initiated a Zero Discharge Project to work toward the goal of zero discharge of persistent toxic substances from its wastewater treatment plant . This multifaceted project focuses on mercury, lead, dioxin, polychlorinated biphenyls, and hexachlorbenzene . Here, the author describes a collaboration with local hospitals to eliminate the use of mercury-containing fixatives by histopathology laboratories . Three primary roadblocks to change were identified: (a) technicians' belief that pathologists would be resistant to change; (b) lack of time to research alternatives; (c) lack of awareness of the hospital's role in polluting the environment.

J Chromatogr A, 1999 Aug 27, 854(1-2), 175 - 85
Use of volatile amines as ion-pairing agents for the high-performance liquid chromatographic-tandem mass spectrometric determination of aromatic sulfonates in industrial wastewater; Storm T et al.; The use of trialkylamines (triethylamine, N,N-dimethyl-n-butylamine, and tri-n-butylamine) as volatile ion-pairing agents for the high-performance liquid chromatographic separation of aromatic sulfonates was investigated . Negative ion electrospray tandem mass spectrometry was used to detect both singly and multiply charged analyte ions . Sensitivity of detection was strongly reduced by amine concentrations above 2.5 mmol l(-1) in the eluent . With tributylamine as ion-pairing agent 19 aromatic sulfonic acids could be determined using time-scheduled selected reaction monitoring . Lowest orders of detection range from 3 to 74 microgl(-1) . Several naphthalenesulfonic acids were determined in dyeing baths and textile wastewater in concentrations ranging from 0.1 mgl(-1) to 2.1 mgl(-1) . A degradation product of sulfonated azodyes was identified in the effluent of a laboratory treatment plant.

J Chromatogr A, 1999 Aug 20, 853(1-2), 503 - 9
Analysis of dyestuff degradation products by capillary electrophoresis; Takeda S et al.; Capillary electrophoresis (CE) with two different detection methods, mass spectrometry (MS) and UV absorption spectroscopy with photodiode array detection (UV/DAD), was used for the analysis of the degradation products of dyestuffs . We have studied wet oxidation with solid catalyst as the treatment method of wastewaters containing dyestuffs . When the Orange II (C.I . Acid Orange 7) solution was used as the model wastewater, treated solution contained unknown highly polar degradation products . We were able to determine the molecular masses of some products by CE-MS . From this clue, we tried to identify these products by CE-UV/DAD . By means of the comparison of the migration time and UV spectra of standard samples, three degradation products were identified . The separation of degradation products was successful within 15 min.

Biodegradation, 1999 Apr, 10(2), 113 - 25
Population dynamics of an introduced bacterium degrading chlorinated benzenes in a soil column and in sewage sludge; Tchelet R et al.; The capacity of the beta-Proteobacterium Pseudomonas sp . strain P51, which degrades chlorinated benzenes, to metabolize 1,2,4-trichlorobenzene (TCB) under environmental conditions was tested by its release into two experimental systems . The first system consisted of laboratory scale microcosms which were operated with and without the addition of TCB and which were inoculated with sludge from a wastewater treatment plant . The second system consisted of a non sterile, water saturated soil column . We determined survival of strain P51 after its introduction and its ability to degrade TCB . The population dynamics was followed by selective plating and applying the polymerase chain reaction (PCR) to detect strain P51 and the chlorobenzene (tcb) genes on catabolic plasmid pP51 . The results showed a completely different behaviour of strain P51 in the two habitats under the applied conditions . In the soil column the P51 bacteria inoculated the entire area and their population reached 2 x 10(6) cells/g soil . The population remained active since TCB was degraded to concentrations below the detection limit of 30 micrograms/l . In the sludge microcosms, the number of strain P51 cells immediately decreased from 4 x 10(7) cells/ml to 10(5) cells/ml over a period of 2 days after inoculation, and then the strain disappeared to levels below our detection limit (10(3)-10(4) cells/ml) . In the reactor without TCB the population of P51 maintained a stable value of 10(5) cells/ml during 8 days but then also decreased to levels below the detection limit . In addition, no significant TCB degradation was found in the sludge reactors . The influence of presence of TCB on maintenance of strain P51 in the two habitats is discussed . This work demonstrates the possibility to successfully apply preselected strains to degrade otherwise poorly degradable substances in complex mixed microbial communities . However, survival and activity may depend strongly on the type of system into which the strain is introduced.

Anal Chem, 1999 Aug 15, 71(16), 3531 - 7
Development of a solid-phase microextraction GC-NPD procedure for the determination of free volatile amines in wastewater and sewage-polluted waters; Abalos M et al.; An analytical procedure for the determination of free volatile C1-C6 amines in aqueous matrixes has been developed and applied to their determination in waste-water, primary and secondary effluents, and sewage-polluted river samples . The developed analytical procedure involves headspace sampling using solid-phase microextraction with a poly(dimethylpolysiloxane) coating (100 microns) followed by GC-NPD determination and GC/MS confirmation using a tailor-made PoraPLOT amines capillary GC column for volatile amines . Procedural detection limits were compound dependent but ranged from 3 to 56 micrograms L-1, being close to or lower than the odor threshold concentration, and the reproducibility was ca . 15% (N = 5) in real water samples . The developed analytical procedure is solvent free, cost-effective (no cryogenic trap needed), and faster than existing methods because no derivatization step is involved in the determination . Linearity was compound dependent but ranged at least from 50 to 600 micrograms L-1.

J Chromatogr A, 1999 Jul 30, 850(1-2), 303 - 9
Analysis of wastewater for anionic and cationic nutrients by ion chromatography in a single run with sequential flow injection analysis; Karmarkar SV; To prevent nutrient enrichment and, hence the undesirable ecological impacts, the nutrients monitored in wastewater samples include two anionic species, i.e., nitrate and orthophosphate, and a cationic species, ammonium . Ion chromatography (IC) is one of the popularly used techniques for determinations of nitrate and phosphate in these samples, whereas determination of ammonium in wastewater samples is typically done using manual or automated wet chemistry, e.g., flow injection analysis (FIA) . We have developed a sequential IC-FIA method, using Lachat's QC8000 IC system, which allows determinations of nitrate, phosphate and ammonia in a single injection . In this system, a QuickChem Small Suppressor cartridge is regenerated in between the samples . A sample is injected while leaving the suppressor off-line . Ammonium, a cation, elutes in the void volume of an anion-exchange column . The unsuppressed column effluent, exiting the conductivity flow cell, up to this point is used for FIA determination of ammonia . When ammonia exits the conductivity flow cell, a fully regenerated suppressor is brought in-line for conductometric detection of the anions . Analog data are simultaneously acquired from colorimetric and conductometric detectors, for the cationic and anionic nutrients, respectively . The method is accurate with spike recoveries in wastewater samples ranging from 91% for nitrate to 114% for chloride . It is precise with RSD values, for replicate analyses (n = 7) of a mid-range standard, ranging from 0.4% for phosphate to 1% for nitrate.

Chemosphere, 1999 Aug, 39(5), 745 - 52
The environmental fate of the primary degradation products of alkylphenol ethoxylate surfactants in recycled paper sludge; Hawrelak M et al.; Alkylphenol ethoxylates (APEOs) are a group of non-ionic surfactants that are degraded microbially into more lipophilic degradation products with estrogenic potential, including nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), octylphenol (4-tOP) and nonylphenol (4-NP) . Nonylphenol ethoxylates are used in paper recycling plants for de-inking paper and have the potential to be released into the environment through spreading of wastewater treatment sludge for soil amendment . Three samples of recycled paper sludge were collected from farmers' fields and analyzed for concentrations of NP1EO, NP2EO, 4-NP and 4-tOP . Each sample differed in the amount of time elapsed since the sludge was placed on farmers' fields . Primary degradation products of APEOs were present at low micrograms/g concentrations in the sludge samples . Differences in the concentrations of these analytes in sludge samples indicated that APEO concentrations declined by 84% over a period of 14 weeks on farmers' fields . Changes in the chromatographic patterns of acetylated 4-NP indicated that there is a group of recalcitrant nonylphenol isomers that degrades more slowly than other isomers . These data indicate that microbial degradation may reduce the risk of environmental contamination by these compounds, but more work is required to assess the toxic potential of APEOs in sludges used for soil amendment.

Science, 1999 Jul 30, 285(5428), 706 - 11
Environmental engineering: energy value of replacing waste disposal with resource recovery
Iranpour R, Stenstrom M, Tchobanoglous G, Miller D, Wright J, Vossoughi M.
Although in the past, environmental engineering has been primarily concerned with waste disposal, the focus of the field is now shifting toward viewing wastes as potential resources . Because reclamation usually consumes less energy than producing new materials, increasing reclamation not only reduces pollution but saves energy . Technological innovations contributing to this shift are summarized here, and are variously classified as emerging technologies or research topics, as either new departures or incremental improvements, and as opportunistic innovations, or examples of a unifying strategy . Both liquid and solid waste examples are given, such as a recent discovery of effects in disinfecting microfiltered reclaimed wastewater with ultraviolet light . In addition to its value in reducing pollution and conserving energy, this reorientation of environmental engineering could contribute to a more general shift toward greater cooperation among organizations dealing with the environment.

Mycopathologia, 1998-99, 144(1), 39 - 54
Ecology of cycloheximide-resistant fungi in field soils receiving raw city wastewater or normal irrigation water; Ali-Shtayeh MS et al.; The effect of raw city wastewater irrigation on biodiversity and population densities of a cycloheximide-resistant (CH) fungal community was studied in 13 field soils receiving either raw city wastewater or normal irrigation, and in raw city wastewater in the Nablus area, using the hair baiting technique (HBT) and a surface soil dilution plating (SSDP) technique . Three of these fields {one had been receiving raw city wastewater for more than ten years and was designated a heavily polluted field, and the other 2 were cultivated for the first time and were either irrigated with raw city wastewater (newly polluted field) or normal irrigation water (nonpolluted)}, were sampled 4-7 times over a 9-month period . The other ten fields, which had been under raw city wastewater irrigation for more than 10 years, were sampled only once . Fifty-seven CH-resistant species belonging to 18 genera were recovered, of which 49 species were recovered from soil habitats and 28 species from raw city wastewater . The HBT had shown to be more efficient in the isolation of pathogenic and potentially pathogenic fungi including dermatophytes . A higher percentage of this group of fungi was recovered from the three main field soils studied using HBT (70% of all isolates), than the SSDP (35.5%); no dermatophytes were recovered by the SSDP method . Two dermatophytes (Microsporum gypseum, and Trichophyton ajelloi), and five more fungi (Arthroderma cuniculi, A . curreyi, Chrysosporium keratinophilum, C . tropicum, C . pannorum), were recovered from these habitats . Wastewater irrigation seemed to have affected the fungal population densities, with the highest population densities being found in the heavily polluted field soil, while lower population densities were found in the nonpolluted field soil . Increases in organic matter were also observed as a result of sewage effluent irrigation . However, basic similarities in the biodiversity of CH-resistant fungal communities existed in nonpolluted and polluted field soils, and raw city wastewater . Comparable numbers of fungal species were recovered from the three main field soils . The species most commonly found in those habitats included: Alternaria alternata, Aspergillus candidus, Geotrichum candidum, and Paecilomyces lilacinus . Field soils receiving either raw city wastewater or normal irrigation water, were found to be rich in pathogenic and potentially pathogenic CH-resistant fungi, including dermatophytes, with raw city wastewater yielding the highest percentage (81%), followed by the newly wastewater irrigated field (77.7%), the nonpolluted field (67%), and the heavily polluted field (63.4%) Hygienic measures should therefore be taken to control the spread of these fungi in the environment of human communities, and to avoid mycotic infections among farmers.

Biosens Bioelectron, 1999 Apr 30, 14(4), 355 - 61
A two-stage minibioreactor system for continuous toxicity monitoring; Gu MB et al.; A two-stage minibioreactor system was successfully developed for continuous toxicity monitoring . This system consists of two minibioreactors in series . Recombinant Escherichia coli DPD2794 containing a RecA::luxCDABE fusion as a model strain was utilized to monitor environmental insults to DNA, with mitomycin C as a model toxicant . Pulse type exposures were used to evaluate the system's reproducibility and reliability . Step inputs of mitomycin C have been adopted to show the system's stability . The system's ability to monitor the possible upsets or accidental discharges of toxic chemicals was also evaluated with these step insults . All the data demonstrated that this two-stage minibioreactor system using recombinant bacteria containing stress promoters fused with lux genes is quite appropriate for continuous toxicity monitoring . Long-term operation and minimized media-usage have been investigated . Thus application to many different areas, including an early warning system of wastewater biotreatment plant upsets and the monitoring and tracking of accidental spills, discharges or failures in plant operation are plausible.

J Food Prot, 1999 Jul, 62(7), 731 - 4
Recovery and survival of Escherichia coli O157:H7 in reconditioned pork-processing wastewater; Rajkowski KT et al.; The pathogen Escherichia coli O157:H7 has been recovered from various water sources and food samples . The growth potential of this bacterium in nutrient-limited, reconditioned wastewater from a pork-processing plant was determined over a temperature range of 4 to 46 degrees C . Even though the biological oxygen demand of the wastewater was <2 mg/liter, results of bioassays for assimilable organic carbon and the coliform growth response of the water suggested that sufficient nutrients were present to support limited bacterial growth . A three-strain mixture of E . coli O157:H7 grew over the temperature range of 10.2 to 29.4 degrees C . Bioassays appear to be a good indicator of the ability of this wastewater to support growth of this pathogen . Statistically higher levels of bacterial growth (P < 0.05) were detected on a nonselective medium (tryptic soy agar) than on a selective medium (sorbitol-MacConkey agar), suggesting that stress or injury of the bacterium occurs when the organism is exposed to the nutrient-limited conditions of the wastewater . These results indicate that E . coli O157:H7 can survive and grow in this particular nutrient-limited wastewater, suggesting a potential hazard if this water becomes contaminated with this pathogen.

Zentralbl Hyg Umweltmed, 1999 Jun, 202(1), 29 - 39
Enterovirus genome detection in wastewater: multi centric evaluation of a commercial kit; Gantzer C et al.; A multi-centric study was carried out in three laboratories, to evaluate the efficiency of a standardized kit for the detection of enterovirus genome in wastewater . Twenty one samples of 20 liters of wastewater were analyzed before and after concentration through glass wool . Each sample was analyzed with the Amplicor kit as well as with techniques developed independently in each laboratory . The results show that the Amplicor kit is well suited to the detection of enterovirus genome in treated wastewater . The results may be compared to those obtained with semi-nested RT-PCR techniques used in each laboratory . However, the Amplicor kit technique is more simple and has the advantage of providing a standardized technique useful for comparative studies . During this work it was observed that the sensitivity of the detection of infectious viruses and virus genome was improved when concentrated samples were used for analysis.

Ann Agric Environ Med, 1999, 6(1), 33 - 8
Importance of sampling, extraction and preservation for the quantitation of biologically active endoto; Laitinen SK; The influence of filter media, extraction solution and preservation method on detection of biologically active endotoxin in the LAL assay was studied with air samples collected from wastewater treatment plants . The four most common types of filters were used as collection media . The extraction solutions compared were nonpyrogenic water, KH2PO4-triethylamine and Trizma buffers . The effect of preservation on endotoxin air samples was ascertained by storing both the filters without extraction, and samples extracted in the collection day for a few weeks at various temperatures . Samples collected on glass fibre filters showed the highest amounts of detectable endotoxin, while the concentrations of endotoxin were significantly lower when cellulose-mixed esters, polycarbonate or polyvinyl chloride membrane filters were used for air sampling . After collection, the best efficiency for glass fibre filters was attained by extraction with nonpyrogenic water within 8 hours after sampling and storage of the extracts at 4 degrees C until they were analysed . If the filters were stored without extraction, the reduction in endotoxin levels of the sample was about 30% after 1 week preservation and about 70% after 2 weeks . The study shows that the effect of the filter material and preservation practice was significant . These factors play critical roles in assessing exposure to bacterial endotoxins within wastewater aerosols.

