Incorporation of toxicity tests into the Turkish industrial discharge monitoring systems

A toxicity evaluation is an important parameter in wastewater quality and in the monitoring of discharged effluents. Some organic and inorganic compounds at toxic levels have been detected in industrial discharges, resulting in plant upsets and discharge permit violations. In some cases, even though the effluent does not exceed the chemical-specific discharge limits, the results of toxicity tests show potential toxicity. Knowledge of the toxicity of effluents can benefit treatment plant operators in optimizing plant operation, protecting receiving water quality, and establishing sewer discharge permits. In the Turkish regulations only toxicity dilution factor with fish is part of the toxicity monitoring program of permissible wastewater discharge. This study investigated the acute toxicity of pulp-paper, leather, and petrochemical industry wastewaters by traditional and enrichment toxicity tests and emphasized the importance of toxicity tests in wastewater discharge regulations. The enrichment toxicity tests are novel applications indicating whether there is potential toxicity or stimulation conditions. Different organisms were used, including bacteria (Floc and Coliform bacteria) algae (Chlorella sp.), fish (Lepistes sp.), and protozoan species (Vorticella sp.) to represent four trophic levels. The toxicity test results were compared with chemical analyses to identify the pollutants responsible for the toxicity in the effluent wastewater samples. Toxicity of the effluents could not be explained by using physicochemical analyses in five cases for the leather and four cases for the pulp-paper and petrochemical industries. The results clearly showed that the use of bioassay tests produce additional information about the toxicity potential of industrial discharges and effluents. Received: 2 August 2001/Accepted: 6 March 2002     

Textile Effluents Induce Biomarkers of Acute Toxicity,Oxidative Stress,and Genotoxicity

The present work consists of a comparative evaluation of the toxicity of a nonremediated textile effluent (NRTE) with an effluent remediated by a pulverized chitosan system (RCTS) or by a conventional effluent process (remediated biologic and physico-chemical effluent [RBPC]). Acute toxicity assays, oxidative stress biomarkers, physico-chemical parameters, and genotoxicity indices were analyzed to achieve the toxicity of all effluents. After RCTS treatment, approximately 80% of dyes were removed, together with a significant decreased of the metal content, compared with a relatively increase in metal content after RBPC treatment. RBPC and RCTS treatments did not cause acute toxicity to Vibrio fischeri and Artemia sp., whereas RBPC caused acute toxicity to Daphnia magna but RCTS did not. Compared with NRTE, chitosan remediation decreased oxidative stress biomarkers, such as the contents of lipoperoxidation (measured as thiobarbituric acid-reactive substances [TBARS], 29.9%) and the reduced form of glutathione (GSH; 73.5%) levels in D. rerio, whereas animals exposed to RBPC showed enhanced TBARS (57.2%) and decreased GSH concentrations (56.4%). RCTS and RBPC remediation elicited catalase activity induction (161.8% and 127.3%, respectively) compared with NRTE. Accordingly, DNA fragmentation and micronucleus frequency in D. rerio decreased after remediation with RBPC or RCTS compared with NRTE, but RCTS treatment was more effective than RBPC in decreasing genotoxicity (90.5% and 73.8% decrease in DNA fragmentation and 67.8% and 50.4% decrease in micronucleus frequency, respectively). The results indicate that chitosan adsorption system is a useful tool for textile effluent remediation compared with the conventional remediation by biologic and physico-chemical processes.     

Persistent organic pollutants (POPs) in the conventional activated sludge treatment process: fate and mass balance

