Water Res, 2002 May, 36(10), 2643 - 55 A new concept for the fractionation of DOM as a basis for its combined chemical and biological characterization; Muller MB et al.; To overcome the problem of non-specific interactions during the preparative fractionation of dissolved organic matter (DOM) for its combined chemical and biological characterization, the concept of standardized fractions (SFs) was developed . The concept is based on the calibration of the fractionation systems with suitable standards for the experimental definition of SFs, and the subsequent preparative fractionation of DOM samples according to the predefined SFs . Undesired non-specific interactions can thus be minimized experimentally . It was applied to the fractionation methods size exclusion chromatography (SEC) and multistage ultrafiltration (mst-UF) . A brownwater sample and an effluent from a sewage treatment plant were fractionated . The two methods performed rather differently which was evidenced both by the polydispersity of the resulting fractions as well as sum parameter fractionation patterns . Consequently, the interpretation of data obtained from the chemical-physical as well as biological analysis must always consider the limitations and particularities of the fractionation method employed. Water Res, 2002 Jun, 36(11), 2869 - 77 Carbamazepine in water: persistence in the environment, ozonation treatment and preliminary assessment on algal toxicity; Andreozzi R et al.; The presence of carbamazepine (CBZ), an antiepilectic drug, has been reported in sewage treatment plant (STP) effluents as a result of its low biodegradability . In the present work, the persistence of CBZ in aquatic environment with respect to abiotic transformation processes along with its toxicity and capability of accumulating in single aquatic organisms (algae) are evaluated . The possibility of removing CBZ from STP effluents is studied by characterizing its ozonation process through the assessment of kinetics and the distribution of oxidation products. Mar Pollut Bull, 2002 May, 44(5), 383 - 7 Caffeine in Boston Harbor seawater; Siegener R et al.; Caffeine has been detected in Boston Harbor seawater with concentrations ranging from 140 to 1600 ng l(-1), and in Massachusetts Bay seawater at concentrations from 5.2 to 71 ng l(-1) . Sources of caffeine appear to be anthropogenic with higher concentrations in the seawater of Boston's inner harbor and in freshwater sources to the harbor . Charles River water and Deer Island sewage treatment plant effluent, the two major sources of freshwater to the harbor, contained 370 and 6700 ng l(-1) of caffeine, respectively, in 1998 . Sewage influent and effluent concentrations appear to be consistent with consumption estimates of caffeinated beverages for the Boston area and total organic carbon removal targets for treated sewage . Caffeine was inversely correlated to salinity in a transect from the mouth of Boston Harbor to Stellwagen Basin, indicating it may be a useful chemical tracer of anthropogenic inputs to marine systems. Anal Chem, 2002 Jul 15, 74(14), 3498 - 504 Determination of estrogens in sludge and sediments by liquid extraction and GC/MS/MS; Temes TA et al.; Two methods have been developed that enable the determination of estrogens down to 2 ng/g in digested and activated sludge from domestic sewage treatment plants (STPs) and down to 0.2 ng/g in freshwater sediments . The method for sludge analysis consists of solvent extraction; a gel permeation chromatography (GPC) cleanup step, a 1 g silica gel column; and finally, detection by GC-ion trap MS/MS of the silylated estrogens with MSTFA . For sediments, the solvent extraction was successively followed by silica gel cleanup, solid phase enrichment (SPE), and a HPLC cleanup before derivatization and GC/MS/MS detection . Mean recoveries of the estrogens mainly exceeded 70% in sludge and 90% in sediments . In activated and digested sewage sludge, estrone and 17beta-estradiol were detected up to 37 ng/g and 49 ng/g, respectively, and 17alpha-ethinylestradiol up to 17 ng/g . The occurrence of estrogens in digested sludge indicates that estrogens can be persistent during sludge digestion . In river sediments, estrone and 17beta-estradiol were detected up to 2 ng/g (estrone), and the contraceptive 17alpha-ethinylestradiol was found with a maximum of 0.9 ng/g . Mestranol, a prodrug for 17alpha-ethinylestradiol, was not detected either in sludge or in sediments. Bioresour Technol, 2002 Aug, 84(1), 69 - 73 Anaerobic biotransformation of carbon tetrachloride under various electron acceptor conditions; Boopathy R; The biotransformation of carbon tetrachloride (CT) under various electron acceptor conditions was investigated using enrichment cultures developed from the anaerobic digester sludge of Thibodaux sewage treatment plant . The results indicated that CT was biotransformed under sulfate-reducing, methanogenic, nitrate-reducing, iron-reducing, fermenting, and mixed electron acceptor conditions . However, the rates of CT removal varied among the conditions studied . The fastest removal of CT (100% removal in 12 days) was observed under mixed electron acceptor conditions followed in order by sulfate-reducing, methanogenic, fermenting, iron-reducing, and nitrate-reducing conditions . Under mixed electron acceptor conditions, the CT was converted to methyl chlorides, which was further metabolized . Under sulfate, iron, nitrate-reducing, and methanogenic conditions, the major metabolite produced from CT metabolism was chloroform (CF) . Under fermenting conditions, methylene chloride was produced from CT metabolism . This study showed evidence for CT metabolism in a mixed microbial population system similar to many contaminated field sites where a heterogeneous microbial population exists. Aquat Toxicol, 2002 Sep 24, 59(3-4), 209 - 23 Algal esterase activity as a biomeasure of environmental degradation in a freshwater creek; Regel RH et al.; This study investigated the potential for using algal esterase activity of Microcystis aeruginosa and Selenastrum capricornutum as a rapid measure of the biological effects of acid mine drainage (AMD) in a South Australian stream (Australia) also affected by sewage pollution and dry-land salinity . Algal bioassays were based on the non-fluorescent substrate, fluorescein diacetate (FDA) which is metabolised by esterases to the fluorescent product, fluorescein . Esterase activity was interpreted as the mean rate of conversion of FDA to fluorescein and expressed as a percentage of the rate achieved by control algae (%FDAC) . Flow cytometry was used to measure the fluorescence of individual algal cells, enabling differentiation of three esterase activity states (low=S(1), normal and stimulated) and calculation of the percentage of algal cells in each activity state relative to that found for control algae (e.g . %S(1)) . Algal esterase activity responded rapidly to AMD-affected water but also to increased conductivity (associated with dry-land salinity) and nutrient concentrations (associated with sewage) . Exposure to AMD-affected water for 1 h reduced %FDAC by 30-70%, and increased %S(1) by 60-90%, a depression of esterase activity that was maintained over 24 h . A similar depression of esterase activity occurred in both algae exposed to comparatively high-conductivity water (ca . 20 mS cm(-1)) for 1 h but the algae recovered from this 'shock' within 24 h . The %FDAC of S . capricornutum increased from 66 to 158% of control values after a 24 h exposure to nutrient-enriched water sampled downstream from a sewage treatment plant, despite the fact that the alga was grown in nutrient-sufficient culture . The combination of cyanobacterial (M . aeruginosa) and green (S . capricornutum) algal cultures with exposure times of 1 and 24 h was successful in distinguishing between the three types of pollution . Correlation of esterase activity measures with water quality parameters indicated that the clearest and least equivocal biological measure of AMD for the study area was the %S(1) for M . aeruginosa after a 24 h exposure . The use of the flow cytometer to define a low esterase activity state was therefore successful in clarifying the response to AMD-affected water . The study demonstrates the successful application of algal esterase activity bioassays, in combination with flow cytometry, to rapidly assess the toxicity of AMD-affected waters and to differentiate this response from the effects of other pollutants (increased nutrients and conductivity). Environ Toxicol Chem, 2002 Jul, 21(7), 1456 - 61 An assessment of in vitro androgenic activity and the identification of environmental androgens in United Kingdom estuaries; Thomas KV et al.; Environmental androgens are a group of compounds that to date have received very little attention . In this study, a yeast-based androgen screen (YAS) was used to determine the level of in vitro androgenic activity in seven United Kingdom estuaries . Surface water, sediment pore water, and sediment particulate material solvent extracts collected from Southampton Water, the Thames, Mersey, Tees, Tyne, Clyde, and Forth were tested for in vitro androgenic activity . Eleven of the 41 surface water samples collected displayed androgenic activity >2 ng dihydrotestosterone (DHT) equivalents/L (3-9 ng DHT/L), while eight of the 39 sediment pore waters collected showed activity >45 ng DHT/L (51-187 ng DHT/L) . High levels of androgenic activity were determined in the solvent extracts of sediments, with 10 of 39 samples exhibiting a level of androgenic activity >454 ng DHT/kg (1,020-15,300 ng DHT/kg) . In vitro YAS testing of five selected sewage treatment works (STW) effluents entering these estuaries showed that measurable levels (34-635 ng DHT/L) of androgenic activity were observed in those receiving only primary treatment (Howdon STW and Irvine Valley Sewer) at the time of the survey . A toxicity identification evaluation (TIE) study of Irvine Valley Sewer effluent using the YAS assay was used to identify the natural steroids/steroid metabolites dehydrotestosterone, androstenedione, androstanedione, 5beta-androstane-3alpha,11beta-diol-17-one, androsterone, and epi-androsterone as responsible for 99% of the in vitro activity determined in the effluent. Environ Toxicol Chem, 2002 Jul, 21(7), 1330 - 7 Fate and effects of triclosan in activated sludge; Federle TW et al.; Triclosan (TCS; 5-chloro-2-{2,4-dichloro-phenoxy}-phenol) is a widely used antimicrobial agent . To understand its fate during sewage treatment, the biodegradation and removal of TCS were determined in activated sludge . In addition, the effects of TCS on treatment processes were assessed . Fate was determined by examining the biodegradation and removal of TCS radiolabeled with 14C in the 2,4-dichlorphenoxy ring in laboratory batch mineralization experiments and bench-top continuous activated-sludge (CAS) systems . In batch experiments with unacclimated sludge, TCS was mineralized to 14CO2, but the total yield varied as a function of test concentration . Systems that were redosed with TCS exhibited more extensive and faster mineralization, indicating that adaptation was a critical factor determining the rate and extent of biodegradation . In a CAS study in which the influent level of TCS was incrementally increased from 40 microg/L to 2,000 microg/L, removal of the parent compound exceeded 98.5% and removal of total radioactivity (parent and metabolites) exceeded 85% . Between 1.5 and 4.5% of TCS in the influent was sorbed to the wasted solids, whereas >94% underwent primary biodegradation and 81 to 92% was mineralized to CO2 or incorporated in biomass . Increasing levels of TCS in the influent had no major adverse effects on any wastewater treatment process, including chemical oxygen demand, biological oxygen demand, and ammonia removal . In a subsequent experiment, a CAS system, acclimated to TCS at 35 microg/L, received two separate 4-h shock loads of 750 microg/L TCS . Neither removal of TCS nor treatment processes exhibited major adverse effects . An additional CAS study was conducted to examine the removal of a low level (10 microg/L) of TCS . Removal of parent equaled 94.7%, and biodegradation remained the dominant removal mechanism . A subsequent series of CAS experiments examined removal at four influent concentrations (7.5, 11, 20, and 50 microg/L) of TCS and demonstrated that removal of parent ranged from 98.2 to 99.3% and was independent of concentration . Although TCS removal across all experiments appeared unrelated to influent concentration, removal was significantly correlated (r2 = 0.87) with chemical oxygen demand removal, indicating that TCS removal was related to overall treatment efficiency of specific CAS units . In conclusion, the experiments show that TCS is extensively biodegraded and removed in activated-sludge systems and is unlikely to upset sewage treatment processes at levels expected in household and manufacturing wastewaters. Sci Total Environ, 2002 Jun 20, 292(1-2), 91 - 100 Phasing out cadmium and lead--emissions and sediment loads in an urban area; Jonsson A et al.; This paper examines how fluxes in the aquatic environment reflect the reduced use of cadmium (Cd) and lead (Pb) in Stockholm, Sweden, between 1975 and 1995 . The sediment deposition of Cd and Pb in the waters around Stockholm was investigated using laminated sediment cores, which facilitated reconstructions of historical annual metal deposition to the sediments . The resulting reconstructions were compared to independent estimations of the emissions to the aquatic environment during the phase-out period . The loads of Cd and Pb from sewage treatment plants, storm water and in atmospheric deposition were studied using literature data . The data set indicates a reduced load of Cd and Pb on the aquatic surroundings of Stockholm . The reduction is, however, not as pronounced in the sediment deposition as in the calculated emissions . This indicates that emissions may be delayed on