Comparison of natural estrogen removal efficiency in the conventional activated sludge process and the oxidation ditch process

The presence of natural estrogens, 17beta-estradiol (E2), estrone (E1) and estriol (E3), as well as estrogenic activity in wastewater influents and secondary effluents were investigated in 20 full-scale wastewater treatment plants in Japan. In all of the influent samples, natural estrogens were detected at concentrations above the minimum limits of detection (0.5ng/L). The concentrations of natural estrogens detected in the effluent of oxidation ditch plants were generally lower than previously reported values. On the other hand, in the conventional activated sludge plants, increments of E1 during biological treatment were frequently observed although E2 and E3 were removed effectively in the process. The removal rates of natural estrogens or estrogenic activity show no observed statistical relationship with the solids retention time (SRT) and the hydraulic retention time (HRT). However, the plants with high SRT or HRT generally showed high and stable removal of both natural estrogens and estrogenic activity.     

Analysis and occurrence of estrogenic hormones and their glucuronides in surface water and waste water in The Netherlands

An analytical procedure was developed that enables routine analysis of four estrogenic hormones in concentrations below 1 ng/l in surface water and waste water. The recovery was 88-98% with a limit of detection of 0.1-2.4 ng/l depending on the compound and the matrix measured. This method was used to determine the occurrence of 17 beta-estradiol, 17 alpha-estradiol, estrone and 17 alpha-ethinylestradiol in the aquatic environment in The Netherlands. The data show that estrogenic hormones can be detected at low concentrations (up to 6 ng/l) at some locations in surface water. In selected effluents of waste water treatment plants estrone and 17 beta-estradiol were detected in concentrations in the ng/l range. Concentrations of 17 alpha-estradiol and the contraceptive 17 alpha-ethinylestradiol were in most of these samples below the limit of detection. Hormone glucuronides were not detected in most surface water and effluents.     

Behavior and occurrence of estrogens in municipal sewage treatment plants--I. Investigations in Germany, Canada and Brazil

The developed method enables the quantification of estrogens in sewage samples down to 1 ng/l and in river water down to 0.5 ng/l. Mean recoveries of the analytes in ground water after SPE extraction, clean-up and derivatization generally exceeded 75%. The determined R.S.D. varied from 0 to 14% at a spiking level of 0.05 microgram/l. Even in the raw influent and the final effluent from municipal STPs the mean recoveries of estrogens were mostly above 70%. Using this method the behavior and occurrence of natural estrogens and synthetic contraceptives in municipal sewage treatment plants (STP) were investigated in German and Canadian facilities. In the sewage of a German municipal STP close to Frankfurt/Main 17 beta-estradiol and estrone were determined, with mean concentrations of 0.015 microgram/l and 0.027 microgram/l, respectively. In two investigated municipal STPs, 17 beta-estradiol and 16 alpha-hydroxyestrone were eliminated with a higher efficiency than 17 alpha-ethinylestradiol and estrone. In Canadian and German STP discharges estrone, 17 beta-estradiol, 17 alpha-ethinylestradiol and 16 alpha-hydroxyestrone were frequently detected within the lower ng/l-range. A maximum concentration was found for estrone with 70 ng/l. In 15 investigated German rivers and streams only estrone was present with a maximum concentration of 1.6 ng/l.     

Rapid loss of estrogenicity of steroid estrogens by UVA photolysis and photocatalysis over an immobilised titanium dioxide catalyst

