Simultaneous quantitative monitoring of four indicator contaminants of emerging concern (CEC) in different water sources of Central India using SPE/LC-(ESI)MS-MS

Environmental occurrence of CECs poses a great threat to both aquatic life and human health. The aim of this study was to optimize and validate SPE/LC-(ESI)MS-MS method for simultaneous quantitative monitoring of two sub-classes of CECs (pharmaceuticals and hormones) and to estimate the concentrations of select CECs in environmental water samples. For all the tested analytes, recoveries in laboratory reagent water were greater than 81%. Average percent (relative standard deviation) RSD of the analytes in recovery, repeatability, and reproducibility experiments were ≤?10%. Determination coefficients (r²) of primidone, diclofenac, testosterone, and progesterone were estimated to be 0.9979, 0.9972, 0.9968, and 0.9962, respectively. Limits of detection (LOD) for primidone, diclofenac, testosterone, and progesterone were 4.63 ng/L, 5.36 ng/L, 0.55 ng/L, and 0.88 ng/L, respectively. Limits of quantification (LOQ) for primidone, diclofenac, testosterone, and progesterone were 14.72 ng/L, 17.06 ng/L, 1.766 ng/L, and 2.813 ng/L, respectively. Average recoveries in environmental water and wastewater samples were greater than 74% and RSD were ≤?7%. Trace levels (68.33–125.70 ng/L) of primidone were detected in four environmental water samples, whereas diclofenac was not detected in any of the tested sample. Trace levels of progesterone were observed in two environmental samples (16.64 –203.73 ng/L), whereas testosterone was detected in STP inlet sample (178.16 ng/L).     

Occurrence of perfluorinated compounds in the aquatic environment as found in science park effluent,river water,rainwater, sediments,and biotissues

The current article maps perfluoroalkyl acids (PFAAs) contamination in the largest Science Park of Taiwan. The occurrence of ten target PFAAs in the effluent of an industrial wastewater treatment plant (IWWTP), its receiving rivers, rainwater, sediment, and the muscles and livers of fish was investigated. All target PFAAs were found in effluent of IWWTP, in which perfluorooctane sulfonate (PFOS) (6,930 ng/L), perfluorohexyl sulfonate (PFHxS) (2,662 ng/L) and perfluorooctanoic acid (PFOA) (3,298 ng/L) were the major constituents. Concentrations of PFBS and PFOS in the IWWTP downstream areas have exceeded safe concentration levels of avian and aquatic life, indicating a potential risk to wildlife in those areas. In sediment samples, predominant contaminants were PFOS (1.5–78 ng/g), PFOA (0.5–5.6 ng/g), and perfluorododecanoic acid (PFDoA) (nd–5.4 ng/g). In biological tissue samples, concentrations as high as 28,933 ng/g of PFOS were detected in tilapia and catfish liver samples. A positive correlation for log (C _sediment/C _water) and log (C _tissue/C _water) was found. The concentration and proportion (percentage of all PFAAs) of PFOS found in biotissue samples from the Keya River (which receives industrial wastewater) were found to be much greater (200 times) than those of samples from the Keelung River (which receives mainly domestic wastewater). These findings suggest that the receiving aquatic environments and, in turn, the human food chain can be significantly influenced by industrial discharges.     

Occurrences and fate of selected human antibiotics in influents and effluents of sewage treatment plant and effluent-receiving river Yamuna in Delhi (India)