their way to the sediments or that there are other sources, e.g . resuspension of older sediments . It is therefore argued that sediment investigations are an essential component in environmental monitoring, in order to get a complete picture of the metal fluxes to and in the environment in urban areas. Proc Natl Acad Sci U S A, 2002 Aug 6, 99(16), 10494 - 9 Epub 2002 Jul 03. Estimating prokaryotic diversity and its limits; Curtis TP et al.; The absolute diversity of prokaryotes is widely held to be unknown and unknowable at any scale in any environment . However, it is not necessary to count every species in a community to estimate the number of different taxa therein . It is sufficient to estimate the area under the species abundance curve for that environment . Log-normal species abundance curves are thought to characterize communities, such as bacteria, which exhibit highly dynamic and random growth . Thus, we are able to show that the diversity of prokaryotic communities may be related to the ratio of two measurable variables: the total number of individuals in the community and the abundance of the most abundant members of that community . We assume that either the least abundant species has an abundance of 1 or Preston's canonical hypothesis is valid . Consequently, we can estimate the bacterial diversity on a small scale (oceans 160 per ml; soil 6,400-38,000 per g; sewage works 70 per ml) . We are also able to speculate about diversity at a larger scale, thus the entire bacterial diversity of the sea may be unlikely to exceed 2 x 10(6), while a ton of soil could contain 4 x 10(6) different taxa . These are preliminary estimates that may change as we gain a greater understanding of the nature of prokaryotic species abundance curves . Nevertheless, it is evident that local and global prokaryotic diversity can be understood through species abundance curves and purely experimental approaches to solving this conundrum will be fruitless. Water Res, 2002 Apr, 36(8), 1955 - 64 The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria; Guardabassi L et al.; The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria were investigated in two large-scale municipal treatment plants during a period of six months . Total and relative numbers of resistant bacteria were determined in raw sewage, treated sewage and anaerobically digested sludge by bacteriological counts on media selective for coliforms (MacConkey agar) and Acinetobacter spp . (Baumann agar) . In addition, the level of antimicrobial susceptibility was determined by the disc-diffusion method in 442 Acinetobacter isolates identified by colony hybridisation with a genus-specific DNA probe . Independent of the different antibiotics and media used, the total numbers of resistant bacteria in treated sewage were 10-1000 times lower than in raw sewage . Based on linear regression analysis of data on bacteriological counts, the prevalences of antimicrobial-resistant presumptive coliforms and Acinetobacter spp . in treated sewage and digested sludge were not significantly higher compared with raw sewage . On the contrary at one plant, statistically significant decreases were observed in the prevalence of ampicillin-resistant presumptive Acinetobacter spp . (p = 0.0188) following sewage treatment, and in the prevalence of either ampicillin-resistant presumptive Acinetobacter spp . (p = 0.0013) or ampicillin- and gentamicin-resistant presumptive coliforms (p = 0.0273 and p = 0.0186) following sludge treatment . The results obtained by bacteriological counts were confirmed by antimicrobial susceptibility testing of Acinetobacter isolates . Based on logistic regression analysis, isolates from treated sewage and digested sludge were generally not significantly more resistant compared with isolates from raw sewage . Based on these evidences, it was concluded that tertiary wastewater treatment did not result in a selection of antimicrobial resistant bacteria. J Hepatol, 2002 Jul, 37(1), 131 - 6 Polymerase chain reaction-based prevalence of hepatitis A, hepatitis E and TT viruses in sewage from an endemic area; Vaidya SR et al.; BACKGROUND/AIMS: Hepatitis A and E viruses (HAV, HEV) are transmitted enterically and are highly endemic in India . This study aims to evaluate prevalence of these and TT virus (TTV) in the sewage . METHODS: Influent and effluent samples from a sewage treatment plant from Pune, India were collected twice a week for 1 year and subjected to nested polymerase chain reaction (PCR) for the detection of HAV RNA, HEV RNA and TTV DNA . HAV and HEV PCR products were sequenced . Effluent samples were not collected for 5 months as the plant was non-functional . RESULTS: The overall prevalence was 24.42% (21/86, HAV), 10.98% (9/82, HEV) and 12.7% (8/63, TTV) . Prevalence of HAV was significantly higher than HEV (P=0.023) . During summer months, significantly higher HAV RNA positivity was noted (P<0.01) . A substantial reduction in HAV RNA positivity (15/48 vs . 2/48, P=0.0008) was recorded for treated sewage samples . However, HEV RNA or TTV DNA positivity did not reduce significantly . Of the 17 HAV and HEV RNA negative sewage samples concentrated using ultracentrifugation, 13 and none were positive for HAV and HEV RNA, respectively . Phylogenetic analyses grouped these viruses in IB and Ia, respectively, the genotypes most prevalent in India . CONCLUSIONS: Sewage may play an important role in maintaining hyper-endemicity of these infections . Sustained efforts are obligatory to render sewage less/non-infectious. Environ Sci Technol, 2002 Jun 1, 36(11), 2387 - 94 Anthropogenic Gd in surface water, drainage system, and the water supply of the city of Prague, Czech Republic; Moller P et al.; The anthropogenic Gd (Gdant) loads and fluxes of surface- and groundwaters, and of effluents from sewage treatment plants of Prague and its surroundings, have been determined . While passing Prague the Gdant load of the Vltava river increases from 4.5 to 19.2 nmol/m3, which is caused by the effluents of the central sewage treatment plant with a 6 day average of 250 nmol/m3 . The Berounka river with its enhanced content doubles the Gdant flux of the Vltava river before entering Prague . All minor creeks draining Prague add less than 3% of the Gdant load in the Vltava river downstream of Prague . The 11-days average of the amount of the administered Gd complexes of the gadopentetic acid (Gd-DTPA), gadobenic acid, and other compounds in Prague's hospitals (22 g-Gdant/d) exceeds the 6 days average of 15 g-Gdant/d in the effluent of the central sewage treatment plant . This strongly indicates uncontrolled losses of sewage from sewers to the groundwater. J Chromatogr A, 2002 Apr 5, 952(1-2), 139 - 47 Analysis of acidic drugs in the effluents of sewage treatment plants using liquid chromatography-electrospray ionization tandem mass spectrometry; Miao XS et al.; A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) method was developed and validated for simultaneous analysis of nine acidic pharmaceutical drugs (bezafibrate, clofibric acid, diclofenac, fenoprofen, gemfibrozil, ibuprofen, indomethacin, ketoprofen and naproxen) in sewage treatment plant (STP) effluents . The mean recoveries of the pharmaceuticals ranged from 58.9 to 91.5% in STP effluent, and the limits of detection of the analytes were 5-20 ng/ml . The method was applied to the quantitative analysis of acidic drugs in the effluents from three Canadian STPs, in which bezafibrate, diclofenac, fenoprofen, gemfibrozil, ibuprofen, indomethacin and naproxen were detected. Aquat Toxicol, 2002 Jul, 58(1-2), 75 - 98 Antioxidant enzymes and peroxisome proliferation in relation to contaminant body burdens of PAHs and PCBs in bivalve molluscs, crabs and fish from the Urdaibai and Plentzia estuaries (Bay of Biscay); Orbea A et al.; With the aim of studying levels of antioxidant and peroxisomal enzymes and the structure of peroxisomes in relation to body burdens of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), mussels Mytilus galloprovincialis, oysters Crassostrea sp., crabs Carcinus maenas and mullets Mugil cephalus were sampled in two Basque estuaries (Bay of Biscay): Urdaibai (Laida, Txatxarramendi, Arteaga, and downstream a sewage treatment plant-STP) and Plentzia . In general, animals showed higher concentrations of contaminants in winter than in summer and no relevant differences were detected among locations . Conversely, antioxidant enzyme activities were higher in summer . Enzyme expression was studied in mullets using immunochemical methods . By immunoblotting season-dependent differences were detected for Mn-superoxide dismutase (Mn-SOD) . As for the immunohistochemical staining, mullets sampled in summer in Plentzia showed significantly higher optical densities for acyl-CoA oxidase and lower for both Cu,Zn-SOD and Mn-SOD than those collected downstream a STP as well as higher catalase immunostaining than those collected in winter . Peroxisomal volume density (V(vp)) of mussels sampled in Laida and Txatxarramendi did not show seasonal variations, while for oysters collected in Laida and Arteaga V(vp) was higher in summer . Crab and mullet V(vp) were also higher in summer . In conclusion, the estuaries of Urdaibai and Plentzia can be considered as low to moderately polluted areas and levels of PAHs and PCBs do not show marked variations apart from seasonal variations . Animals can be adapted to low pollution conditions and, under these circumstances, seasonal factors might affect biomarker responses to a greater extent than pollution variations. Chemosphere, 2002 May, 47(6), 655 - 65 Environmental risk assessment of phosphonates, used in domestic laundry and cleaning agents in The Netherlands; Jaworska J et al.; In the long-term cooperative project Voluntary Plan of Action (1990) between the Dutch Soap and Detergent Association (NVZ) and the Dutch Ministry of Housing, Spatial Planning and the Environment (VROM) environmental risk assessments of several main components of laundry cleaning formulations were completed . As a part of that project the environmental risk assessment of HEDP, ATMP, EDTMP and DTPMP phosphonates used in detergent applications has been carried out according to the EU Technical Guidance Document for Environmental Risk Assessment for New and Existing Chemicals . All PEC/PNEC ratios were well below 1 . Results of this assessment based on the total industry volumes from 1995 and 1998 indicate that the environmental risk of these phosphonates is low in The Netherlands with properly functioning sewage treatment plants. Ann Ist Super Sanita, 2001, 37(4), 615 - 25 {Alkylphenols: assessment of risks for aquatic ecosystems and for human health with particular reference to endocrine effects}; Ferrara F et al.; (Alkylphenols: evaluation of the risk to aquatic ecosystems and human health with reference to endocrine effects).--Endocrine disrupting chemicals (EDC) are a heterogeneous group of substances that can interfere with many endocrine functions . Their effects have been demonstrated in different taxa and they are suspected to affect human health . Alkylphenols are an important group of EDC . They are formed from the degradation of alkylphenol polyethoxylates in the environment or in the sewage treatment plants . They are generally characterized by a high bioconcentration factor (BCF) and accumulate both in sediments and aquatic species . Alkylphenols (APE) show estrogenic activity: studies on fish and rodents put into evidence on both reproductive and developmental effects . In a recent study, the levels of APE detected in seafood from the Adriatic Sea showed a no negligible human health risk for strong fish consumers. Water Res, 2002 Apr, 36(7), 1834 - 42 Potential phosphorus recovery by struvite formation; Jaffer Y et al.; Formation of struvite (MgNH4PO4 x 6H2O) at sewage treatment works can cause operational problems and decrease efficiency . Struvite has a commercial value and the controlled formation and recovery of it would be beneficial . A mass balance was conducted at full scale across the whole sewage treatment plant in order to identify a stream to conduct bench-scale struvite crystallisation studies . The most suitable stream was identified as the centrifuge liquors . The average flow of the liquor stream was 393 m3 d(-1) and the composition was as follows: 167 mg L(-1) phosphorus, 44 mg L(-1) magnesium, 615 mg L(-1) ammonium, 56 mg L(-1) calcium and 2580 mg L(-1) of alkalinity . The pH averaged at 7.6 and the stream had a predicted struvite precipitation potential of 140 mg L(-1) . Struvite crystallisation occurred quickly during the trials, by raising the pH of the centrifuge liquors to 9.0 and dosing with magnesium . Up to 97% phosphorus removal as struvite was achieved . Struvite formation occurred when the molar ratio of magnesium:phosphorus was at least 1.05:1 . Below this ratio phosphorus removals of 72% were observed, but not exclusively as struvite . Annual yields of struvite were calculated to be 42-100 tonnes a year, depending on the dose regime . Revenue from the sale of produced struvite could be between Pound Sterling8400 and Pound Sterling20,000 a year. Appl Environ Microbiol, 2002 Jun, 68(6), 2838 - 42 High prevalence of vancomycin-resistant enterococci in Swedish sewage; Iversen A et al.; In Europe the use of the growth promoter avoparcin is considered to have selected for vancomycin-resistant enterococci (VRE) . Sweden ceased using avoparcin in 1986, and only occasional cases of VRE from hospitals have been reported since 1995 . Within the framework of a European study, samples from urban raw sewage, treated sewage, surface water, and hospital sewage in Sweden (n = 118) were screened for VRE . Surprisingly, VRE were isolated from 21 of 35 untreated sewage samples (60%), from 5 of 14 hospital sewage samples (36%), from 6 of 32 treated sewage samples (19%), and from 1 of 37 surface water samples . Thirty-five isolates from 33 samples were further characterized by geno- and phenotyping, MIC