The presence of low levels of natural and synthetic steroid estrogens in the aquatic environment, and their biological effects on aquatic organisms, are presently issues of concern. In this study, we investigated the temporal removal of estrogenic activity of several potent and environmentally relevant steroid estrogens by photocatalysis over an immobilised titanium dioxide (TiO2) catalyst. We used a recombinant yeast assay to measure estrogenic activity, which provided detection limits within the reactor of 53 ng/l for 17beta-estradiol and 17alpha-ethinylestradiol, and 100 ng/l for estrone. Pseudo-first-order kinetic data showed that photocatalysis over titanium dioxide was equally effective at removing the estrogenic activity of all three steroid substrates in aqueous solutions (initial concentrations of 10 microg/l) with a 50% reduction in estrogenicity within 10 min. In control experiments without TiO2 catalyst, the rate of UVA photolysis of the steroid substrates varied, but was most effective with 17alpha-ethinylestradiol followed by estrone, and was least effective with 17beta-estradiol (0.42, 0.2 and < 0.1 times the rate achieved with photocatalysis, respectively). The application of photocatalysis for the removal of steroid compounds within STW effluent released into the aquatic environment is discussed.     

Occurrence and removal of pharmaceuticals and endocrine disruptors in South Korean surface, drinking, and waste waters

Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) was used to measure the concentrations of 14 pharmaceuticals, 6 hormones, 2 antibiotics, 3 personal care products (PCPs), and 1 flame retardant in surface waters and wastewater treatment plant effluents in South Korea. Tris (2-chloroethyl) phosphate (TCEP), iopromide, naproxen, carbamazepine, and caffeine were quite frequently observed (>80%) in both surface waters and effluents. The analytes of greatest concentration were iopromide, TCEP, sulfamethoxazole, and carbamazepine. However, the primary estrogen hormones, 17alpha-ethynylestradiol and 17beta-estradiol, were rarely detected, while estrone was detected in both surface water and wastewater effluent. The elimination of these chemicals during drinking water and wastewater treatment processes at full- and pilot-scale also was investigated. Conventional drinking water treatment methods were relatively inefficient for contaminant removal, while efficient removal (approximately equal to 99%) was achieved by granular activated carbon (GAC). In wastewater treatment processes, membrane bioreactors (MBR) showed limited target compound removal, but were effective at eliminating hormones and some pharmaceuticals (e.g., acetaminophen, ibuprofen, and caffeine). Membrane filtration processes using reverse osmosis (RO) and nanofiltration (NF) showed excellent removal (>95%) for all target analytes.     

Development of a sensitive E-screen assay for quantitative analysis of estrogenic activity in municipal sewage plant effluents

A simplified proliferation test with human estrogen receptor-positive MCF-7 breast cancer cells (E-screen assay) was optimized and validated for the sensitive quantitative determination of total estrogenic activity in effluent samples from municipal sewage plants. After solid phase extraction of 1 l sewage on either 0.2 g polystyrene copolymer (ENV+) or 1 g RP-C18 material and removal of the solvent, analysis of the extracts in the E-screen assay could be performed without any clean-up step. This was even possible with untreated sewage. Parallel extraction of four sewage samples on both different solid phase materials gave comparable quantitative results in the E-screen. A blank sample did not induce cell proliferation. As additive behaviour of the estrogenic response of single compounds was proven for two different mixtures each containing three xenoestrogens, total estrogenic activity in the sewage samples, expressed as 17 beta-estradiol equivalent concentration (EEQ), could be calculated comparing the EC50 values of the samples with those of the positive control 17 beta-estradiol. The detection limit of the E-screen method was 0.05 pmol EEQ/l (0.014 ng EEQ/l), the limit of quantification 0.25-0.5 pmol EEQ/l (0.07-0.14 ng EEQ/l). In total, extracts of nine effluent and one influent sample from five different municipal sewage plants in South Germany were analyzed in the E-screen. All samples strongly induced cell proliferation in a dose-dependent manner which was completely inhibited by coincubation with 5 nM of the estrogen receptor-antagonist ICI 182,780. The proliferative effect relative to the positive control 17 beta-estradiol (RPE) was between 30 and 101%. 17 beta-Estradiol equivalent concentrations were between 2.5 and 25 ng/l indicating a significant input of estrogenic substances via sewage treatment plants into rivers.     