J Eukaryot Microbiol, 1999 May-Jun, 46(3), 283 - 9
Description of Opisthonecta matiensis n . sp . (Protozoa, Ciliophora), a new peritrich ciliate from wastewater; Martin-Cereceda M et al.; Opisthonecta matiensis n . sp . was isolated from the inlet water of a wastewater treatment plant near Madrid, Spain, and studied in vivo, with silver methods, and using electronic and indirect immunofluorescence microscopy . This new species shows an amphora-like cell shape and has a size of 45-73 microns (x 58.2) x 25-40 microns (x 31.3) . The oral infraciliature is formed by one haplokinety, three polykineties, and a short row of kinetosomes (epistomial membrane) . The aboral infraciliature is made up of the trochal band and the scopula . From the trochal band arise three fibrillar systems: oral fibers, aboral fibers, and oblique fibers . The myoneme system is composed of a delicate peristomial ring, longitudinal branched fibers that reach the trochal band and of radial fibers extending from the scopula to the trochal band . The silverline system consists of an average of 147 lines . This new species is separated from other known forms by its smaller size, the presence of one single vacuole, and its higher number of silverlines.

Curr Opin Biotechnol, 1999 Jun, 10(3), 259 - 62
Biopolymers in wastewater treatment
Houghton JI, Quarmby J.
Studies investigating the formation and manipulation of biopolymers produced by the heterogeneous microbial cultures found in wastewater treatment are not advancing at a fast rate, reflecting the inherent complexity of the systems involved . Adjustment of the nutrients present within the treatment process currently appears to offer more potential than bioaugmentation with genetically modified organisms for improving certain aspects, such as sludge settling properties and chlorinated organic pollutant removal . An area likely to be of increasing importance in the future is the role of the microbial biopolymer in retaining water within the sludge matrix . Modification of the biopolymer to aid the removal of water from waste sludges could have immense implications for the treatment and minimization of the waste sludge produced.

Curr Opin Biotechnol, 1999 Jun, 10(3), 230 - 3
Developments in terrestrial bacterial remediation of metals; Stephen JR et al.; Recent advances in understanding the role and application of bacteria to the remediation of toxic metal and radionuclide contaminated terrestrial environments have come from several avenues . Novel species capable of mobilization and immobilization of metal ions have been discovered . Remediation of toxicity has been accelerated by nutrient amendment, the use of chelating agents and novel methods for phosphate amendment . Major advances in the use of natural and genetically engineered species for bioprotection and remediation of organic co-contaminants have been reported . Construction of wetland function continues to be developed for containment and decontamination of wastewaters.

Mutat Res, 1999 May 19, 426(2), 211 - 4
Genotoxicity of soil from farmland irrigated with wastewater using three plant bioassays; Cabrera GL et al.; Three well known plant bioassays, the Allium root chromosome aberration (AL-RAA) assay, the Tradescantia micronucleus (Trad-MCN) assay, and the Tradescantia stamen hair (Trad-SHM) mutation assay were validated in 1991 by the International Programme on Chemical Safety (IPCS) under the auspices of the World Health Organization, and the United Nations Environment Programme (UNEP) . These plant bioassays have proven to be efficient tests for chemical screening and especially for in situ monitoring for genotoxicity of environmental pollutants . As a result of this validation study, standard protocols of these three plant bioassays were used by some of the 11 participating countries in the IPCS to carry on genotoxicity tests on air, water and soil as a follow up activity . In the city of Queretaro, Mexico, wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the farm crops, polluting the soil . Potentially the pollutants could reach the food chain . For the above reason, soil irrigated with wastewater was sampled and monitored for the presence of genotoxic agents using the above three bioassays . Extracts from soil samples were made using distilled water and organic solvents by shaking the sample for about 12 h under a relatively low temperature (15-20 degrees C) . Plant cuttings of Tradescantia or the roots of Allium were treated by submerging them in the extracts . Three replicates of each sample were analyzed in each of the three bioassays . Extracts using DMSO, ethanol and distilled water tested positive in the three bioassays and there were no differences for the genotoxicity of the extracts with the different solvents .

Mutat Res, 1999 May 19, 426(2), 183 - 8
Genotoxicity of wastewater samples from sewage and industrial effluent detected by the Allium root anaphase aberration and micronucleus assays; Grover IS et al.; The genotoxicity of wastewater samples from sewage, and industrial effluent from the Amritsar, India, area were investigated using the Allium micronucleus and anaphase aberration assays . Raw sewage samples and acetone extracts of the dehydrated sewage were use for treatment of the Allium roots . Industrial effluents were collected and stored in the form of sludge (semi-dried matter) . The acetone extracts of the sludge samples were also used for treatment of the Allium roots . From the Allium root micronuclei tests on the sewage extracts, no significant increase in the number of micronuclei was found in comparison with negative controls . All the other extracts from industrial effluent showed positive responses both in the micronucleus and anaphase aberration assays .

Mutat Res, 1999 May 19, 426(2), 127 - 31
Tradescantia bioassays for the determination of genotoxicity of water in the Panlong River, Kunming, People's Republic of China; Duan CQ et al.; The Panlong river passes through Kunming City and receives a large quantity of municipal sewage and wastewater from industrial effluent . Along the river, 20 sites were selected to collect water samples to assess the genotoxicity using two Tradescantia assays, the micronucleus (Trad-MCN) and the stamen-hair-mutation (Trad-SHM) assays . The lowest frequencies in the Trad-MCN assay and the Trad-SHM assay are 3.19 MCN/100 tetrads and 1.32 M/1000 stamen hairs, respectively . In the water samples obtained from the Songhua Reservoir, the MCN frequencies and mutation rates are not statistically significantly different from the data found for the negative control (2.49 MCN/100 tetrads and 0.71 M/1000 stamen hairs) . Among the other water samples, 19 in Trad-MCN assay and 17 in Trad-SHM assay show significantly higher genotoxicity than the control . The highest genotoxicity was in samples No . 19 for the MCN assay (8.73 MCN/100 cells), over three times higher than the negative control, and in sample No . 11 for the SHM assay (4.30 M/1000), six times higher than the negative control, and were about the same as for the positive control (10.0 mg/l NaN3, 9.28 MCN/100 tetrads and 7.44 SHM/1000 stamen hairs), respectively . The peak frequencies for the Trad-MCN assays were observed in the water samples obtained from the sites that were near industrial and municipal wastewater that ran into the river as effluent . In general, the frequency of MCN and SHM mutations increased where the river passed through Kunming . The Trad-MCN assay seemed more sensitive than that of the Trad-SHM assay in detecting genotoxicity of the river water pollution .

Mutat Res, 1999 May 19, 426(2), 103 - 6
The international program on plant bioassays and the report of the follow-up study after the hands-on workshop in China; Ma TH; Among the seven plant bioassays reviewed by the US Environmental Protection Agency (EPA) Gene-Tox program in 1980, the Allium/Vicia root tip chromosome aberration assay and the Tradescantia stamen hair mutation and micronucleus assays were adopted by the International Program on Plant Bioassays (IPPB) for monitoring or testing environmental pollutants . These assays are highly sensitive and capable of detecting mutagens, clastogens and carcinogens from the environment . They are effective in situ monitors . These bioassays were validated and their protocols were standardized through a program under the International Program on Chemical Safety (IPPB), the precursor of the IPPB program which currently is in operation under the auspices of the United Nations Environment Program (UNEP) . Six different categories of environmental studies, ranging from wastewater, surface or ground water, soil samples, ambient air, pesticides, and radiation, were carried out and are reported in this special issue . The mission of the IPPB/UNEP is to use these bioassays to monitor or test environmental mutagens and clastogens in the air, water, and soil to safeguard the quality of these essential elements in life and to use these simple and clear indicators of pollution damage as the tool for environmental education for the general public . The published reports of the monitoring and testing results will establish the database for environmental conditions in a number of locations around the world . An international monitoring network for the detection of genotoxicity of environmental pollutants is being established under the auspices of UNEP to protect the global environment .

Environ Manage, 1999 Jul, 24(1), 25 - 37
Restoration of a Canadian Prairie Wetland with Agricultural and Municipal Wastewater; White JS et al.; / A rapid development and approval process was employed by Ducks Unlimited Canada and other stakeholders to restore a 1246-ha (3079-acre) northern prairie wetland in southern Alberta, Canada, with 3640 m3/day (800,000 US gallons) of municipal wastewater and beef processing wastewater . A large nongovernmental organization hastened restoration with a development process that outlined restoration goals and management objectives to satisfy a dual mandate of wastewater treatment and wildlife habitat creation . In 1995, after five years of wastewater additions, the basins had been refilled and the surrounding uplands had been acquired and restored . The Frank Lake Conservation Area currently provides high-quality habitat for a variety of wildlife in a region where many of the native plants and animals species have been lost due to habitat loss and fragmentation . The success of upland and water management strategies is reflected in the increase of target species' abundance and richness: 50 shorebird species, 44 waterfowl species, 15 raptor species, and 28 other new bird species have returned to the marsh since restoration . As well, significant N and P reduction occurs as waters flow through the first basin of the marsh . The management strategies of this project that satisfied a dual mandate serve as a model to guide managers of other large-scale wetland restoration projects.KEY WORDS: Frank Lake; Wetland restoration; Adaptive management; Prairie; Wastewaterhttp://link.springer-ny.com/link/service/journals/00267/bibs/24n1p25.html

J Hazard Mater, 1999 Feb 15, 64(3), 313 - 22
Photocatalytic decomposition of 4-chlorophenol over oxide catalysts; Hugul M et al.; 4-Chlorophenol in the presence of catalysts was decomposed in aqueous solution by a 125 W medium pressure mercury lamp in a thermostated quartz batch photoreactor, and the organic bound chlorine was catalytically converted into the environmentally less harmful inorganic chloride . Differences in the concentration of 4-chlorophenol and of the intermediates, such as hydroquinone and quinone, are followed by HPLC . The best catalyst among a homolog series for the photo-decomposition of 4-chlorophenol was selected as finely dispersed platinum oxide on a TiO2 semiconductor support, and kinetic parameters of the Langmuir-Hinshelwood type decomposition reaction were reported for the selected catalyst . A simple mechanism of substrate degradation in accord with the chosen kinetic model was postulated . The developed process may serve photooxidative removal of chlorophenols in wastewater without using costly oxidants.

Appl Biochem Biotechnol, 1999 Jan, 76(1), 15 - 32
Anaerobic treatment of low-strength brewery wastewater in expanded granular sludge bed reactor; Kato MT et al.; Anaerobic treatment of low-strength brewery wastewater, with influent total chemical oxygen demand (COD) (CODin) concentrations ranging from 550 to 825 mg/L, was investigated in a pilot-scale 225.5-L expanded granular sludge bed (EGSB) reactor . In an experiment in which the temperature was lowered stepwise from 30 to 12 degrees C, the COD removal efficiency decreased from 73 to 35%, at organic loading rates (OLR) of 11-16.5 g COD/L/d . The applied hydraulic retention time (HRT) and liquid upflow velocity (Vup) were 1.2 h and 5.8 m/h, respectively . Under these conditions, the acidified fraction of the CODin varied from 45 to 90% . In addition to the expected drop in reactor performance, problems with sludge retention were also observed . In a subsequent experiment set at 20 degrees C, COD removal efficiencies exceeding 80% were obtained at an OLR up to 12.6 g COD/L/d, with CODin between 630 and 715 mg/L . The values of HRT and Vup applied were 2.1-1.2 h, and 4.4-7.2 m/h, respectively . The acidified fraction of the CODin was above 90%, but sludge washout was not significant . These results indicate that the EGSB potentials can be further explored for the anaerobic treatment of low-strength brewery wastewater, even at lower temperatures.

Rev Argent Microbiol, 1999 Jan-Mar, 31(1), 49 - 52
Inactivation of poliovirus by gamma irradiation of wastewater sludges; Kaupert N et al.; The effect of gamma radiation on poliovirus infectivity seeded in sludge samples was investigated in order to determine the radiation dose required to inactivate 90% of viral infectivity (D10) . Sludges were obtained from anaerobic pretreated sewages produced by San Felipe, a wastewater treatment facility located at the Tucuman province, Argentina . A D10 of 3.34 kGy was determined for poliovirus type III, Sabin strain, suspended in sludge samples . This value dropped to 1.92 kGy when the virus was suspended in water . A virucidal effect associated to sludges was also demonstrated . These results will be of interest when considering the dose of gamma radiation to be applied to wastewater sludges in order to preserve the environment from viral contamination.

Int J Syst Bacteriol, 1999 Apr, 49 Pt 2, 675 - 80
Nocardioides nitrophenolicus sp . nov., a p-nitrophenol-degrading bacterium; Yoon JH et al.; A p-nitrophenol-degrading bacterial strain was isolated from industrial wastewater . This strain (NSP41T) was identified as a member of the genus Nocardioides from chemotaxonomic characterizations and phylogenetic inference based on 16S rDNA sequence analysis . The G + C content is 71.4 mol% . The diamino acid in the cell-wall peptidoglycan is LL-diaminopimelic acid . The predominant menaquinone is MK-8(H4) . The cellular fatty acid profile is similar to those of Nocardioides species . 16S rDNA sequence analysis show that strain NSP41T is the most related to Nocardioides simplex strains with a level of nucleotide similarity of 98.6% . The levels of 16S rDNA similarity between strain NSP41T and other Nocardioides species ranged from 93.8 to 95.1% . This organism is distinguishable from some other Nocardioides species as well as N . simplex strains by DNA-DNA relatedness data . This organism is different from N . simplex strains in some phenotypic characteristics . Therefore, on the basis of the data presented, a new species of the genus Nocardioides, Nocardioides nitrophenolicus, is proposed . The type strain of the new species is strain NSP41T (= KCTC 0457BPT).

Chemosphere, 1999 Jun, 38(13), 3155 - 68
Effects of cadmium on the performance and microbiology of laboratory-scale lagoons treating domestic sewage; Bonnet JL et al.; Two experiments were performed to assess the impact of cadmium on the sewage lagoon wastewater treatment process . For each one, three laboratory-scale pilot plants with one tank receiving the same raw effluent were used; one plant served as control and the other two were contaminated once only with cadmium . In the first study, the effects of a shock load of two concentrations of cadmium chloride (60 and 300 micrograms/l) on the plant performance, microbial populations (protists and bacteria) and enzyme activities were determined . Initially, most of the performance parameters were affected concentration-dependently . A reduction in the protist population density and some influence on the total bacterial population were observed, and the potential enzymatic activities were also modified . A second experiment with a lower cadmium concentration (30 micrograms/l), supplied as chloride or sulphate, still perturbed most of the parameters studied, and the effects of the two cadmium salts were identical.

Appl Environ Microbiol, 1999 Apr, 65(4), 1696 - 702
High-rate anaerobic treatment of wastewater at low temperatures; Lettinga G et al.; Anaerobic treatment of a volatile fatty acid (VFA) mixture was investigated under psychrophilic (3 to 8 degrees C) conditions in two laboratory-scale expanded granular sludge bed reactor stages in series . The reactor system was seeded with mesophilic methanogenic granular sludge and fed with a mixture of VFAs . Good removal of fatty acids was achieved in the two-stage system . Relative high levels of propionate were present in the effluent of the first stage, but propionate was efficiently removed in the second stage, where a low hydrogen partial pressure and a low acetate concentration were advantageous for propionate oxidation . The specific VFA-degrading activities of the sludge in each of the modules doubled during system operation for 150 days, indicating a good enrichment of methanogens and proton-reducing acetogenic bacteria at such low temperatures . The specific degradation rates of butyrate, propionate, and the VFA mixture amounted to 0.139, 0.110, and 0.214 g of chemical oxygen demand g of volatile suspended solids-1 day-1, respectively . The biomass which was obtained after 1.5 years still had a temperature optimum of between 30 and 40 degrees C.