determination, and PCR analysis . Most isolates (30 of 35) carried the vanA gene, and the majority (24 of 35) of the isolates were Enterococcus faecium . Most of the VRE were multiresistant . The typing revealed high diversity of the isolates . However, one major cluster with seven identical or similar isolates was found . These isolates came from three different sewage treatment plants and were collected at different occasions during 1 year . All VRE from hospital sewage originated from one of the two hospitals studied . That hospital also had vancomycin consumption that was 10-fold that of the other . We conclude that VRE were commonly found in sewage samples in Sweden . The origin might be both healthy individuals and individuals in hospitals . Possibly, antimicrobial drugs or chemicals released into the sewage system may sustain VRE in the system. FEMS Microbiol Lett, 2002 Apr 23, 210(1), 143 - 7 Rapid detection of human rotavirus using colorimetric nucleic acid sequence-based amplification (NASBA)-enzyme-linked immunosorbent assay in sewage treatment effluent; Jean J et al.; A colorimetric nucleic acid sequence-based amplification-enzyme-linked immunosorbent assay (NASBA-ELISA) was developed for rapid detection and identification of human rotavirus . Oligonucleotide primers targeting gene 9 encoding a serotype-specific antigen VP7 were selected and used for the amplification of viral RNA by the isothermal NASBA process, resulting in the accumulation of biotinylated RNA amplicons . Amplicons were hybridized with a specific amino-linked oligonucleotide probe covalently immobilized on microtiter plates . The DNA-RNA hybrids were colorimetrically detected by the addition of streptavidin-peroxidase conjugate and tetramethylbenzidine substrate . Using the NASBA-ELISA system, as little as 0.2 PFU (4 x 10(1) PFU ml(-1)) and 15 PFU (3 x 10(3) PFU ml(-1)) of rotavirus were detected within 6 h in spiked MQ water and sewage treatment effluent respectively . No interference was encountered in the amplification and detection of rotavirus in the presence of non-target RNA or DNA . Moreover, the presence of non-target bacteria and virus does not generate any non-specific signal, confirming the specificity of the developed NASBA-ELISA system and its effectiveness in specifically detecting rotavirus . The NASBA-ELISA system offers several advantages in terms of sensitivity, rapidity and simplicity . This technique should be readily adaptable for detection of other RNA viruses in both foods and clinical samples. Chemosphere, 2002 Feb, 46(5), 729 - 35 Potential role of fire retardant-treated polyurethane foam as a source of brominated diphenyl ethers to the US environment; Hale RC et al.; Five tetra- to hexabrominated diphenyl ether (BDE) congeners (BDE-47, -99, -100, -153 and -154) are the most frequently reported in wildlife and humans . The commercial penta-BDE product, used predominantly to flame-retard polyurethane foam, consists primarily of these same congeners . In 1999, North American demand accounted for 98% of the total global penta-market of 8500 metric tons . Frogs, housed with flame retardant-treated polyurethane foam as a dry substrate, accumulated 10,100 microg/kg (wet weight) of the above BDEs . Crickets kept therein as food contained 14,400 microg/kg . The crickets are believed to have browsed directly on the foam and, in turn, were consumed by the frogs . BDE congener composition in all three matrices matched that of the penta-commercial product . Similar congeners were also observed in soil and stream sediments collected near a polyurethane foam manufacturing plant . Summed concentrations of BDE-47, -99 and -100, the dominant congeners observed in these samples, ranged from < 1 to 132 microg/kg (dry weight basis) . Sunfish fillets obtained from a nearby, off-site pond contained a total of 624 microg/kg (lipid basis) . Sewage treatment plant (STP) sludge exhibited these same congeners at 1370 microg/kg (dry weight) . BDE-209, the fully brominated congener predominant in the commercial deca-BDE product, was also present at 1470 microg/kg . While no known polyurethane foam manufacturers discharged to this plant, the distribution pattern of the low brominated congeners in the sludge matched that of the penta-product . After four weeks of exposure to ambient outdoor conditions, the surface of flame-retarded polyurethane foam became brittle and began to disintegrate . Subsequent dispersal of these penta-containing foam fragments may be one mechanism by which these BDEs reach the environment. Water Res, 2002 Mar, 36(6), 1429 - 38 Occurrence of phthalates and bisphenol A and F in the environment; Fromme H et al.; Certain xenoestrogens, namely bisphenol A (BPA), bisphenol F (BPF), butylbenzyl phthalate (BBP), dibutyl phthalate (DBP), and di(2-ethylhexyl)phthalate (DEHP), were measured in various compartments (surface water, sediments, sewage treatment plant effluents, sewage sludge, dump water, liquid manure) in order to contribute to a better understanding of exposure to these compounds in different environments . Hundred and sixteen surface-water samples and 35 sediments from rivers, lakes and channels, 39 sewage effluents, and 38 sewage sludges were collected in Germany . Furthermore, ten liquid manure, two waste-dump and two compost-runoff water samples were also analysed . BPA measurements showed low concentrations from 0.0005 to 0.41 microg L(-1) in surface water, in sewage effluents from 0.018 to 0.702 microg L(-1), in sediments from 0.01 to 0.19 mgkg(-1) and in sewage sludge from 0.004 to 1.363mgkg(-1) dw . Measured concentrations of BPF were clearly lower than BPA in all environmental media . DEHP dominated the phthalate concentrations, which ranged from 0.33 to 97.8 microg L(-1) (surface water), 1.74 to 182 microg L(-1) (sewage effluents), 27.9 to 154 mgkg(-1) dw (sewage sludge) and 0.21 to 8.44 mgkg(-1) (sediment) . DBP was found only in minor concentrations and BBP, only in a few samples in low amounts . Very high concentrations of BPA and phthalates were confirmed in waste dump water and compost water samples as well as in the liquid manure samples. Chemosphere, 2002 Apr, 47(1), 71 - 80 Effect of 17beta-estradiol on the reproduction of Japanese medaka (Oryzias latipes); Kang IJ et al.; Estrogenic compounds such as 17beta-estradiol (E2) and its analogs are present in the aquatic environment and can adversely affect the reproductive systems of aquatic organisms . Although E2 has been detected at a maximum concentration of 64 ng/l in effluents of sewage treatment works (STWs), few reports address the associated effects on reproduction in fish . Therefore, we exposed adult medaka (Oryzias latipes) to mean measured E2 concentrations of 29.3, 55.7, 116, 227, and 463 ng/l for 21 d and assessed the effects on the egg number and fertility of paired medaka during the exposure period . In addition, we determined the hepatic vitellogenin (Vtg) concentration and histologically assessed the gonads of these fish . The number of egg produced and fertility of the paired medaka exposed to 463 ng/l E2 were significantly less compared with those of the control fish . Males in all treatment groups had developed testis-ova . Males treated with E2 concentrations = 55.7 ng/l contained relating great concentrations of hepatic Vtg . Therefore, although only the greatest E2 concentration tested in our study affected fecundity and fertility, effects of E2 were observed on induction of Vtg and testis-ova in male medaka exposed to environmentally relevant concentrations of E2. Chemosphere, 2002 May, 47(5), 499 - 505 Measured variation in boron loads reaching European sewage treatment works; Fox KK et al.; Per capita boron loads reaching 48 sewage treatment works (STWs) in The Netherlands, Germany, Italy, and the UK have been determined from monitoring data . These have been compared with the per capita input predicted from boron in detergents, as determined from detergent product sales data . The resulting distribution of the ratios of measured boron to boron predicted from consumer usage has a 90th percentile of less than 1.5 . Boron has previously been shown to be a good marker for substances contained in detergent products, as it cannot be biodegraded and is not substantially adsorbed in the sewer, and there is little or no removal during sewage treatment processes . The monitoring information on the distribution of boron loads found at the different STWs should thus be indicative of the distribution of other substances released to the environment by detergent products, as specified by the relevant industrial category (IC 5-personal/domestic) in the Technical Guidance Documents . Variation in detergent product consumption figures from 18 European countries is also low, with the country with the highest per capita detergent consumption having only 1.3 times the European average detergent use . Thus the present practice of determining a "reasonable worst case" by multiplying the average per capita consumption by a factor of four to account for geographic differences in distribution, is considered to be inappropriate . This should be replaced by a factor of less than two, which combines within country and between country variations to provide a reasonable worst case approximation of the load reaching the sewage treatment facility. Arch Environ Contam Toxicol, 2002 May, 42(4), 447 - 53 Synthetic musks in the environment . Part 2: Enantioselective transformation of the polycyclic musk fragrances HHCB, AHTN, AHDI, and ATII in freshwater fish; Gatermann R et al.; A method for the enantioselective separation of the chiral polycyclic musks HHCB, AHTN, AHDI, and ATII is presented . Eighteen fish samples (rudd, tench, crucian carp, eel) and one pooled zebra mussel sample from the pond of a municipal sewage treatment plant were investigated with regard to their concentrations and the enantiomeric ratios (ERs) of polycyclic musks . In addition, three water samples taken at the effluent of the sewage plant, as well as two water samples and two series of semipermeable membrane devices (SPMDs) consisting of six samples each from the pond were included in the present study . This comprehensive data set allowed a reliable evaluation of species-dependent metabolization processes . The pattern of the polycyclic musks in the chromatograms obtained by enantioselective gas chromatography seems to be typical of each species, like a fingerprint . The highest deviations from the racemic ER were found for trans-HHCB and trans-ATII in crucian carp with values of or below 0.1 . Calculations showed that enantioselective transformation seems to be the most important process, resulting in the observed lower concentrations in crucian carp compared to tench . Consequences for a risk assessment are discussed. Arch Environ Contam Toxicol, 2002 May, 42(4), 437 - 46 Synthetic musks in the environment . Part 1: Species-dependent bioaccumulation of polycyclic and nitro musk fragrances in freshwater fish and mussels; Gatermann R et al.; Bioaccumulation of polycyclic musks (HHCB, AHTN) and nitro musks (musk xylene, musk ketone, and their amino metabolites) in aquatic biota was investigated by analyzing 18 fish samples (rudd, tench, crucian carp, eel) and 1 pooled zebra mussel sample from the pond of a municipal sewage treatment plant . Furthermore, water samples taken at the effluent of the sewage plant as well as water samples and two series of semipermeable membrane devices (SPMDs) from the pond were included . This comprehensive data set allowed the determination of species-dependent bioaccumulation factors on a lipid basis (BAF(L)), e.g., for HHCB the BAF(L) in tench were more than 20 times higher than in eel . The BAF(L) for HHCB and AHTN in biota were lower than the partition coefficients K(SPMD/W) obtained from SPMD samples, which are assumed to represent model bioconcentration values . This stresses that metabolism of these compounds in fish must not be neglected. Arch Environ Contam Toxicol, 2002 May, 42(4), 405 - 9 Mouthpart deformities and nucleolus activity in field-collected Chironomus riparius larvae; Meregalli G et al.; Chironomid mouthpart deformities and aberrations of their polytenic chromosomes are sublethal responses to toxic stress . These endpoints have been used in several cases as bioindications for sediment pollution . In the present study we aimed to establish whether there was an association between mouthpart deformities and nucleolus activity in the polytenic chromosomes . Such information could be useful to gain insight into the mechanisms involved in the occurrence of mouthpart deformities and their consequences on the larvae . Third-instar larvae of Chironomus riparius were collected at a site downstream of a sewage treatment plant mostly contaminated by pesticides . Larvae were then raised in the laboratory in aquaria containing sediment and water from the study location . During a 16-day period, larvae ready to molt to the fourth instar were reared individually . Within a few hours of their molt, the larvae were preserved . The presence of mouthpart deformities (mentum, mandibles, and pecten epipharyngis) and the percentage of active nucleoli were assessed . Those larvae presenting mentum deformities had a significantly higher incidence of active nucleoli in their polytenic chromosomes than nondeformed larvae . Because a high number of active nucleoli generally indicates increased rRNA synthesis, deformed larvae seemed to exhibit a higher protein synthesis than normal individuals . The synthesis of additional proteins may increase deformed larva tolerance to toxicants. Ying Yong Sheng Tai Xue Bao, 2002 Feb, 13(2), 159 - 62 {Artifical improvement of soil fertility in a regraded forest ecosystem by using municipal sewage sludge}; Li G et al.; The increasing occurrence of forest ecosystem degradation is a serious problem in tropical and subtropical regions . Field experiments showed that the application of sludge from a sewage treatment plant could not only