Pharmaceutical chemicals and endocrine disrupters in municipal wastewater in Tokyo and their removal during activated sludge treatment

We measured six acidic analgesics or anti-inflammatories (aspirin, ibuprofen, naproxen, ketoprofen, fenoprofen, mefenamic acid), two phenolic antiseptics (thymol, triclosan), four amide pharmaceuticals (propyphenazone, crotamiton, carbamazepine, diethyltoluamide), three phenolic endocrine disrupting chemicals (nonylphenol, octylphenol, bisphenol A), and three natural estrogens (17beta-estradiol, estrone, estriol) in 24-h composite samples of influents and secondary effluents collected seasonally from five municipal sewage treatment plants in Tokyo. Aspirin was most abundant in the influent, with an average concentration of 7300 ng/L (n = 16), followed by crotamiton (921 ng/L), ibuprofen (669 ng/L), triclosan (511 ng/L), and diethyltoluamide (503 ng/L). These concentrations were 1 order of magnitude lower than those reported in the USA and Europe. This can be ascribed to lower consumption of the pharmaceuticals in Japan. Aspirin, ibuprofen, and thymol were removed efficiently during primary + secondary treatment (> 90% efficiency). On the other hand, amide-type pharmaceuticals, ketoprofen, and naproxen showed poor removal (< 50% efficiency), which is probably due to their lower hydrophobicity (logKow < 3). Because of the persistence of crotamiton during secondary treatment, crotamiton was most abundant among the target pharmaceuticals in the effluent. This is the first paper to report ubiquitous occurrence of crotamiton, a scabicide, in sewage. Because crotamiton is used worldwide and it is persistent during secondary treatment, it is a promising molecular marker of sewage and secondary effluent.     

Responses of Hexaplex (Murex) trunculus to selected pollutants

We report the results of a recent survey of the concentration of natural estrogens (17beta-estradiol, 17alpha-estradiol, estrone, estriol) and the synthetic estrogen, 17alpha-ethynylestradiol in representative animal wastes and sewage treatment plant (STP) effluents in the Waikato region of New Zealand. Dairy farm effluent samples showed high levels of estradiol (19-1360 ng/L) and its breakdown product estrone (41-3123 ng/L) compared with piggery or goat farm effluents. The combined load for these estrogens (excluding beta epimer) varied from 60 to >4000 ng/L. The piggery effluent provided the lowest total estrogen load (46 ng/L), with estrone accounting for nearly 60% of the measured estrogens in this sample. The synthetic analogue, 17alpha-ethynylestradiol was detected only in one wastewater treatment plant sample, albeit at trace level. An estrogen receptor competitive binding assay was used to test the biological activity of the samples and confirmed that most agricultural waste samples contain high levels of estrogenic compounds. The potential of these wastes to cause endocrine disruption in the receiving ecosystem is unknown at present.     

Sources of pharmaceutical pollution in the New York City Watershed

An investigation was carried out in the New York City Watershed for the presence of selected pharmaceuticals. In four seasonal sampling events between August 2003 and May 2004, surface water was collected from eight reservoir keypoints and effluent was collected from four wastewater treatment plants. We evaluated the following twelve compounds: amoxicillin, atenolol, caffeine, carbamazepine, cephalexin, estrone, 17alpha-ethinylestradiol, 17beta-estradiol, ibuprofen, sulfamethoxazole, trimethoprim, and valproic acid. In the treated effluents, carbamazepine was detected most frequently (100%; concentration range: 22-551 ng/L), followed by atenolol (94%; ND - 14,200 ng/L), trimethoprim (83%; ND - 37,000 ng/L), ibuprofen (61%; ND - 14,600 ng/L), and caffeine (49%; ND - 37,200 ng/L), while estrone was detected once (56 ng/L). In the reservoir keypoint samples, only ibuprofen (2.5%; ND - 932 ng/L) and caffeine (2.9%; ND - 177 ng/L) were detected. The other analytes were not detected in any sample. It is expected that investigation of other wastewater treatment plants in the New York City Watershed would show that their effluents are also a potential source of pharmaceuticals, but that these pharmaceuticals are unlikely to be detected in the Watershed's surface waters.     

