Effluent Discharge Point Research Articles

Assessment of persistent organic pollutants in water samples from River Challawa in Kano, Nigeria

<p>This study was aimed at assessing the levels Persistent Organic Pollutant in Challawa River Basin of Kano State, Nigeria. The investigation was particularly plan to assess the presence of PCBs and PAHs in River Challawa and compare the concentrations of the pollutants with the acceptable limit set by Nigerian Standard and other international regulatory agencies. Data were collected using reconnaissance survey; laboratory experiment as well as other secondary data sources. A total of 26 water samples were collected through stratified and systematic random sampling. Three sampling points were chosen and designated A, B and C along the stretch of the river from Yan Danko Bridge to Tamburawa bridge. The result shows that Polychlorinated biphenyls were not detected but polycyclic aromatic hydrocarbons were detected in all the samples analyzed using GCMS. The total concentrations of PAHs in the water samples range between 0.001 to 0.087mg/l. The analytical results revealed that most of the pollutants present in water were at significantly very high levels especially at Zamawa village situated very close to Challawa industrial estate - the major sources of effluent discharge point, making the drinking water around area is not fit for consumption. In conclusion, it can be said that industrial activities had impact on Challawa River basin and its environment. It is recommended among others that the industries should treat their effluents before releasing them into Challawa river basin. </p><p> </p><p>Keywords: persistent, organic, pollutant, challawa river, Nigeria</p>

Composition of Fungal Flora in Raw Refinery Effluent, Effluent Retention Pond and a Treated Effluent Recipient River

Investigations were carried out to determine the composition of fungal flora in the studied sites. Samples of the raw effluent were collected along the flow channel and the retention pond. Water samples were also collected at the discharge point and up and down stream of the river from the discharge point. The samples were spinned at a speed of 250rpm for 10minutes and spread inoculated the deposits on potato carrot agar (PCA) and potato agar supplemented with 7.5% Nacl. Inoculated plates were incubated aerobically at room temperature in dark cupboard for 7days. Fungal colonies that emerged on the primary culture plates were distinguished into types. The pure isolates were characterized into genera using standard taxonomic guides. Genera such as Aspergillus, Penicillium, Curvularia, Fusarium, Microsporum, Trichoderma, Rhizoctonia, Nigrospora and Chaetophoma species were detected in the raw effluent. However, Microsporum, Trichoderma, Rhizoctonia, Nigrospora and Chaetophoma species were conspicuously absent in the effluent retention pond. Only Trichoderma and Chaetophoma species were absent in water samples collected at the treated effluent discharge point into the recipient River. Samples of water collected up stream of the discharge point did not contain Geotrichum, Nigrospora and Chaetophoma species. Curvularia, Microsporum, Rhizoctonia and Nigrospora species were not detected in water samples collected downstream of the discharge point. It was therefore concluded that, fungi constitute a significant proportion of the microflora of sites contaminated with the refinery effluent and could be playing an important role in the remediation of sites receiving the effluent. © JASEM Keywords : Fungal flora, Refinery effluent, Retention ponds, Discharge point, Upstream, Downstream

Ecological risk assessment of the antibiotic enrofloxacin applied to Pangasius catfish farms in the Mekong Delta, Vietnam