promote the growth and reproduction of trees, including the increase in the height and diameter of trees and thus being advantageous to the growth of shrub and herb of trees, but also improve soil fertility such as increasing soil organic matter and available nitrogen and phosphorus . The test of residual heavy metals of soil indicated that the application of sludge increased the content of Pb in the soil and the increment of Pb was varied with the increase of sludge usage . There was no significant increase in other heavy metals. Water Sci Technol, 2002, 45(6), 177 - 86 Experience and extensions to the ASM2 family of models; Dudley J et al.; The development of ASM2 has created a complex model for biological phosphorus removal . Most of the published work on calibrating this model has focused on the design of experiments to maximise information with which to calibrate the model, or the use of hourly data collected around and within an aeration tank . But many sewage works do not collect such data, nor have such instrumentation . The application of ASM2 with sparse data collected at a low frequency, and mostly only input-output, is considered in this paper, based on data collected at a Swedish sewage works . This paper shows that ASM2 can be calibrated with such measurements . This paper also looks at a modification to ASM2d to better handle heterotrophic usage of volatile fatty acids, and the use of this model to study the effects of large increases in in-sewer storage on sewage treatment works . Concern about the generation of large quantities of VFAs, and their effect on the sewage treatment processes, was unfounded. Toxicol Lett, 2002 May 10, 131(1-2), 137 - 43 Environmental risk assessment for new human pharmaceuticals in the European Union according to the draft guideline/discussion paper of January 2001; Straub JO; Since 1993, an environmental risk assessment (ERA) for a new drug application has been stipulated by EU Directive 93/39/EEC amending Directive 65/65/EEC . In early 2001, after several unpublished draft versions for an ERA guideline, a draft guideline/discussion paper for an ERA for non-GMO-containing drugs was published by the European Medicines Evaluation Agency (EMEA) . The draft guideline describes a step-wise, tiered procedure for the ERA . The first tier consists of deriving a crude predicted environmental concentration (PEC) in the aquatic compartment for the active pharmaceutical ingredient (API) or its major metabolites, based on predicted amounts used and specific removal rates in sewage treatment or surface waters . If this crude PEC is <0.01 microg/l and no environmental concerns are apparent, no further assessment is deemed necessary . Else, in the second tier, a crude predicted no-effect level (PNEC) for the aquatic compartment is to be extrapolated by dividing the lowest 50%-effect concentration from acute ecotoxicity tests with algae, daphnia or fish (EC(50), LC(50)) by an assessment factor (usually 1000) . If the ratio PEC/PNEC is <1, no further assessment is deemed necessary . Lastly, in the third tier, further considerations on a case-by-case basis are needed . This may encompass refining the environmental fate information and thereby the PEC, considering further environmental compartments and their respective PECs (up to and including field studies), but also refining the PNEC . While the ERA addresses mainly the API, excipients of the formulated drug should be considered as well . In the case of medicinal products, the benefit for patients has relative precedence over environmental risks, meaning that even in the case of an unacceptable residual risk for new drugs after third-tier considerations, prohibition of a new API is not taken into consideration . Instead, possible mitigating or precautionary safety measures may consist of specific product labelling (i.e . package leaflets for the patients regarding returning and proper disposal of unused medicines), restricted use through in-hospital or in-surgery administration under supervision only, or the recommendation of environmental analytical monitoring up to ecological field studies. Toxicol Lett, 2002 May 10, 131(1-2), 51 - 63 Morphological sex reversal upon short-term exposure to endocrine modulators in juvenile fathead minnow (Pimephales promelas); Zerulla M et al.; Indications of effects on fish endocrine system have been noted when exposed to effluents of sewage treatment plants and subsequently in the receiving surface waters . For screening purposes, the concentration of vitellogenin (VTG) in plasma is employed to detect potential exposure of fish, to (anti-)estrogenic substances . However, little is known about the variability of VTG determinations and morphological endpoints (secondary sexual characteristics) in fish under exposure conditions employing compounds with hormonal activity other than estrogens . An in vivo test system was established to study the effects of methyltestosterone (MT, a potential model androgen) and fadrozole (F, an aromatase inhibitor) as well as the combination of MT and F on juvenile, sexually undifferentiated fathead minnows (Pimephales promelas) . Fish were exposed to those compounds continuously in the (nominal) microg/l range (MT, 10, 50 and 100 microg/l; F, 25, 50, 100 microg/l; MT+F, 10 microg MT per l +50 microg F per l), for 14 days (MT+F) or 21 days (MT and F) using a flow-through system . The concentration of VTG and the expression of VTG mRNA was determined using whole body homogenates in an enzyme linked immunosorbant assay (ELISA) or reverse transcription-polymerase chain reaction (RT-PCR), respectively . Exposure to MT alone led to de novo mRNA expression as well as up to a four-fold increase of VTG . F had no effect on the VTG mRNA expression and VTG protein synthesis . The combination of MT and F had no effect on VTG concentrations, however, this produced a strong masculinisation of the juvenile fish, e.g . after 13 days of exposure 100% of the fish showed typical male sex characteristics, e.g . formation of nose tubercles and pigmentation of the dorsal fin . The above findings suggest that in fish MT may be aromatised to an estrogen . F, on the other hand, inhibits testosterone aromatisation . Consequently, the combination of MT and F strongly morphologically masculinised the juvenile fathead minnows . VTG detection at the mRNA and protein level is a sensitive parameter, however, it does not provide for any information regarding the baseline "estrogenicity" of a given parent compound. Toxicol Lett, 2002 May 10, 131(1-2), 29 - 37 Concentrations of the UV filter ethylhexyl methoxycinnamate in the aquatic compartment: a comparison of modelled concentrations for Swiss surface waters with empirical monitoring data; Straub JO; UV filters in sunscreens and cosmetics protect the skin from damage through UV radiation . Many tonnes per year of UV filters are being used in Europe and will be present, at least seasonally, in detectable concentrations in surface waters similar to common pharmaceutically active substances . Predicted environmental concentrations (PECs) of ethylhexyl methoxycinnamate (EHMC; CAS 5466-77-3) were extrapolated for Switzerland, taking into consideration substance-specific environmental fate data and marketing estimates, by crude worst-case reckoning and by applying two environmental models (Mackay Level III; USES 3.0), both configured for Swiss hydrological and area data . By worst-case reckoning the summer PEC is 70.8-81.3 ng/l while for the remaining 8 months of the year the PEC is 13.1-15.1 ng/l . The Level III model results in concentrations of 2.4 ng/l during the summer and 0.44 ng/l during the rest of the year, while the USES 3.0 model gives an average PEC for the whole year of 7.6 ng/l . Pooling summer monitoring data (90 single analyses) from the River Rhine below Basel in the year 1997 (Water Protection Board of Basel) and from Lakes Zurich and Huttner in 1998 (Poiger et al., in preparation) allowed a derivation of a probabilistic median concentration of 4.6 ng/l, a 95th-percentile concentration of 18.6 ng/l and a 99th-percentile concentration of 33.5 ng/l . The 6-fold range from the median value to the maximum calls for caution in interpreting published monitoring concentrations . Comparison of modelled PECs with realistic median concentrations shows that crude reckoning overestimates actual concentrations by a factor of about 10, probably through insufficient consideration of (further) degradation of EHMC in sewage works, surface waters, sediments or river banks . Both computer models, in contrast, are within the same order of magnitude as the actual summer concentrations . Based on the available data, both these environmental fate and distribution models give realistic PECs. Toxicol Lett, 2002 May 10, 131(1-2), 5 - 17 Occurrence, fate, and removal of pharmaceutical residues in the aquatic environment: a review of recent research data; Heberer T; The occurrence and fate of pharmaceutically active compounds (PhACs) in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry . In some investigations carried out in Austria, Brazil, Canada, Croatia, England, Germany, Greece, Italy, Spain, Switzerland, The Netherlands, and the U.S., more than 80 compounds, pharmaceuticals and several drug metabolites, have been detected in the aquatic environment . Several PhACs from various prescription classes have been found at concentrations up to the microg/l-level in sewage influent and effluent samples and also in several surface waters located downstream from municipal sewage treatment plants (STPs) . The studies show that some PhACs originating from human therapy are not eliminated completely in the municipal STPs and are, thus, discharged as contaminants into the receiving waters . Under recharge conditions, polar PhACs such as clofibric acid, carbamazepine, primidone or iodinated contrast agents can leach through the subsoil and have also been detected in several groundwater samples in Germany . Positive findings of PhACs have, however, also been reported in groundwater contaminated by landfill leachates or manufacturing residues . To date, only in a few cases PhACs have also been detected at trace-levels in drinking water samples. Environ Toxicol Chem, 2002 Apr, 21(4), 729 - 36 Environmental fate and chemistry of raloxifene hydrochloride; Teeter JS et al.; Raloxifene hydrochloride is a selective estrogen receptor modulator (SERM) used for the prevention and treatment of osteoporosis in women . Excretion of raloxifene occurs through the feces of patients . Raloxifene has the potential to be discharged into waste treatment systems after therapeutic use . Raloxifene hydrochloride was investigated using a battery of studies designed to describe its physical/chemical characteristics and define its fate in the environment . The mean measured solubility of raloxifene hydrochloride (+/- standard deviation) was 345.2 +/- 15.6 microg/ml, 13.3 +/- 0.6 microg/ml, 0.9224 +/- 0.015 microg/ml, and 627.4 +/- 132.0 microg/ml in aqueous buffers at pH 5, 7, and 9 and in unbuffered water, respectively . Raloxifene exhibited a mean molar absorptivity of 34,000 and a wavelength absorbance maximum at 287 nm for pH 5 and 7 aqueous buffer solutions and 297 nm at pH 9 . Mean measured Kow values were 516 +/- 17, 1,323 +/- 91, and 1,556 +/- 135 at pH 5, 7, and 9, respectively . After 5 d at 50 degrees C, raloxifene hydrolyzed 8.02, 10.61, and 23.81% in pH 5, 7, and 9 aqueous buffers, respectively . In a 28-d hydrolysis study at 25 degrees C, the calculated first-order hydrolysis rates were 6.92 x 10(-4), 1.70 x 10(-3), and 7.66 x 10(-3)/d, and the corresponding half-lives were 1,001, 410, and 90 d in pH 5, 7, and 9 aqueous buffers, respectively . Raloxifene sorbed significantly to sewage treatment solids with Freundlich isotherm adsorption coefficients K between 2,000 and 3,000 . Raloxifene degraded rapidly in the presence of sewage solids . In a system containing 0.470 g/L sludge solids, the raloxifene biodegradation rate and half-life were 0.0966/h and 7.17 h, respectively . In a 28-d aerobic-aquatic biodegradation study containing 30 mg/L sludge solids, the raloxifene biodegradation rate and half-life were 0.0188/d and 37 d, respectively . Given the fate and behavior of raloxifene in these studies, it is anticipated that raloxifene would rapidly dissipate in the environment. Environ Sci Technol, 2002 Mar 15, 36(6), 1147 - 54 Including transformation products into the risk assessment for chemicals: the case of nonylphenol ethoxylate usage in Switzerland; Fenner K et al.; A method for applying the risk assessment approach using ratios of predicted environmental concentrations (PECs) and predicted no-effect concentrations (PNECs) to mixtures of parent compounds and their environmental transformation products is presented . Nonylphenol ethoxylates (NPnEOs) and a selection of their most relevant transformation products are investigated as a case study illustrating the method . The PEC values of NPnEO and its transformation products are calculated with a regional multimedia fate model including the transformation kinetics of the NPnEO degradation cascade . PNEC values are derived from a selection of toxicity data on NPnEO and its transformation products . The toxicity of the emerging mixture of NPnEO and its transformation products is then estimated under the assumption of concentration addition (similar mode of action) . On this basis, PEC-to-PNEC ratios for the aquatic environment and the sediment are calculated for the individual components of the mixture and the mixture itself . For this purpose, average release rates of NPnEO and its transformation products from Swiss sewage treatment plants were used . While the PEC values of the individual components do not exceed the corresponding PNEC values, the risk quotient of the mixture in water is greater than 1 . In sediment, the mixture does not exceed a risk quotient of 1 . A combination of sensitivity and scenario analyses is employed to identify the upper and lower bounds of the results. Water Sci Technol, 2002, 45(4-5), 279 - 87 Real time control of a combined UASB-activated sludge wastewater treatment configuration; Poiito-Braga CM et al.; This paper presents a combined wastewater treatment configuration composed by an Upflow Anaerobic Sludge Blanket (UASB) reactor followed by an Activated Sludge (AS) system . A control strategy has been developed for this innovative (especially for domestic sewage) treatment configuration and tested in a real pilot-scale system called STEPAA-Wastewater Treatment System by Anaerobic and Aerobic Processes . The proposed UASB-AS control strategy, including fault detection and recovery, and its successful implementation in real time is presented . This novel control strategy was developed to keep the final effluent suspended solids concentration in the range specified by the State environmental agency, in spite of incoming load disturbances . The control strategy is based on two cascaded PI (Proportional + Integral) controllers, which manipulates the recycling rate into the AS-reactor to control the effluent suspended solids concentration . A 2-dimensional nonlinear mapping (an empirical look-up table), which gives the sludge waste rate as a function of the influent flowrate and AS-reactor biomass concentration, is used to keep the AS-reactor biomass concentration in a range that guarantees a good substrate removal without inconveniences to the AS-settler operation (and consequently to the solids removal) . Experimental results are provided to demonstrate the system performance. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002 Mar, 37(3), 309 - 20 Filamentous fungi in Indah Water Konsortium (IWK) sewage treatment plant for biological treatment of domestic wastewater sludge; Fakhrul-Razi A et al.; A study was carried out to isolate and identify filamentous fungi for the treatment of domestic wastewater sludge by enhancing biodegradability, settleability and dewaterability of treated sludge using liquid state bioconversion process . A total of 70 strains of filamentous fungi were isolated from three different sources (wastewater, sewage sludge and leachate) of IWK's (Indah Water Konsortium) sewage treatment plant, Malaysia . The isolated strains were purified by conventional techniques and identified by microscopic examination . The strains isolated belonged to the genera of Penicillium, Aspergillus, Trichoderma, Spicaria and Hyaloflorae The distribution of observed isolated fungi were 41% in sewage sludge followed by 39% in wastewater and 20% in leachate . The predominant fungus was Penicillium (39 strains) . The second and third most common isolates were Aspergillus (14 strains) and Trichoderma (12 strains) . The other isolates were Spicaria (3 strains) and Hyaloflorae (2 strains) . Three strains (WWZP1003, LZP3001, LZP3005) of Penicillium (P . corylophilum, P . waksmanii, and P . citrinum respectively), 2 strains (WWZA1006 and SS2017) of Aspergillus (A . terrues and A . flavus respectively) and one strain (SSZT2008) of Trichoderma (T . harzianum) were tentatively identified up to species level and finally verified by CABI Bioscience Identification Services, UK. Appl Environ Microbiol, 2002 Apr, 68(4), 2057 - 60 Degradation of 17beta-estradiol by a gram-negative bacterium isolated from activated sludge in a sewage treatment plant in Tokyo, Japan; Fujii K et al.; A 17beta-estradiol (E2)-degrading bacterium was isolated from activated sludge in a sewage treatment plant in Tokyo, Japan . The isolate was suggested to be a new Novosphingobium species . Gas chromatography-mass spectrometry and (1)H nuclear magnetic resonance analyses of the metabolites of E2 degradation suggested that no toxic products accumulated in the culture medium. Environ Pollut, 2002, 117(2), 337 - 45 The spatial variability of nitrogen and phosphorus concentration in a sand aquifer influenced by onsite sewage treatment and disposal systems: a case study on St . George Island, Florida; Corbet DR et al.; Groundwater from a shallow freshwater lens on St . George Island, a barrier island located in the Panhandle of Florida, eventually discharges into Apalachicola Bay or the Gulf of Mexico . Nutrient concentrations in groundwaters were monitored downfield from three onsite sewage treatment and disposal systems (OSTDS) on the island . Estimates of natural groundwater nutrient concentrations were obtained from an adjacent uninhabited island . Silicate, which was significantly higher in the imported drinking water relative to the surficial aquifer on St . George Island (12.2+/-1.9 mg Si l(-1) and 2.9+/-0.2 mg Si l(-1), respectively), was used as a natural conservative tracer . Our observations showed that nitrogen concentrations were attenuated to a greater extent than that of phosphorus relative to the conservative tracer . At the current setback distance (23 m), both nitrogen and phosphate concentrations are still elevated above natural levels by as much as 2 and 7 times, respectively . Increasing the setback distance to 50 m and raising the drainfields 1 m above the ground surface could reduce nutrient levels to natural concentrations (1.1+/-0.1 mg N l(-1), 0.20+/-0.02 mg P l(-1)). Water Sci Technol, 2002, 45(3), 125 - 9 A practical application of integrated urban pollution modelling in Flanders (Belgium): the catchment of Tielt; Van Assel J et al.; In view of a European Innovation Project (DG XIII) on the application of the Urban Pollution Management (UPM) procedure, a European consortium was set up to carry out pilot studies in Belgium, France, Ireland, Italy and Portugal . On the Belgian pilot catchment of Tielt the impact from sewer system and sewage treatment plant (STP) on the receiving water courses was studied for both the existing situation and for a number of possible improvement schemes, using the Intermittent Standards, described in the UPM procedure . The integrated modelling revealed some interesting conclusions on the relative impact of the schemes considered. J Environ Sci (China), 2002 Jan, 14(1), 27 - 33 Greenhouse gas emissions from a constructed wetland for municipal sewage treatment; Tai PD et al.; The fluxes of greenhouse gases (methane and nitrous oxide) emission from a constructed wetland in the Eastern China as municipal sewage treatment were measured from June 1999 to August 2000 by the closed chamber method . The constructed wetland for municipal sewage treatment is a significant source of methane, up to 976.6 x 10(6) g CH4/a, which was emitted from the constructed wetland with the area of 495,000 m2 and wastewater loading rate of 12,000 m3/d . Its daily mean methane flux reached 5.22 g CH4/(m2.d), 250 times as much as that in natural wetland in the same latitude region . 227.8 mg CH4 was produced from the treatment of 1 liter wastewater, up to 700-1000 times as much as that in the secondary treatment . The emission of nitrous oxide from the constructed wetland is not higher than that from secondary treatment of wastewater, only 0.07 mg N2O/L. Environ Toxicol Chem, 2002 Mar, 21(3), 515 - 9 Reduction in the estrogenic activity of a treated sewage effluent discharge to an English river as a result of a decrease in the concentration of industrially derived surfactants; Sheahan DA et al.; As a result of the introduction of tighter discharge limits and effluent treatment processes at source, the concentration of alkylphenol ethoxylates and nonylphenol present in the final effluent discharge from a sewage treatment works that treats trade effluent from the textiles industry was reduced . The estrogenic effects of the final effluent discharge to the Aire River were compared over a four-year period during which various treatment measures were introduced . Male rainbow trout exposed to the effluent on four occasions in consecutive years (1994-1997) showed a reduction in the level of induced vitellogenesis between 1994 and 1997 . A marked decrease in gonadosomatic index (GSI) and increase in heptaosomatic index (HSI) was measured in fish exposed to the effluent in 1994 . In successive years, these differences diminished, and in the case of the GSI no measurable difference was observed between fish exposed to the final effluent or those in the control group in 1997 . However, an increase in HSI was still measurable in 1997 in fish exposed to the final effluent and at sites farther downstream . The reduction in the effects of the effluent paralleled the reduction in the concentration of nonylphenol as well as its mono- and diethoxylates, which have been demonstrated to produce estrogenic effects in trout exposed to these compounds in the laboratory . This study demonstrates that the setting of more restricted discharge limits for known estrogenic chemicals of industrial origin can lead to significant reductions in the estrogenic activity of the watercourses into which the effluents are discharged. Environ Toxicol Chem, 2002 Mar, 21(3), 507 - 14 Estrogenic activity measured in a sewage treatment works treating industrial inputs containing high concentrations of alkylphenolic compounds--a case study; Sheahan DA et al.; Chemical analyses were combined with a biological assay to investigate the main estrogenic chemicals as they passed through a sewage treatment works (STW) and entered a river . The STW studied was unusual in that it received wastewater from the textile trade . This wastewater was shown to contain high concentrations of alkylphenol polyethoxylates and their degradation products, such as nonylphenol . High-performance liquid chromatography fractionation, combined with biological assay, showed that the majority of the estrogenic activity was contributed by the alkylphenolic chemicals and the natural estrogens 17beta-estradiol and estrone . Despite removal of a high proportion of the alkylphenolic chemicals by the various treatment processes within the STW, concentrations in the final effluent were still high compared to most other STW effluents in the United Kingdom . The effluent was very estrogenic to caged fish, as was the river water 2 and 5 km downstream of the STW, even though less so . Using various approaches, attempts were made to determine which group of chemicals contributed most to the estrogenic activity of the effluent . The analysis suggested that, in this unusual situation, the alkylphenolic chemicals may contribute the majority of the estrogenic activity of the effluent . However, this conclusion was based on a number of uncertainties that are presently unresolved and hence can be considered only tentative. Ambio, 2001 Dec, 30(8), 458 - 66 Four decades of research on the Swedish large lakes Mälaren, Hjälmaren, Vättern and Vänern: the significance of monitoring and remedial measures for a sustainable society; Willen E; The large lakes of Sweden, Malaren, Hjalmaren, Vattern and Vanern, have been subjected to water-quality monitoring for almost four decades . Physicochemical variables, plankton and benthic invertebrates have been regularly assessed . Hydrological and sediment conditions, macrophytes, fish, primary production, bacteria and attached algae have been periodically investigated . The human impact, including industrial activities, was reflected in excessive amounts of organic matter, nutrients, metals and persistent organic compounds . From the late 1960s all municipal sewage works in the catchments of the lakes were upgraded to the highest technical standard, including chemical precipitation of phosphorus, and phosphorus discharge from the sewage works was thereby reduced by 90-95% . In addition, industries were obliged to restrict discharge of harmful substances . The reactions of the lakes to the remedial measures are discussed as well as the value of various indicators . The studies were instrumental in designing a national lake monitoring program . Additionally, results from large lake monitoring have contributed to the establishment of national water-quality criteria including, physical, chemical, and biological indicators. Huan Jing Ke Xue, 2001 Nov, 22(6), 76 - 8 {Sewage treatment by the canal reactor with biomembrane}; Zhao L et al.; This paper studies that utilizing sewage canal (waterway) of city to treat sewage on bases of researching water pollution, hydrological data and topography of the canal . A new canal reactor of bacteria membrane with continuous operation was designed, made and studied in the laboratory . The operation results of the reactor show that the reactor could effectively treat the sewage of city . The average data of continuous operation during 3 months showed that the removal ratios of CODCr and BOD5 were 88% and 95% in the range of CODCr concentration 180 mg.L(-1)-450 mg.L-1 in the inlet, separately . The technology also has the advantage of low capital cost, low operation cost . This will create the condition to apply the way to practical living sewage treatment of canal. Sci Total Environ, 2002 Jan 23, 282-283, 121 - 42 A comparison of the macrophyte cover and macroinvertebrate fauna at three sites on the River Kennet in the mid 1970s and late 1990s; Wright JF et al.; In 1974-1976, baseline studies were carried out on the flora and macroinvertebrate fauna of the R . Kennet at two sites downstream of Marlborough (Savernake Upper and Lower) and at one site upstream of Hungerford (Littlecote) . Simplified maps of each site, showing the cover of macrophytes, were obtained monthly between April 1974 and April/June 1976, and replicated quantitative samples of the macroinvertebrates were collected on the dominant macrophyte and on gravel in June 1974, and also in June and December 1975 . As a consequence of two major droughts and increasing concern over water quality in the Upper Kennet in the 1990s, the studies recommenced in the summer of 1997 using the same sites and methodologies . Maps and macroinvertebrate samples were obtained in early July and December 1997 and in June of both 1998 and 1999 . At the Savernake sites, mapping in summer 1997 confirmed what had been apparent for some years . That is, macrophyte