Behavior of pharmaceuticals, cosmetics and hormones in a sewage treatment plant

Two cosmetic ingredients (galaxolide, tonalide), eight pharmaceuticals (carbamazepine, diazepam, diclofenac, ibuprofen, naproxen, roxithromycin, sulfamethoxazole and iopromide) and three hormones (estrone, 17beta-estradiol and 17alpha-ethinylestradiol) have been surveyed along the different units of a municipal Sewage Treatment Plant (STP) in Galicia, NW Spain. Among all the substances considered, significant concentrations in the influent were only found for the two musks (galaxolide and tonalide), two anti-inflammatories (ibuprofen and naproxen), two natural estrogens (estrone, 17beta-estradiol), one antibiotic (sulfamethoxazole) and the X-ray contrast medium (iopromide), where the other compounds studied were below the limit of quantification. In the primary treatment, only the fragrances (30-50%) and 17beta-estradiol (20%) were partially removed. On the other hand, the aerobic treatment (activated sludges) caused an important reduction in all compounds detected, between 35% and 75%, with the exception of iopromide, which remained in the aqueous phase. The overall removal efficiencies within the STP ranged between 70-90% for the fragrances, 40-65% for the anti-inflammatories, around 65% for 17beta-estradiol and 60% for sulfamethoxazole. However, the concentration of estrone increased along the treatment due to the partial oxidation of 17beta-estradiol in the aeration tank.     

An assessment of estrogenic organic contaminants in Canadian wastewaters

A suite of 30 primarily estrogenic organic wastewater contaminants was measured in several influent/effluent wastewater samples from four municipal wastewater treatment plants and effluents from one bleached kraft pulp mill (BKME) using an ultra-trace analytical method based on gas chromatography-high resolution mass spectroscopy (GC-HRMS). In vitro recombinant yeast assay detection of the estrogenic equivalent (EEq) on whole and solid phase extracted (SPE) and fractionated wastewater was also performed. 19-norethindrone was the most frequently detected and abundant (26-224 ng/L) of all the synthetic estrogens/progesterones in the influent samples. 17alpha-ethinylestradiol was the more frequently detected synthetic estrogen/progesterone in the effluents occurring at or below 5 ng/L with some sporadic occurrences of up to 178 ng/L. The greatest levels of steroidal estrogens in municipal effluents were E1>E2>E3 which were all <20 ng/L. Nonylphenol and di(2-ethylhexyl) phthalate were found to be the highest non-steroidal synthetic compounds surveyed in both municipal influent and effluent samples, both occurring at 6-7 microg/L in municipal effluents. BKME contained relatively large amounts of the plant sterol stigmasterol (4 microg/L) but low amounts of fecal sterols, and steroidal estrogens (E2 only at 6 ng/L) when compared to the municipal effluents. In vitro EEq in the wastewater surveyed ranged from 9-106 ng E2/L and ranked from municipal influent>municipal effluent approximately BKME, with most of the estrogenicity fractionating in the 100% methanol SPE fraction followed by a secondary amount in the diethyl ether (for municipal) or methyl-tert butyl ether (for BKME) SPE fractions. Most correlations between chemical and in vitro estrogenic equivalency were weak (p>0.05 in most cases). Unexpected inverse correlations between in vitro estrogenic activity and concentrations of the estrogenic contaminant bisphenol A were found which likely contributed to the weakness of these correlations. A modified toxicity identification and evaluation procedure was continued with the SPE extracts from the more potent 100% methanol SPE fractions of municipal effluent. High performance liquid chromatography band elution retention times, based on in vitro estrogen detection, indicated that steroidal estrogens such as E2 were responsible for most of the estrogenicity of the samples. Subsequent collection and GC-MS analysis of active bands did not confirm the presence of steroidal estrogens, but expanded the possibility of phthalate esters (i.e. dibutyl phthalate) and natural sterols (i.e. beta-sitosterol) contributing to the overall estrogenic load.     

