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Treatment Plants (treatment + plant)
Kinds of Treatment Plants Selected AbstractsUsing artificial streams to assess the effects of metal-mining effluent on the life cycle of the freshwater midge (Chironomus tentans) in situENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2004Kimberly A. Hruska Abstract In 2002, we developed an in situ life-cycle bioassay with Chironomus tentans in artificial streams to evaluate the effects of a complex metal mine effluent under ambient environmental conditions. The bioassay was tested in the field using effluent from the Copper Cliff Waste Water Treatment Plant at INCO (Sudbury, ON, Canada). Chironomus tentans were exposed throughout the life cycle to 45% Copper Cliff effluent, which is the average effluent concentration measured in Junction Creek (ON, Canada), the natural receiving environment. Chironomus tentans in the effluent treatment exhibited reduced survival (p = 0.001), reduced total emergence (p = 0.001), increased time-to-emergence (p = 0.001), and reduced hatching success (p = 0.001) relative to animals in the reference water treatment. Chironomus tentans in the effluent treatment were not significantly different from the reference in terms of growth, sex ratio, number of egg cases/female, and number of eggs/egg case. This research showed how a life-cycle bioassay could be used in situ to assess metal mine effluent effects on a benthic invertebrate. [source] Olive oil mineral content of two local genotypes as influenced by recycled effluent irrigation under arid environmentJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2009Khaled M Al-Absi Abstract BACKGROUND: An alternative plan for saving scarce water could include use of non-conventional water resources such as reclaimed wastewater originating from wastewater treatment plants. The main health risks are associated with contamination of crops by wastewater due to its chemical composition. Therefore, the effect of recycled effluent irrigation was investigated on mineral composition and quality of olive oil of two local olive cultivars under field conditions during two complete cycles. RESULTS: The treated wastewater used in this study was taken from the HUIE Wastewater Treatment Plant. This water is mainly generated by textile firms, mixed with municipal domestic effluent. The analysis of the effluent indicated that element concentrations fall within the permissible range in irrigation water used for plants. The concentrations of mineral composition were relatively higher in olive oils irrigated with treated wastewater but lower than the maximum permissible concentration. Concentrations ranged from 8.91 to 26.16 mg kg,1 for Ca; 6.25,16.11 mg kg,1 for Na, 53.20,111.76 mg kg,1 for K, 0.19,0.36 mg kg,1 for Zn, 0.97,1.46 mg kg,1 for Mn and 0.07,0.13% for Cl. No statistically significant differences were found between the oil quality indices (peroxide and acidity). CONCLUSION: These results indicate that this kind of effluent is suitable for irrigation of olive genotypes grown for oil purposes. Copyright © 2009 Society of Chemical Industry [source] Clarified cashew apple juice as alternative raw material for biosurfactant production by Bacillus subtilis in a batch bioreactorBIOTECHNOLOGY JOURNAL, Issue 5 2009Maria Estela Aparecida Giro Abstract Clarified cashew apple juice was evaluated as carbon source for surfactin production by Bacillus subtilis LAMI005 isolated from the tank of chlorination at the Wastewater Treatment Plant on Campus do Pici (WWTP-PICI) in the Federal University of Ceará, Brazil. The highest surfactin concentration using clarified cashew apple juice (CCAJ) supplemented with mineral medium (MM-CCAJ) was 123 mg/L, achieved after 48 h of fermentation. Almost 2-fold less than the amount produced using mineral medium supplemented with 10 g/L of glucose and 8.7 g/L of fructose (MM-GF). However, critical micelle concentration of the biosurfactants produced using MM-CCAJ was 2.5-fold lower than the one produced using MM-GF, which indicates it is a more efficient biosurfactant. Surface tension decreased from 38.50 ± 0.0 to 29.00 ± 0.0 dyne/cm when B. subtilis was grown on MM-CCAJ media (24.68% of reduction on surface tension) and remained constant up to 72 h. Emulsification index was 51.15 and 66.70% using soybean oil and kerosene, respectively. Surfactin produced in MM-CCAJ showed an emulsifying activity of, respectively, 1.75 and 2.3 U when n-hexadecane or soybean oil was tested. However, when mineral medium supplemented with 10 g/L of glucose (MM-G) was used an emulsifying activity of 2.0 and 1.75 U, with n-hexadecane and soybean oil, respectively, was obtained. These results indicate that it is feasible to produce surfactin from CCAJ, a renewable and low-cost carbon source. [source] A simple system for biofilm potential monitoring in drinking waterJOURNAL OF BASIC MICROBIOLOGY, Issue 1 2006Eric Delahaye Dr. SAGEP-EAU DE PARIS produces drinking water for the city of Paris (France). In order to supply a high quality water, one of the main SAGEP's concerns is to monitor the Biofilm Formation Potentials of the produced drinking waters. Biofilm incubators were installed at the outlet of three Water Treatment Plants (WTP). These incubators allowed biofilm formation and quantification in terms of Fixed Total Organic Carbon (FTOC), fixed culturable bacteria (HPC-R2A) and fixed total bacteria. During this study, quantitative differences appeared between the biofilms formed at the outlet of the three WTPs, leading to different classifications of the Biofilm Formation Potentials of the three produced waters, depending on the used parameter for biofilms quantification. This observation underlined the necessity of a multi-parametric approach for the study of biofilms. More generally, our results validated the use of these sturdy stainless steel incubators, highly adapted to industrial field conditions, for the monitoring of Biofilm Formation Potentials in drinking water networks. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Removing pharmaceuticals and endocrine-disrupting compounds from wastewater by photocatalysisJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2007Omatoyo K Dalrymple Abstract Widespread concerns continue to be raised about the increasing presence of emerging contaminants in the environment. Such compounds include a wide range of persistent organic chemicals, including pharmaceuticals and endocrine-disrupting compounds whose effects are poorly known, often because they have only begun to enter the environment and are showing up in wastewater treatment plants. The occurrence and behavior of these compounds in wastewater are key issues with regard to water reclamation and reuse. Treatment plants are now faced with the challenge of removing the compounds from their effluent before they enter natural waterways. In this regard, photocatalysis is a promising technology for wastewater treatment that offers many advantages over conventional and some advanced treatment options. The application of photocatalysis for the removal of pharmaceuticals and endocrine-disrupting compounds for wastewater is comprehensively surveyed in this paper. This treatment technology is not intended to replace conventional systems but to supplement for higher-quality effluent. The assessment places emphasis on the process fundamentals, advantages, and disadvantages of the technology. It also focuses on the current limitations and future research needs. Copyright © 2007 Society of Chemical Industry [source] Fate of air toxics and VOCs in the odor control scrubbers at the deer island treatment plantENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2000Thomas Myslinski Process off-gases at the Deer Island wastewater treatment plant in Boston are collected and treated and its stack emissions regulated for selected gases including volatile organic compounds (VOCs), which are monitored as nonmethane hydrocarbons (NMHC). The air treatment processes of countercurrent wet oxidation scrubbing and granulated activated carbon adsorption are available for emissions control at Deer Island. In addition, since the wastewater treatment process of biochemical oxidation is fully enclosed at the site, microbial destruction of VOCs is an intrinsic treatment process for organic gases. Surveyed results of wastewater research literature indicate that the use of scrubbers for the removal of VOCs is controversial, as the fate of volatile hydrocarbon molecules across odor control scrubbers is complex and not fully understood. Continuous emission monitoring tests across the Deer Island scrubbers have consistently shown a VOC removal efficiency in excess of 50%. The fate of the scrubber inlet VOCs at Deer Island was researched as part of a plant-wide, on-going VOC study. Removal efficiencies across the pure oxygen bioreactors were also investigated. Preliminary results of this study indicate chemical reactions involving VOCs in odor control scrubbers partially oxidize and chlorinate derivatives possibly destroying a fraction of the compounds by complete oxidation. In addition, VOC reduction across the enclosed aerobic bioreactors was found to be significant. This article represents the opinions and(legal) conclusions of the authors and not necessarily those of the MWRA. [source] A new morphospecies of Microcystis sp. forming bloom in the Cheffia dam (Algeria): Seasonal variation of microcystin concentrations in raw water and their removal in a full-scale treatment plantENVIRONMENTAL TOXICOLOGY, Issue 4 2007Hichčm Nasri Abstract Toxic cyanobacterial blooms are an increasing problem in Algeria. The production of cyanotoxins (microcystins) and their presence in drinking water represent growing hazards to human health. In this study, seasonal variations in the concentrations of total microcystins and physicochemical parameters (pH, temperature, dissolved oxygen, nitrate, orthophosphate, and chlorophyll- a) were analyzed in the Cheffia dam (Algeria), mainly used to supply drinking water. The removal of cyanobacterial cells and microcystins was also evaluated in full-scale plant associated with the Cheffia reservoir. The levels of microcystins (MCYSTs) in both raw and drinking water were evaluated using the protein phosphatase type 2A (PP2A) inhibition test as MCYST-LR equivalents. Identification of microcystin variants was achieved by LC/MS/MS. During the period of study (March,December 2004), microscopic observation showed the dominance in the autumn months (September,November) of a new morphospecies of Microcystis sp. The MCYST-LR equivalent concentrations in raw water varied between 50.8 and 28,886 ng L,1. The highest level of toxins was observed in October 2004 and was significantly correlated with the chlorophyll- a. Three variants of microcystins assigned as microcystin-YR (MCYST-YR), microcystin-LR (MCYST-LR), and 6Z -Adda stereoisomer of MCYST-LR were observed in the crude extract of the Microcystis sp. bloom sample. During the bloom period, total elimination of Microcystis sp. and toxins were achieved through a classical treatment plant comprised of coagulation and flocculation, powdered activated carbon at 15 mg L,1, slow sand filtration and chlorination before storage. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 347,356, 2007. [source] Occurrence and fate of micropollutants in the Vidy Bay of Lake Geneva, Switzerland.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2010Part II: Micropollutant removal between wastewater, raw drinking water Abstract The occurrence and removal of 58 pharmaceuticals, endocrine disruptors, corrosion inhibitors, biocides, and pesticides, were assessed in the wastewater treatment plant (WWTP) of the city of Lausanne, Switzerland, as well as in the effluent-receiving water body, the Vidy Bay of Lake Geneva. An analytical screening method to simultaneously measure all of the 58 micropollutants was developed based on ultra performance liquid chromatography coupled to a tandem mass spectrometer (UPLC-MS/MS). The selection of pharmaceuticals was primarily based on a prioritization study, which designated them as environmentally relevant for the Lake Geneva region. Except for the endocrine disruptor 17,-ethinylestradiol, all substances were detected in 24-h composite samples of wastewater entering the WWTP or in the treated effluent. Of these compounds, 40% were also detected in raw drinking water, pumped from the lake 3,km downstream of the WWTP. The contributions of dilution and degradation to