cover (both Ranunculus and Schoenoplectus) was much lower than in the 1970s . In contrast, the site downstream at Littlecote retained a relatively high cover of Ranunculus, despite the drought . In late autumn 1997, phosphate stripping commenced at Marlborough Sewage Treatment Works, the drought ended and in addition, the spring of 1998 was unusually wet . Ranunculus recolonised both Savernake sites with remarkable speed by summer 1998 and retained this dominant position in 1999 . Quantitative samples of macroinvertebrates collected on gravel and the dominant macrophyte at each of the three study sites indicated that there was no evidence of major loss of family richness between the 1970s and 1990s as a result of the low flows or enrichment . However, at Savernake (but not Littlecote) in summer 1997, the macroinvertebrate assemblage was affected by low flows and/or enrichment . This took the form of changes in the abundance of some families, with lentic forms being favoured in relation to some lotic families . Following the end of the drought, many macroinvertebrate families at Savernake showed a rapid response to the new conditions and the assemblages reverted to those expected in a fast-flowing cretaceous chalk stream . Continued monitoring through the next drought is advisable to provide a greater understanding of the interplay between water quality, the discharge regime, habitat quality (including macrophyte growth) and the response of the macroinvertebrate fauna. J Appl Microbiol, 2001 Dec, 91(6), 1030 - 5 Simultaneous detection of Cryptosporidium parvum and Giardia in sewage sludge by IC-PCR; Rimhanen-Finne R et al.; AIMS: The aim of this study was to develop a method based on immunomagnetic capture and polymerase chain reaction (IC-PCR assay) for detection of Cryptosporidium parvum and Giardia intestinalis in sewage sludge . METHODS AND RESULTS: The detection limit of the IC-PCR assay for both organisms was 625 oocysts and cysts ml(-1) . By hybridization of PCR products the sensitivity could be increased to 125 oocysts and cysts ml(-1) . Forty-four sludge samples from 12 wastewater treatment plants were examined . The samples positive for Giardia (9 out of 44) were from eight wastewater plants and the C . parvum genotype 2 samples (3 out of 44) originated from different sewage works . CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: IC-PCR offers the possibility to distinguish between Cryptosporidium and Giardia genotypes . This assay can be used to monitor the presence of these organisms in a community and to determine contamination of sludge used as soil amendment. Water Res, 2002 Feb, 36(4), 982 - 8 Degradation of polyethoxylated nonylphenols in a sewage treatment plant . Quantitative analysis by isotopic dilution-HRGC/MS; Planas C et al.; Polyethoxylated alkylphenols (APnEO, where n is the number of ethylene oxide molecules), are non-ionic surfactants widely used for domestic and industrial purposes . Most of APnEO are polyethoxylated nonylphenols (NPnEO) . NPnEO are widespread environmental pollutants with relatively low toxicity for mammals and higher toxicity for aquatic organisms . In addition, they have been described as endocrine disrupters in recent publications . One of the main problems related to these surfactants is their uncomplete degradation, even in the most effective sewage treatment plants . Usually, the final products, more toxic and resistant to biological degradation than NPnEO, are nonylphenol (NP), monoethoxylated nonylphenol (NP1EO), diethoxylated nonylphenol (NP2EO), nonylphenoxy acetic acid (NP1EC), and nonylphenoxyethoxy acetic acid (NP2EC) . In this paper, the degradation of NPnEO was studied in the different processes of a sewage treatment plant . For this purpose, NP, NP1EO and NP2EO were analysed in composite samples collected at different points along the plant (influent, pre-treatment effluent, primary effluent, plant effluent) . Analyses were carried out by isotopic dilution-HRGC/MS, using available labelled nonylphenols (13C6-NP, 13C6-NP1EO, 13C6-NP2EO) as internal standards . Extraction of NPnEO from aqueous samples, previous to analysis, was performed by the Likens-Nickerson method (simultaneous steam distillation/solvent extraction, SDE). Water Res, 2002 Feb, 36(4), 1102 - 5 Occurrence of an anthropogenic gadolinium anomaly in river and coastal waters of southern France; Elbaz-Poulichet F et al.; This study reports a pronounced positive Gd anomaly in a small river and in the largest French Mediterranean lagoon . Along the studied catchment, this anomaly is also present in the effluents of the municipal sewage treatment plants, suggesting an anthropogenic origin for the Gd excess . The anomaly corresponds to a distinct increase of Gd concentrations (up to 19 pmol/l) in the river and around 5.4 pmol/l in the lagoon . The excess flux of Gd is compatible with the medical use of water soluble Gd complexes as contrasting agent in magnetic resonance imaging. Water Res, 2002 Feb, 36(4), 1025 - 33 Calibration of model constants in a biological reaction model for sewage treatment plants; Amano K et al.; Various biological reaction models have been proposed which estimate concentrations of soluble and insoluble components in effluent of sewage treatment plants . These models should be effective to develop a better operation system and plant design, but their formulas consist of nonlinear equations, and there are many model constants, which are not easy to calibrate . A technique has been proposed to decide the model constants by precise experiments, but it is not practical for design engineers or process operators to perform these experiments regularly . Other approaches which calibrate the model constants by mathematical techniques should be used . In this paper, the optimal regulator method of modern control theory is applied as a mathematical technique to calibrate the model constants . This method is applied in a small sewage treatment testing facility . Calibration of the model constants is examined to decrease the deviations between calculated and measured concentrations . Results show that calculated values of component concentrations approach measured values and the method is useful for actual plants. Sci Total Environ, 2002 Jan 23, 282-283, 471 - 90 Water quality functioning of lowland permeable catchments: inferences from an intensive study of the RIVER KENNEt and upper River Thames; Nea C et al.; This paper brings together information on the water quality functioning of the River Kennet and other parts of the upper River Thames in the south east of England . The Kennet represents a groundwater fed riverine environment impacted by agricultural and sewage sources of nutrient pollution . Descriptions of the general water quality of the area, nutrient sources, sinks and within river processes are provided together with biological responses to driving issues of agriculture, sewage treatment and climatic change . Models are developed and applied to assess the key processes involved for a highly dynamic system and to provide initial estimates of the likely responses to environmental change . Furthermore, the economic aspects of pollution control are reviewed, together with legislation issues, which are presented within the context of a landmark case known as the 'Axford Inquiry', the implications of which extend to regional and national dimensions . The paper concludes with a discussion on the present state of knowledge, key issues and future research on the science and management of groundwater fed nutrient impacted riverine systems. Sci Total Environ, 2002 Jan 23, 282-283, 395 - 415 On modelling the impacts of phosphorus stripping at sewage works on in-stream phosphorus and macrophyte/epiphyte dynamics: a case study for the River Kennet; Wade AJ et al.; A new model of in-stream phosphorus and macrophyte dynamics, 'The Kennet model', was applied to a reach of the River Kennet, southern England . The reach, which is 1.5 km long, is immediately downstream of Marlborough sewage treatment works, where phosphorus reduction by tertiary effluent treatment began in September 1997 . The model is used to simulate the flow, water chemistry and macrophyte biomass within the reach, both before and after phosphorus removal from the effluent . Monte Carlo experiments coupled with a general sensitivity analysis indicate that the model offers a feasible explanation for the salient aspects of the system behaviour . Model simulations indicate that epiphyte smothering is an important limitation to macrophyte growth, and that higher stream and pore water soluble reactive phosphorus (SRP) concentrations allow the earlier onset of growth for the epiphytes and macrophytes, respectively . Higher flow conditions are shown to reduce the simulated peak epiphyte biomass; though at present, the effect of flow on the macrophyte biomass is unclear . Another simulation result suggests that phosphorus will not be released from the bed sediments in this reach following phosphorus removal from the effluent. Sci Total Environ, 2002 Jan 23, 282-283, 375 - 93 On modelling the flow controls on macrophyte and epiphyte dynamics in a lowland permeable catchment: the River Kennet, southern England; Wade AJ et al.; A new in-stream model of phosphorus (P) and macrophyte dynamics, the Kennet Model, was applied to a reach of the River Kennet to investigate the impacts of changing flow conditions on macrophyte growth . The investigation was based on the assessment of two flow change scenarios, which both included the simulation of decreasing total phosphorus concentrations from a sewage treatment works due to improved effluent treatment . In the first scenario, the precipitation and potential evaporation outputs from a climate change model (HadCM2 GGx) where input into the catchment model INCA to predict the mean daily flows in the reach . In the second scenario, the mean daily flows observed in a historically dry year were repeated as input to the in-stream model to simulate an extended low flow period over 2 years . The simulation results suggest that changes in the seasonal distribution of flow were not detrimental to macrophyte growth . However, the simulation of extended periods of low flow suggests that a proliferation of epiphytic algae occurs, even when the in-stream phosphorus concentrations are reduced due to effluent treatment . This epiphytic growth was predicted to reduce the macrophyte peak biomass within the reach by approximately 80% . Thus, the model simulations suggest that flow was more important in controlling the macrophyte biomass in the River Kennet, than the in-stream phosphorus concentrations, which are elevated due to agricultural diffuse sources. Sci Total Environ, 2002 Jan 23, 282-283, 295 - 310 Phosphorus-calcium carbonate saturation relationships in a lowland chalk river impacted by sewage inputs and phosphorus remediation: an assessment of phosphorus self-cleansing mechanisms in natural waters; Neal C et al.; The relationship between calcium carbonate saturation and phosphorus concentrations for seven sites on the upper reaches of the River Kennet are examined . The findings are related to issues of groundwater supplies and the introduction of phosphorus treatment of effluent from the Marlborough sewage treatment works (STW) at part of the way along the study reach . Being supplied from a Cretaceous Chalk aquifer, the Kennet is mainly of a calcium-bicarbonate type and has a relatively constant composition of many major water quality determinands . Typically, the waters average a pH of approximately eight (range approx . 7.5-8.5) during the day with the lowest values occurring at the upstream site . Dissolved carbon dioxide varies from approximately 5 to 35 times atmospheric pressure during the late morning with the highest values occurring at the upstream site . However, in-stream biological activity gives rise to marked diurnal fluctuations in pH and dissolved carbon dioxide concentrations and during the summer months, by mid to late afternoon, pH is at its maximum and dissolved carbon dioxide is at its lowest: this is shown by continuous measurements at one of the river sites . Alkalinity and calcium concentrations remain relatively constant at approximately 4,700 microEq/l (range 3,500-6,000 microEq/l) and 120 mg/l (range 85-150 mg/l), respectively, and the waters are oversaturated with respect to calcium carbonate (calcite) typically by a factor of six (range 2-25) . Along the reach, soluble reactive phosphate (SRP) increases from the first to the second site with the introduction of sewage supplies from the Marlborough STW, and then declines further downstream as sewage dilution and uptake by the river bed/aquatic plants increases . The differences in concentration decrease after phosphorus removal from Marlborough STW . Despite this change, there is no clear indication of any calcite solubility control except perhaps at times of extreme baseflow during the growing season when within-stream photosynthesis is maximal and within-stream residence times are longer . A comparison of river and groundwater data shows that the groundwaters have similar alkalinities and calcium concentrations . However, the groundwaters have (a) higher carbon dioxide saturations (a factor of 2-5 times the value for the river), (b) lower pHs (0.5-1.5 units), (c) lower SRP concentrations (a quarter or less of the river values) and (d) waters near calcite saturation (unlike the surface waters which are oversaturated) . The findings indicate a river system dominated by the input carbon dioxide laden groundwaters in approximate equilibrium with calcite attenuated by within-channel biological and physical processes . Within the river: (a) the waters degas carbon dioxide increasing the pH, producing oversaturated conditions; and (b) oscillating pH-dissolved carbon dioxide levels occur between day and night due to changing balances between photosynthesis and respiration . It seems that lowering the phosphorus levels have not