Appl Radiat Isot, 1999 Apr, 50(4), 655 - 60
The use of clinoptilolite and its sodium form for removal of radioactive cesium, and strontium from nuclear wastewater and Pb2+, Ni2+, Cd2+, Ba2+ from municipal wastewater; Faghihian H et al.; Three different samples of Iranian natural zeolites (clinoptilolite) and its sodium exchanged forms have been investigated for uptaking several different cations . Ion-exchange isotherms, have been given and discussed.

Biotechnol Bioeng, 1999 May 5, 63(3), 363 - 72
A comprehensive model of anaerobic bioconversion of complex substrates to biogas
Angelidaki I I, Ellegaard L, Ahring BK.
A dynamic model describing the anaerobic degradation of complex material, and codigestion of different types of wastes, was developed based on a model previously described (Angelidaki et al., 1993) . In the model, the substrate is described by its composition of basic organic components, i.e., carbohydrates, lipids, and proteins, the concentration of intermediates such as volatile fatty acids and long-chain fatty acids, and important inorganic components, i.e., ammonia, phosphate, cations, and anions . This allows dynamic changes of the process during a shift of substrate composition to be simulated by changing the input substrate data . The model includes 2 enzymatic hydrolytic steps, 8 bacterial steps and involves 19 chemical compounds . The model also includes a detailed description of pH and temperature characteristics . Free ammonia, acetate, volatile fatty acids, (VFA) and long-chain fatty acids (LCFA) constitute the primary modulating factors in the model . The model was tested with success in lab-scale reactors codigesting manure with glycerol trioleate or manure with gelatin . Finally, the model was validated using results from a full-scale biogas plant codigesting manure together with a proteinous wastewater and with bentonite-bound oil, which is a waste with high content of lipids .

Biotechnol Bioeng, 1999 Apr 20, 63(2), 216 - 23
Detoxification of organophosphate nerve agents by immobilized Escherichia coli with surface-expressed organophosphorus hydrolase; Mulchandani A et al.; An improved whole-cell technology for detoxifying organophosphate nerve agents was recently developed based on genetically engineered Escherichia coli with organophosphorus hydrolase anchored on the surface . This article reports the immobilization of these novel biocatalysts on nonwoven polypropylene fabric and their applications in detoxifying contaminated wastewaters . The best cell loading (256 mg cell dry weight/g of support or 50 mg cell dry weight/cm2 of support) and subsequent hydrolysis of organophosphate nerve agents were achieved by immobilizing nongrowing cells in a pH 8, 150 mM citrate-phosphate buffer supplemented with 1 mM Co2+ for 48 h via simple adsorption, followed by organophosphate hydrolysis in a pH 8, 50 mM citrate-phosphate buffer supplemented with 0.05 mM Co2+ and 20% methanol at 37 degrees C . In batch operations, the immobilized cells degraded 100% of 0.8 mM paraoxon, a model organophosphate nerve agent, in approximately 100 min, at a specific rate of 0.160 mM min-1 (g cell dry wt)-1 . The immobilized cells retained almost 100% activity during the initial six repeated cycles and close to 90% activity even after 12 repeated cycles, extending over a period of 19 days without any nutrient supplementation . In addition to paraoxon, other commonly used organophosphates, such as diazinon, coumaphos, and methylparathion were hydrolyzed efficiently . The cell immobilization technology developed here paves the way for an efficient, simple, and cost-effective method for detoxification of organophosphate nerve agents .

Biotechnol Bioeng, 1999 Apr 5, 63(1), 79 - 86
Use of thiobacillus ferrooxidans in a coupled microbiological-electrochemical system for wastewater detoxification
Lopez-Lopez A, Exposito E, Anton J, Rodriguez-Valera F, Aldaz A.
We have developed a mixed system, electrochemical-microbiological, that can be used for detoxifying organic compounds present in wastewater . In this system, organic matter oxidation takes place at the anode of an electrochemical reactor while ferric iron reduction takes place at the cathode . We have used a growing culture of Thiobacillus ferrooxidans to regenerate the ferric ions consumed . The culture is used as the catholyte (solution in the cathode compartment) of the system and is therefore permanently subjected to an electric field . We have verified that, under our working conditions, the culture is able to oxidize ferrous ions for long periods of time (up to 15 days) depending on the intensity of the applied current . We have checked the performance of this system in methanol oxidation . Our results show that it decreases the energy cost by 35% when com- pared with the pure electrochemical system traditionally used .

Biotechnol Bioeng, 1998 Oct 5, 60(1), 36 - 43
Mixing and phase hold-ups variations due to gas production in anaerobic fluidized-bed digesters: influence on reactor performance
Buffiere P, Fonade C, Moletta R.
The influence of mixing and phase hold-ups on gas-producing fluidized-bed reactors was investigated and compared with an ideal flow reactor performance (CSTR) . The liquid flow in the anaerobic fluidized bed reactor could be described by the classical axially dispersed plug flow model according to measurements of residence time distribution . Gas effervescence in the fluidized bed was responsible for bed contraction and for important gas hold-up, which reduced the contact time between the liquid and the bioparticles . These results were used to support the modeling of large-scale fluidized-bed reactors . The biological kinetics were determined on a 180-L reactor treating wine distillery wastewater where the overall total organic carbon uptake velocity could be described by a Monod model . The outlet concentration and the concentration profile in the reactor appeared to be greatly influenced by hydrodynamic limitations . The biogas effervescence modifies the mixing characteristics and the phase hold-ups . Bed contraction and gas hold-up data are reported and correlated with liquid and gas velocities . It is shown that the reactor performance can be affected by 10% to 15%, depending on the mode of operation and recycle ratio used . At high organic loading rates, reactor performance is particularly sensitive to gas effervescence effects .

J Colloid Interface Sci, 1999 Apr 15, 212(2), 212 - 219
Some Thermodynamic Data on Copper-Chitin and Copper-Chitosan Biopolymer Interactions; Monteiro OA Jr et al.; Chitin and chitosan are good removers of cations from aqueous solution and wastewater . The interactive effect of cation with both biopolymers in aqueous medium was studied by the batch method at 298 +/- 1 K . The results were fitted to the modified Langmuir equation . The same adsorption was followed by calorimetric titration . In this process, 50.0 mg of each polymer was suspended in 19.0 cm3 of bidistilled water at 298.15 +/- 0.02 K, maintained under mechanical turbine stirring . The titration was performed by adding increments of 10 microL of 0.10 mol dm-3 Cu(NO3)2 aqueous solution to the system . The resulting isotherm was also adjusted to a modified Langmuir equation . From the thermal effects K and DeltaH values were determined, enabling the calculation of DeltaG and DeltaS for the interaction of copper cations with chitin and chitosan, giving the enthalpic values of -19.85 +/- 0.34 and -41.27 +/- 1.57 kJ mol-1, respectively . The spontaneity of this interaction is shown from DeltaG values of -35.9 +/- 0.1 and -36.8 +/- 0.1 kJ mol-1, which are followed by DeltaS values of +54 and of -15 J mol-1 K-1, respectively . The complexation is probably associated with the lack of order of the chitin polymeric chain or with the freedom of water molecules initially bonded to cations . The copper ion is coordinated to the pendant groups of the polymeric chain to form stable complexes .

Lett Appl Microbiol, 1999 Jan, 28(1), 27 - 30
Escherichia hermanii--a new bacterial strain for chlorobenzene degradation; Kiernicka J et al.; A new bacterial strain capable of chlorobenzene degradation has been isolated from sludge of an industrial wastewater treatment plant . The micro-organism is short, rod-shaped, Gram-negative, yellow-pigmented and has been identified as Escherichia hermanii . It was observed that high chlorobenzene concentrations (up to 394 mg l-1) had low toxic effects towards this strain, which was able to degrade chlorobenzene without any previous adaptation.

Biodegradation, 1998, 9(3-4), 247 - 57
An integrated algal sulphate reducing high rate ponding process for the treatment of acid mine drainage wastewaters; Rose PD et al.; Acid mine drainage pollution may be associated with large water volume flows and exceptionally long periods of time over which the drainage may require treatment . While the use and role of sulphate reducing bacteria has been demonstrated in active treatment systems for acid mine drainage remediation, reactor size requirement and the cost and availability of the carbon and electron donor source are factors which constrain process development . Little attention has focussed on the use of waste stabilisation ponding processes for acid mine drainage treatment . Wastewater ponding is a mature technology for the treatment of large water volumes and its use as a basis for appropriate reactor design for acid mine drainage treatment is described including high rates of sulphate reduction and the precipitation of metal sulphides . Together with the co-disposal of organic wastes, algal biomass is generated as an independent carbon source for SRB production . Treatment of tannery effluent in a custom-designed high rate algal ponding process, and its use as a carbon source in the generation and precipitation of metal sulphides, has been demonstrated through piloting to the implementation of a full-scale process . The treatment of both mine drainage and zinc refinery wastewaters are reported . A complementary role for microalgal production in the generation of alkalinity and bioadsorptive removal of metals has been utilised and an Integrated 'Algal Sulphate Reducing Ponding Process for the Treatment of Acidic and Metal Wastewaters' (ASPAM) has been described.

Biodegradation, 1998, 9(3-4), 233 - 45
Full-scale and laboratory-scale anaerobic treatment of citric acid production wastewater; Colleran E et al.; This paper reviews the operation of a full-scale, fixed-bed digester treating a citric acid production wastewater with a COD:sulphate ratio of 3-4:1 . Support matrix pieces were removed from the digester at intervals during the first 5 years of operation in order to quantify the vertical distribution of biomass within the digester . Detailed analysis of the digester biomass after 5 years of operation indicated that H2 and propionate-utilising SRB had outcompeted hydrogenophilic methanogens and propionate syntrophs . Acetoclastic methanogens were shown to play the dominant role in acetate conversion . Butyrate and ethanol-degrading syntrophs also remained active in the digester after 5 years of operation . Laboratory-scale hybrid reactor treatment at 55 degrees C of a diluted molasses influent, with and without sulphate supplementation, showed that the reactors could be operated with high stability at volumetric loading rates of 24 kgCOD.m-3.d-1 (12 h HRT) . In the presence of sulphate (2 g/l-1; COD/sulphate ratio of 6:1), acetate conversion was severely inhibited, resulting in effluent acetate concentrations of up to 4000 mg.l-1.

Int J Occup Environ Health, 1996 Oct, 2(4), 311 - 318
Industrial Counseling: Linking Occupational and Environmental Health in Tanneries of Kanpur, India; Ory FG et al.; This paper describes an occupational health program in tanneries in Kanpur, India . The program was instituted as part of a bilateral cooperative effort of India and The Netherlands focusing on providing engineering solutions to prevent industrial waste and community sewage from polluting the Ganges river . The occupational health program was linked to the environmental activities by adopting the concept of industrial counseling . This method aims to increase production and product quality of enterprises and at the same time improve working conditions in these enterprises . The tanneries in Kanpur were targeted for industrial counseling by the Indo-Dutch Environmental and Sanitary Engineering Project Kanpur- Mirzapur under the Ganga Action Plan . Recovery of chrome from wastewater, automation of hydraulic press machines, use of an air-pollution-prevention system in the spray-painting section, and automation of transport are examples of measures used to increase productivity and improve leather quality . Working conditions were improved by adding local exhaust ventilation, mechanizing material transfer, instituting safer procedures for storage and use of toxic materials, and introducing breathing apparatus for operations done in confined spaces to prevent hydrogen sulfide intoxication . The linkage of occupational health problems to environmental issues proved to be effective in drawing attention to working conditions . Also, the application of simple survey techniques to identify and evaluate environmental and occupational hazards substantially increased awareness of these hazards and comprehension of the need to adopt changes among employers, workers, and occupational health professionals . The article discusses the core elements of this successful program.

J Chromatogr A, 1998 Dec 31, 829(1-2), 223 - 33
Solid-phase microextraction with pH adjustment for the determination of aromatic acids and bases in water; van Doorn H et al.; Adjusting the pH of water samples before performing solid-phase microextraction (SPME) analysis can be used to selectively extract organic acids (at pH 2) and bases (at pH 12) . Sorption behavior of test organics is predictable based on the acid dissociation constant in water . In general, polyacrylate (PA) and Carbowax-divinylbenzene (CW-DVB) show substantially higher fiber/water sorption coefficients (Kd values) than a polydimethylsiloxane (PDMS) coated fiber . Gas chromatography-flame ionization detection (GC-FID) detection limits with the CW-DVB sorbent are approximately 0.5 to 10 ng/ml in a 2-ml water sample for a variety of aromatic amines, phenols, and chlorinated phenols, and are approximately 1 to 50 ng/ml for the same solutes using the PA sorbent . However, the PA fiber is more selective (depending on the water pH) for the acid or base components than the CW-DVB fiber . With proper pH adjustment, the recovery of spiked aromatic amines and phenols from a surface wetlands water ranged from 73 to 118% of the known values, with a precision (R.S.D.) of approximately 5 to 20% . SPME quantitation of phenols in a coal gasification wastewater using a PA fiber also gave excellent agreement with conventional methylene chloride extraction, although continued use of a single fiber with this wastewater led to poorer precision.

Qual Assur, 1998 Jan-Mar, 6(1), 23 - 44
Screening of illicit toxic substances discharged in chemical toilet sludge; Robidoux PY et al.; This article presents an integrative approach, using toxicological and chemical analyses, to screen for toxic substances that could be illegally added to the chemical-toilet sludge received at the wastewater treatment plant of the Montreal urban community . Four toxicity tests (Microtox, bacterial-respiration, root-elongation, and seed-germination tests) were used to establish the toxicity range of a "normal" sludge and the determination of threshold limits criteria . Chemical-toilet sludge samples were spiked with two types and amounts of contaminants (zinc, phenol) . Conservative criteria were used to detect abnormal toxicity with great reliability and avoid false positives (i.e., detecting abnormal toxicity in nonspiked sludge) . Taken individually, the seed-germination test was the least discriminating toxicological method (detecting only 10% of the spiked samples); the bacterial-respiration test was relatively better (detecting 72% of the spiked samples) . Using a limited battery of two toxicity tests (Microtox and respiration test), the identification of contaminated chemical-toilet sludge can be detected with good efficiency and possibly great reliability (more than 80% of the spiked samples) . This proposed procedure is efficient, easy to apply, cost-effective, and very fast (an abnormal toxicity level can be determined within a few hours).

Arch Environ Contam Toxicol, 1999 Feb, 36(2), 115 - 9
Primary DNA damage but not mutagenicity correlates with ciprofloxacin concentrations in German hospital wastewaters; Hartmann A et al.; Recently, we showed for the wastewater of a large Swiss university hospital that primary DNA damage, assessed by a bacterial SOS repair assay (umuC test), could be largely assigned to a specific class of antibiotics, the fluoroquinolones (FQs) (Hartmann et al . {1998} Environ Toxicol Chem 17:377-382) . In an attempt to confirm the significance of FQs for the bacterial DNA damaging effects in native hospital wastewaters, 25 samples from five German clinics were screened in this study by the umuC test . The results were compared to HPLC-derived concentrations of ciprofloxacin, an important member of the FQs . Ten samples (40%) were umuC-positive and ciprofloxacin concentrations ranged from 0.7 to 124.5 microg/L (n = 24) . Primary DNA damage, as indicated by the umuC test, correlated strongly with ciprofloxacin concentrations in a logistic, dose-dependent manner (r2 = 0.896), almost irrespective of the use of S9 metabolic activation . The lowest observed effect concentration (LOEC) for ciprofloxacin was 5.2 microg/L (+S9) and 5.9 microg/L (-S9) . Similar to our previous findings, these results indicate that positive umuC results in hospital wastewater are strongly dependent on the presence of fluoroquinolone antibiotics . In a second part of the study, previously generated Ames and V79 chromosomal aberration data of the same samples (Gartiser and Brinker {1995} in Umweltbundesamt Texte 74/95) were compared with the newly generated results . Neither the mutagenic effects detected by the Ames assay (8%, n = 25) nor the positive V79 results (46% n = 13) seemed to be caused by ciprofloxacin . Therefore, the Ames and V79 results suggest the presence of additional mutagens that are yet to be identified.