micropollutant elimination between the WWTP outlet and the raw drinking water intake were established in different model scenarios using hypothetical residence times of the wastewater in Vidy Bay of 1, 4, or 90 d. Concentration decrease due to processes other than dilution was observed for diclofenac, beta-blockers, several antibiotics, corrosion inhibitors, and pesticides. Measured environmental concentrations (MECs) of pharmaceuticals were compared to the predicted environmental concentrations (PECs) determined in the prioritization study and agreed within one order of magnitude, but MECs were typically greater than the corresponding PECs. Predicted no-effect concentrations of the analgesic paracetamol, and the two antibiotics ciprofloxacin and sulfamethoxazole, were exceeded in raw drinking water samples and therefore present a potential risk to the ecosystem. Environ. Toxicol. Chem. 2010; 29:1658,1668. © 2010 SETAC [source] Antidepressants and their metabolites in municipal wastewater, and downstream exposure in an urban watershedENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2010Chris D. Metcalfe Abstract Antidepressants are a widely prescribed group of pharmaceuticals that can be biotransformed in humans to biologically active metabolites. In the present study, the distribution of six antidepressants (venlafaxine, bupropion, fluoxetine, sertraline, citalopram, and paroxetine) and five of their metabolites was determined in a municipal wastewater treatment plant (WWTP) and at sites downstream of two WWTPs in the Grand River watershed in southern Ontario, Canada. Fathead minnows (Pimephales promelas) caged in the Grand River downstream of a WWTP were also evaluated for accumulated antidepressants. Finally, drinking water was analyzed from a treatment plant that takes its water from the Grand River 17 km downstream of a WWTP. In municipal wastewater, the antidepressant compounds present in the highest concentrations (i.e., >0.5 µg/L) were venlafaxine and its two demethylation products, O - and N -desmethyl venlafaxine. Removal rates of the target analytes in a WWTP were approximately 40%. These compounds persisted in river water samples collected at sites up to several kilometers downstream of discharges from WWTPs. Venlafaxine, citalopram, and sertraline, and demethylated metabolites were detected in fathead minnows caged 10 m below the discharge from a WWTP, but concentrations were all <7 µg/kg wet weight. Venlafaxine and bupropion were detected at very low (<0.005 µg/L) concentrations in untreated drinking water, but these compounds were not detected in treated drinking water. The present study illustrates that data are needed on the distribution in the aquatic environment of both the parent compound and the biologically active metabolites of pharmaceuticals. Environ. Toxicol. Chem. 2010;29:79,89. © 2009 SETAC [source] Pharmaceutical industry effluent diluted 1:500 affects global gene expression, cytochrome P450 1A activity, and plasma phosphate in fish,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2009Lina Gunnarsson Abstract Patancheru, near Hyderabad, India, is a major production site for the global bulk drug market. Approximately 90 manufacturers send their wastewater to a common treatment plant in Patancheru. Extraordinary high levels of a wide range of pharmaceuticals have recently been demonstrated in the treated effluent. As little as 0.2% of this effluent can strongly reduce the growth rate of tadpoles, but the underlying mechanisms of toxicity are not known. To begin addressing how the effluent affects aquatic vertebrates, rainbow trout (Oncorhynchus mykiss) were exposed to 0.2% effluent for 5 d. Several physiological endpoints, together with effects on global hepatic gene expression patterns, were analyzed. The exposed fish showed both an induction of hepatic cytochrome P450 1A (CYP1A) gene expression, as well as enzyme activity. Clinical blood chemistry analyses revealed an increase in plasma phosphate levels, which in humans indicates impaired kidney function. Several oxidative stress-related genes were induced in the livers; however, no significant changes in antioxidant enzyme activities or in the hepatic glutathione levels were found. Furthermore, estrogen-regulated genes were slightly up-regulated following exposure, and moderate levels of estriol were detected in the effluent. The present study identifies changes in gene expression triggered by exposure to a high dilution of the effluent, supporting the hypothesis that these fish are responding to chemical exposure. The pattern of regulated genes may contribute to the identification of mechanisms of sublethal toxicity, as well as illuminate possible causative agents. [source] Influence of heavy metals on microbial growth kinetics including lag time: Mathematical modeling and experimental verification,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2009S. Sevinç, engör Abstract Heavy metals can significantly affect the kinetics of substrate biodegradation and microbial growth, including lag times and specific growth rates. A model to describe microbial metabolic lag as a function of the history of substrate concentration has been previously described by Wood et al. (Water Resour Res 31:553,563) and Ginn (Water Resour Res 35:1395,1408). In the present study, this model is extended by including the effect of heavy metals on metabolic lag by developing an inhibitor-dependent functional to account for the metabolic state of the microorganisms. The concentration of the inhibiting metal is explicitly incorporated into the functional. The validity of the model is tested against experimental data on the effects of zinc on Pseudomonas species isolated from Lake Coeur d'Alene sediments, Idaho, USA, as well as the effects of nickel or cobalt on a mixed microbial culture collected from the aeration tank of a wastewater treatment plant in Athens, Greece. The simulations demonstrate the ability to incorporate the effect of metals on metabolism through lag, yield coefficient, and specific growth rates. The model includes growth limitation due to insufficient transfer of oxygen into the growth medium. [source] Reproductive health of bass in the Potomac, USA, drainage: Part 1.