Antibiotics applied in aquaculture production may be released into the environment and contribute to the deterioration of surrounding aquatic ecosystems. In the present study, we assessed the ecological risks posed by the use of the antibiotic enrofloxacin (ENR), and its main metabolite ciprofloxacin (CIP), in a Pangasius catfish farm in the Mekong Delta region, Vietnam. Water and sediment samples were collected in a stream receiving effluents from a Pangasius catfish farm that had applied ENR. The toxicity of ENR and CIP was assessed on three tropical aquatic species: the green-algae Chlorella sp. (72h – growth inhibition test), the micro-invertebrate Moina macrocopa (48h – immobilization test), and the Nile tilapia (Oreochromis niloticus). The toxic effects on O. niloticus were evaluated by measuring the cholinesterase (ChE) and catalase (CAT) activities in the fish brain and muscles, respectively, and by considering feed exposure and water exposure separately. Ecological risks were assessed by comparing maximum exposure concentrations with predicted no effect concentrations for cyanobacteria, green algae, invertebrates and fish derived with available toxicity data. The results of this study showed that maximum antibiotic concentrations in Pangasius catfish farm effluents were 0.68μgL−1 for ENR and 0.25μgL−1 for CIP (dissolved water concentrations). Antibiotics accumulated in sediments down-stream the effluent discharge point at concentrations up to 2590μgkg−1 d.w. and 592μgkg−1 d.w. for ENR and CIP, respectively. The calculated EC50 values for ENR and CIP were 111000 and 23000μgL−1 for Chlorella sp., and 69000 and 71000μgL−1 for M. macrocopa, respectively. Significant effects on the ChE and CAT enzymatic activities of O. niloticus were observed at 5gkg−1 feed and 400–50000μgL−1, for both antibiotics. The results of the ecological risk assessment performed in this study indicated only minor risks for cyanobacteria communities, suggesting that residual concentrations of ENR and CIP after medication are not likely to result in severe toxic effects on exposed aquatic ecosystems. However, more studies should be performed by considering other antibiotic treatments used in Pangasius catfish production and the potential ecotoxicological effects of relevant antibiotic mixtures on sediment communities.

Industrial Effluent Induced Chromosomal Aberration in Catfish from Ogun River, Lagos, Nigeria

The aim of the study is to evaluate the cytotoxic effect of effluents at inducing chromosomal aberrations, using this as a biomarker tool in wild Clarias pachynema for assessing and monitoring pollution of the aquatic environment. A total of 60 live fish (30 each downstream and upstream) were obtained and subjected to chromosomal analysis. Chromosomal aberration in the fish samples from the downstream sector was recorded at a rate of 30%, while there were no aberrations in the samples collected upstream the effluent discharge point. Water sample analysis revealed a high concentration of Ammonia and Nitrates above permissible standards of Federal Environmental Protection Agency (FEPA) guidelines. Heavy metal analysis also revealed the presence of Cr (0.05), Cu (0.01), Pb (0.05), Zn (5.0) and Fe (0.3) above permissible standards from the downstream section of the river. This study shows clearly that the ever increasing discharge of effluents from the industry could increase chromosomal damage in the aquatic components.

Analysis of surface water pollution from abattoirs and the interrelationship between physico-chemical properties (A case study of the New Calabar River)

The effects of discharged untreated abattoir waste on water quality and the interrelationship between analysed physico-chemical properties were studied. Samples were taken at the point of effluent discharge, up as well as downstream of source and basic water quality parameters were determined. Correlations were observed between the oxygen availability (BOD5 COD) and Cl, Mg as well as Ca concentrations. An increase in the salt content of the river was observed to correlate with an increase in the Total Solids (TS) and Total Suspended Solids (TSS), while the dissolved oxygen content, also showed an increasing effect with increasing river pH .Using the Prati et al, classification of surface water quality, the river was assessed to be polluted. Although the discharge of human and domestic waste into the water body was a major source of pollution, the introduction of the abattoir effluent midstream had a significant negative effect, contributing to the poor health of the analysed river.

Comprehensive monitoring of synthetic musk compounds from freshwater to coastal environments in Korea: With consideration of ecological concerns and bioaccumulation

This study investigated the concentration levels of synthetic musk compounds (SMCs), including HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), MK (Musk ketone), and MX (Musk xylene), in freshwater, freshwater and coastal sediments, and coastal bivalves from freshwater to coastal environments. The levels in freshwater close to sewage treatment plants (STPs) showed higher contamination and suggested a medium to high ecological risk, especially posed by MK making more than 65% contribution to the combined risk by the total SMCs. STP effluent discharge points showed higher SMC concentrations in freshwater and coastal sediments. Predominant HHCB contributions regardless of sample types such as abiota and biota were consistent with the greater usage of HHCB than AHTN and MK in Korea. However, the higher contributions of AHTN than those predicted from AHTN consumption in Korea indicate the need for further research on the characteristic properties of individual SMCs, including partitioning, biomagnification, degradation, and metabolism for a realistic risk characterization. With respect to the highest HHCB levels in coastal bivalves reported, we determined the biota-sediment accumulation factor (BSAF) to understand the bioaccumulation of SMCs between coastal sediment and bivalves. The calculated BSAF values suggested that SMCs in bivalves were not biomagnified via the food chain but mostly partitioned from sediment. To our knowledge, this is the first study to measure BSAF values of SMCs, especially HHCB, AHTN, and MK, in coastal bivalve samples.