Environ Health Perspect, 1999 Jan, 107(1), 3 - 8
The removal of mercury from dental-operatory wastewater by polymer treatment; Pederson ED et al.; The mercury (Hg) content of dental-operatory wastewater has become an issue in many localities, and Hg removal is rapidly becoming a matter of concern for all dental clinics . This preliminary study tested the efficacy of polymers for the removal of Hg contaminants from the dental-unit wastewater stream . Two commercially available polymers were used to treat dental-operatory wastewater . Used separately, each polymer removed from 74.9% to 88.4% of the Hg from dental-wastewater supernatant . The polymers used in combination, within the recommended pH range, removed up to 99.9% of the total Hg from dental-wastewater supernatant . The estimated optimal concentration of the two polymers is approximately 2.33 ml of each per liter of waste, and more than 90% of the Hg may be removed with 0.13 ml/l . Results indicate that a combination of the two polymers may sufficiently reduce Hg levels to allow discharge of clarified supernatants into public sewer systems.

Anal Chem, 1998 Dec 1, 70(23), 5042 - 6
Biosensor for direct determination of organophosphate nerve agents using recombinant Escherichia coli with surface-expressed organophosphorus hydrolase . 2 . Fiber-optic microbial biosensor; Mulchandani A et al.; A fiber-optic microbial biosensor suitable for direct measurement of organophosphate nerve agents was developed . The unique features of this novel microbial biosensor were the recombinant Escherichia coli cells expressing the enzyme organophosphorus hydrolase on the cell surface and the optical detection of the products of enzyme-catalyzed organophosphate hydrolysis . The use of cells with the metabolic enzyme expressed on the cell surface as a biological sensing element provides advantages of no resistance to mass transport of the analyte and product across the cell membrane and low cost due to elimination of enzyme purification, over the conventional microbial biosensors based on cells expressing enzyme intracellularly and enzyme-based sensors, respectively . The use of an optical transducer allows the detection of different organophosphates in a mixture, presently not feasible with acetylcholinesterase-based biosensors . E . coli cells expressing organophosphorus hydrolase (OPH) on the cell surface were immobilized in low melting temperature agarose on a nylon membrane and attached to the common end of a bifurcated fiber-optic bundle . OPH-expressing E . coli cells catalyzed the hydrolysis of organophosphorus pesticides to form stoichiometric amounts of chromophoric products that absorb light at specific wavelengths . The backscattered radiation of the specific wavelength incident light was measured using a photomultiplier detector and correlated to the organophosphate concentration . The best sensitivity and response time were obtained using a sensor constructed with 1.5 mg of cells operating in pH 9, 50 mM HEPES buffer with 100 mM NaCl and 0.05 mM CoCl2 at 30 degrees C . At optimized conditions, the biosensor measured paraoxon, parathion, and coumaphos pesticides with high selectivity against triazine and carbamate pesticides in approximately 10 min . The lower detection limits were 3 microM for paraoxon and parathion and 5 microM for coumaphos . When stored in the buffer at 22 degrees C, the biosensor was stable for over a 1-month period and showed no decline in the response for over 75 repeated usages . The new fiber-optic microbial biosensor is an ideal tool for on-line monitoring of the detoxification process for organophosphate pesticides-contaminated wastewaters but may not be suitable for environmental monitoring.

J AOAC Int, 1998 Nov-Dec, 81(6), 1209 - 16
Determination of 17 beta-estradiol and its metabolites in sewage effluent by solid-phase extraction and gas chromatography/mass spectrometry; Lee HB et al.; The paper describes a simple and quantitative method for monitoring non-conjugated 17 beta-estradiol (E2) and its metabolites estrone (E1) and estriol (E3) as environmental contaminants in municipal sewage effluents . Estrogens were preconcentrated and cleaned up by solid-phase extraction using a reversed-phase C18 cartridge . They were derivatized with pentafluoropropionic acid anhydride, and the products were analyzed by gas chromatography/mass spectrometry . Recoveries from spiked distilled water and sewage were better than 87% at fortification levels of 100 and 20 ng/L . For a 1 L sewage sample and a concentration factor of 5000, detection limits were 5 ng/L for E1 and E2 and 10 ng/L for E3 . In a brief survey of Canadian wastewater, these estrogens were detected in many raw sewage and effluent samples at concentrations ranging from 6 to 109 ng/L for E1, from < 5 to 15 ng/L for E2, and from < 10 to 250 ng/L for E3.

Biotechnol Prog, 1998 Nov, 14(6), 856 - 64
Psychrophilic (6-15 degreesC) high-rate anaerobic treatment of malting wastewater in a two-module expanded granular sludge bed system
Rebac S, van Lier JB, Lens P, van Cappellen J, Vermeulen M, Stams AJM, Dekkers F, Swinkels KTM, Lettinga G.
Psychrophilic (6-15 degreesC) anaerobic treatment of malting wastewater was investigated . A two-module expanded granular sludge bed reactor system with a total volume of 140 dm3 was used to treat malting wastewater having a soluble and total chemical oxygen demand (COD) between 233 and 1778 mg dm-3 and between 317 and 4422 mg dm-3, respectively . The removal efficiencies at 6 degreesC were 47 and 71% of the soluble and volatile fatty acids (VFA) COD, at organic loading rates (OLR) ranging between 3.3 and 5.8 kg of COD m-3 day-1 . The removal efficiencies at 10-15 degreesC were 67-78 and 90-96% of the soluble and VFA COD at an OLR between 2.8 and 12.3 kg of COD m-3 day-1 . The specific methanogenic activity of the sludge present in each module increased 2-3-fold during system operation for 400 days . The relatively high concentration of suspended solids in the influent (25% of the total COD) caused a deterioration of the sludge bed in the first reactor module . This was aggravated by excessive growth of acidifying biomass, which persisted in the first module sludge bed and resulted in granular sludge flotation . However, the second module could accommodate the increased OLR, thus providing a very high effluent quality (soluble COD < 200 mg dm-3) of the total system . The stability of module I concerning suspended solids could be restored by presettling the wastewater.

Biotechnol Prog, 1998 Nov-Dec, 14(6), 851 - 5
Desulfurization of diesel oils by a newly isolated dibenzothiophene-degrading Nocardia sp . strain CYKS2; Chang JH et al.; A dibenzothiophene (DBT)-degrading bacterial strain was isolated from dyeing industry wastewater and identified as Nocardia sp . CYKS2 . The newly isolated bacterial strain Nocardia sp . CYKS2 was able to convert DBT to 2-hydroxybiphenyl (2-HBP) as the dead-end metabolite through a sulfur-specific pathway . Other organic sulfur compounds, such as thiophene derivatives, thiazole derivatives, sulfides, and disulfides were also desulfurized by Nocardia sp . CYKS2 . In batch culture, 0.2 mM DBT was completely desulfurized in 60 h . After DBT was depleted, neither cell growth nor 2-HBP production was observed . When a model oil which DBT was dissolved in hexadecane was treated with growing cells, DBT was desulfurized from 10 mM to about 2 mM in 80 h . In this case, desulfurization rate was 0.279 mg-sulfur/(L-dispersion.h), which was about 2.5 times higher than that in the previous case of batch culture . When diesel oil was treated, the sulfur content decreased from 0.3 to 0.24 wt % in 48 h . A volumetric phase ratio of oil to water was 1/10 in this case . The sulfur decreased from 0.3 to 0.2 wt % in 48 h, when the volumetric phase ratio was 1/20 . The desulfurization rates were 0.909 and 0.992 mg-sulfur/(L-dispersion.h), respectively.

Chemosphere, 1998 Dec, 37(14-15), 2823 - 32
Bioindicators for toxicity assessment of effluents from a wastewater treatment plant; Ciccotelli M et al.; The discharge of effluents and toxic compounds into aquatic systems represents a growing environmental problem involving an impact on water ecology and potential effect on human health . Most municipal wastewaters are complex mixtures; their complexity led as to carry out a hazard assessment using chemical analyses and biological tests . This study investigates biochemical alteratiobns in two sentinel organisms, the Anodonta cygnea mussel and the Xenopus laevis frog exposed for different lengths of time to various concentration of wastewater of the S . Antonino Ticino treatment plant . The results point out the long-life of toxic compounds.

Chemosphere, 1998 Oct-Nov, 37(9-12), 1957 - 72
Characterization of emissions of dioxins and furans from ethylene dichloride (EDC), vinyl chloride (VCM) and polyvinylchloride (PVC) manufacturing facilities in the United States . I . Resin, treated wastewater, and ethylene dichloride; Carroll WF Jr et al.; Under the auspices of its Dioxin Characterization Program, members of The Vinyl Institute (VI), have analyzed for potential polychlorinated dibenzodioxin/furan (PCDD/F) concentrations in polyvinylchloride (PVC) resins, treated wastewater effluent and ethylene dichloride (EDC) product at EDC, vinyl chloride monomer (VCM) and PVC manufacturing facilities in the U.S . and Canada . No 2,3,7,8-tetrachlorodibenzodioxin (TCDD) was detected in any sample analyzed under the program to date . Trace concentrations (low pg/g) of PCDD/F were detected in only a few samples of PVC resins and EDC product . Treated wastewater contained low ppq concentrations of PCDD/F . All concentrations are expressed as Toxic Equivalents (TEQ) . Extrapolation of these data shows that the contribution of EDC/VCM/PVC manufacturing via these media constitutes substantially less than 1 percent of the estimated annual U.S . dioxin releases to the environment.

Chemosphere, 1998 Oct-Nov, 37(9-12), 1973 - 85
Progress in reducing the TCDD/TCDF content of effluents, pulps and wastewater treatment sludges from the manufacturing of bleached chemical pulp; Gillespie WJ et al.; This report summarizes the data received in response to NCASI's 1996 "Industry-Wide Dioxin Profile" and data on tissue concentrations in fish taken downstream from mill discharges . The current survey was the sixth effort to update industry accomplishments since the "104 Mill Study" in 1988 . As of the end of 1996, bleaching export vector TCDD/TCDF contents have been reduced by 94% on a TEQ basis from the 1988 level . The few observations above nominal detection limits tend to be from mills that have not supplied new data to NCASI . Current releases are approaching the point where the difference between the estimate and "non-detect" levels is hardly quantifiable . The analysis of data on fish tissue taken downstream of pulp mill discharges showed an average 24% per year decrease, reflecting reductions in effluent loadings.

J Chromatogr A, 1998 Oct 9, 823(1-2), 219 - 30
Optimization and validation of solvent and supercritical-fluid extractions for the trace-determination of polycyclic aromatic hydrocarbons in sewage sludges by liquid chromatography coupled to diode-array and fluorescence detection; Miege C et al.; There is a need for a better characterization of sludges from wastewater treatment plants which are destined to be spread on agricultural land . Inorganic pollutants are regularly controlled, but organic pollutants have received little attention up to now . The main problem for trace analysis of organic pollutants comes from the complexity of the various matrices of sludges, which depends on their origins . Therefore, methods described for soils and sediments cannot be directly applied to sludges which contain high amount of lipids . This paper provides a method for trace-determination of polycyclic aromatic hydrocarbons in the range of mg/kg of dried sludge including an extraction step, and an analysis step by liquid chromatography with fluorescence detection for sensitive quantification and UV-diode-array detection for confirmation . The extraction step was optimized by a selection of the solvent used for both Soxhlet and supercritical-fluid extraction and by setting the experimental conditions (temperature, pressure, modifier, etc.) used for SFE . Extraction recoveries were found similar and quantitative for the two procedures . However supercritical-fluid extraction appears to be a good alternative to Soxhlet extraction because of the consumption of less time and solvent . Detection limits were obtained in the range of 0.1-1 mg/kg of dried sludges, with possible confirmation by UV spectra . The whole method (extraction/quantification/confirmation) was validated using sludges which have been certified by the Community Bureau of Reference from Brussels (CRM No . 088) . Application to the determination of PAHs in urban sludges is presented.

Otolaryngol Head Neck Surg, 1998 Nov, 119(5), 502 - 5
Pollutants in our water: effects on human health and the environment; Hicks JN; The American Academy of Otolaryngology-Head and Neck Surgery has concerns about the effects of our environment on human health . In this review we evaluate waterborne biologic organisms, microorganisms, and other disease-causing agents that might pollute our drinking water . Next, we evaluate chemical toxins that might pollute our drinking water . Then we examine our drinking water and wastewater treatment systems . Finally, we discuss management strategies.

Arch Environ Contam Toxicol, 1998 Nov, 35(4), 615 - 9
Effects of boron and nitrate on hatching success of amphibian eggs; Laposata MM et al.; As part of a land-application wastewater disposal system in central Pennsylvania, vernal ponds are commonly exposed to wastewater effluent containing high levels of boron and nitrate . We examined the individual effects of these compounds on the eggs of amphibians breeding in these ponds . Wood frog (Rana sylvatica), Jefferson salamander (Ambystoma jeffersonianum), spotted salamander (A . maculatum), and American toad (Bufo americanus) eggs were exposed to boron (0, 50, and 100 mg L-1) and nitrate (0, 10, 25, and 40 mg L-1) under laboratory conditions . There was no difference in the hatching success or proportion of deformed larvae among the four nitrate levels in any of the species . High boron concentrations reduced the hatching success of B . americanus and produced more deformed offspring in R . sylvatica, A . jeffersonianum, and A . maculatum . Deformed R . sylvatica and A . jeffersonianum hatchlings displayed a "curling defect" in which the larvae had a crescent body shape and expressed difficulty in swimming . A . maculatum larvae from high boron treatments displayed a different abnormality, possibly because of longer times to hatching, characterized by a swelling of the thoracic region and altered gill morphology . Although the concentrations of boron and nitrate tested were within the range measured in wastewater effluent, maximum levels of boron and nitrate in breeding ponds were only 1.5 mg L-1 and 26.7 mg L-1 respectively, likely due to rainwater dilution and biological and chemical processes reducing the levels of these compounds in vernal ponds . Nonetheless, these studies are the first to examine the effects of boron and nitrate on amphibian egg hatching success, and to demonstrate that elevated boron concentrations can detrimentally affect the development of amphibian embryos.

J Med Entomol, 1998 Sep, 35(5), 818 - 24
Culicoides variipennis (Diptera: Ceratopogonidae) complex in Virginia; Schmidtmann ET et al.; Immature Culicoides variipennis (Coquillett) were sampled from aquatic habitats throughout Virginia, reared to adults, and examined by isozyme electrophoresis to assess their taxonomic status . Data from 22 counties showed that C . v . variipennis is widespread and common, the predominant taxon throughout Virginia, and genetically similar to C . v . variipennis in Maryland . Because C . v . variipennis is considered an inefficient vector of the bluetongue viruses, this observation is consistent with the low seroprevalence of bluetongue in indigenous livestock of the mid-Atlantic region . Culicoides v . sonorensis Wirth & Jones, considered to be the primary North American vector of the bluetongue viruses, was recovered in large numbers only from a wastewater lagoon at a dairy in southeastern Virginia, but also was detected at low levels in 6 other counties . Comparison of genetic distances and patterns of discriminating alleles among Virginia populations of C . v . variipennis and C . v . sonorensis showed that respective subspecies are genetically distinct and show no evidence of introgression, irrespective of geographic- and habitat-level sympatry . The persistence of a pure C . v . sonorensis population in a dairy wastewater lagoon may reflect physico-chemical factors that influence the distribution of immature C . variipennis complex populations . A better understanding of the distribution of the C . variipennis complex will benefit regionalization of U.S . exports of livestock and livestock germplasm to bluetongue-free countries.

Appl Environ Microbiol, 1998 Oct, 64(10), 4068 - 72
Development of bacterium-based heavy metal biosorbents: enhanced uptake of cadmium and mercury by Escherichia coli expressing a metal binding motif; Pazirandeh M et al.; A gene coding for a de novo peptide sequence containing a metal binding motif was chemically synthesized and expressed in Escherichia coli as a fusion with the maltose binding protein . Bacterial cells expressing the metal binding peptide fusion demonstrated enhanced binding of Cd2+ and Hg2+ compared to bacterial cells lacking the metal binding peptide . The potential use of genetically engineered bacteria as biosorbents for the removal of heavy metals from wastewaters is discussed.