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2009Exploring the effects of proximity to wastewater treatment plant discharge Abstract Intersex (specifically, testicular oocytes) has been observed in male smallmouth bass (SMB; Micropterus dolomieu) and other centrarchids in the South Branch of the Potomac River, USA, and forks of the Shenandoah River, USA, during the past five years. This condition often is associated with exposure to estrogenic endocrine-disrupting chemicals in some fish species, but such chemicals and their sources have yet to be identified in the Potomac. In an attempt to better understand the plausible causes of this condition, we investigated the reproductive health of bass sampled up- and downstream of wastewater treatment plant (WWTP) effluent point sources on the Potomac River in Maryland, USA. Smallmouth bass were sampled from the Conococheague Creek and the Monocacy River, and largemouth bass (LMB; Micropterus salmoides) were collected near the Blue Plains WWTP on the mainstem of the Potomac River. Chemical analyses of compounds captured in passive samplers at these locations also were conducted. A high prevalence of intersex (82,100%) was identified in male SMB at all sites regardless of collection area. A lower prevalence of intersex (23%) was identified in male LMB collected at the Blue Plains site. When up- and downstream fish were compared, significant differences were noted only in fish from the Conococheague. Differences included condition factor, gonadosomatic index, plasma vitellogenin concentration, and estrogen to testosterone ratio. In general, chemicals associated with waste-water effluent, storm-water runoff, and agriculture were more prevalent at the downstream sampling sites. An exception was atrazine and its associated metabolites, which were present in greater concentrations at the upstream sites. It appears that proximity to effluent from WWTPs may influence the reproductive health of bass in the Potomac watershed, but inputs from other sources likely contribute to the widespread, high incidence of testicular oocytes. [source] Reproductive health of bass in the Potomac, USA, drainage: Part 2.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2009Seasonal occurrence of persistent, emerging organic contaminants Abstract The seasonal occurrence of organic contaminants, many of which are potential endocrine disruptors, entering the Potomac River, USA, watershed was investigated using a two-pronged approach during the fall of 2005 and spring of 2006. Passive samplers (semipermeable membrane device and polar organic chemical integrative sampler [POCIS]) were deployed in tandem at sites above and below wastewater treatment plant discharges within the watershed. Analysis of the samplers resulted in detection of 84 of 138 targeted chemicals. The agricultural pesticides atrazine and metolachlor had the greatest seasonal changes in water concentrations, with a 3.1- to 91-fold increase in the spring compared with the level in the previous fall. Coinciding with the elevated concentrations of atrazine in the spring were increasing concentrations of the atrazine degradation products desethylatrazine and desisopropylatrazine in the fall following spring and summer application of the parent compound. Other targeted chemicals (organochlorine pesticides, polycyclic aromatic hydrocarbons, and organic wastewater chemicals) did not indicate seasonal changes in occurrence or concentration; however, the overall concentrations and number of chemicals present were greater at the sites downstream of wastewater treatment plant discharges. Several fragrances and flame retardants were identified in these downstream sites, which are characteristic of wastewater effluent and human activities. The bioluminescent yeast estrogen screen in vitro assay of the POCIS extracts indicated the presence of chemicals that were capable of producing an estrogenic response at all sampling sites. [source] Determination and fate of oxytetracycline and related compounds in oxytetracycline production wastewater and the receiving river,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2008Dong Li Abstract This study investigated the occurrence and fate of oxytetracycline (OTC) and its related substances, 4-epi-oxytetracycline (EOTC), ,-apo-oxytetracycline (,-apo-OTC), and ,-apo-oxytetracycline (,-apo-OTC), in a wastewater treatment plant (WWTP) treating OTC production wastewater and a river receiving the effluent from the WWTP using liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). The percent removal of OTC in the WWTP was 38.0 ± 10.5%, and the concentration of OTC was still up to 19.5 ± 2.9 mg/L in the treated outflow. The concentration slightly decreased along the river, from 641 ± 118 ,g/L at site R2 (discharging point) to 377 ± 142 ,g/L at site R4 (,20 km from site R2), which was still higher than the minimal inhibition concentration of OTC reported (,250 ,g/L). On the other hand, the total amount of its related substances in the treated effluent was less than 5% of OTC. Concentrations of ,-apo-OTC and ,-apo-OTC increased along the river, from 5.76 ± 0.63 and 2.08 ± 0.30 ,g/L at site R2 to 11.9 ± 4.9 and 12.0 ± 4.6 ,g/L at R4, respectively, although EOTC decreased from 31.5 ± 3.8 to 12.9 ± 1.1 ,g/L, respectively. The mean concentration of ,-apo-OTC in river sediments was 20.8 ± 7.8 mg/kg, and its ratio to OTC was approximately 0.11, nearly twice the ratio of ,-apo-OTC and EOTC to OTC (0.058 ± 0.014 and 0.061 ± 0.015, respectively). [source] Seasonality effects on pharmaceuticals and s -triazine herbicides in wastewater effluent and surface water from the Canadian side of the upper Detroit RiverENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2006Wen Yi Hua Abstract The influence of seasonal changes in water conditions and parameters on several major pharmacologically active compounds (PhACs) and s -triazine herbicides was assessed in the wastewater and sewage treatment plant (WSTP) effluent as well as the downstream surface water from sites on the Canadian side of the upper Detroit River, between the Little River WSTP and near the water intake of a major drinking water treatment facility for the City of Windsor (ON, Canada). The assessed PhACs were of neutral (carbamazepine, cotinine, caffeine, cyclophosphamide, fluoxetine, norfluoxetine, pentoxifylline, and trimethoprim) and acidic (ibuprofen, bezafibrate, clofibric acid, diclofenac, fenoprofen, gemfibrozil, indomethacin, naproxen, and ketoprofen) varieties. The major assessed s -triazine herbicides were atrazine, simazine, propazine, prometon, ametryn, prometryn, and terbutryn. At sampling times from September 2002 to June 2003, 15 PhACs were detected in the WSTP effluent at concentrations ranging from 1.7 to 1,244 ng/L. The PhAC concentrations decreased by as much 92 to 100% at the Little River/Detroit River confluence because of the river dilution effect, with further continual decreases at sites downstream from the WSTP. The only quantifiable s -triazine in WSTP effluent, atrazine, ranged from 6.7 to 200 ng/L and was higher in Detroit River surface waters than in WSTP effluent. Only carbamazepine, cotinine, and atrazine were detectable at the low-nanogram and subnanogram levels in surface waters near a drinking water intake site. Unlike the PhACs, atrazine in the Detroit River is not attributable to point sources, and it is heavily influenced by seasonal agricultural usage and runoff. Detroit River surface water concentrations of carbamazepine, cotinine, and atrazine may present a health concern to aquatic wildlife and to humans via the consumption of drinking water. [source] Evaluation of the ishikawa cell line bioassay for the detection of estrogenic substances from sediment extractsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2005Shinya Hashimoto Abstract This study examines the application of Ishikawa human endometrial adenocarcinoma cells to measure the estrogenic activity of fractionated extracts of sediments from Tokyo Bay, Japan. Estrogen stimulates alkaline phosphatase activity in this cell line. The results of these assays were compared with those of a yeast estrogen screen (YES) assay. The Ishikawa cell line bioassay showed higher sensitivity to 17,-estradiol (median effective concentration [EC50], 10.7 pM) than did the YES assay (EC50, 480 pM). Fractionation of sediment extracts (all samples collected from 5 sites) showed that the nonpolar fraction was poisonous to yeast cells; the estrogenic activity of this fraction, therefore, could not be measured by YES. However, the nonpolar fraction did not kill the Ishikawa cells. The 17,-estradiol-equivalent values of 15 extracts (3 fractions from each of 5 sediment samples) ranged from 5.7 to 697 pg/g dry weight according to the Ishikawa cell line bioassay. Chemical analysis using gas chromatography-mass spectrometry revealed that the highest concentrations of endocrine-disrupting chemicals were observed at the sampling station near the sewage treatment plant. The results support that the Ishikawa cell line bioassay is suitable for measuring the estrogenic activity of sediment samples. [source] Identification of chlorfenvinphos toxicity in a municipal effluent in Sydney, New South Wales, AustraliaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2005Howard C. Bailey Abstract Acute toxicity in a municipal sewage treatment plant in Sydney, New South Wales, Australia, was traced to chlorfenvinphos, an organophosphorous pesticide. Toxicity identification evaluation procedures led to the tentative identification of chlorfenvinphos as the toxic contaminant in the sample. Subsequent analytical verification revealed 0.95 ,g/L of chlorfenvinphos in the effluent sample, and spiking studies confirmed that it accounted for the observed toxicity. The 48-h median lethal concentration of chlorfenvinphos to Ceriodaphnia dubia averaged 0.28 ,g/L (n = 4). Source-control measures were effective at eliminating chlorfenvinphos and associated toxicity from the discharge. [source] Development of a fish reporter gene system for the assessment of estrogenic compounds and sewage treatment plant effluentsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2002Gabriele E. Ackermann Abstract This study reports on the development and application of a fish-specific estrogen-responsive reporter gene assay. The assay is based on the rainbow trout (Oncorhynchus mykiss) gonad cell line RTG-2 in which an acute estrogenic response is created by cotransfecting cultures with an expression vector containing rainbow trout estrogen receptor a complementary DNA (rtER, cDNA) in the presence of an estrogen-dependent reporter plasmid and an estrogen receptor (ER) agonist. In a further approach, RTG-2 cells were stably transfected with the rtER, cDNA expression vector, and clones responsive to 17,-estradiol (E2) were selected. The estrogenic activity of E2, 17,-ethinylestradiol, 4-nonylphenol, nonylphenoxy acetic acid, 4- tert -octylphenol, bisphenol A, o,p,-DDT, p,p,-DDT, o,p,-2,2-bis(chlorophenyl)-1,1-dichloroethylene (o,p,-DDE), p,p,-DDE, o,p,-2,2-bis(chlorophenyl)-1,1-di-chloroethane (o,p,-DDD), p,p,-DDD, and p,p,-2,2-bis(chlorophenyl)acetic acid (p,p,-DDA) was assessed at increasing concentrations. All compounds except o,p,-DDT, p,p,-DDE, and p,p,-DDA showed logistic dose-response curves, which allowed the calculation of lowest-observed-effect concentrations and the concentrations at which half-maximal reporter gene activities were reached. To check whether estrogen-responsive RTG-2 cells may be used to detect the estrogenic activity of environmental samples, an extract from a sewage treatment plant (STP) effluent was assessed and found to have estrogenic activity corresponding to the transcriptional activity elicited by 0.05 nM of E2. Dose-response curves of nonylphenol, octylphenol, bisphenol A, and o,p,-DDD revealed that the RTG-2 reporter gene assay is more sensitive for these compounds when compared to transfection systems recombinant for mammalian ERs. These differences may have an effect on the calculation of E2 equivalents when estrogenic mixtures of known constitution, or environmental samples, such as STP effluents, are assessed. [source] Toxic event detection by respirometry and adaptive principal components analysisENVIRONMETRICS, Issue 6 2005Sébastien Le Bonté Abstract Two methods based on adaptive principal components analysis (APCA) are compared to extract, from primary measurements, information related to the changes of wastewater characteristics induced by variable weather conditions and/or