The Optimized Model of Town Sewage Structure Charge and its Computing

In reference to international regional sewage pipe network and sewage treatment plant planning, the actual situation of China's villages and small town was investigated. According to the costs data from presented sewage pipe and sewage treatment plant construction system, the model on the sewage pipe network and sewage treatment plant charge was obtained. Then the model was simplified to be calculating the shortest distance between the wastewater treatment plant and the effluent discharge point. The suitable computing method for the shortest distance is building the minimum spanning tree. The software for computing was written with prim algorithm. The computing results can be used as a planning and design reference of sewage pipe network. The model method can be used for design program to select long-distance transmission or local treatment of the sewage.

Study of heavy metals pollution and physico-chemical assessment of water quality of River Owo, Agbara, Nigeria

The various selected physicochemical and biological condition of freshwater bodies which receive varying number of outfalls of industrial and domestic effluents containing heavy metals of River Owo, Agbara Industrial Estate, a boundary town between Lagos and Ogun state, along Badagry Expressway in Nigeria, was assessed for five consecutive months. Four sampling points were chosen from the water body to reflect the effect of industrial effluent, domestic effluent and lotic habitats. Temperature, pH, salinity, total alkalinity, total hardness (TH), total settle-able solids (TSS), dissolved oxygen (DO), turbidity, biochemical oxygen demand (BOD), ammonia, phosphate, chloride level, sulphate, nitrate, cadmium, chromium, copper, iron, lead, manganese zinc, colour were analyzed monthly between November 2007 and March 2008 using standard methods and procedures. The ranges of these factors were found to be comparable to the recommended limit of the Lagos State Environment Protection Agency (LASEPA) 2001 and the Federal Environmental Protection Agency (FEPA) except for biochemical oxygen demand (BOD), ammonia, phosphate, cadmium, chromium, lead, copper and Iron which were found in higher concentrations at sampling point B (effluent discharge point) above LASEPA, FEPA and Freshwater limit. DO of the three sampling points A, C and D were between recommended limit but slightly low at point B (effluent discharge point), which is less than the recommended limit. The level of pollution is more pronounced at sampling point B due to the greater amount of BOD and the release of some heavy metals like cadmium, chromium and lead which greatly affect the water quality of the river. The study concludes that River Owo is slightly polluted while the pollution is as a result from the discharge of effluents by the companies, factory and materials from other anthropogenic sources. Key words: Industrial and domestic effluent, biochemical physicochemical condition oxygen demand (BOD), heavy metals, monitoring, anthropogenic sources.

Assessment and monitoring of nutrient loading in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam

Coastal shrimp farming may lead to the contamination of sediments of surrounding estuarine and marine ecosystems as shrimp farm effluent often contains high levels of pollutants including a range of organic compounds (from uneaten feed, shrimp feces, and living and dead organisms) which can accumulate in the sediments of receiving waterways. The assessment and monitoring of sediment quality in tidal creeks receiving shrimp farm effluent can support environmental protection and decision making for sustainable development in coastal areas since sediment quality often shows essential information on long-term aquatic ecosystem health. Within this context, this paper investigates nutrient loadings in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam, which now have a high concentration of intensive and semi-intensive shrimp farms. Sediment samples taken from inside creek sections directly receiving effluent from concentrated shrimp farms (IEC), from main creeks adjacent to points of effluent discharge outside concentrated shrimp farms (OEC), and few kilometers away from shrimp farms (ASF) as reference sites were collected and analyzed before and after shrimp crops to investigate spatial and temporal variation. The results showed that there were statistically significant differences in the concentrations of total nitrogen, total phosphorus, and total organic carbon among IEC, OEC, and ASF sites while the seasonal variation being limited over study times. A sediment nutrient index (SNI) computed from coefficient scores of the factor analysis efficiently summarizes sediment nutrient loads, which are high, albeit quite variable, in canals directly receiving effluents from farms but then decline sharply with distance from shrimp farms. The visualization and monitoring of sediment quality data including SNI on maps can strongly support managers to manage eutrophication at concentrated shrimp farming areas, contributing to sustainable development and management at coastal zones.