The fate and the mass balance of persistent organic pollutants (POPs) during the conventional activated sludge treatment process were investigated in the wastewater treatment plant of the city of Thessaloniki, northern Greece. The POPs of interest were 7 polychlorinated biphenyls and 19 organochlorine pesticides. Target compounds were determined at six different points across the treatment system: the influent, the effluent of the primary sedimentation tank, the effluent of the secondary sedimentation tank, the primary sludge, the activated sludge from the recirculation stream, and the digested/dewatered sludge. The distribution of POPs between the dissolved and the adsorbed phases of wastewater and sludge was investigated. A good linear relationship between the distribution coefficients, Kd, and the octanol-water partition coefficients, Kow, of the solutes was observed only in raw wastewater, suggesting that other factors affect the phase distribution of organic compounds in treated wastewater. For all POPs, a significant increase in partitioning with a decreasing solids concentration was observed, revealing an effect from non-settling microparticles remaining in the "dissolved" phase during the separation procedure. A good linear relationship was also revealed between logKd and the dissolved organic carbon (DOC) content of wastewater, suggesting that DOC favors the advective transport of POPs in the dissolved phase. Almost all POPs showed good mass balance agreements at both the primary and the secondary treatment. The losses observed for some species could be attributed to biodegradation/biotransformation rather than volatilization. The relative distribution between the treated effluent and the waste sludge streams varied largely among different compounds, with p-p'-DDE being highly accumulated in the waste sludge (98%) but almost 60% of alpha-HCH remaining in the treated effluent.     

Comparison of sediment extract microtox® toxicity with semi-volatile organic priority pollutant concentrations

A total of 105 sediment samples were extracted with acetonitrile and subjected to cleanup with C-18 columns and copper powder. Extracts were analyzed for semi-volatile organic priority pollutants and for acute toxicity using the Microtox® bioassay. Polynuclear aromatic hydrocarbons (PAHs) accounted for 85% of all priority pollutant identifications. The results of statistical comparisons made between PAH concentrations and extract toxicity depended upon the correlation procedures used. Total PAHs were significantly correlated with toxicity using Spearman's correlation procedure, but not correlated using a linear correlation procedure. Many extracts with below or barely detectable levels of priority pollutants were highly toxic. On an individual extract basis, concentrations of priority pollutants were poor indicators of extract toxicity. Toxicity determinations were also made for commonly detected priority pollutants dissolved in dimethyl sulfoxide.     

Investigations into Using the Nematode Caenorhabditis elegans for Municipal and Industrial Wastewater Toxicity Testing

This investigative study assesses the ease and usefulness of the nematode Caenorhabditis elegans for identifying contributors to effluent toxicity within an industrial and municipal wastewater treatment plant (WWTP) system. Several different types of industries, including fiberglass manufacturing, paper packaging, and yarn dyeing, discharge effluent into the municipal wastewater treatment plant, which in turn discharges into a local creek. A major objective of this study was to identify primary sources of toxicity throughout the system with a nematode toxicity test. Twenty-four-hour composite water samples were taken periodically over a ten-month period at five strategic points within the system: (1) at the point of discharge at each of the three industries, (2) at the combined industrial influent of the wastewater treatment plant, (3) at the effluent of the WWTP, (4) upstream of the WWTP discharge, and (5) downstream of the WWTP discharge. Samples were analyzed for basic water chemistry, and each sample was tested for whole effluent toxicity using a 72-h nematode test with mortality as the end point. Results suggest that interactions between the wastewaters of certain industries may increase the overall nematode toxicity in the wastewater treatment facility's composite influent and effluent. Nematode mortality trends indicate relatively high toxicity levels in wastewater entering the WWTP from contributing industries. High WWTP influent toxicity may potentially be due to varying flow rate ratios of industrial discharges, release of varying toxic constituents in wastewaters, and toxic interactions between chemical constituents of industrial wastewaters. The evaluation of toxicity within the treatment system may pinpoint locations where pollution prevention strategies may be implemented to reduce overall toxicity at the point of discharge. Received: 21 September 1996/Accepted: 15 July 1997     

含酚废水治理技术研究进展

酚是工业废水中常见的高毒性、难降解的有机污染物,同时,又是化工生产中的重要原料之一,因此,经济高效地治理与回收废水中的酚类物质极为重要.笔者介绍了含酚废水的来源及危害,分类综述了国内外含酚废水治理技术的研究现状,主要包括吸附法、萃取法、氧化法以及生物技术,分析比较了各种相关处理工艺的特点、存在的问题、适用范围以及应用前景,并进一步展望了含酚废水治理技术的研究进展及趋势,指出多种技术的联用是今后治理含酚废水的研究热点.     