to the presence of toxic substances. The primary measurements are activated sludge respiratory data obtained by short-term experiments in an on-line batch respirometer, combined with indirect information on soluble pollution (UV-visible absorbance, turbidity, pH, etc.) and wastewater flow rate. The Benchmark Simulation Model 1 (BSM1), which simulates the functioning of a large wastewater treatment plant by activated sludge, has been used to obtain large data sets and to test the proposed APCA method, which has then been applied to real wastewater characteristics. Copyright © 2005 John Wiley & Sons, Ltd. [source] Ecophysiology of the filamentous Alphaproteobacterium Meganema perideroedes in activated sludgeFEMS MICROBIOLOGY ECOLOGY, Issue 1 2005Caroline Kragelund Abstract A comprehensive study of the ecophysiology of the filamentous Meganema perideroedes affiliated to the Alphaproteobacteria, possessing a "Nostocoida limicola Type II" filamentous morphology was conducted. This morphotype often causes serious bulking problems in activated sludge wastewater treatment plants, and hardly anything is known about its physiology. The study was carried out by applying a suite of in situ methods in an industrial activated sludge treatment plant with excessive growth of this species. The experiments revealed a very versatile organism able to take up a large variety of organic substrates under aerobic conditions. It had a remarkably high storage capacity forming polyhydroxyalkanoates from most substrates tested. When nitrate was present as e-acceptor, the number of substrates to be consumed by M. perideroedes was more restricted compared to aerobic conditions. With nitrite as e-acceptor, only acetate and glucose among the substrates tested could be assimilated and used for storage and possibly growth. This indicated that M. perideroedes might be able to denitrify under certain conditions, which is unusual for filamentous bacteria in activated sludge. No substrate uptake or storage was seen under anaerobic conditions. M. perideroedes was relatively hydrophobic, compared to other filamentous bacteria and microcolonies present in the sludge, indicating the presence of a hydrophobic sheath. Several excreted surface-associated exoenzymes were detected in the sludge, but M. perideroedes never showed any activity, except once after a breakdown in the production facility. This confirmed that M. perideroedes mainly grows on soluble substrates. Based on the studies of the ecophysiology of M. perideroedes, potential control strategies are suggested. [source] Competition between two nitrite-oxidizing bacterial populations: a model for studying the impact of wastewater treatment plant discharge on nitrification in sedimentFEMS MICROBIOLOGY ECOLOGY, Issue 1 2002Christine Féray Abstract Nitrobacter, a ubiquitous nitrite oxidizer in natural and anthropized environments, is commonly studied as the model genus performing the second stage of nitrification. In rivers, wastewater treatment plant discharges may affect the nitrite-oxidizing activity and the responsible genera that are largely associated with sediment. We used a laboratory batch culture approach with Nitrobacter wynogradskyi ssp. agilis strain AG and Nitrobacter hamburgensis strain X14 to characterize the possible stress effect of wastewater effluent on these populations and to study the possible competition between an effluent strain (X14) and a sediment strain (AG) over a 42-day incubation time. Immunofluorescence enumerations of each strain showed that they both survived and settled in the sediment, indicating that there was no significant stress effect due to chemical changes caused by the effluent. The development of the strains' density and activity was directly correlated with the available nitrite concentration. Nevertheless, the potential specific activity was not constant along the so-called mixotrophic (non-limiting nitrite concentration) and heterotrophic (nitrite depletion) conditions. This illustrates the inducibility of the nitrite oxidoreductase and indicates the metabolic versatility of the strains. In our experimental conditions, the preferentially autotrophic AG strain appeared more competitive than the preferentially mixo- or heterotrophic X14 strain, including in heterotrophic environment. [source] Effects of stream restoration and wastewater treatment plant effluent on fish communities in urban streamsFRESHWATER BIOLOGY, Issue 10 2006ROBERT M. NORTHINGTON Summary 1. Fish community characteristics, resource availability and resource use were assessed in three headwater urban streams in Piedmont North Carolina, U.S.A. Three site types were examined on each stream; two urban (restored and unrestored) and a forested site downstream of urbanisation, which was impacted by effluent from a wastewater treatment plant (WWTP). Stream basal resources, aquatic macroinvertebrates, terrestrial macroinvertebrates and fish were collected at each site. 2. The WWTPs affected isotope signatures in the biota. Basal resource, aquatic macroinvertebrate and fish ,15N showed significant enrichments in the downstream sites, although ,13C signatures were not greatly influenced by the WWTP. Fish were clearly deriving a significant part of their nutrition from sewage effluent-derived sources. There was a trend towards lower richness and abundance of fish at sewage-influenced sites compared with urban restored sites, although the difference was not significant. 3. Restored stream sites had significantly higher fish richness and a trend towards greater abundance compared with unrestored sites. Although significant differences did not exist between urban restored and unrestored areas for aquatic and terrestrial macroinvertebrate abundances and biotic indices of stream health, there appeared to be a trend towards improvements in restored sites for these parameters. Additional surveys of these sites on a regular basis, along with maintenance of restored features are vital to understanding and maximising restoration effectiveness. 