Foraging at wastewater treatment works increases the potential for metal accumulation in an urban adapter, the banana bat (Neoromicia nana)

Wastewater treatment works (WWTWs) are known to provide profitable foraging areas for insectivorous bats in Europe and the New World because of their association with high abundance of pollution-tolerant midges (Diptera). However, bats that feed on these insects may also accumulate metal pollutants such as cadmium and copper in their tissues, with acute or chronic effects on their health. Using a time expansion bat detector, the activity (number of passes and feeding buzzes) of Neoromicia nana (family Vespertilionidae) was quantified at threeWWTWpoints – upstream, the point of wastewater effluent discharge, and downstream – along three urban rivers in South Africa. In addition, metal concentrations in the kidney, liver and muscle tissue of N. nana caught at the sites were quantified. The diversity of aerial insects, sampled over the same period as the bat surveys, was measured using a black light trap and sweep-netting. Relative abundance and feeding activity of N. nana were higher at wastewater-polluted sites than at upstream sites. The most abundant insect order at wastewater-polluted sites and in the diet of resident bats was Diptera. Essential metals (copper, zinc and iron) were detected in all N. nana tissue samples, but the toxic metals cadmium, chromium and nickel were mostly present in tissue of bats at wastewater-polluted sites. Thus, although WWTWs provide an optimal food resource to bats in the short-term, it may pose serious long-term health risks for these top predators.

Identification of organic xenobiotics in urban aquatic environments using time-of-flight mass spectrometry

Qualitative non-target and post-target analysis methods using gas chromatography–time-of-flight mass spectrometry were applied for analysing neutral and acidic organic xenobiotics in urban and suburban water samples. Ten water samples representing wastewater, stormwater and surface water matrices were collected and concentrated using solid phase extraction. Compound identification was performed using a spectral deconvolution program, accurate mass measurements and comparisons with library spectra. The non-target and post-target analyses identified 36 and 18 compounds, respectively. The identification of 10 compounds was afterwards confirmed with standard compounds. Organophosphate esters were the most abundant compound group detected. The combination of non-target and post-target analyses proved a useful tool in the tentative identification of xenobiotics in water samples. Post-target analysis can complement non-target analysis results at low analyte concentrations. Results showed that several organic xenobiotics originate in urban areas and accumulate in the environment. The wastewater sample produced the highest number of identified compounds, but most of these compounds were also found in stormwater samples from the city centre. Nearly all the compounds present in wastewater were additionally detected in the surface water sample taken 3km downstream from the wastewater effluent discharge point. Only a few xenobiotics were otherwise detected in the surface water samples.

Fish community responses to multiple municipal wastewater inputs in a watershed

Municipalities utilize aquatic environments to assimilate their domestic effluent resulting in eutrophication, anoxia, toxicity and endocrine disruption of aquatic biota. The objective of this study was to assess the potential cumulative impacts of municipal wastewater effluent (MWWE) discharges in the Grand River on the health status of a sentinel species and the fish community downstream of 2 MWWE discharges. The fish communities downstream of the MWWE outfalls demonstrated differences in the abundance and diversity, species and family richness, % tolerance and % vulnerability when compared to the fish community upstream or further downstream of these points of effluent discharge. In both years studied, the fish community exposed to MWWE in the riffle-run habitats demonstrated reductions in the proportion of the most prominent fish (Rainbow Darter, Ethoestoma caeruleum) downstream of the outfalls, and a significant increase in the proportion of large mobile, tolerant-omnivorous fish species such as suckers and sunfish. There was less variability in the responses of the fish community to MWWE in the same season between years than between seasons within the same year. An examination of how impaired health of a sentinel species exposed to MWWE discharges parallels changes in the fish community is also conducted. This study successfully demonstrates the cumulative impact of urban development, including multiple outfalls of treated wastewater effluents on fish populations and communities. Municipalities are the major source of nutrients and pharmaceuticals and personal care products to aquatic systems, and they need to consider their impacts carefully with increasing urban population growth and ageing demographics.