Evaluation of Bleached Kraft Mill Process Water Using Microtox®, Ceriodaphnia dubia, and Menidia beryllina Toxicity Tests

To determine whether a 7- to 10-d embryo toxicity/teratogenicity test with the inland silverside fish, Menidia beryllina, is a sensitive indicator for evaluation of bleached kraft mill effluents, we compared this test with the Microtox? 15-min acute toxicity test and the Ceriodaphnia dubia 7-d chronic toxicity test. Water samples used in each test were collected from three areas in a bleached kraft pulp and paper mill using a 100% chlorine dioxide bleaching process: 1) river water prior to use in the mill; 2) the combined acid/base waste stream from the pulping process prior to biological treatment in the aerated stabilization basin (ASB); and 3) the effluent from the ASB with a retention time of approximately 11 d. Relative toxicity determined by the three tests for each water sampling location was compared. All three toxicity tests were predictive indicators of toxicity; however, the C. dubia and M. beryllina tests were the more similar and sensitive indicators of toxicity. Process water (ASB influent) prior to biological treatment in the ASB was toxic at all concentrations using the Microtox? and C. dubia tests. The fish embryo test showed no toxicity at 1% concentrations, slight toxicity at 10%, and acute toxicity at the 100% ASB influent concentration. Tests with biologically-treated ASB effluent indicated a substantial reduction in observed toxicity to Microtox? bacteria, C. dubia, and M. beryllina. No toxic responses were observed in any test at a 1% ASB effluent concentration which was the approximate effluent concentration in the receiving river following mixing. No relationship was found among any toxicological response and effluent levels of adsorbable organic halides, polychlorinated phenolic compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran, total suspended solids, color, chemical oxygen demand, or total organic carbon. Received: 27 February 1996/Revised: 4 September 1996     

Toxicity reduction evaluation at a municipal wastewater treatment plant using mutagenicity as an endpoint

Previous work revealed substantial levels of mutagenicity in effluents from certain municipal wastewater treatment plants. One of these treatment plants was selected for further study to track the effluent mutagenicity to its sources, to chemically characterize the mutagenicity, and to assess the treatability of the mutagens. Mutagenicity testing using the Salmonella/microsome assay was performed on methylene chloride extracts of influent and effluent samples from the municipal wastewater treatment plant, as well as on four selected industrial effluents entering the plant. The mutagenicity of the influent samples was detected only in the presence of a microsomal metabolic activation system and was highest in Salmonella strain TA98. About two-thirds of the mutagenicity passed through the treatment plant, suggesting that the mutagenic compounds were refractory to conventional biological treatment. No significant mutagenic activity was detected in three of the industrial waste streams, all paper products plant discharges. However, a high level of mutagenicity (1.2 million TA98 revertants/liter) was detected in the effluent from a coke oven plant. This source could account for all of the mutagenicity entering the wastewater treatment plant. After fractionation of the coke oven effluent by sequential extraction at neutral, acidic and basic pH with methylene chloride, 93% of the TA98 (+S9) mutagenicity was found in the neutral fraction. A C₁₈ column fractionation scheme using a methanol/water elution gradient revealed that 92% of the mutagenicity eluted with the 75% and the 80% methanol in water fractions. The C₁₈ fractionation also provided good separation of mutagenicity from toxicity to fathead minnows. This study has demonstrated the potential of toxicity reduction evaluation (TRE) methodology for tracing effluent toxicity to its source, using genotoxicity as an endpoint.Disclaimer. This article has been reviewed by the U.S. Environmental Protection Agency and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

Textile wastewater effluent toxicity identification evaluation

The need to control toxic substances in industrial and municipal wastewater effluents has led to the inclusion in National Pollutant Discharge Elimination System (NPDES) permits of requirements for testing toxicity to aquatic species. Recently, permitted wastewater effluents from particular textile dyeing and finishing operations exhibited a low degree of toxicity to the freshwater Cladoceran Daphnia pulex in acute, static, 48-h testing. An extensive effort was launched to determine components contributing to effluent toxicity. The toxicity identification evaluation combined three elements: fractionation of wastewater effluents, testing for aquatic toxicity, and analyses for specific chemicals. An anionic, speciated form of zinc was implicated as a major contributor to the toxicity. Water hardness was a principal determinant of zinc toxicity to Daphnia pulex.     