4. A pattern of enriched ,13C in fish in restored and unrestored streams in conjunction with enriched ,13C of terrestrial invertebrates at these sites suggests that these terrestrial subsidies are important to the fish, a conclusion also supported by isotope cross plots. Furthermore, enriched ,13C observed for terrestrial invertebrates is consistent with some utilisation of the invasive C4 plants that occur in the urban riparian areas. [source] Biodegradation and transport of benzene, toluene, and xylenes in a simulated aquifer: comparison of modelled and experimental resultsHYDROLOGICAL PROCESSES, Issue 16 2002Jiin-Shuh Jean Abstract Both laboratory experiments and numerical modelling were conducted to study the biodegradation and transport of benzene,toluene,xylenes (BTX) in a simulated semi-confined aquifer. The factors incorporated into the numerical model include advection, hydrodynamic dispersion, adsorption, and biodegradation. The various physico-chemical parameters required by the numerical model were measured experimentally. In the experimental portion of the study, BTX compounds were introduced into the aquifer sand. After the contaminants had been transported through the system, BTX concentrations were measured at 12 equally spaced wells. Subsequently, microorganisms obtained from the activated sludge of a sewage treatment plant and cultured in BTX mixtures were introduced into the aquifer through the 12 sampling wells. The distribution data for BTX adsorption by the aquifer sand form a nonlinear isotherm. The degree of adsorption by the sand varies, depending on the composition of the solute. The degradation time, measured from the time since the bacteria were added to the aquifer until a specific contaminant was no longer detectable, was 35,42 h for BTX. The dissolved oxygen, after degradation by BTX compounds and bacteria, was consumed by about 40,60% in the entire simulated aquifer; thus the aerobic conditions were maintained. This study provides insights for the biodegradation and transport of BTX in aquifers by numerical modelling and laboratory experiments. Experimental and numerical comparisons indicate that the results by Monod degradation kinetics are more accurate than those by the first-order degradation kinetics. Copyright © 2002 John Wiley & Sons, Ltd. [source] Peracetic acid as an alternative wastewater disinfectant to chlorine dioxideJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002S. Stampi Aims: The aim of this study was to compare the efficiency of peracetic acid with that of chlorine dioxide in the disinfection of wastewater from a sewage treatment plant (serving about 650 000 inhabitants) that has been using peracetic acid as a disinfectant since 1998. Methods and Results: A total of 23 samplings were made, each consisting of three samples: from secondary effluent, effluent disinfected with 2 mg l,1 of peracetic acid and effluent disinfected with 2·2 mg l,1 of chlorine dioxide (contact time 20 min). For each sample, measurements were made of the heterotrophic plate count at 36°C, total and faecal coliforms, Escherichia coli, enterococci, pH, suspended solids and chemical oxygen demand (COD). During the first phase of the experiment the peracetic acid was seen to be less efficient than chlorine dioxide. To improve the disinfectant action a system of mechanical agitation was added which led to a greater efficiency in the inactivation of bacteria of faecal origin. Conclusions: Both products were found to be influenced by the level of microbial contamination, the amount of suspended solids and COD but not by the pH of the effluent before disinfection. The immediate mixing of the wastewater and disinfectant caused a greater reduction in enterococci. Significance and Impact of the Study: Since peracetic acid was seen to produce a high abatement of micro-organisms, it can be considered as a valid alternative to chlorine dioxide in the disinfection of wastewaters. [source] Development of a correlation to study parameters affecting nitrification in a domestic wastewater treatment plantJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2008Gulnur Coskuner Abstract BACKGROUND: Nitrification performance of an activated sludge reactor treating weak domestic wastewater was investigated for 11 months. Ammonia nitrogen removals were investigated as a function of wastewater composition and operational conditions. Backward elimination experimental design was used to determine the influence of the most important independent variables on NH3 -N removal efficiencies. Influent ammonia and biological oxygen demand (BOD5) concentrations, hydraulic retention time (HRT), mixed liquid suspended solids (MLSS), temperature, pH and dissolved oxygen (DO) concentration were considered as independent variables. This study aimed to find the most important parameters to describe nitrification performance. RESULTS: The presence of nitrification was confirmed by ammonia and nitrate variations throughout the reactor; ammonia oxidizing bacteria (AOB) populations were determined using a fluorescence in situ hybridization (FISH) method. MLSS concentration, influent BOD5 concentration and temperature were found to be the most influential factors on nitrification performance. The empirical correlation using multiple linear regressions was statistically significant and produced an adjusted coefficient of multiple determinations (R2adj) of 92.5%. CONCLUSION: Correlation provides a good understanding of the various parameters that affect the nitrification process, and could be extended to other case studies. Using these results, operators can apply proper operational strategies to maintain nitrification in wastewater treatment plants. Copyright © 2007 Society of Chemical Industry [source] Biodegradation kinetics of benzene, methyl tert -butyl ether, and toluene as a substrate under various substrate concentrationsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2007Chi-Wen Lin Abstract Owing to the complexity of conventional methods and shortcomings in determining kinetic parameters, a convenient approach using the nonlinear regression analysis of Monod or Haldane type nonlinear equations is presented. This method has been proven to provide accurate estimates of kinetic parameters. The major work in this study consisted of the testing of aromatic compound-degrading cultures in batch experiments for the biodegradation of benzene, methyl tert -butyl ether (MTBE), and toluene. Additionally, batch growth data of three pure