Impact of Aquaculture on Water Quality in Lake Kariba, Zimbabwe

This study investigated the water quality at the aquaculture effluent discharge points in Lake Kariba. Water samples were collected at three sites designated Site 1 (Crocodile Farm effluent discharge point), Site 2 (Fish Farm effluent discharge point) and Site 3 (Control point) from the month of September 2011 to January, 2012. Physico-chemical variables (temperature, total dissolved solids, turbidity, pH, conductivity, nitrates, ammonia, and ortho-phosphate) were measured. Turbidity, total dissolved solids, pH and conductivity were found to be significantly (ANOVA, p<0.05) high at aquaculture effluentdischarge points compared to the control point. Relative to the World Health Organisation (WHO) and Environmental Management Authority of Zimbabwe (EMA-SI) guidelines for aquatic waters, turbidity, nitrates and ammonia at site 1 and site 2 were found to exceed the maximum allowable limit (5NTU), 10 mg/L and 0.05 mg/L respectively while dissolved oxygen was below the minimum allowable limit of 5 mg/L. All other physico-chemical parameters were within the accepted range at all stations. While the physico-chemical results indicated deteriorating water quality at the discharge point due to the effluent inflow, the large water volume in Lake Kariba plays an important factor in diluting aquaculture effluent.

Foraging at Wastewater Treatment Works Increases the Potential for Metal Accumulation in an Urban Adapter, the Banana Bat (Neoromicia nana)

Wastewater treatment works (WWTWs) are known to provide profitable foraging areas for insectivorous bats in Europe and the New World because of their association with high abundance of pollution-tolerant midges (Diptera). However, bats that feed on these insects may also accumulate metal pollutants such as cadmium and copper in their tissues, with acute or chronic effects on their health. Using a time expansion bat detector, the activity (number of passes and feeding buzzes) of Neoromicia nana (family Vespertilionidae) was quantified at threeWWTWpoints – upstream, the point of wastewater effluent discharge, and downstream – along three urban rivers in South Africa. In addition, metal concentrations in the kidney, liver and muscle tissue of N. nana caught at the sites were quantified. The diversity of aerial insects, sampled over the same period as the bat surveys, was measured using a black light trap and sweep-netting. Relative abundance and feeding activity of N. nana were higher at wastewater-polluted sites than at upstream sites. The most abundant insect order at wastewater-polluted sites and in the diet of resident bats was Diptera . Essential metals (copper, zinc and iron) were detected in all N. nana tissue samples, but the toxic metals cadmium, chromium and nickel were mostly present in tissue of bats at wastewater-polluted sites. Thus, although WWTWs provide an optimal food resource to bats in the short-term, it may pose serious long-term health risks for these top predators. Key words : Neoromicia nana , urban adapter, wastewater metal pollution, chironomid midge, diet.

The effect of sewage effluent on the physico-chemical and biological characteristics of the Sand River, Limpopo, South Africa