Ecotoxicity Assessment of Artificial Groundwater Recharge with Reclaimed Water: A Pilot-Scale Study

A demonstration of artificial groundwater recharge with tertiary effluent was evaluated using a set of bioassays (acute toxicity to Daphnia, genotoxicity, estrogenic and antiestrogenic toxicity). Around 95 % genotoxicity and 53 % antiestrogenicity were removed from the feed water by ozonation, whereas significant reduction of acute toxicity to Daphnia magna was achieved during a 3 days vadose soil treatment. The toxicity was further removed to the same level as the local groundwater during a 20 days aquifer soil treatment. The pilot study has shown that ozonation and soil treatments can improve the quality of municipal wastewater treatment plant effluents for possible groundwater recharge purposes.     

Ecotoxicological and chemical characterization of selected treatment process effluents of municipal sewage treatment plant

The triolein-containing semipermeable membrane devices (SPMDs) were deployed for 4 weeks in a sewage treatment plant in Beijing, China, to sample and concentrate priority hydrophobic organic pollutants in a sewage treatment process. The chemical analyses and ecotoxicities of the residuals of SPMDs dialysate were examined. The data from the chemical analyses by gas chromatography-mass spectrometry selected ion monitoring mode indicated the lower removal for polychlorinated biphenyls (PCB) congeners and polycyclic aromatic hydrocarbons (PAHs) coincided with the persistence of them in the environment. The acute toxicity examined by bioluminescence test with Vibrio fischeri revealed approximately only 20% decrease in the overall toxicity of the influent after the activate sludge treatment process. The ethoxy resorufin-O-deethylase (EROD) induction with a micro-EROD assay in vitro using H4-IIE rat hepatoma cell cultures demonstrated the presence of persistent organics in influent and sequency effluents. Results obtained suggested that integration of the SPMD technique and chemical analyses and bioassay might be a valuable approach for the risk assessment of hydrophobic organic pollutants in water ecosystem. It revealed the necessity for organic pollutants monitoring and ecotoxicities examining of sewage treatment plants.     

Evaluation of wastewater effluents by small-scale biotests and a fractionation procedure

Municipal and industrial effluents were screened with a battery of biotests and with a modified toxicity identification evaluation Phase I procedure. The acute toxicities of the effluent samples were low and the submitochondrial reverse electron-transport (RET) test was the most sensitive toxicity test. Estrogenic effects were found in almost all effluent samples, and genotoxicity was detected in one concentrated effluent sample. The fractionation methods we used proved to be especially effective at tracking toxicity caused by metals and organic contaminants, with the RET test being particularly suited to evaluating pH-dependent toxicity. The used solid-phase extraction columns with both hydrophilic and hydrophobic binding properties turned out to be suitable for removing or reducing organic toxicity-causing substances from the effluent samples. The results of this study show that the use of only conventional acute toxicity tests for effluent assessment will not be sufficient-the genotoxic, hormonal, and even bioaccumulative potential of the effluents and effluent fractions should be evaluated as well.     

Toxicity of Herbal Pharmaceutical Wastewater to a Freshwater Crustacean <Emphasis Type="Italic">Ceriodaphnia dubia</Emphasis>

The main objective of this study was to evaluate the acute toxicity of raw, neutralized and physico-chemically treated and biologically treated effluent of herbal pharmaceutical industry. The acute toxicity test was determined using freshwater crustacean Ceriodaphnia dubia under laboratory conditions. LC₅₀ values for raw, neutralized and physico-chemically treated effluent for 12, 24, 36 and 48 h ranged between 3.0–4.5%, 3.9–10.8% and 22–28% respectively. It is evident from the results that physicochemical treatment reduced the toxicity by around 25% while biological treatment reduced the toxicity completely. Results subjected to statistical evaluation depicted regression coefficient of more than 0.9 indicating good correlation between the mortality rate and effluent concentrations.     