resulted in calcite precipitation within the water column and that no significant within-stream self-cleansing mechanisms are occurring that might be predicted from theory: other components in the water such as dissolved organic carbon may inhibit calcite nucleation . However, the low SRP levels in the groundwater coupled with calcite saturation, may well indicate that phosphorous concentrations within the groundwater are regulated by such processes: the number of calcite nucleating sites are orders of magnitude higher and the calcite inhibitors may be less prevalent. Sci Total Environ, 2002 Jan 23, 282-283, 263 - 94 Patterns in nutrient concentrations and biological quality indices across the upper Thames river basin, UK; Jarvi HP et al.; This paper examines the nutrient chemistry and biological quality indices {Mean Trophic Rank (MTR) and Trophic Diatom Index (TDI)} for rivers within the upper Thames basin . The predominant sources of nitrogen within the rivers monitored were diffuse and agricultural in nature . However, phosphorus showed both diffuse and point source signals . MTR surveys undertaken both upstream and downstream of major STWs indicate that these rivers are 'at risk' of eutrophication or 'badly damaged' . MTR surveys also indicate increased trophic status downstream of STWs, whereas TDI does not indicate such a consistent pattern . Phosphorus treatment at selected major sewage treatment works in the upper Thames basin resulted in significant reductions in in-stream P concentrations and reductions in fluxes by a half to two thirds . However, the effects of P-reduction on in-stream ecology (measured as MTR and TDI) were more difficult to ascribe, owing to: (1) the high variability in river flow rates experienced since P-reduction was introduced; (2) lag effects related to P stores in river bed sediments; and (3) diffuse and smaller point source inputs upstream . The results of this study indicate that control of upstream sources of phosphorus may prove critical in improving the biological quality status of UK lowland rivers, including ecological responses to P-source controls on the major sewage treatment works downstream . Upstream sources include both diffuse (agricultural) sources and small point source inputs which, at present, are not classified as 'qualifying discharges' under the Urban Wastewater Treatment Directive (UWWTD) and are thus not subject to phosphorus control measures . These results are of relevance for integrated, sustainable management and protection of European freshwater resources, particularly in terms of new ecological targets for water quality management under the new Water Framework Directive. Sci Total Environ, 2002 Jan 23, 282-283, 25 - 47 Phosphorus in rivers--ecology and management; Mainston CP et al.; This paper examines the nature of the risk to riverine ecosystems from artificially enhanced loads of phosphorus, considers the key sources of phosphorus enrichment and ways of controlling them, and provides a framework for developing control strategies . The aquatic plant community is the foundation for a healthy and diverse riverine ecosystem, providing food, shelter and breeding habitats for a wide range of animal species . Phosphorus enrichment in rivers can degrade the plant community by altering the competitive balance between different aquatic plant species, including both higher plants and algae . This has consequences for the whole ecosystem . To promote healthy riverine plant communities and the wide range of animal species dependent on them, phosphorus concentrations need to be reduced to as near to background levels as possible . The risk of adverse effects declines as phosphorus concentrations approach background levels, such that any incremental reduction should be seen as a positive step towards trophic restoration . Pragmatic management targets vary between 0.02 and 0.1 mg(-1) soluble reactive phosphorus, depending on river type, with an interim target of 0.2 mg(-1) for heavily enriched rivers . Continuous point sources of phosphorus, dominated by sewage treatment works, have a highly important influence on levels of bioavailable phosphorus in the water column through the growing season . It is important to tackle point sources comprehensively so that reductions in phosphorus concentrations are maximised during this critical time of year . Diffuse sources of phosphorus, particularly from agriculture, are a major contributor to phosphorus levels in riverine sediments, where it can be utilised by benthic algae and rooted plants . This phosphorus can also be released into the water column by a variety of processes . As point sources are brought under control, the relative contribution from diffuse sources becomes increasingly important . An integrated programme of control, involving proactive action on both point and diffuse sources, will be required in most circumstances to bring phosphorus levels in the water column and sediment down to near background levels. Sci Total Environ, 2002 Jan 23, 282-283, 233 - 51 The phosphorus budget of the Thame catchment, Oxfordshire, UK: 1 . Mass balance; Cooper DM et al.; The relative magnitudes of annual diffuse and point source loads of phosphorus (P) to the River Thame were estimated from daily and monthly measurements of discharge and concentration . Existing data from gauging and monitoring sites on the river network and at point sources were supplemented by survey data at a range of spatial scales . Results showed that during low flow periods most of the P could be attributed to point sources, while at high flows the figure was less than 10% . The introduction of P stripping at Aylesbury, a major sewage treatment works in the catchment, was estimated to have reduced the annual load of P from the sewage treatment works by approximately 45 t, with a similar reduction in loss from the catchment . This gave a reduction in low flow concentrations of soluble reactive phosphorus (SRP) from 2.5 to 1.7 mg l(-1) . Concentrations of SRP in river water remain above eutrophication thresholds because of the influence of other STWs in the catchment and insufficient natural discharge to dilute this. Sci Total Environ, 2002 Jan 23, 282-283, 175 - 203 Phosphorus sources, speciation and dynamics in the lowland eutrophic River Kennet, UK; Jarvi HP et al.; This paper examines the behaviour of phosphorus (P) in a lowland chalk (Cretaceous-age) stream, the upper River Kennet in southern England, which has been subject to P remediation by tertiary treatment at the major sewage treatment works in the area . The effects of treatment are examined in relation to boron, a conservative tracer of sewage effluent and in terms of the relative contributions of soluble reactive phosphorus (SRP) loads from point and diffuse sources, and in-stream SRP loads . These results indicate a baseline reduction in in-stream SRP concentrations immediately following P-treatment of approximately 72% . Subsequent high flows result in a greater contribution of diffuse inputs and increases in SRP levels relative to the initial post-treatment period . The dynamics of SRP and particulate phosphorus (PP) are examined under a wide range of river flow conditions . Given the flashy nature of near-surface runoff in the River Kennet, sub-weekly (daily automated) sampling was used to examine the dynamics in SRP and PP concentrations in response to storm events . Simple empirical models linking weekly SRP concentrations with flow were developed . The empirical models were successfully applied to the daily data, to partition TP measurements and provide an estimate of daily SRP and PP concentrations . Mass balance studies were used to examine net gains and losses along the experimental river reach and indicate large net losses (up to 60%) during the extreme low flows and high SRP concentrations prior to P-treatment, which may be linked to extensive epiphytic growth . Phosphorus dynamics and response to P-treatment are discussed in relation to hydrological controls in permeable chalk catchments and wider implications for eutrophication management are examined. Sci Total Environ, 2002 Jan 23, 282-283, 143 - 57 Macrophyte and periphyton dynamics in a UK Cretaceous Chalk stream: the river Kennet, a tributary of the Thames; Flyn NJ et al.; An initial study to observe the seasonal trends and to determine the factors influencing macrophyte and periphyton growth patterns was undertaken on a representative reach of the River Kennet (UK) over a 2-year period (1998-2000) . Maximum average macrophyte and average periphyton dry matter biomass recorded during the growing season were 200 and 21 g m(-2), respectively . The relationships between macrophyte and periphyton percentage cover and biomass data with physico-chemical variables were investigated . Regression analysis indicated that of the parameters measured, flow, and in the case of the dominant Ranunculus spp., solar radiation, were best able to predict macrophyte biomass and cover . The periphytic biomass within the reach was low, possibly as a result of relatively high flows and low phosphorus concentrations following the introduction of effluent treatment at the sewage works immediately upstream of the reach . Periphytic biomass was poorly correlated with the physical variables measured . This indicates that biomass is regulated by complex interactions between the physical and chemical factors, such as flow, solar radiation and phosphorus concentration . These interrelationships require further investigation. Environ Toxicol Chem, 2002 Feb, 21(2), 275 - 80 Speciation of copper in sewage effluents and its toxicity to Daphnia magna; van Veen E et al.; Copper complexation capacity was determined in a range of sewage treatment works final effluents and receiving waters, upstream and downstream of the discharge point . Forty-eight-hour immobilization tests on Daphnia magna were used to assess the toxicity of copper in the effluent matrix . Complexation capacities in effluents were typically in the range 50 to 100 microg Cu/L, with higher values being found in the poorer-quality effluents with higher dissolved organic carbon (DOC) concentrations . The tolerance of Daphnia to dissolved copper concentrations was more than quadrupled in a 50% effluent matrix, with the increase in tolerance being related to complexation capacity . Ligand concentrations in effluents were found to correlate strongly with effluent DOC . No such relationship was observed in surface waters . On mixing with river water, sewage-derived ligands behaved conservatively and were relatively stable over time scales of up to 10 d. Int J Hyg Environ Health, 2001 Dec, 204(4), 231 - 8 Airborne coagulase negative staphylococci produced by a sewage treatment plant; De Luca G et al.; Since some coagulase-negative staphylococci species are involved in clinical and environmental situations, the authors carried out a study on the spread of these bacteria in the air of a sewage treatment plant . For these purposes a total of 196 samples were taken from 16 sampling stations, 11 during the day and 5 at night (only at 4 points), using the settle plate technique . Altogether 13 species of coagulase negative staphylococci were isolated: S . haemolyticus, S . xylosus and S . cohnii were particularly common . Station no . 2 (an area almost always kept closed containing the fine screens) was found to be the most contaminated . The presence of coagulase negative staphylococci was favoured by high temperatures and low humidity . No differences were found due to variations in wind speed and direction or between day and night. Water Res, 2002 Jan, 36(2), 482 - 90 Sludge population optimisation: a new dimension for the control of biological wastewater treatment systems; Yuan Z et al.; The activated sludge comprises a complex microbiological community . The structure (what types of microorganisms are present) and function (what can the organisms do and at what rates) of this community are determined by external physico-chemical features and by the influent to the sewage treatment plant . The external features we can manipulate but rarely the influent . Conventional control and operational strategies optimise activated sludge processes more as a chemical system than as a biological one . While optimising the process in a short time period, these strategies may deteriorate the long-term performance of the process due to their potentially adverse impact on the microbial properties . Through briefly reviewing the evidence available in the literature that plant design and operation affect both the structure and function of the microbial community in activated sludge, we propose to add sludge population optimisation as a new dimension to the control of biological wastewater treatment systems . We stress that optimising the microbial community structure and property should be an explicit aim for the design and operation of a treatment plant . The major limitations to sludge population optimisation revolve around inadequate microbiological data, specifically community structure, function and kinetic data . However, molecular microbiological methods that strive to provide that data are being developed rapidly . The combination of these methods with the conventional approaches for kinetic study is briefly discussed . The most pressing research questions pertaining to sludge population optimisation are outlined. Water Res, 2002 Feb, 36(3), 685 - 701 The phosphorus content of fluvial sediment in rural and industrialized river basins; Owens PN et al.; The phosphorus content of fluvial sediment (suspended sediment and the < 63 microm fraction of floodplain and channel bed sediment) has been examined in contrasting rural (moorland and agricultural) and industrialized catchments in Yorkshire, UK . The River Swale drains a rural catchment with no major urban and industrial areas, and the total phosphorus (TP) content of fluvial sediment is generally within the range 500-1,500 microg g(-1) . There is little evidence of any major downstream