Mutat Res, 1998 Oct 12, 418(2-3), 113 - 9
Genotoxicity testing of wastewater sludge using the Allium cepa anaphase-telophase chromosome aberration assay; Rank J et al.; Wastewater sludges were analysed in the Allium cepa genotoxicity test . They were sampled during three winter periods from three Danish municipal wastewater treatment plants differing in size and industrial load . The toxicity of the sludge was tested in the Allium root inhibition assay, and the results expressed as EC30 and EC50 values showed that the toxicity could be positive correlated to the industrial load . However, when genotoxicity was tested at concentrations corresponding to the EC30 and EC50 values in the A . cepa anaphase-telophase assay, only two sludge samples from the smallest plant with the lowest industrial load induced significant chromosome aberrations . Concentrations of the heavy metal's Pb, Ni, Cr, Zn, Cu, and Cd were also determined and could partly be correlated with the toxicity of the sludge and the industrial load of the treatment plants .

Ecotoxicol Environ Saf, 1998 Sep, 41(1), 19 - 28
Impact assessment of a wastewater treatment plant effluent using the fish biomarker ethoxyresorufin-O-deethylase: field and on-site experiments; Kosmala A et al.; The impact of a wastewater treatment plant (WWTP) effluent was assessed with the fish biomarker ethoxyresorufin-O-deethylase (EROD) using field and on-site laboratory experiments . EROD activity was measured in chub (Leuciscus cephalus) and stone loach (Noemacheilus barbatulus) caught at three sites of the Chalaronne River (southeast France) . Liver somatic index (LSI) and organochloride bioaccumulation in muscle were estimated for chub only . In September, EROD activity and LSI of chub increased significantly between the sites above and below the WWTP effluent discharge . EROD induction detected in chub was confirmed by on-site tank experiments . EROD levels were determined in juvenile rainbow trout (Oncorhynchus mykiss) and mirror carp (Cyprinus carpio) exposed to different concentrations of the WWTP effluent and river water for 16 days . After a 4-day exposure, EROD activities of the carp exposed to the effluent increased significantly compared with the control . The response was linked to the effluent concentration and was stable with exposure time . WWTP effluent induced EROD activity, whereas organic and metal analyses, performed on fish muscle and sediment, did not indicate any difference between upstream and downstream of the discharge .

J Appl Microbiol, 1998 Aug, 85(2), 282 - 6
Presence of Helicobacter species DNA in Swedish water; Hulten K et al.; Municipal water, treated waste-water and well-water from all 25 counties in Sweden were analysed for the presence of Helicobacter spp . DNA . Bacteria were concentration by immunomagnetic separation . Culture, Gram staining and urease tests were performed before lysis of bacteria . Two polymerase chain reaction (PCR) assay with high sensitivity (adhesin and 16S rRNA) were followed by Helicobacter spp . specific hybridization . Nine of 24 private wells, three of 25 municipal tapwater and three of 25 wastewater samples were positive for both PCR assays . Positive municipal and waste-water samples were positive for counties . Non-specificity of PCR methods due to the presence of unknown bacteria within the genus helicobacter cannot be totally ruled out . Thus, the clinical significance of findings Helicobater spp . DNA in drinking water needs to be further evaluated.

J Appl Microbiol, 1998 Aug, 85(2), 263 - 70
Discharge of disinfected wastewater in recipient aquatic systems: fate of allochthonous bacterial and autochthonous protozoa populations; Muela A et al.; The discharge of disinfected effluents affects the bacterivorous ability of protozoa and the effect depends on the disinfectant applied . Chlorine provokes a decrease in the number of protozoa and a delay in the bacterivorous ability . The discharge of ozonated and peracetic acid-treated wastewater provokes only an initial slight decrease in bacterivorous ability . No correlation was found between toxicity values detected using the Microtox assay and the effect of disinfected effluents on freshwater protozoa population . After the disinfection processes, recipient systems (fresh and marine water) have different effects on the survival of Escherichia coli populations discharged to them . The effect of the freshwater recipient system is less negative than the effect provoked by sea-water, and the differences detected depend on the disinfection treatment applied . The wastewater bacterial population as a whole is able to grow after discharge of disinfected wastewater to receiving waters . However, in the absence of predation or competition, the recipient systems exert selection, with rod-shaped bacteria predominating.

Syst Appl Microbiol, 1998 Mar, 21(1), 72 - 88
A qualitative evaluation of the published oligonucleotides specific for the 16S rRNA gene sequences of the ammonia-oxidizing bacteria; Utaker JB et al.; Over the past few years, there has been an increasing interest in making oligonucleotides specific for ammonia-oxidizing bacteria (AOB), in order to detect and monitor these slow growing bacteria in environmental samples, in enrichment cultures and in wastewater treatment plants . Based on 16S rDNA sequences, a broad selection of oligonucleotides have been designed, either encompassing all known AOB in the beta-subgroup of the Proteobacteria (beta AOB), or subclasses within beta AOB . Thirty different oligonucleotides have so far been published, with varying specificity . The first AOB-specific oligonucleotides published were obtained as a result of an alignment of only eleven 16S rDNA sequences from AOB . Including the present study, there are now forty nearly full length 16S rDNA sequences available from these bacteria, in addition to a number of partial sequences, so that an improved evaluation of the published oligonucleotides can be done . Two new 16S rRNA gene sequences from Nitrosospira are presented here, in a phylogenetic analysis containing every 16S rRNA gene sequences (> 1 kb) available from AOB . On the basis of an alignment of all these sequences, combined with searches in the nucleotide sequence databases, an evaluation of the thirty published oligonucleotides is presented . The analysis expose the strength and weakness of each oligonucleotide and discuss the use of oligonucleotides specific for 16S rRNA genes in future studies of AOB . The present work also identifies one new, broad range primer, specific for the AOB in the beta-subgroup of the Proteobacteria.

J Environ Sci Health B, 1998 Sep, 33(5), 623 - 43
Fractions of calcium in the plant-soil system affected by the application of olive oil wastewater; Gallardo-Lara F et al.; A pot experiment using calcareous soil was conducted in a growth chamber to examine the effects of olive oil wastewater applications on Ca fractions in the plant and on exchangeable Ca in soil after plant growth . The experimental treatments consisted of two rates of olive oil wastewater, two mineral fertilizer treatments including K, which supplied K in amounts equivalent to the K supplied by the olive oil wastewater treatments, a mineral fertilizer without K treatment (F), and a control . The pots were sown with ryegrass which was harvested 3 times at monthly intervals . The high rate of olive oil wastewater resulted in a prolonged increases in dry matter production . It also resulted in a reduction in the concentrations of soluble Ca, bound Ca, inorganic insoluble Ca and organic insoluble Ca in the plant shoots relative to the control and the F treatment . The low rate of olive oil wastewater produced similar but less marked effects, with decreases being observed in the soluble Ca and bound Ca fractions . After 3 months of plant growth, soil exchangeable Ca was higher in the control and F treatment soils than in the soils receiving olive oil wastewater or K fertilizer . At this time, there were no significant differences in exchangeable Ca between the soils receiving olive oil wastewater and those treated with K fertilizer.

Chemosphere, 1998 Sep, 37(6), 1079 - 90
Highly polar metabolites of nitroaromatic compounds in ammunition wastewater; Schmidt TC et al.; Transformation processes of nitroaromatic compounds (NAC) are described that lead to polar and highly hydrophilic metabolites in ammunition waste water . For the identification of proposed metabolites, several analytical methods for the separation and determination of these compounds were developed and applied to the investigation of a former ammunition plant and its surroundings . The compound classes which were investigated include nitro and amino substituted toluenesulfonic acids, nitrobenzoic acids, aminobenzoic acids and nitromethylphenols . Method development was usually done with high performance liquid chromatography and ion pairing or ion suppression techniques . In the leachate water of a disposal site of a former ammunition plant in Stadtallendorf, Germany, 15 compounds from the above-mentioned categories have been found to be present in concentrations up to a few hundred microgram/L . The presence of so many polar compounds suggest that current and future surveying programs should include representative analytes of the investigated categories.

Sci Total Environ, 1998 Jul 3, 217(3), 231 - 9
Clover and cress as indicator species of impacts from limed sewage sludge and landfill wastewater land application; Vasseur L et al.; This study evaluated the performance of cress and clover as bioindicators to evaluate the impact of limed sewage sludge and landfill wastewater application on soil . The use of these two species, and the subsequent parameters measured, were also compared for their effectiveness in evaluating potential effects . Sewage sludge was added to the soil at a rate of 23 mg ha-1 and also at twice this dose . Wastewater was added at a level of 2 and 10% of the soil volume . Germination rate, height increase per week and final dry biomass were measured for both species . Heavy metal (Cd, Pb, Fe, Cu, Ni, and Zn) concentration was determined only for the shoot and root of clover . In general, the results showed that, compared to the control, the overall performance improved for plants exposed to both treatments . However, plants appeared to respond better to the wastewater addition than the sewage sludge amendment . The germination rate as well as other traits indicate that clover may be more sensitive to these fertilizers than cress . The lime addition did not appear to influence growth, nor heavy metal accumulation in clover . There were major differences in heavy metal accumulation in the root vs . shoot of clover . Hence, the concentrations of Cd, Cu, Fe, Zn, and Pb did not vary in the shoots of the plants under either treatments . The concentrations of the heavy metals in the roots however, greatly varied according to the type of metals . The concentrations of these metals appeared to increase with the increase of the addition treatments . The results suggest that for both species, the levels of fertilizers used in the present study were below the toxicity levels . Since the types of soils and the doses of fertilizers influence the rate of heavy metal absorption and their effects on plants, methods for rapid evaluation/monitoring as well as the types of indicators used should be explored as in the present study.

Biotechnol Prog, 1998 Jul, 14(4), 645 - 8
Axial dispersion model for upflow anaerobic sludge blanket reactors
Singhal A, Gomes J, Praveen VV, Ramachandran KB.
Fluid flow in UASB reactors is usually described by multicompartment models consisting of separate ideally mixed zones, plug flow zones, and stagnant zones linked with bypassing flows and back-mixing flows . A closer look at UASB reactor behavior indicates that this complexity is unnecessary . Our study on the startup and steady-state operation of a UASB reactor shows that its fluid flow can be explained just as well with a simple axial dispersion model . The physical transitions, which occur in different zones of the UASB reactor as the microorganisms acclimate to the wastewater, are adequately described by the model . Further, the number of parameters, which is six in standard UASB reactor models, is reduced to four in the case of the axial dispersion model.

Chemosphere, 1998 Aug, 37(4), 753 - 69
Differences in the measurement of cytotoxicity of complex mixtures with rainbow trout hepatocytes and fibroblasts; Gagne F et al.; The purpose of this study was to compare cytotoxicity tests for industrial/municipal wastewaters using two different cell systems: rainbow trout hepatocytes and gonadal fibroblasts . They were exposed to concentrations of industrial/municipal wastewaters for 48 h at 15 degrees C . In addition, wastewater toxicity was evaluated concurrently with the 96-h rainbow trout acute lethality bioassay . Hepatocyte viability was assayed with the propidium iodide (PI) exclusion and neutral red (NR) uptake inhibition tests, while gonadal fibroblast viability was assayed with the NR uptake test . The results show that hepatocyte viability measurement by the PI exclusion test and NR uptake are in agreement with complex mixture exposures . Moreover, cytotoxicity was correlated with trout mortality for most of the effluents (80%) . Although a low correlation was found between the trout fibroblast and the hepatocyte NR uptake assays, the NR uptake assay using gonadal fibroblasts was correlated with trout mortality, but in only 60% of the samples tested . Hepatocyte cytotoxicity data, whether determined by the PI exclusion test or the NR uptake test, appeared to be more strongly associated with trout toxicity than did the rainbow trout gonadal fibroblasts, in the case of complex environmental mixtures.

J Chromatogr A, 1998 Jun 12, 810(1-2), 173 - 82
Gas chromatographic determination of aromatic amines in water samples after solid-phase extraction and derivatization with iodine . II . Enrichment; Less M et al.; A procedure for the enrichment of aromatic amines via solid-phase extraction was developed . A HR-P phase based on styrene-divinylbenzene was used for the investigations, generally followed by derivatization with iodine and determination via GC-ECD . The recoveries of 53 aromatic amines in a drinking water matrix at pH 9 were determined . Most anilines showed relative recoveries between 80-120% with relative standard deviations of< or = 5% at concentration levels between 10 and 20 micrograms 1(-1) . The comparison with a wastewater matrix led to similar results . The enrichment procedure was applied to real samples, e.g., samples of ammunition wastewater.

J Chromatogr A, 1998 Jun 12, 810(1-2), 161 - 72
Gas chromatographic determination of aromatic amines in water samples after solid-phase extraction and derivatization with iodine . I . Derivatization; Schmidt TC et al.; A new method for the selective determination of aromatic amines is presented, which is based on the solid-phase extraction at pH 9 and subsequent derivatization of the analytes to the corresponding iodobenzenes . These can selectively and sensitively be determined with gas chromatography and electron-capture detection . Separation of at least 30 compounds in a single chromatographic run in 30 min is possible . With this method, 56 aromatic amines were investigated, and only in six cases no derivatives were obtained . Limits of quantitation were between 0.5 and 8 micrograms 1(-1), but may still be lowered with higher sample volumes or different injection techniques . The application to water samples revealed the suitability for the investigation of ground, leachate and wastewater.

Ecotoxicol Environ Saf, 1998 Jul, 40(3), 184 - 93
Experimental field exposure of brown trout to river water receiving effluent from an integrated newsprint mill; Johnsen K et al.; Effects of effluents from mechanical pulp production on brown trout were studied for 8 weeks at environmentally relevant concentrations . The exposure took place in laboratory-based pools upstream and downstream of the effluent discharge point of an integrated newsprint mill using ground wood/thermomechanical pulp . The mill had no secondary treatment of the wastewater . The pools were supplied with water pumped directly from the river . To determine the relevance of this approach, wild fish were also caught at the respective sites upstream and downstream from the mill . Sublethal effects were assessed using physiological and biochemical parameters including liver histology, hematology, serum biochemistry, and hepatic enzyme assays . Exposure was verified by analyzing water samples, fish bile, and tissues for resin acid concentrations . The downstream experimental fish and captured feral fish displayed responses and changes in physiological parameters similar to those previously observed in laboratory experiments with untreated effluents . The most obvious effects were liver damage and growth inhibition.

Appl Environ Microbiol, 1998 Jul 1, 64(7), 2726 - 9
Phanerochaete flavido-alba Laccase Induction and Modification of Manganese Peroxidase Isoenzyme Pattern in Decolorized Olive Oil Mill Wastewaters; Perez J et al.; Lignin-degrading enzymes were partially purified from supernatant solutions obtained from Phanerochaete flavido-alba-decolorized olive oil mill wastewaters (OMW) . The dominant enzymes, manganese peroxidases, exhibited different isoform patterns in decolorized OMW-containing cultures than in residue-free samples . Laccase induction was also detected in OMW-containing cultures but not in control cultures.

Folia Biol (Krakow), 1997, 45(3-4), 153 - 6
The "comet" assay for detection of potential genotoxicity of polluted water; Kosz-Vnenchak M et al.; The aim of this study was to determine the potential genotoxic activity of polluted water samples taken from wastewater from selected industrial plants in Krakow: 1 . the Thermal-electric Power Station 2 . the Institute of Metal Cutting . The recently developed single cell gel assay (SCG or comet assay), which is a quick and simple technique for the evaluation of DNA damage and repair in individual cells, was used . The assay was carried out on human hepatoma cells (Hep G2) as target cells . A greater number of cells with comets was observed in those treated in vitro with the polluted water samples (70%-88%) than in those in the control (22%, 33%) . These preliminary results indicate that comet assay can have an application in biomonitoring studies for determining the potential genotoxicity of water pollutants.