cultures (i.e., Pseudomonas aeruginosa YAMT421, Ralstonia sp. YABE411 and Pseudomonas sp. YATO411) isolated from an industrial petrochemical wastewater treatment plant under aerobic conditions were assessed with the nonlinear regression technique and with a trial-and-error procedure to determine the kinetic parameters. The growth rates of MTBE-, benzene-, and toluene-degrading cultures on MTBE, benzene, and toluene were significant. Monod's model was a good fit for MTBE, benzene and toluene at low substrate concentrations. In contrast, Haldane's equation fitted well in substrate inhibition concentration. Monod and Haldane's expressions were found to describe the results of these experiments well, with fitting values higher than 98%. The kinetic parameters, including a maximum specific growth rate (µm), a half-saturation constant (Ks), and an inhibition constant (Ki), were given. Copyright © 2007 Society of Chemical Industry [source] Palm oil mill effluent pretreatment using Moringa oleifera seeds as an environmentally friendly coagulant: laboratory and pilot plant studiesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2006Subhash Bhatia Abstract This research paper covers the suitability of the coagulation,flocculation process using Moringa oleifera seeds after oil extraction as a natural and environmentally friendly coagulant for palm oil mill effluent treatment. The performance of M. oleifera coagulant was studied along with the flocculant KP 9650 in removal of suspended solids, organic components and in increasing the floc size. The optimum values of the operating parameters obtained from the laboratory jar test were applied in a pilot-scale treatment plant comprised of coagulation,flocculation and filtration processes. Pilot-scale pretreatment resulted in 99.7% suspended solids removal, 71.5% COD reduction, 68.2% BOD reduction, 100% oil and grease removal and 91% TKN removal. In pilot plant pretreatment, the percentage recovery of water was 83.3%, and 99.7% sludge was recovered after dewatering in a filter press. Copyright © 2006 Society of Chemical Industry [source] Sequential anaerobic/aerobic biological treatment of olive mill wastewater and municipal wastewaterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2006Nikolaos Gizgis Abstract This work investigated the efficiency of the combined anaerobic/aerobic biological co-treatment of olive mill wastewater and primary municipal wastewater. A laboratory-scale (6.5 L) upflow anaerobic sludge bed reactor received a mixture of olive mill wastewater and primary municipal wastewater at a loading rate ranging between 3 and 7 kg chemical oxygen demand (COD) m,3 day,1. The input COD concentration ranged between 1800 and 4400 mg L,1. The anaerobic reactor was operated at mesophilic conditions (35 °C). The effluent organic load was between 400 and 600 mg COD L,1, while the suspended solids removal efficiency varied between 75 and 95%. Average biogas production ranged between 3 and 4 L g,1 COD removed. The anaerobic reactor effluent was further treated in a laboratory-scale activated sludge treatment plant. Aerobic treatment reduced the organic load even further to 85,175 mg COD L,1. However, the final effluent still retained a significant level of colour. Removal of colour was possible by ozonation or coagulation. Finally, the treated effluent was non-ecotoxic, as indicated by the Daphnia magna toxicity test. This treatment method showed that it is feasible to treat olive mill wastewater in a municipal wastewater treatment plant by means of a high-rate anaerobic reactor located between the primary clarifier and the aeration tank. Copyright © 2006 Society of Chemical Industry [source] Evaluation of a simple batch distillation process for treating wastes from metalworking industriesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2004P Cańizares Abstract A simple batch distillation process for the treatment of two types of industrial waste generated in a metalworking factory has been evaluated. Both types of waste are oil-in-water emulsions composed of numerous compounds and each type has a high content of water-soluble species. The water-soluble nature of the wastes precludes the use of conventional treatment technologies, such as ultrafiltration or chemical emulsion breaking, since they need to be complemented with additional treatment processes that would probably increase the cost considerably. A simple characterization of the liquid,vapour equilibrium and a scale-up study has demonstrated the applicability of this technology. The process allows 90% of the waste to be recovered as water, thus achieving the required quality limits for discharge into a municipal wastewater treatment plant. An approximate estimation of capital investment and operating costs for an existing case has shown the economic viability of this process. Copyright © 2004 Society of Chemical Industry [source] Evaluation of the environmental implications to include structural changes in a wastewater treatment plantJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2002Núria Vidal Abstract The environmental implications of including structural changes in a wastewater treatment plant to decrease effluent concentrations of nitrogen were evaluated in this study. Environmental effects from these structural changes were assessed by using the Life Cycle Assessment theoretical framework. The wastewater treatment plant selected as a reference scenario had an activated sludge configuration. The Ludzack,Ettinger and Oxidation Ditch configurations were selected as modifications of the reference scenario. Results from this study show that the inclusion of nitrogen removal mechanisms in the configuration of the plant reduces the effect of the plant on the eutrophication, but simultaneously increases the effect on the consumption of abiotic resources, global warming, acidification and human toxicity. These general trends, however, vary depending on the configuration selected to remove nitrogen. Taking all the impacts together, the Oxidation Ditch configuration would cause less environmental impact than the Ludzack,Ettinger configuration, given the characteristics of the selected scenarios. © 2002 Society of Chemical Industry [source] | ||||||||||||||||||||||||||||||||||||||||