北京污水厂进、出水中内分泌干扰物的分布

以三种酚类化合物(4-OP、4-n-NP、BPA)、五种雌激素(E1、E2、E3、17α-E2、EE2)为目标物,对其在北京市三个污水处理厂进、出水中的浓度及工艺流程中的分布、迁移进行了研究.结果表明,污水处理厂出水中浓度最高的物质是BPA、EE2,分别为(56～140)、(78～115)ng/L.BPA和天然雌激素(17α-E2除外)主要被生物降解去除,而对EE2的去除主要发生在初级处理过程,去除率约为63%.两种烷基酚在污水处理厂并不能被有效去除.与欧美国家、日本等相比,北京市污水处理厂进、出水中的内分泌干扰物浓度偏高,尤其是出水中的雌激素浓度较高,具有一定的环境风险.     

Pharmaceuticals and personal care products (PPCPs) in surface and treated waters of Louisiana,USA and Ontario,Canada

A newly developed analytical method was used to measure concentrations of nine pharmaceuticals and personal care products (PPCPs) in samples from two surface water bodies, a sewage treatment plant effluent and various stages of a drinking water treatment plant in Louisiana, USA, and from one surface water body, a drinking water treatment plant and a pilot plant in Ontario, Canada. The analytical method provides for simultaneous extraction and quantification of the following broad range of PPCPs and endocrine-disrupting chemicals: naproxen; ibuprofen; estrone; 17beta-estradiol; bisphenol A; clorophene; triclosan; fluoxetine; and clofibric acid. Naproxen was detected in Louisiana sewage treatment plant effluent at 81-106 ng/l and Louisiana and Ontario surface waters at 22-107 ng/l. Triclosan was detected in Louisiana sewage treatment plant effluent at 10-21 ng/l. Of the three surface waters sampled, clofibric acid was detected in Detroit River water at 103 ng/l, but not in Mississippi River or Lake Pontchartrain waters. None of the other target analytes were detected above their method detection limits. Based on results at various stages of treatment, conventional drinking-water treatment processes (coagulation, flocculation and sedimentation) plus continuous addition of powdered activated carbon at a dosage of 2 mg/l did not remove naproxen from Mississippi River waters. However, chlorination, ozonation and dual media filtration processes reduced the concentration of naproxen below detection in Mississippi River and Detroit River waters and reduced clofibric acid in Detroit River waters. Results of this study demonstrate that existing water treatment technologies can effectively remove certain PPCPs. In addition, our study demonstrates the importance of obtaining data on removal mechanisms and byproducts associated with PPCPs and other endocrine-disrupting chemicals in drinking water and sewage treatment processes.     

Comparing steroid estrogen, and nonylphenol content across a range of European sewage plants with different treatment and management practices

The effluent of 17 sewage treatment works (STW) across Norway, Sweden, Finland, The Netherlands, Belgium, Germany, France and Switzerland was studied for the presence of estradiol (E2), estrone (E1), ethinylestradiol (EE2) and nonylphenol (NP). Treatment processes included primary and chemical treatment only, submerged aerated filter, oxidation ditch, activated sludge (AS) and combined trickling filter with activated sludge. The effluent strength ranged between 87 and 846 L/PE (population equivalent), the total hydraulic retention time (HRT) ranged between 4 and 120 h, sludge retention time (SRT) between 3 and 30 d, and water temperature ranged from 12 to 21 °C. The highest estrogen values were detected in the effluent of the STW which only used primary treatment (13 ng/L E2 and 35 ng/L E1) and on one occasion in one of the STW using the AS system (6.5 ng/L E2, 50.5 ng/L E1, but on three other occasions the concentrations in this STW were at least a factor of 6 lower). For the 16 STW employing secondary treatment E2 was only detected in the effluent of six works during the study period (average 0.7-5.7 ng/L). E1 was detected in the effluent of 13 of the same STW. The median value for E1 for the 16 STW with secondary treatment was 3.0 ng/L. EE2 was only detected in two STW (1.1, <0.8-2.8 ng/L). NP could be detected in the effluent of all 14 STW where this measurement was attempted, with a median of 0.31 μg/L and values ranging from 0.05 to 1.31 μg/L. A comparison of removal performance for E1 was carried out following prediction of the probable influent concentration. A weak but significant (α<5%) correlation between E1 removal and HRT or SRT was observed.     