Performance of Anaerobic Process on Toxicity Reduction During Treating Printing and Dyeing Wastewater

The paper was to evaluate anaerobic treatment efficiency of reducing toxic compounds by gas chromatography mass spectrometry (GC-MS) analysis combined with biological toxicity test during the treatment process of printing and dyeing wastewater. There had an obvious decrease trend in the response abundance of GC-MS chromatograms between raw influent and anaerobic effluents with the removal of COD. A main component of the raw effluent was long-chain n-alkanes. Alkanes in the expanded granular sludge bed (EGSB) categories could be reduced by 75%. EGSB had a better degradation performance on some complicated pollutants and toxicity. The most sensitive bioassay was Microtox bioassay.     

Assessment of toxicological profiles of the municipal wastewater effluents using chemical analyses and bioassays

The hazardous chemical contamination of untreated wastewater and secondary effluent from the wastewater treatment plant (WWTP) of the city of Zagreb, Croatia was comprehensively characterized using large-volume solid-phase extraction (SPE) and silica gel fractionation, followed by a detailed analysis of the resulting extracts by a combination of chemical and bioassay methods. Over 100 individual contaminants or closely related-contaminant groups were identified by high-resolution gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-QTOF). Ecotoxicity profiling of the investigated samples, including cytotoxicity, chronic toxicity and EROD activity; inhibition of the multixenobiotic resistance (MXR), genotoxicicity and estrogenic potential, revealed the most significant contribution of toxic compounds to be present in polar fractions. Wastewater treatment using conventional activated sludge process reduced the initial toxicity of raw wastewater to various extents, ranging from 28% for algal toxicity to 73.2% for an estrogenic activity. The most efficient toxicity removal was observed for the polar compounds.     

Influence of Dissolved Organic Matter on Acute Toxicity of Zinc to Larval Fathead Minnows (Pimephales promelas)

We conducted laboratory toxicity tests in support of the development of a biotic ligand model (BLM) to predict acute toxicity of zinc (Zn) to fathead minnows (Pimephales promelas). To test the effect of dissolved organic matter (DOM) on Zn toxicity, we exposed larval fathead minnows to Zn in water containing elevated concentrations of dissolved organic carbon (DOC) in 96-h static-renewal toxicity tests. We tested DOM isolated from four surface waters: Cypress Swamp, Delaware; Edisto River, South Carolina; Suwannee River, Georgia; and Wilmington, Delaware, wastewater treatment effluent. The DOM isolates from the Edisto River and Wilmington wastewater treatment effluent contained elevated concentrations of NaCl (20–110× control NaCl) due to the use of a Na⁺-exchange resin to remove Ca²⁺ and Mg²⁺ during the DOM isolation process. Therefore, we also performed Zn toxicity tests in which we added up to 20 mM NaCl to exposure solutions containing Cypress Swamp and Suwannee River DOM. A threshold concentration of 11 mg DOC/L was needed to decrease Zn toxicity, after which the 96 h Zn LC50 was positively correlated with DOC concentration. Elevated NaCl concentrations did not alter Zn toxicity in the presence of DOM. In conjunction with data from other studies with fish and invertebrates, results of this study were used to calibrate Version 2.1.1 of the Zn BLM. BLM-predicted LC50s for our exposure waters containing elevated DOM concentrations were within the range of acceptable deviation relative to the observed LC50s (i.e., 0.5–2× observed LC50s); however, BLM-predicted LC50s for our exposure waters containing < 1 mg DOC/L were 2–3× lower than the observed LC50s (i.e., the BLM over-predicted the toxicity). Therefore, the current composite-species BLM for Zn could be improved for fathead minnows if that species were modeled separately from the other species used to calibrate Version 2.1.1.     