Mutat Res, 1998 Jun, 410(3), 223 - 36
The genotoxic hazards of domestic wastes in surface waters; White PA et al.; Despite the noteworthy genotoxic potency of many industrial wastewaters, the genotoxic hazard posed to the downstream ecosystem and its associated biota will be determined by genotoxic loading . Municipal wastewaters, although ranking low in potency, can achieve loading values that are several orders of magnitude greater than those of most industries . Although these wastewaters are generally mixtures of wastes from several different sources, the volumetric proportion of the daily discharge that is of industrial origin rarely exceeds 30% . Genotoxicity calculations for the Montreal Urban Community (MUC) municipal wastewater treatment facility indicate that over 90% of the genotoxic loading (31.1 kg benzo(a)pyrene equivalents per day) is nonindustrial in origin . Moreover, a mass balance of surface water genotoxicity for St . Lawrence river at Montreal indicates that over 85% of the total contributions from the Montreal region are nonindustrial in origin . Additional calculations for the Great Lakes, and other rivers throughout the world, provide further support of a strong relationship between surface water genotoxicity and population . Despite some information about physical/chemical properties, the identity of the putative genotoxins in municipal wastewaters and surface waters remains a mystery . Likely candidates include potent genotoxins, such as N-nitroso compounds and aromatic amines, known to be present in human sanitary wastes, as well as genotoxic PAHs known to be present in many municipal wastewaters . Calculations based on literature data indicate that human sanitary wastes may be able to account for a substantial fraction (4-70%) of the nonindustrial loading from municipal wastewaters . Similar calculations suggest that pyrogenic PAHs that enter municipal wastewaters via surface runoff can only account for a small fraction (<5%) of the genotoxic loading values discussed .

Ecotoxicol Environ Saf, 1998 May-Jun, 40(1-2), 88 - 93
Assessing the environmental impact of wastewaters; Isnard P; The conventional approach for assessing the environmental impact of wastewaters uses a set of global physicochemical and ecotoxicological parameters and is well adapted to the vast majority of wastewaters . When some chemicals may be particularly harmful for the environment, a specific approach based on a comparison between the predicted environmental concentration (PEC) and the predicted no-effect concentration (PNEC) may be used . The four steps of extrapolation required for PNEC evaluation are discussed and the importance of the interspecies extrapolation is highlighted . It may also be useful to use an integrated approach relating the characteristics of the wastewater to that of specific compounds . For physicochemical parameters, a simple addition is adequate, whereas, for ecotoxicity, the problem is more complex . The toxicity of a mixture of compounds acting by the same mechanism is often described by the concentration addition model . Although this model is very useful for practical applications owing to its simplicity, a statistical evaluation of its performance indicates that it slightly over-predicts the toxicity of mixtures . A new model derived from the statistically sound "independence action" principle and based on a precise mathematical description of the dose-response relationship is proposed . Applications of this model to mixtures tested with algae demonstrate the accuracy of this model with the experimental data.

Appl Environ Microbiol, 1998 Jun, 64(6), 2284 - 6
Detection of Cyclospora cayetanensis in wastewater; Sturbaum GD et al.; Cyclospora cayetanensis causes diarrheal disease worldwide without a confirmed mode of transmission . Wastewater was examined for the presence of this organism . Oocysts were detected microscopically, and their identity was confirmed by molecular techniques . These findings verify that current techniques can isolate Cyclospora oocysts and suggest that fecally contaminated water may act as a vehicle of transmission.

Can J Microbiol, 1998 Mar, 44(3), 211 - 20
Functional and structural successions in arbitrary samples of heterotrophic bacteria during aerobic treatments of lignite-carbonization wastewater in in situ enclosures; Becker PM et al.; In situ mesocosm experiments were performed in Lake Schwelvollert (located in the district of Weissenfels, Saxony-Anhalt, Germany), an anaerobic lignite-carbonization effluent lake containing phenolic compounds and their autoxidation products (anthropogenic humic matter) . In the aeration enclosure, the anaerobic Schwelvollert wastewater was aerated and in the flocculation enclosure, it was flocculated to precipitate the oxygen-trapping anthropogenic humic matter to enhance the input of oxygen by diffusion . To gain an insight into the metabolic state of the aerobic heterotrophic microbiota during the treatments, arbitrary samples of bacterial isolates were taken from a general agar medium and tested for their abilities to cleave predominant phenolic contaminants by a procedure called the isolate sample assay . In this way, successions of degradation potentials were observed in both mesocosms, with degradation abilities for meta- and para-alkylated phenols appearing before degradation abilities for ortho-substituted phenols as a common phenomenon . To examine the structure of samples, the respective isolates were characterized using the Biolog GN MicroPlate system, the random amplified polymorphic DNA nucleic acid (RAPD) fingerprinting technique, and amplified ribosomal DNA restriction analysis (ARDRA) . Although similar functional patterns occurred in both mesocosms, the compositions and diversities of the respective bacterial communities varied significantly, even at different depths from the same enclosure, with members of the Pseudomonas RNA group I being predominant.

Am J Ind Med, 1998 Jun, 33(6), 571 - 7
Prevalence of infectious diseases and associated symptoms in wastewater treatment workers; Khuder SA et al.; Wastewater treatment workers (WWTW) are potentially exposed to a variety of infectious agents and toxic materials . We conducted a retrospective epidemiological study to examine the prevalence of infectious diseases and associated symptoms in WWTW . From a possible 242 WWTW, 150 completed a questionnaire that provided data pertaining to the diagnosis of an infectious disease or the prevalence of associated symptoms over a 12-month period . Comparison data were obtained from questionnaires completed by 54 college maintenance and oil refinery workers . The WWTW exhibited a significantly higher prevalence of gastroenteritis, gastrointestinal symptoms (specifically abdominal pain), and headaches . No significant differences were found with regard to respiratory and other symptoms . Employees classified by exposure categories did not exhibit significant differences in the prevalence of symptoms . While significant differences were found with regard to the health status of WWTW and controls, it appears that these risks are confined to symptoms and infectious diseases associated with the gastrointestinal system and are not inclusive of all such symptoms or diseases.

New Microbiol, 1998 Apr, 21(2), 161 - 7
Hepatitis A virus detection in wastewater by PCR and hybridization; Divizia M et al.; Hepatitis A virus is a member of the Picornaviridae family and is a principal agent of acute hepatitis worldwide, causing from mild to severe illness . Although the incidence of hepatitis A is in decline, the risk of this disease is still high in the Mediterranean area . Detection of hepatitis A in the environment is difficult because this virus needs a prolonged incubation in cell culture, therefore we used an antigen capture PCR (AC-PCR) followed by a hybridization on membrane to identify HAV in wastewater samples . The raw sewage, concentrated by ultrafiltration, showed 8 positive samples out of 10 (80%), while after the oxidation step of the sewage, 2 out of 10 (20%) and 3 out of 10 (30%) were found positive respectively after concentration by electronegative (HAWP Millipore) and electropositive (1MDS Cuno-Div.) membranes . In the final effluent the positivity was 1 out of 10 (10%) for the electronegative membranes and 3 out of 10 (30%) for the electropositive membranes . Our results indicate: i) the possibility of HAV to cross the wastewater treatment plant and contaminate water and food (such as mussels); ii) PCR-hybridization as a rapid method for HAV identification in the environment.

Chemosphere, 1998 Apr, 36(10), 2291 - 304
A simplified modeling approach using microbial growth kinetics for predicting exposure concentrations of organic chemicals in treated wastewater effluents; McAvoy DC et al.; Various mathematical relationships have been used to assess exposure concentrations of organic chemicals when emissions occur via wastewater treatment . These relationships range from a simple removal factor calculation to more sophisticated approaches using kinetic based mathematical models . While these existing approaches have been used by decision makers to screen new chemicals for exposure assessments, they all have limitations in the predictive capabilities . Thus, a simplified modeling approach grounded in sound scientific fundamentals that utilizes relatively easy to obtain input parameters is needed . In this paper a simplified modeling approach that utilizes microbial growth kinetics was developed for predicting effluent concentrations in secondary biological wastewater treatment systems . Receiving water predicted exposure concentrations (PEC) are assessed by using a dilution factor . One advantage of this approach is that it allows for wastewater treatment plant effluent concentrations, and therefore receiving water exposure levels, to be predicted with a minimum amount of experimental data . It also provides quantitative data that can be used to assess the relative biodegradability of different chemicals for use in regulatory and risk assessment activities.

Chemosphere, 1998 Apr, 36(10), 2375 - 90
The use of the mitochondrial transmembrane electric potential as an effective biosensor in ecotoxicological research; da Silva EM et al.; In this work, the mitochondrial transmembrane electric potential (delta psi) of isolated mitochondria was used to evaluate the toxicity of some chemicals (endosulfan, 3,4-dichloroaniline, parathion, tributyltin and cadmium) and wastewater . Mitochondria were isolated from rat liver, and the delta psi measured in a suitable assay medium, using a sensitive tetraphenylphosphonium (TPP+) electrode . The test substance was pre-incubated in a rotenone-containing medium during 3 min with 1.0 mg of mitochondrial protein . Mitochondria were energised with succinate and after the establishment of a constant maximal potential ADP was added to induce the phosphorylative cycle . Chosen endpoints were the membrane potential from mitochondria oxidising succinate and the depolarisation induced by ADP . After the appropriate transformations the EC50 (effective concentration) was calculated for each toxicant . Even very low concentrations of a toxicant were able to affect the delta psi, thus showing its suitability as a biosensor in ecotoxicology and results were reproducible between tests . The utilisation of delta psi in screening tests of pure substances and wastewater seems to be very effective and can be carried out routinely.

Arch Environ Contam Toxicol, 1998 Apr, 34(3), 259 - 64
Determining toxicity trends in the ozonation of synthetic dye wastewaters using the nematode Caenorhabditis elegans; Hitchcock DR et al.; The nematode Caenorhabditis elegans was used in 72-h toxicity tests to evaluate the influence of ozonation on the toxicity of three synthetic azo dye wastewaters (two reactive dyes and one acid-based dye) . The two reactive dye wastewaters contained high concentrations of NaCl (89-112 g/L) in addition to potentially toxic dye components . To determine the contribution of NaCl to toxicity, simulated dye wastewater samples with and without NaCl were tested . Samples were collected at various times during ozonation (t = 0, 8, 32, 64 min); nematodes were exposed to the samples for 72 h . The influence of ozonation on toxicity varied between dye wastewater types . For the acid-based dye wastewater, toxicity increased as duration of ozonation increased . For the reactive dyes without NaCl, toxicity did not appear to be influenced by ozonation . For the reactive dyes with NaCl, mortality was 100% with or without ozonation . Range-finding experiments with NaCl in water and NaCl in dye wastewaters suggested an additive toxic interaction between NaCl and the dyes in wastewater to the nematodes . The duration of ozonation for acid-based dyes and the relatively high NaCl concentrations for the reactive dyes appear to influence effluent toxicity in the ozonated dye wastewaters.

Zentralbl Hyg Umweltmed, 1998 Feb, 200(5-6), 553 - 61
Epidemiological study of intestinal helminthiasis in a Marrakech raw sewage spreading zone; Bouhoum K et al.; It has been suspected for some time that raw sewage is a potential source of protozoan and helminthic infections (10) . Shuval et al . (16, 17) and W.H.O . (21) have shown that irrigating crops with untreated wastewater causes significant intestinal infections in both consumers and farm workers . This study compared the stools of "sewage farming" children exposed to raw sewage (El Azzouzia area) and those of a control group . Stool specimens from 253 exposed children and 275 controls were analyzed . 73% of the exposed were infected with one or more helminths verses 30% of the control group . The main parasites were Ascaris and Trichuris . The El Azzouzia children were more heavily infected and their polyparasitism index (PPI: 13%) was considerably higher than that of the controls (PPI: 2%) . Thus "sewage farming" children are exposed to detectable risk from the parasitic nematodes in raw sewage.

Biodegradation, 1997, 8(4), 237 - 49
Enhancement of the biodegradability of model wastewater containing recalcitrant or inhibitory chemical compounds by photocatalytic pre-oxidation; Bolduc L et al.; m-Dinitrobenzene, diphenylamine and resorcinol, three aromatic compounds found inhibitory or recalcitrant to biological treatments, were chosen as model chemicals for this study on the integration of photocatalytic-biological treatments . The degradation of each of these compounds was achieved by ultraviolet photocatalytic oxidation, leading to the formation of intermediate compounds . The photocatalytic treatment was performed in a TiO2 slurry reactor containing an aqueous solution of one of the three chemicals . The biodegradability of model wastewater treated photocatalytically was measured in terms of BOD1/TOC . Intermediate compounds that appeared at early stages of the photocatalytic degradation of m-dinitrobenzene or diphenylamine seemed to be more inhibitory than the parent compounds but this was not the case for resorcinol . A substantial improvement in BOD1/TOC could be achieved, but it required the mineralization of at least 80% of the organic carbon originally in the water . Microtox toxicity results confirmed the BOD1/TOC trends for diphenylamine.

Ecotoxicol Environ Saf, 1998 Jan, 39(1), 31 - 40
Procedure to screen illicit discharge of toxic substances in septic sludge received at a wastewater treatment plant; Robidoux PY et al.; This paper presents an integrative approach, using toxicological and chemical analyses, to screen toxic and illegal substances that could be added to the septic sludge transported by a tanker truck to the wastewater treatment plant of the Montreal Urban Community (MUC) . Microtox, lettuce root elongation, and a bacterial respiration test were used to establish the toxicity range of a normal sludge and the determination of threshold limit criteria . Septic sludge samples were spiked with different types and amounts of contaminants (copper, zinc, phenol, industrial sludge) . Conservative criteria were applied to detect abnormal toxicity with great reliability while avoiding false positives (i.e., detecting abnormal toxicity in nonspiked sludge) . Taken individually, toxicity tests using Microtox were revealed to be the least discriminating toxicological method (efficiency of 45% when the ratio of the IC50 values is considered), whereas lettuce root elongation was relatively the most efficient (80% of spiked samples) . As a whole, the battery of toxicity tests detected at least 93% of the spiked sludge samples . This procedure is also very efficient, i.e., easy to apply, cost effective, and rapid . In certain cases, an abnormal toxicity level can be determined within a few hours, whereas a septic sludge can be classified as normal within 5 days.

Sci Total Environ, 1997 Dec 3, 208(1-2), 59 - 69
Time series analysis on chlorides, nitrates, ammonium and dissolved oxygen concentrations in the Seine river near Paris; Cun C et al.; Graphical and statistical time series techniques have been used to analyze the trends and specified time changes, in a 90-year record of annual average value of Seine river water quality data . The information obtained may be associated with some socio-economic variables, such as industrial or agricultural development, urban increase and wastewater discharge around or upstream of the measure station . Such a study may now be applied to more rural stations in order to compare the evolution of water quality and, perhaps, historical monthly average values to evaluate the seasonality effect on annual trends.

J Chromatogr A, 1998 Jan 16, 793(2), 378 - 82
Simultaneous determination of seven sulfonamide residues in swine wastewater by high-performance liquid chromatography; Jen JF et al.; A HPLC-UV method was used for simultaneous determination of the residual sulfonamides in swine wastewater . Sulfonamides were extracted with ethyl acetate prior to chromatographic analysis . An ODS column was used for separation and UV detection was used to monitor the sulfonamides . Factors that affect the chromatographic behavior and the recovery have been studied . Calibration graphs were linear with very good correlation coefficients (r > 0.9999) from 0.05 to 10 micrograms/ml . The applicability of the method to the analysis of swine wastewater samples was demonstrated.