Removal of estrogenicity in Swedish municipal sewage treatment plants

The human estrogen receptor alpha-test, hosted in a yeast strain, was used to quantify estrogenicity in three-week composite samples of untreated and treated effluents from 20 Swedish municipal sewage treatment plants. The treatment plants were selected to represent different treatment processes regarding chemical precipitation and microbial procedures. The discharge from Swedish domestic sewage treatment plants contained estrogenic compounds corresponding to <0.1-15 ng estradiol equivalents/L. Low levels of estrogenic activity were also found in a river receiving municipal effluents, 3.5-35 km downstream the outlet from a sewage treatment works. The range of estrogenicity in untreated, raw sewage effluents was found to be 1-30 ng estradiol equivalents/L. Generally, wastewater treatment reduced the estrogenicity and extended biological treatment was most effective in its removal. Activated sludge treatment tended to be more effective than trickling filters, whereas chemical precipitation using iron or aluminium salts without biological treatment showed little effectivity. The study showed that treatment methods in current use are able to eliminate or largely reduce estrogenicity in domestic wastewater.     

Effect of microwave hydrolysis on transformation of steroidal hormones during anaerobic digestion of municipal sludge cake

Fate and removal of 16 steroidal (estrogenic, androgenic and progestogenic) hormones were studied during advanced anaerobic digestion of sludge cake using microwave (MW) pretreatment. Effect of pretreatment temperature (80, 120, 160 °C), operating temperature (mesophilic at 35 ± 2 °C, thermophilic at 55 ± 2 °C) and sludge retention time (SRT: 20, 10, 5 days) were studied employing eight lab-scale semi-continuously fed digesters. To determine the potential effect of MW hydrolysis, hormones were quantified in total (sorbed + soluble) and supernatant (soluble) phases of the digester influent and effluent streams. Seven of 16 hormones were above the method reporting limit (RL) in one or more of the samples. Hormone concentrations in total phase of un-pretreated (control) and pretreated digester feeds ranged in <157–2491 ng/L and <157–749 ng/L, respectively. The three studied factors were found to be statistically significant (95% confidence level) in removal of one or more hormones from soluble and/or total phase. MW hydrolysis of the influent resulted in both release (from sludge matrix) and attenuation of hormones in the soluble phase. Accumulation of estrone (E1) as well as progesterone (Pr) and androstenedione (Ad) in most of the digesters indicated possible microbial transformations among the hormones. Compared to controls, all pretreated digesters had lower total hormone concentrations in their influent streams. At 20 days SRT, highest total removal (E1+E2+Ad +Pr) was observed for the thermophilic control digester (56%), followed by pretreated mesophilic digesters at 120 °C and 160 °C with around 48% efficiency. In terms of conventional performance parameters, relative (to control) improvements of MW pretreated digesters at a 5-d SRT ranged in 98–163% and 57–121%, for volatile solids removal and methane production, respectively.     