Mutagenicity assessment of produced water during photoelectrocatalytic degradation

Oilfield produced water was treated by photocatalysis, electro-oxidation, and photoelectrocatalysis, respectively. The chemical composition and toxicity of the raw effluent and treated products were assessed by chemical and mutagenicity analysis. The raw effluent exhibited mutagenic activity in both strains of Salmonella typhimurium. The lowest concentration of the dichloromethane extract capable of inducing a positive response in strains TA98 and TA100 were as low as 4 and 5 microg/plate, respectively. All three technologies could detoxify direct-acting mutagenic organic pollutants efficiently, although they could not completely eliminate mutagenicity in the water after 60 min of treatment. At equivalent doses, photoelectrocatalysis exhibited the greatest capability to reduce genotoxicity, whereas photocatalysis was the least effective and did not cause appreciable change in mutagenicity. The gas chromatography-mass spectrometry (GC-MS) analysis revealed that n-alkanes (259.4 ng/L) and phenolic compounds (2,501.4 ng/L) were the main organic constituents in the oilfield produced water. Thus, the results of both biological and chemical analysis indicate that photoelectocatalysis was the most effective technology for degradation of oilfield wastewater.     

Evaluation of Ionic Contribution to the Toxicity of a Coal-Mine Effluent Using Ceriodaphnia dubia

The United States Environmental Protection Agency has defined national in-stream water-quality criteria (WQC) for 157 pollutants. No WQC to protect aquatic life exist for total dissolved solids (TDS). Some water-treatment processes (e.g., pH modifications) discharge wastewaters of potentially adverse TDS into freshwater systems. Strong correlations between specific conductivity, a TDS surrogate, and several biotic indices in a previous study suggested that TDS caused by a coal-mine effluent was the primary stressor. Further acute and chronic testing in the current study with Ceriodaphnia dubia in laboratory-manipulated media indicated that the majority of the effluent toxicity could be attributed to the most abundant ions in the discharge, sodium (1952 mg/L) and/or sulfate (3672 mg/L), although the hardness of the effluent (792 ± 43 mg/L as CaCO₃) ameliorated some toxicity. Based on laboratory testing of several effluent-mimicking media, sodium- and sulfate-dominated TDS was acutely toxic at approximately 7000 μS/cm (5143 mg TDS/L), and chronic toxicity occurred at approximately 3200 μS/cm (2331 mg TDS/L). At a lower hardness (88 mg/L as CaCO₃), acute and chronic toxicity end-points were decreased to approximately 5000 μS/cm (3663 mg TDS/L) and approximately 2000 μS/cm (1443 mg TDS/L), respectively. Point-source discharges causing in-stream TDS concentrations to exceed these levels may risk impairment to aquatic life.     

Comparative Whole Effluent Toxicity Assessment of Wastewater Treatment Plant Effluents using Daphnia magna

An approach to compare the toxicities employing the whole effluent toxicity (WET) test, using Daphnia magna and chemical analysis with GC/MS and ICP/MS, was conducted to the nine South Korean wastewater treatment plants (WWTPs). From the chemical analysis and bioassay experiments, heavy metals (i.e., Cu and Zn) were found to be the major compounds causing toxic effects toward D. magna. In the whole effluent toxicity (WET) tests using D. magna, toxicities were observed in 34% of the effluent samples. However, the biological toxic unit (TU) value showed a non-toxic response (i.e., 0 TU) in many samples despite the response indicated by the chemical TU values. This may be due to the species sensitivity, environmental parameters, mixture effects, and limitation of the chemical analyses.     

Potential Risks of Effluent from Acid Mine Drainage Treatment Plants at Abandoned Coal Mines

The lethal and sublethal toxicity of effluent from three acid mine drainage treatment plants were monitored from August 2009 to April 2010 using Daphnia magna (reference species) and Moina macrocopa (indigenous species). Acute lethal toxicity was observed in Samma effluent due to incomplete neutralization of acid mine drainages by the successive alkalinity producing system (SAPS). Additionally, there was no significant difference in toxicity values (TU) between D. magna and M. macrocopa (p < 0.05). Toxicity identification results of the final effluent collected in January 2010 showed that Al and Zn were key toxicants in addition to acidic pH. Unlike the Samma effluent, both Hwangji and Hamtae effluent had pH values that were near neutrality and showed either no acute toxicity or toxicity values less than 1 TU. However, the feeding rates of D. magna and M. macrocopa were significantly reduced when compared to the control (p < 0.05). These findings suggest that the Hamtae and Hwangji effluent likely have a sublethal effect on aquatic organisms in receiving water bodies.