J Am Mosq Control Assoc, 1997 Dec, 13(4), 398 - 401
Experimental host range studies with Heleidomermis magnapapula (Mermithidae), a parasite of Culicoides variipennis (Ceratopogonidae); Mullens BA et al.; Infectivity of the mermithid nematode Heleidomermis magnapapula, a parasite of Culicoides variipennis variipennis and C . v . sonorensis in dairy wastewater pond habitats, was tested against larvae of aquatic Diptera in the laboratory . Observations were made on preparasite penetration . If the host species could be reared after parasitization, further observations determined nematode development and emergence . Genera in the families Syrphidae (Eristalis), Psychodidae (Psychoda), and Chironomidae (Tanypus), common in wastewater pond habitats, were not attacked . Larvae of Bezzia and Dasyhelea (Ceratopogonidae) also were not attacked . Larvae of Chironomus (Chironomidae) were penetrated, but rapidly encapsulated the nematodes . All Culicoides spp . exposed were readily penetrated by H . magnapapula preparasites . The nematodes successfully emerged from C . v . occidentalis . Some nematode maturation was seen in C . lahontan, and limited adult nematode emergence was seen in C . boydi and C . cacticola . No nematode development was observed in 5 other Culicoides spp . penetrated.

Appl Microbiol Biotechnol, 1997 Nov, 48(5), 621 - 5
Transformation system for a wastewater treatment yeast, Hansenula fabianii J640: isolation of the orotidine-5'-phosphate decarboxylase gene (URA3) and uracil auxotrophic mutants; Kato M et al.; A transformation system for Hansenula fabianii J640, a commonly used wastewater treatment yeast, was constructed . As a host cell, a uracil auxotrophic mutant designated as H . fabianii J640 u-1, which was confirmed to have a mutation at the locus of the gene for orotidine-5'-phosphate (OMP) decarboxylase (URA3), was obtained by positive selection using 5-fluoroorotic acid . A plasmid named pHFura3, which includes a 795-bp open-reading frame of the OMP decarboxylase H . fabianii, was obtained by complementation of the Escherichia coli pyrF mutant, pHFura3 could transform H . fabianii J640 u-1 by a non-homologous and frequently multicopy integration into the host genomic DNA.

Environ Manage, 1998 Jan, 22(1), 119 - 27
Long-Term Growth Enhancement of Baldcypress (Taxodium distichum) from Municipal Wastewater Application
Hesse ID, DAY JR JW, Doyle TW.
/ Tree ring analysis was used to document the long-term effects of municipal wastewater on the growth rate of baldcypress {Taxodium distichum (L.) Rich.} . The study site, a swamp in St . Martin Parish, Louisiana, has received municipal wastewater for the last 40 years . Growth chronologies from 1920 to 1992 were developed from cross-dated tree core samples taken from treated and control sites with similar size and age classes . Mean diameter increment (DINC) and mean basal area increment (BAI) chronologies were constructed separately for each stand . These chronologies were then summarized by tree and stand into seven nine-year intervals resulting in three pretreatment intervals from 1926 to 1952 and four treatment intervals from 1953 to 1988 . Significant differences in growth response between sites showed a consistent pattern of growth enhancement in the treated site coincident with the onset of effluent discharge . The ratio of treated to control baldcypress growth rates (computed from DINC) averaged 0.74 during the pretreatment period and 1.53 during the treatment period . Over the period of study, control DINC decreased from 77 mm to 29 mm/nine-year interval, while treatment DINC increased slightly from 40 mm to 47 mm/nine-year interval . Control BAI did not increase significantly and averaged 192 cm2/nine-year interval . There was a significant increase in treatment BAI from 129 to 333 cm2/nine-year interval over the period of record . These results clearly demonstrate sustained long-term baldcypress growth enhancement throughout 40 years of municipal effluent discharge.KEY WORDS: Taxodium; Tree-ring analysis; Dendroecology; Wetlands; Natural wetland wastewater treatment; Long-term growth enhancement

Res Microbiol, 1997 Jan, 148(1), 71 - 8
Detection of Legionella pneumophila in wastewater by nested polymerase chain reaction; Catalan V et al.; The study of Legionella in treated wastewater acquires special importance when this water is used in irrigation by spray, as Legionella is transmitted via the inhalation of aerosols and may consequently represent a health risk . In this study, we applied polymerase chain reaction (PCR) amplification as an alternative method to plate culture for detecting L . pneumophila in twelve heavily biocontaminated samples from a wastewater treatment plant . Moreover, we studied the efficiency of rapid gel filtration methods and filtration through chelating ion exchange resin in the elimination of PCR inhibitors from wastewater samples . When Legionella was investigated by PCR without any previous treatment, no amplification occurred, and when we used chromatographic methods to eliminate PCR inhibitors, nine out of twelve samples became positive . These results indicate the abundant presence of Legionella in wastewater, and although the methods used to eliminate PCR inhibitors are effective in the preparation of clean samples, the possible presence of different metal-organic matter compounds, which are not eliminated, may produce false-negative results.

J Colloid Interface Sci, 1997 Aug 15, 192(2), 475 - 80
Preparation and Characterization of Active Carbon Adsorbents for Wastewater Treatment from Elutrilithe
Deng X, Yue Y, Gao Z.
Active carbon adsorbents were prepared from natural elutrilithe by chemical activation with K2CO3 . The effect of pyrolysis temperature and time and K2CO3/elutrilithe ratio on the surface area, porosity, and ash content of the adsorbents was studied . Various prior and post treatments have been tried to improve the quality of the adsorbents . An ideal active carbon adsorbent with a BET surface area of 1236 m2/g and a total pore volume of 0.679 cm3/g has been obtained . The adsorbent is hydrophobic in nature and exhibits large adsorption capacities for various phenolic compounds from aqueous solutions .

Arch Environ Contam Toxicol, 1997 Oct, 33(3), 252 - 60
Investigations into using the nematode Caenorhabditis elegans for municipal and industrial wastewater toxicity testing; Hitchcock DR et al.; This investigative study assesses the ease and usefulness of the nematode Caenorhabditis elegans for identifying contributors to effluent toxicity within an industrial and municipal wastewater treatment plant (WWTP) system . Several different types of industries, including fiberglass manufacturing, paper packaging, and yarn dyeing, discharge effluent into the municipal wastewater treatment plant, which in turn discharges into a local creek . A major objective of this study was to identify primary sources of toxicity throughout the system with a nematode toxicity test . Twenty-four-hour composite water samples were taken periodically over a ten-month period at five strategic points within the system: (1) at the point of discharge at each of the three industries, (2) at the combined industrial influent of the wastewater treatment plant, (3) at the effluent of the WWTP, (4) upstream of the WWTP discharge, and (5) downstream of the WWTP discharge . Samples were analyzed for basic water chemistry, and each sample was tested for whole effluent toxicity using a 72-h nematode test with mortality as the end point . Results suggest that interactions between the wastewaters of certain industries may increase the overall nematode toxicity in the wastewater treatment facility's composite influent and effluent . Nematode mortality trends indicate relatively high toxicity levels in wastewater entering the WWTP from contributing industries . High WWTP influent toxicity may potentially be due to varying flow rate ratios of industrial discharges, release of varying toxic constituents in wastewaters, and toxic interactions between chemical constituents of industrial wastewaters . The evaluation of toxicity within the treatment system may pinpoint locations where pollution prevention strategies may be implemented to reduce overall toxicity at the point of discharge.

Environ Health Perspect, 1997 Aug, 105(8), 794 - 9
Growing pains in South America; Joyce S; PIP: This article describes some negative effects from modernization and urban growth in South America, including disease, pesticides, occupational hazards, poor environmental controls of water and garbage, sanitation, and environmental degradation . South America is following the global trend toward urbanization and the problems that accompany it . Agricultural expansion led to an expanded market for pesticides that includes the deadly DDT, paraquat, and heptachlor . Brazil and Colombia are the largest consumers . Latin American officials justify use of DDT, which is banned in the US and many European countries, as an effective means of combating mosquitos that carry malaria . Exposure occurs during harvesting, transporting, forestry, livestock farming, and vector control activities . Methyl bromide, which is used post-harvest and as a soil fumigant, is dangerous enough to be banned in the US in 2001, and in developing countries in 2002 . Exposure to toxic chemicals can severely inhibit enzyme action that is necessary for neurological functioning . A hot climate, which prevents protective clothing, lack of education on proper application, and absence of water to wash exposed skin, make pesticide protection very difficult . Over 40 million agricultural workers are at risk of pesticide poisoning . Habitat destruction has contributed to increased mosquito infestations . Children in the workplace are at even greater risk of noise pollution and chemical poisoning . South America pollutes almost 11 times more fresh water per capita than Europe . About 70% of domestic garbage is collected, and about 30% is disposed of correctly . Only 10% of urban wastewater is treated before discharge into waterways . The loss of coastal wetlands reduces the ability of waterways to filter and absorb nutrients . Environmental health problems suggest an interlinkage between environmental sustainability, human health, and economic growth .

Ecotoxicol Environ Saf, 1997 Aug, 37(3), 223 - 8
Effects on growth and accumulation of zinc in six seaweed species; Amado Filho GM et al.; Seaweed species from a coastal area contaminated by heavy metals (Sepetiba Bay) in Rio de Janeiro State (Brazil) presented different levels of Zn concentrations . In some species the levels were 20 times higher than that from a noncontaminated area . The present study was undertaken to investigate the capability of different species to tolerate and accumulate zinc . For this purpose six species, Ulva lactuca, Enteromorpha flexuosa, Padina gymnospora, Sargassum filipendula, Hypnea musciformis, and Spyridia filamentosa, were cultivated under laboratory semistatic conditions in five Zn concentrations in seawater, 10, 20, 100, 1000, and 5000 micrograms.liter-1 for a period of 21 days . All species died at 5000 micrograms.liter-1 of Zn, two species (U . lactuca and E . flexuosa) died at 1000 micrograms.liter-1, and one, H . musciformis, died with 100 micrograms.liter-1 . The lowest concentration of Zn that presented growth inhibition in the six species was 20 micrograms.liter-1 . The brown alga P . gymnospora presented the highest accumulation level of Zn, and H . musciformis the lowest level . The results of tolerance and accumulation under laboratory conditions, associated with field results, indicate the species of Padina and Sargassum as the best species for monitoring heavy metals in tropical coastal areas, and the potential use of their biomass to remove heavy metals from wastewaters.

Chemosphere, 1997 Sep, 35(6), 1343 - 63
Predicting the toxicity of complex mixtures using artificial neural networks; Gagne F et al.; Industrial and municipal wastewaters constitute major sources of contamination of the aquatic compartment and represent a threat to aquatic life . Artificial neural networks based on three different learning paradigms were studied as a means of predicting acute toxicity to trout (5 days exposure to wastewaters) using input data from two simple microbiotests requiring only 5 or 15 min of incubation . These microbiotests were 1) the chemoluminescent peroxidase (Cl-Per) assay, which can detect radical scavengers and enzyme-inhibiting substances, and 2) the luminescent bacteria toxicity test (Microtox), in which reduction of light emission by bacteria during exposure is taken as a measure of toxicity . The responses obtained with the trout bioassay, the Cl-Per and the Microtox test were analyzed through statistical correlation (Pearson product-moment correlation), unsupervised learning by a self-organizing network, and assisted learning by the backpropagation and the Boltzmann machine (probabilistic) paradigms . No significant correlation (p < 0.05) was found between the responses obtained with either the Cl-Per assay (p = 0.121) or the Microtox (p = 0.061) microbiotest and those resulting from the trout bioassay . The self-organizing network was able to identify by itself a maximum of five classes that were more or less relevant for predicting toxicity to fish: class 1 contained 2 samples that were toxic to fish, class 2 contained 2/3 samples that were toxic, class 3 showed 6/8 samples that were non toxic, class 4 contained 5/6 samples that were non-toxic and class 5 comprised one sample that was toxic . Supervised learning with backpropagation analysis yielded two kinds of networks that hold potential . The first one was able to predict the actual toxic wastewater concentration with an overall performance of 65% when fed fresh data, while the second one, which was designed to differentiate between toxic and non-toxic effluents, exhibited a much better performance (90%) . However, the probabilistic network also proved to be a very good predictive model for toxicity to fish, with an overall performance of 90% . Although more data are needed, the network based on the backpropagation paradigm seems to be a better predictor or classifier of trout toxicity when used with the Cl-Per and the Microtox microbiotests.

J Chromatogr A, 1997 Jun 27, 773(1-2), 139 - 46
Determination of phosphonates in natural waters by ion-pair high-performance liquid chromatography; Nowack B; The paper describes a new method for the determination of phosphonates by ion-pair high-performance liquid chromatography . The phosphonates are complexed with Fe(III) and separated on a reversed-phase polymer column . The eluent consists of a bicarbonate solution at pH 8.3, tetrabutylammoniumbromide as counter-ion and 14% acetonitrile . The complexes are detected at 260 nm . The four phosphonates HEDP (1-hydroxyethylene-1,1-diphosphonic acid) . ATMP (aminotris {methylenephosphonic acid}), EDTMP {ethylenediaminetetra(methylenephosphonic acid)}, and DTPMP {diethylenetriaminepenta (methylenephosphonic acid)} are well separated within 20 min . The limits of detection are 5.10(-8) M for ATMP and EDTMP, 1.10(-7) M for DTPMP and 5.10(-7) M for HEDP . The method is suitable for the determination of phosphonates in the influent and effluent of wastewater treatment plants . A preconcentration of 10 is easily achieved by adsorption of the phosphonates onto freshly precipitated calcium carbonate and subsequent dissolution of the solid-phase by HCl.

J Virol Methods, 1997 May, 65(2), 281 - 6
Elution and reconcentration of coliphages in water from positively charged membrane filters with urea-arginine phosphate buffer; Jothikumar N et al.; Coliphages in drinking water and waste water samples have been adsorbed onto positively charged membrane filters, eluted with urea-arginine phosphate buffer (UAPB), reconcentrated, and detected with Escherichia coli C (ATCC 13706) . The proposed membrane filter-based UAPB method for concentration and detection of coliphages compares favorably with the beef extract elution and reconcentration procedure and also with the proposed coliphage detection procedure described in Standard Methods for the Examination of Water and Wastewater . The higher recovery of coliphages with UAPB elution from positively charged membrane filters is attributed to testing the whole volume of concentrated sample, rather than partial analysis of the sample as in the procedure described in Standard Methods for the Examination of Water and Wastewater, especially when the titre is very low.

J Virol Methods, 1997 May, 65(2), 265 - 71
Enterovirus genomes in wastewater: concentration on glass wool and glass powder and detection by RT-PCR; Gantzer C et al.; Standard methods for detecting enteroviruses in environmental samples require cell culture, which is time consuming and expensive . The reverse transcription-polymerase chain reaction (RT-PCR) is a rapid, sensitive method for detecting enteroviruses in water . However, environmental samples often contain substances that inhibit PCR amplification of target RNA . Hence the virus must be concentrated by procedures that do not interfere with amplification . This study shows that virus concentration by adsorption onto glass powder or glass wool supports is suitable for detecting viral genomes in treated wastewater by RT semi-nested PCR . No enterovirus genome was detected directly in 25 samples of treated wastewater by RT semi-nested PCR . However, samples concentrated by adsorption onto glass wool or glass powder showed that 48% (glass powder) and 56% (glass wool) contained virus . Secondary concentration by organic flocculation was unsuitable for detecting virus concentrated on glass wool (20% positive samples), but it helped to increase the detection of the genome after concentration on glass powder (72% positive samples).

Arch Environ Contam Toxicol, 1997 May, 32(4), 358 - 66
Detection of toxic organometallic complexes in wastewaters using algal assays; Wong SL et al.; Chlorella (a unicellular green alga) and Cladophora (a filamentous alga) were used in algal assays to identify the presence and toxicity of organometallic complexes in four industrial wastewaters . Toxicities of inorganic Pb and organometallic compounds (trimethyl, tetramethyl and tetraethyl leads, cacodylic acid and Cu-picolinate) were examined, using algal cells grown in 10% BBM solution . Inorganic Pb and organometallic compounds altered the fine structure of Chlorella cells in a distinguishable manner . X-ray microanalysis revealed that organometallic compounds accumulated in the neutral lipids of Cladophora cells . By applying the above techniques to the wastewater assays, two of the four wastewaters tested were found to contain organometallic complexes . Wastewater from a chemical company contained only traces of organo-Cu, but one mining effluent contained significant quantities of organo-Cu and organo-Pb, and traces of organo-Cr and organo-Tl (thallium) . These studies suggest that X-ray microanalysis of algae may be a useful tool in identifying aquatic systems contaminated with metals and organometallic compounds.