Determination of estrogens and estrogenic activity in wastewater effluent by chemical analysis and the bioluminescent yeast assay

A scheme of bioassay-directed analysis has been developed which combines a yeast assay screening for estrogenic activity with a liquid chromatographic-mass spectrometric (LC-MS/MS) chemical analysis, chromatographic fractionation, solid phase extraction and freeze-drying. The test scheme was applied on effluent samples collected from a municipal sewage treatment plant. The aim was to determine the substances responsible for main portion of the estrogenic activity in the samples and to compare the efficiency of different procedures for isolation and concentration of estogenicity. LC-MS/MS analyses were used for the quantification of 17beta-estradiol, estrone, estriol and 17alpha-ethinylestradiol, and the measured concentrations compared with the activities found in the yeast assay. Following conversion of the concentrations measured by LC-MS/MS to 17beta-estradiol equivalents it was concluded that freeze-drying, solid phase extraction and the chemical analysis gave comparable activities. Since estrone was the major estrogen in the effluent, this estrogen was also the major contributor to the estrogenic activity in the effluent. The estrogenic activity was equivalent to 4-7 ng/L of 17beta-estradiol. The yeast assay results from the tests of the chromatographic fractions showed that the major activity resides in the fraction where estrone, 17beta-estradiol and 17alpha-ethinylestradiol eluted. The activity of this fraction was substantially higher than the activity of the original wastewater sample. The reason for this could in part be explained by an inhibition of activity occurring in the original water sample.     

The use of in vitro bioassays to quantify endocrine disrupting chemicals in municipal wastewater treatment plant effluents

In vitro bioassays are widely used to detect and quantify endocrine disrupting chemicals (EDCs) in the influents and effluents of municipal wastewater treatment plants (WWTP). These assays have sometimes led to false positive or negative results, partly due to the low EDC concentrations in the samples. The objectives of the present study were: (a) to compare the estrogen screen (E-Screen) and the yeast estrogen screen (YES) bioassays using the 17beta-estradiol (E2) or its equivalence and (b) to investigate if a combination of the E-Screen and YES assays can be used to improve the accuracy of EDC detection and quantification. The E-Screen bioassay was conducted with the MCF-7 (BOS) human breast cancer cell line while the YES bioassay employed two different types of recombinant yeast. The influent and effluent samples collected from the five WWTPs operated by the Greater Vancouver Regional District (GVRD) were analyzed by both the E-Screen and the YES bioassays. Since the results of the E-Screen and YES bioassays varied by up to 4-fold on the same split sample of a nominal E2 concentration, the mean value of the E-screen and YES bioassays was used to represent the EDC activity of a given WWTP sample. Results of these studies showed that the E2 equivalent concentration in each WWTP sample was consistently higher than 1 ng/L, a concentration that may potentially cause endocrine disruption in different aquatic species. The composition of selected EDCs in a subset of effluent samples was examined using a gas chromatograph-high resolution mass spectrometer (GC-HRMS). EDC composition in 10 WWTP samples correlated with the mean endocrine disrupting activities of the E-Screen and YES bioassays. Results also indicated that secondary treatment plants are comparable to the primary treatment plants in removing EDCs from the final effluents.     

One-year monthly monitoring of Torque teno virus (TTV) in wastewater treatment plants in Japan

Torque teno virus (TTV) is a novel hepatitis virus which is considered to be transmitted by the fecal-oral route. Wastewater samples were collected monthly from eight wastewater treatment plants in Japan for 1 year, from July 2003 to June 2004, and tested for the presence of TTV by TaqMan PCR. TTV was detected in 97% (93/96) of influent samples, implying that TTV is epidemic in Japan. TTV was also isolated in 18% (17/96) of secondary effluent samples before chlorination and in 24% (23/95) of final effluent samples after chlorination. There was no significant difference between the concentration of total coliform in TTV-positive final effluents and that in TTV-negative final effluents, which indicates that total coliform cannot be used as an indicator of TTV. No TTV was detected in 24 effluents for reuse from two wastewater treatment plants using sand filtration and ozonation.