increase in TP content . In contrast, fluvial sediment from the industrialized catchments of the Rivers Aire and Calder exhibits both higher levels of TP content and marked downstream increases, with values of TP content ranging from < 2,000 microg g(-1) in headwater areas upstream of the main urban and industrial areas, to values > 7,000 microg g(-1) at downstream sites . These elevated levels reflect P inputs from point sources, such as sewage treatment works (STWs) and combined sewer overflows . The influence of STWs is further demonstrated by the downstream increase in the inorganic P/organic P ratio from < 2 in the headwaters to > 4 in the lower reaches . Comparison of the P content of suspended sediment with that of the <63 microm fraction of potential source materials suggests that topsoil from upland moorland/pasture and from cultivated areas, and channel bank material are likely to be the main sources of particulate P (PP) in the River Swale and in the headwaters of the Rivers Aire and Calder . In the middle and lower reaches of the Rivers Aire and Calder, inputs associated with urban and industrial land uses, such as STWs, industrial effluents and street dust, are likely to represent the dominant sources of PP . During high flow events, such urban inputs may be diluted by inputs from moorland and agricultural land in the headwaters . Consequently, for all three rivers, there are inverse relationships between the TP content of suspended sediment and both discharge and suspended sediment concentration, reflecting changes in sediment and P sources during high flow events . Spatial variations in the P contents of the < 63 microm fraction of overbank floodplain deposits and channel bed sediment evidence a similar pattern as those for suspended sediment, with relatively low levels of TP in the River Swale and elevated levels in the middle and downstream reaches of the Rivers Aire and Calder . The PP concentrations associated with floodplain and channel bed sediment are, however, lower than equivalent values for suspended sediment, and this primarily reflects the differences in the particle size composition between the three types of sediments . Rates of floodplain deposition and the amounts of fine-grained sediment stored in the river channels are relatively high, and suggest that such environments may represent important sinks for PP . Based on the sediment samples collected from the study basins, a simple four-fold classification which relates the TP content of suspended sediment to upstream land use has been established . Both the range and the absolute values of TP content tend to increase with an increase in the level of urbanization and industrialization. Chemosphere, 2002 Jan, 46(2), 225 - 33 The cytotoxic and genotoxic potential of surface water and wastewater effluents as determined by bioluminescence, umu-assays and selected biomarkers; Dizer H et al.; Two bacterial tests employing Photobacterieum phosphoreum (Microtox bioluminescence test) and Salmonella typhimurium TA 1535 pSK1002 (umu-assay) were evaluated to estimate the cytotoxic and genotoxic potential of water samples from the selected rivers in Germany as well as the primary and secondary effluents of some sewage treatment plants . Rainbow trout (Onchorynchus mykiss) were exposed to different concentrations (20-40%) of secondary effluent in the model online aquatic monitoring plant WaBoLu-Aquatox . The toxic potential of water samples from the exposure tanks was determined in two prokaryotic test systems and the biomarkers acethylcholinesterase (AChE) activity in muscle tissue and DNA unwinding assay in liver tissue of fish . Samples from the tested rivers showed no inhibition of the bioluminescence of P . phosphoreum or growth of umu-bacteria . Only primary effluent samples from the treatment plants at the Saale River inhibited the light emission or the growth of test bacteria by more than 20% . The induction ratio of umu-bacteria was in most of the river samples less than the threshold for genotoxicity (IR < 1.5) . Only some samples from the Saale River, especially at sites downstream of secondary effluents caused genotoxic responses in the umu-assay . Samples of primary effluents contained the greatest genotoxic potential up to GEUI = 6 which was not detectable in samples of secondary effluents . A concentration range 20-40% secondary effluent inhibited AChE activity in muscle tissue and significantly increased DNA fragmentation in liver tissue of rainbow trout . In contrast, no cytotoxic or genotoxic responses in the umu-assay were caused by water samples . Both bacterial methods can be successfully used to analyse the cytotoxic and genotoxic response of industrial and domestic wastewater and to estimate the effectiveness of sewage treatment units . However, because of their low sensitivity and high susceptibility, they are not reliable as a single test for the detection of cytotoxicity and genotoxicity in surface water . The application of prokaryotic tests systems with biomarkers such as AChE activity and DNA fragmentation in different tissues of test organisms seems to be a useful combination for the assessment of cytotoxic and genotoxic potential in surface water and secondary effluent. Mar Pollut Bull, 2001 Dec, 42(12), 1221 - 35 Honduras: Caribbean Coast; Harborne AR et al.; The coast of Honduras, Central America, represents the southern end of the Mesoamerican Barrier Reef System, although its marine resources are less extensive and studied than nearby Belize and Mexico . However, the coastal zone contains mainland reef formations, mangroves, wetlands, seagrass beds and extensive fringing reefs around its offshore islands, and has a key role in the economy of the country . Like most tropical areas, this complex of benthic habitats experiences limited annual variation in climatic and oceanographic conditions but seasonal and occasional conditions, particularly coral bleaching and hurricanes, are important influences . The effects of stochastic factors on the country's coral reefs were clearly demonstrated during 1998 when Honduras experienced a major hurricane and bleaching event . Any natural or anthropogenic impacts on reef health will inevitably affect other countries in Latin America, and vice versa, since the marine resources are linked via currents and the functioning of the system transcends political boundaries . Much further work on, for example, movement of larvae and transfer of pollutants is required to delineate the full extent of these links . Anthropogenic impacts, largely driven by the increasing population and proportion of people living in coastal areas, are numerous and include key factors such as agricultural run-off, over-fishing, urban and industrial pollution (particularly sewage) and infrastructure development . Many of these threats act synergistically and, for example, poor watershed management via shifting cultivation, increases sedimentation and pesticide run-off onto coral reefs, which increases stress to corals already affected by decreasing water quality and coral bleaching . Threats from agriculture and fishing are particularly significant because of the size of both industries . The desire to generate urgently required revenue within Honduras has also led to increased tourism which provides an overarching stress to marine resources since most tourists spend time in the coastal zone . Hence the last decade has seen a dramatic increase in coastal development, a greater requirement for sewage treatment and more demand for freshwater, particularly in the Bay Islands . Although coastal zone management is relatively recent in Honduras, it is gaining momentum from both large-scale initiatives, such as the Ministry of Tourism's 'Bay Islands Environmental Management Project', and national and international NGO projects . For example, a series of marine protected areas and legislative regulations have been established, but management capacity, enforcement and monitoring are limited by funding, expertise and training . Existing and future initiatives, supported by increased political will and environmental awareness of stakeholders, are vital for the long-term economic development of the country. Environ Pollut, 2002, 116(1), 65 - 74 Spatial distribution of mercury in the sediments and riparian environment of the River Yare, Norfolk, UK; Birkett JW et al.; Concentrations of total mercury (T-Hg) were determined in sediments and riparian (bankside) soils from the River Yare, Norfolk, UK to assess the current extent of contamination arising from a historical point source discharge . The results demonstrate that the spatial distribution pattern in surficial sediments and soils follows that of a distinct pollution plume with an initial increase 2-3 km downstream from the point source discharge at Whitlingham Sewage Treatment Works (STW) outfall . Average T-Hg concentrations in the surficial sediments ranged from 0.1 to 8.13 mg kg(-1); bankside soil concentrations ranged from 0.1 to 2.63 mg kg(-1) . There has been a decline in downstream background sediment concentrations of Hg over time . This is likely to be the result of burial by fresh relatively uncontaminated sediments and possibly in the lower reach as a consequence of the influence of the freshwater-saline interface occurring near Cantley . Channel morphology was also shown to be an important factor in determining the large variations of Hg concentrations between sample points within transects . The predominant source of Hg to the soils appears to be due to dredging and the deposition of sediments during flooding. Arch Environ Contam Toxicol, 2002 Feb, 42(2), 137 - 44 Glutaraldehyde in hospital wastewater; Jolibois B et al.; Glutaraldehyde (GA) solutions are widely used in hospitals to disinfect reusable fiber-optic endoscopes . These solutions are dumped after use in the aquatic environment without any particular safety precautions . Taking into account the quantity of GA consumed daily and the released water volume, the predicted hospital wastewater concentration was estimated at 0.50 mg/L . To measure the real GA concentration present in hospital wastewater, we developed an analytical technique that is simple, sensitive, and reliable . This method consists of a water sample concentration and purification by solid phase extraction and then a spectrophotometric determination . This analytical method was used for a 1-week surveillance program at Rouen University Hospital (2,600 beds) . The wastewater tested showed the presence of a concentrated peak approximately eight times higher than the predicted wastewater concentration . The environmental impact of GA release into the aquatic environment was then studied . A predicted no-effect concentration (PNEC) < 1 microg/L was calculated . In most situations the predicted environmental concentration (PEC) was found to be <0.5 microg/L taking into account the hospital wastewater dilution in its way to the sewage treatment plant and GA biodegradation . The PEC/PNEC ratio is then < 1, showing that this release are not expected to present a significant risk to the aquatic environment . However in situations of insufficient dilution or of major release, the PEC/PNEC ratio become > 1, and an environmental risk should be expected . An internal prevention program of the various hospital departments to assure GA rational use, and a release spreading would give an additional safety margin to consider GA as safe in terms of environmental risk. J Toxicol Environ Health A, 2002 Jan 11, 65(1), 1 - 142 Sources, pathways, and relative risks of contaminants in surface water and groundwater: a perspective prepared for the Walkerton inquiry; Ritter L et al.; On a global scale, pathogenic contamination of drinking water poses the most significant health risk to humans, and there have been countless numbers of disease outbreaks and poisonings throughout history resulting from exposure to untreated or poorly treated drinking water . However, significant risks to human health may also result from exposure to nonpathogenic, toxic contaminants that are often globally ubiquitous in waters from which drinking water is derived . With this latter point in mind, the objective of this commission paper is to discuss the primary sources of toxic contaminants in surface waters and groundwater, the pathways through which they move in aquatic environments, factors that affect their concentration and structure along the many transport flow paths, and the relative risks that these contaminants pose to human and environmental health . In assessing the relative risk of toxic contaminants in drinking water to humans, we have organized our discussion to follow the classical risk assessment paradigm, with emphasis placed on risk characterization . In doing so, we have focused predominantly on toxic contaminants that have had a demonstrated or potential effect on human health via exposure through drinking water . In the risk assessment process, understanding the sources and pathways for contaminants in the environment is a crucial step in addressing (and reducing) uncertainty associated with estimating the likelihood of exposure to contaminants in drinking water . More importantly, understanding the sources and pathways of contaminants strengthens our ability to quantify effects through accurate measurement and testing, or to predict the likelihood of effects based on empirical models . Understanding the sources, fate, and concentrations of chemicals in water, in conjunction with assessment of effects, not only forms the basis of risk characterization, but also provides critical information required to render decisions regarding regulatory initiatives, remediation, monitoring, and management . Our discussion is divided into two primary themes . First we discuss the major sources of contaminants from anthropogenic activities to aquatic surface and groundwater and the pathways along which these contaminants move to become incorporated into drinking water supplies . Second, we