J Med Entomol, 1997 May, 34(3), 277 - 84
Field morphological variation and laboratory hybridization of Culicoides variipennis sonorensis and C . v . occidentalis (Diptera:Ceratopogonidae) in southern California; Velten RK et al.; Two field populations of Culicoides variipennis (Coquillett) from southern California, C . v . occidentalis Wirth & Jones from the Salton Sea and C . v . sonorensis Wirth & Jones from a dairy wastewater pond in the Chino Basin, were sampled monthly from February to July (6-7 mo) . Morphometric analyses of slide-mounted adults reared from field-collected larvae and pupae indicated that females of the 2 forms were indistinguishable . Two of the standard characters, wing length and mandibular teeth, were correlated with seasonal temperature changes . Males of C . v . sonorensis were distinguishable by the presence of spicules on the aedeagus, which were entirely lacking in C . v . occidentalis . Two populations of C . v . occidentalis (Salton Sea and Bolsa Chica Marsh) and a laboratory strain of C . v . sonorensis hybridized successfully in the laboratory and were maintained for 6 generations . Differential hybrid viability (F1) was observed in reciprocal crosses . Males of C . v . occidentalis mated with females of C . v . sonorensis resulted in a lower egg hatch (7.4%) than did the reciprocal cross (75.6%) . Hybrid males displayed spicules on the aedeagus (a character of C . v . sonorensis), but the number of spicules was sometimes reduced compared with parental C . v . sonorensis (AA strain) . Spicules in a field population of C . v . sonorensis were similar in number to the laboratory C . v . sonorensis-C . v . occidentalis hybrids . Based on successful hybridization, the 2 forms should be considered closely related . The 2 forms are separated ecologically by the nature and distribution of their larval habitats.

Ecotoxicol Environ Saf, 1997 Apr, 36(3), 275 - 81
Ecosystem recovery following selenium contamination in a freshwater reservoir; Lemly AD; Belews Lake, North Carolina, was contaminated by selenium in wastewater released from a coal-fired electric generating facility during 1974-1985 . Selenium bioaccumulated in aquatic food chains and caused severe reproductive failure and teratogenic deformities in fish . Beginning in 1986, the electric utility company changed its ash disposal practices and selenium-laden wastewater no longer entered the lake . A survey of selenium present in the water, sediments, benthic invertebrates, fish, and aquatic birds was conducted in 1996 . Concentrations were compared to pre-1986 levels to determine how much change occurred during the decade since selenium inputs stopped . The data were also examined using a hazard assessment protocol to determine if ecosystem-level hazards to fish and aquatic birds had changed as well . Results reveal that waterborne selenium fell from a peak of 20 micrograms/liter before 1986, to < 1 microgram/liter in 1996; concentrations in biota were 85-95% lower in 1996 . Hazard ratings indicate that high hazard existed prior to 1986 and that moderate hazard is still present, primarily due to selenium in the sediment-detrital food pathway . Concentrations of selenium in sediments have fallen by about 65-75%, but remain sufficiently elevated (1-4 micrograms/g) to contaminate benthic food organisms of fish and aquatic birds . Field evidence confirmed the validity of the hazard ratings . Developmental abnormalities in young fish indicate that selenium-induced teratogenesis and reproductive impairment are occurring . Moreover, the concentrations of selenium in benthic food organisms are sufficient to cause mortality in young bluegill and other centrarchids because of Winter Stress Syndrome . At the ecosystem level, recovery has been slow . Toxic effects are still evident 10 years after selenium inputs were stopped . The sediment-associated selenium will likely continue to be a significant hazard to fish and aquatic birds for years.

Ecotoxicol Environ Saf, 1997 Apr, 36(3), 238 - 48
Design and construction of wetlands for aqueous transfers and transformations of selected metals; Hawkins WB et al.; Two pilot-scale wetland cells (6.1 x 30.5 m) were integratively designed and constructed to emphasize and enhance transfers and transformations of selected metals (Cu, Pb, and Zn) in an aqueous matrix . A series of preliminary experiments and analyses were conducted to select macrofeatures (hydroperiod, hydrosoil, and vegetation) of the constructed wetland system . These wetland cells were designed to operate in series or parallel with nominal hydraulic retention times of 24-48 hr, respectively . With water at a depth of 30 cm, both wetland cells had hydrosoil (45 cm) planted with Scirpus californicus . After 250 days of wetland operation, average hydrosoil redox potentials in each wetland cell decreased from +90 mV to -165 mV, and average plant height increased from 0.3 to 2.7 m . Aqueous samples were collected over a 4.5-month period at the inflow and outflow sites of the wetland cells . Average inflow concentrations of total recoverable Cu, Pb, and Zn were 22.4, 10.5, and 565.9 micrograms/L, respectively . After a 46-hr HRT, average outflow concentrations of total recoverable Cu, Pb, and Zn were 15, 2.2, and 85.9 micrograms/L, resulting in removals of 33, 79, and 85%, respectively . Initial results suggest that these constructed wetlands can be designed to remove targeted metals in wastewater.

Int J Syst Bacteriol, 1997 Apr, 47(2), 529 - 34
Janibacter limosus gen . nov., sp . nov., a new actinomycete with meso-diaminopimelic acid in the cell wall; Martin K et al.; New gram-positive bacteria were isolated from 1-year-old sludge from a wastewater treatment plant . The isolates are coccoid to rod-shaped, nonmotile aerobes that form neither spores nor mycelia . They are characterized by a peptidoglycan with directly cross-linked meso-diaminopimelic acid (type A1 gamma), by the presence of menaquinone MK-8(H4), and by the lack of mycolic acids . The strains have complex fatty acid patterns with i-C16:0 and straight-chain saturated and unsaturated fatty acids as major components . The G + C content of the DNA is 70 mol% . The results of chemotaxonomic studies and a 16S ribosomal DNA sequence comparison support our proposal to assign these bacteria to a new genus, the genus Janibacter gen . nov.; the type species is Janibacter limosus sp . nov., and the type strain of J . limosus is strain HKI 83 (= DSM 11140).

Appl Microbiol Biotechnol, 1997 Feb, 47(2), 185 - 8
Aerobic degradation of olive mill wastewaters; Benitez J et al.; The degradation of olive mill wastewater by aerobic microorganisms has been investigated in a batch reactor, by conducting experiments where the initial concentration of organic matter, quantified by the chemical oxygen demand, and the initial biomass were varied . The evolution of the chemical oxygen demand, biomass and the total contents of phenolic and aromatic compounds were followed through each experiment . According to the Contois model, a kinetic expression for the substrate utilization rate is derived, and its biokinetic constants are evaluated . This final predicted equation agrees well with all the experimental data.

Antonie Van Leeuwenhoek, 1997 Feb, 71(1-2), 109 - 16
Metabolism of micro-organisms responsible for enhanced biological phosphorus removal from wastewater . Use of dynamic enrichment cultures; van Loosdrecht MC et al.; The removal of phosphorus from wastewater is already widely applied . In many cases use is made of micro organisms capable of accumulating phosphorus as polyphosphate inside the cell . The main characteristic providing the competitive advantage to these polyphosphate accumulating bacteria is the capability to use polyphosphate, in the absence of external electron acceptors, as energy source for the uptake and storage of acetic acid in the form of polyhydroxybutyrate (PHB) . The reduction equivalents for the formation of PHB are derived from the conversion of glycogen to PHB . Despite the widespread use and study of enhanced biological phosphorus removal no pure culture, having the above mentioned characteristics, has been isolated yet . All ecophysiological studies on these type of cultures have therefore been performed by enrichment cultures . This paper reviews the research on these type of organisms, and shows that it is possible to understand a complex microbial process on a metabolic level, both stoichiometrically and kinetically, without the availability of a pure culture.

Appl Microbiol Biotechnol, 1997 Jan, 47(1), 73 - 7
Use of immobilized bacteria to treat industrial wastewater containing a chlorinated pyridinol; Feng Y et al.; Pseudomonas sp . strain M285 immobilized on diatomaceous earth beads was used to remove 3,5,6-trichloro-2-pyridinol (TCP) from industrial wastewater . Batch studies showed that immobilized Pseudomonas sp . strain M285 mineralized {2,6-14C}TCP rapidly; about 75% of the initial radioactivity was recovered as 14CO2 . Transformation of TCP was inhibited by high concentrations of salt, and addition of osmoprotectants (proline and betaine at 1 mM) did not reduce the adverse effect of salt . TCP-containing wastewater (60-140 mg/l) was passed through columns containing immobilized Pseudomonas sp . strain M285 at increasing flow rates and increasing TCP concentrations; TCP removal of 80%-100% was achieved . Addition of nutrients, such as glucose and yeast extract, retarded TCP degradation . Growing cell cultures were found to be better inocula for immobilization than resting cells.

J Am Mosq Control Assoc, 1996 Dec, 12(4), 647 - 50
Possible Culex pipiens pallens control by improvement of flow rates in water channels of Saga City, southwest Japan; Mogi M et al.; Water levels and flow rates (no . censuses with flow/no . censuses per year) were analyzed for 208 mosquito-productive and 422 mosquito-free channel segments during 1986-88 in Saga City, southwest Japan . Mean water levels tended to be higher at mosquito-free segments than at mosquito-productive segments, but the differences were < 5 cm and usually not significant . Flow rates exceeded 80% at 60-67% of mosquito-free segments . In contrast, flow rates were < 20% at 49-62% of mosquito-productive segments . Expected flow speeds at cement-lined segments exceeded 20 cm/sec (a flow speed required for mosquito control) for water levels of > 15 cm . Most mosquito-productive segments had mean water levels of > 15 cm, indicating that water stagnancy at those segments was due not to low water levels but to their structure . Engineering is necessary to yield flow speeds high enough to prevent mosquito breeding at mosquito-productive segments . Alternatively, engineering to prevent wastewater discharge into open channels may improve water quality, leading to mosquito suppression through colonization of larvivorous predators.

Microbiologia, 1996 Dec, 12(4), 525 - 36
Wastewater treatment and elimination of pathogens: new prospects for an old problem; Lopez-Pila JM et al.; Although the development of wastewater treatment technology is more than one hundred years old, most wastewater treatment plants existing today do not eliminate pathogens satisfactorily . Even in highly developed nations, receiving waters, serving in many cases as drinking water resources, are contaminated with pathogens . Surface waters also contain large concentration of phosphate due to long lasting wastewater discharges . Cyanobacteria and algal overgrowth is the consequence . Present drinking water technology only partially overcomes the pollution; it can not be ruled out that drinking water originating from polluted resources contains pathogens . This situation frequently goes on unnoticed because current indicator organisms are not representative for all pathogens . As studies have shown that small concentrations of pathogens also pose a risk for the consumer health, this state of affairs is a matter of concern . Microfiltration technology is able to significantly eliminate bacteria and protists from wastewater . Viruses, although smaller than the pore size of the filters, are reduced too because, in wastewater, they are frequently bound to larger particles . If the microfiltration of wastewater is preceded by the addition of coagulants for the precipitation of phosphate, the precipitate will be retained by the filter . The effluent obtained contains very low concentrations of phosphate . As viruses also adsorb to the precipitate, the amount of viruses eliminated increases and with increasing amounts of coagulant they become undetectable.

J Infect Dis, 1996 Dec, 174(6), 1372 - 6
Cryptosporidiosis in Washington State: an outbreak associated with well water; Dworkin MS et al.; In 1994, an outbreak of cryptosporidiosis occurred in a rural community in Washington State where water was supplied by two deep unchlorinated wells . Confirmed case-patients had a stool specimen containing Cryptosporidium parvum oocysts . Probable case-patients had diarrhea lasting > or = 5 days . Sixty-two households (68.1% of 91) responded to a survey . Eighty-six cases (15 confirmed, 71 probable) were identified, for an attack rate of 50.9% (86/169 residents) . Drinking unboiled well water was associated with being a case-patient (relative risk, 1.84; 95% confidence interval, 0.89-3.82), and a significant dose-response relationship was found between water consumption and illness (P = .004) . Water that was presumed to be treated wastewater from a piped irrigation system was found dripping along one well's outer casing, which was extensively rusted . Presumptive Cryptosporidium oocysts were found in well water and in treated wastewater . This investigation demonstrates that even underground water systems are vulnerable to contamination.

J Chromatogr A, 1996 Nov 22, 754(1-2), 103 - 23
Occurrence and determination of pesticides in natural and treated waters; Biziuk M et al.; Pesticides as environmental pollutants are described in detail along with their sources and paths of entry into various elements of the environment . Comprehensive literature data on the concentration of these pollutants in natural and treated waters and wastewaters are discussed . A wide selection of isolation and preconcentration techniques for these pollutants in water is presented and discussed . An emphasis is put on solid-phase extraction . In the case of the authors' work, a more detailed description is given.

Microchem J, 1996 Nov, 54(4), 338 - 47
Elements in Wastewater for Agricultural Use
Santarsiero A, Veschetti E, Ottaviani M.
With the increase in the application of wastewaters for agricultural purposes, the determination of the concentrations of some elements that can be found in such waters and their temporal behavior are of great interest . In this work, treated and untreated sewage samples were analyzed to determine the concentrations of Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Ni, Pb, and Zn . Ca, Mg, and Na concentrations were determined to estimate the sodium adsorbed ratio index . Total residue and setteable solids volume in every samples were also determined . With a view to understanding the effects of rainwater on such parameters and on treatment plant process efficiency, rain data for the period of observations were also collected . Analyses were conducted by atomic absorption spectrophotometry . A Perkin-Elmer Model 460 with a nebulizer-flame system and a Perkin-Elmer Model 5000 with an HGA graphite furnace were used to perform analyses . Principal components analysis was performed to simplify the description of the above 13 parameters and gain a better understanding of their interrelationships . Preliminary results showed that rainwater's impact on the concentrations of the investigated elements cannot be considered as simple dilution . Each parameter follows its own evolution; there is no correlation between treated and untreated sewage.

Arch Environ Contam Toxicol, 1996 Nov, 31(4), 557 - 62
Photolytic hydrogen peroxide oxidation of 2-chlorophenol waste water; Li YS; A kinetic model of degradation of 2-chlorophenol waste water by the photolytic hydrogen peroxide oxidation method was proposed . A high-pressure mercury lamp located in the center of the photoreactor was used as the UV radiation source and hydrogen peroxide was added as a catalyst which proved to be effective for the degradation of 2-chlorophenol . To calculate the reaction rate constants, two different types of batch experiments were conducted, UV radiation alone and hydrogen peroxide with UV radiation . A fourth-order Runge-Kutta method with the Rosen-Brock optimization algorithm were used to calculate the reaction rate constants from the experimental data . It was shown that the theoretical prediction from the proposed kinetic model and the calculated reaction rate constants fit the experimental data well for different concentrations of hydrogen peroxide and a continuous treatment of 2-chlorophenol wastewater . By using this model and changing the operating conditions, different concentration of hydrogen peroxide and influent flow rate, one can predict and achieve the desired output concentration of 2-chlorophenol in the continuous photolytic hydrogen peroxide oxidation process.

Analyst, 1996 Oct, 121(10), 1479 - 84
Analytical assessment of two sequential extraction schemes for metal partitioning in sewage sludges; Perez-Cid B et al.; Two sequential extraction schemes were employed for speciation of Cu, Cr, Pb, Ni and Zn in sewage sludges: the conventional Tessier scheme and the sequential extraction scheme proposed by the European Communities Bureau of Reference (BCR) . Both sequential extraction schemes were compared in terms of operation time, matrix effects and extraction efficiency . Two sludge samples collected from an urban wastewater processing plant at different seasons were analysed by FAAS for total contents and for extractable metals present in each fraction . Partitioning patterns were obtained for each metal so that metal mobility could be predicted . Both sequential extraction schemes yielded similar performance when extraction efficiencies were compared but matrix effects caused by concomitants were less pronounced in the BCR scheme in comparison with the Tessier scheme.

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