Population growth in urban areas is putting pressure on sewage treatment plants. The improper treatment of sewage entering the aquatic ecosystems causes deterioration of the water quality of the receiving water body. The effect of sewage effluent on the Sand River was assessed. Eight sampling sites were selected, site 1 and 2 were upstream of the sewage treatment plant along the urbanised area of Polokwane, whilst sites 3, 4, 5, 6, 7 and 8 were downstream. The physico-chemical parameters and coliform counts in the water samples were determined. The suitability of the water for irrigation was also determined. Hierarchical average linkage cluster analysis produced two clusters, grouping two sites above the sewage treatment works and six sites downstream of the sewage effluent discharge point. Principal component analysis (PCA) identified total nitrogen, total phosphorus, conductivity and salinity as the major factors contributing to the variability of the Sand River water quality. These factors are strongly associated with the downstream sites. Canonial correspondence analysis (CCA) indicated the macroinvertebrates, Chironomidae, Belastomatidae, Chaoborus and Hirudinea being strongly associated with nitrogen, phosphorus, conductivity and temperature. Escherichia coli levels in the Polokwane wastewater treatment works maturation ponds, could potentially lead to contamination of the Polokwane aquifer. The Sodium Adsorption Ratio was between 1.5 and 3.0 and residual sodium carbonate was below 1.24 Meq/l, indicating that the Sand River water is still suitable for irrigation. The total phosphorus concentrations fluctuated across the different site. Total nitrogen concentrations showed a gradual decrease downstream from the point of discharge. This shows that the river still has a good self-purification capacity.

Anthropogenic radiotracers assessment as tool to environmental compliance rules and management

A framework, within models and studies can be applied, to develop coherent and logical environmental impact management methodologies for ionizing radiation, is essential. A number of components, which form the basis for such a system, included the dilution factor for radioactive liquid effluent releases. In this study we established a strategic, fast and cheap methodology to estimate the dilution factor for the release of liquid radioactive effluents at IPEN. The radioisotopes 3H, 54Mn, 60Co, 65Zn, and 137Cs, generated in the routine operation of the Research Reactor IEA-R1, were used as radiotracers. The generated liquid radioactive effluent was stored in a 300 m3 capacity tank. The initial concentration of its present radioisotopes were determined. A planned release of effluent from the storage tank was carried-out. Simultaneously, the sampling was made upstream of the storage tank discharge point and the concentration 3H, 54Mn, 60Co, 65Zn and 137Cs in the mix sewerage system discharge point E1 at IPEN were monitored. The estimated dilution factor of discharge point of the aqueous effluent for 3H was 4.3 and 7.4, 54Mn was12 and 16.1, 60Co was 12.6 and 14.2, 65Zn was 12 and 27.9 and 137Cs was 6.2 and 13.9, respectively.

Impact of Shrimp Farm Effluent on Water Quality in Coastal Areas of the World Heritage-Listed Ha Long Bay

Problem statement: Shrimp farming has rapidly developed in coastal areas of the World Heritage-listed Ha Long Bay since the last decade. Effluent discharged from shrimp farms with high levels of nutrient waste may cause eutrophication in receiving waterways. Therefore, assessing water quality at tidal creeks receiving shrimp farm effluent in coastal areas of Ha Long Bay supports environmental protection and decision making for sustainable development of the region. Approach: Water samples were collected at 3 different locations for spatial assessment: inside sections of creeks directly receiving farm effluent (IEC), from main creeks adjacent to points of effluent discharge outside concentrated shrimp farms (OEC) and a few kilometers away from shrimp farm (ASF). Samples were taken on 3 occasions for temporal assessment. Parameters related to nutrient waste from shrimp farms, including: Total Ammonia Nitrogen (TAN), Nitrite-Nitrogen (NO2-N), Nitrate-Nitrogen (NO3-N), Total Phosphorus (TP), Dissolved Orthophosphate (PO4-P), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), Chlorophyll-a (Chl-a), Temperature, Salinity, pH and Dissolved Oxygen (DO) were determined using standard methods. Results: There were statistically significant differences in the concentrations of TAN, NO2-N, NO3-N, TP, PO4-P, BOD, COD and Chl-a among IEC, OEC, ASF and the levels of these parameters increased after shrimp crops, especially after the main shrimp crop of the season in North Vietnam. The concentrations of TAN, NO3-N, TP, BOD, COD, Chl-a, TSS at IEC sites were higher than recommended for protecting aquatic ecosystems. Principal Component Analysis (PCA) efficiently summarized patterns of co-variation in water quality parameters among locations and study times. Conclusion/Recommendations: The findings of this study indicate that greater awareness of the environmental impacts of shrimp farms is required if this industry is to be sustainable and if the highly valued marine ecosystem of Ha Long Bay is to be protected for the future.

Monitoring release of pharmaceutical compounds: Occurrence and environmental risk assessment of two WWTP effluents and their receiving bodies in the Po Valley, Italy

This study describes an investigation on the occurrence of 27 pharmaceutical compounds, belonging to different classes, in the effluent from two wastewater treatment plants (WWTPs) and their receiving water bodies in the sensitive area of the Po Valley (northern Italy). These canals were monitored upstream and downstream of the effluent discharge points in order to evaluate the effluent impact on the quality of surface waters, commonly used for irrigation. An environmental risk assessment was also conducted by calculating the risk quotient, i.e. the ratio between measured concentration and predicted no effect concentration.Collected data show that, although average values of the selected compounds were in general higher in the effluent than in the surface waters, some compounds not detected in the WWTP effluent were detected in the receiving water (upstream as well as downstream), indicating that sources other than treated effluents are present as contaminations during extraction and analysis have to be excluded. The most critical compounds for the environment were found to be the antibiotics sulfamethoxazole, clarithromycin and azithromycin. The study shows that the potential toxicological effects of persistent micropollutants can be mitigated to some extent by a high dilution capacity, i.e. a high average flow rate in the receiving water body with respect to the effluent.

Spatial and temporal trends in water quality in a Mediterranean temporary river impacted by sewage effluents

This paper analyzes how changes in hydrological conditions can affect the water quality of a temporary river that receives direct inputs of sewage effluents. Data from 12 spatial surveys of the Vène river were examined. Physico-chemical parameters, major ion, and nutrient concentrations were measured. Analyses of variance (ANOVA) and multivariate analyses were performed. ANOVA revealed significant spatial differences for conductivity and major ion but no significant spatial differences for nutrient concentrations even if higher average concentrations were observed at stations located downstream from sewage effluent discharge points. Significant temporal differences were observed among all the parameters. Karstic springs had a marked dilution effect on the direct disposal of sewage effluents. During high-flow periods, nutrient concentrations were high to moderate whereas nutrient concentrations ranged from moderate to bad at stations located downstream from the direct inputs of sewage effluents during low-flow periods. Principal component analysis showed that water quality parameters that explained the water quality of the Vène river were highly dependent on hydrological conditions. Cluster analysis showed that when the karstic springs were flowing, water quality was homogeneous all along the river, whereas when karstic springs were dry, water quality at the monitoring stations was more fragmented. These results underline the importance of considering hydrological conditions when monitoring the water quality of temporary rivers. In view of the pollution observed in the Vène river, "good water chemical status" can probably only be achieved by improving the management of sewage effluents during low-flow periods.

Acidic pharmaceuticals in domestic wastewater and receiving water from hyper-urbanization city of China (Shanghai): environmental release and ecological risk

The occurrence, behavior, and release of five acidic pharmaceuticals, including ibuprofen (IBP), naproxen (NPX), ketoprofen (KEP), diclofenac (DFC), and clofibric acid (CA), have been investigated along the different units in a tertiary-level domestic wastewater treatment plant (WWTP) in hyper-urbanization city of China (Shanghai). IBP was the most abundant chemicals among the measured in raw wastewater. The loads of the acidic pharmaceuticals in the WWTP influent ranged from 7.5 to 414 mg/day/1,000 inh, which were lower than those reported in the developed countries suggesting a less per capita consumption of pharmaceuticals in Shanghai. IBP obtained by highest removal (87 %); NPX and KEP were also significantly removed (69-76 %). However, DFC and CA were only moderately removed by 37-53 %, respectively. Biodegradation seemed to play a key role in the elimination of the studied pharmaceuticals except for DFC and CA. An annual release of acidic pharmaceuticals was estimated at 1,499 and 61.7 kg/year through wastewater and sludge, respectively, from Shanghai. Highest pharmaceuticals concentrations were detected in the effluent discharge point of the WWTP, indicating that WWTP effluent is the main source of the acidic pharmaceuticals to its receiving river. Preliminary results indicated that only DFC in river had a high risk to aquatic organisms. Nevertheless, the joint toxicity effects of these chemicals are needed to further investigate.