Antibiotics consumption has increased worldwide, and their residues are frequently reported in aquatic environments. It is believed that antibiotics reach aquatic water bodies through sewage. Medicine consumed for healthcare practices are often released into sewage, and after sewage treatment plant, it reaches the receiving water bodies of lakes or rivers. In the present study, we determined the fate of some commonly used antibiotics in a sewage treatment plant (STP) located in Delhi and the environmental concentration of these antibiotics in the Yamuna River, which receives the sewage and industrial effluent of Delhi. There are many reports on antibiotics occurrences in STP and river water worldwide, but monitoring data from the Indian subcontinent is sparse. Samples were taken from a STP and from six sampling sites on the Yamuna River. Several antibiotics were tested for using offline solid-phase extraction followed by high-performance liquid chromatography equipped with photodiode array analysis. Recoveries varied from 25.5–108.8 %. Ampicillin had the maximum concentration in wastewater influents (104.2?±?98.11 μg l^?1) and effluents (12.68?±?8.38 μg l^?1). The fluoroquinolones and cephalosporins had the lower concentrations. Treatment efficiencies varied between 55 and 99 %. Significant amounts of antibiotics were discharged in effluents and were detected in the receiving water body. The concentration of antibiotics in the Yamuna River varied from not detected to 13.75 μg l^?1 (ampicillin) for the compounds investigated.     

Behaviour of selected endocrine-disrupting chemicals in three sewage treatment plants of Beijing, China

Occurrence and fate of eight kinds of selected endocrine-disrupting compounds (EDCs) in three sewage treatment plants (STPs) of Beijing, China was investigated. These EDCs, composed of 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), bisphenol A (BPA), estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2), in every step of STPs, were simultaneously analysed by gas chromatography/mass spectrometry after derivatisation. All the EDCs were detected in the influents of three STPs, and BPA was the most abundant compound. The concentrations of EDCs ranged from 36.6 ng/l of 17α-E2 (STP C) to 1342.3 ng/l of BPA (STP B) in the influent sewages and from below limits of detection of E2 and E3 (STP C) to 142.5 ng/l of E1 (STP B) in the effluent sewages. The STPs could not remove alkylphenols effectively from the aqueous phase with less than 40% reduction. BPA decreased over 90%, and steroid estrogens achieved considerable reductions from 64.8% of E2 to 94.9% of E3. Generally, biological treatment was more effective in removing alkylphenols, BPA and natural estrogens from the aqueous phase than primary treatment. However, the synthetic estrogen, EE2, was mostly removed by the primary treatment with about 63.5% reduction. It is the first time that the concentration of 17α-E2 in the sewage of China was reported in this paper. The compound might have a bearing with the waste effluents of dairy farms around urban area of Beijing.     

Occurrence and behavior of non-steroidal anti-inflammatory drugs and lipid regulators in wastewater and urban river water of the Pearl River Delta, South China

Occurrence of five non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, naproxen, indomethacin and diclofenac) and three lipid regulators (bezafibrate, clofibric acid and gemfibrozil) was investigated in wastewater, sewage sludge, and river water of the urban section of the Pearl River at Guangzhou in South China. Behavior and fate of the pharmaceuticals during treatment in two sewage treatment plants (STPs) were also studied in depth by determining concentrations in the influents and effluents at major treatment units and the sewage sludge. Concentrations of the pharmaceuticals in the raw wastewater were mostly at ng L(-1) levels except salicylic acid whose concentrations ranged from 9.6 to 23.3 μg L(-1). No significant amount of the pharmaceuticals was detected in the suspended particulate matter of wastewater and sewage sludge. Salicylic acid, indomethacin, and naproxen were almost completely removed (≥ 99%); gemfibrozil, ibuprofen and bezafibrate were significantly removed (>75%), whereas diclofenac and clofibric acid were removed by 60-70% during treatment in the STPs. Generally, biodegradation was the governing process for elimination of the investigated pharmaceuticals. Anaerobic biodegradation was responsible for most of the removal of diclofenac whereas aerobic biodegradation also played an important role in elimination of the other pharmaceuticals except SA, which was nearly completely removed after the anoxic process. In the Pearl River, the pharmaceuticals were widely detected. Both the concentrations and detection frequency were higher in March 2008 than those in the other seasons, which may be ascribed mainly to less dilution caused by lower precipitation. Besides the STPs, urban canals directly connected with the Pearl River may also be important contributors to the pharmaceutical contamination in the river.     

Dissipation and residues of bispyribac-sodium in rice and environment

The dissipation and residues of bispyribac-sodium in rice cropping system were studied. Bispyribac-sodium residues were extracted by a simple analytical method based on QuEChERs and detected by LC-MS/MS. The limit of detection for bispyribac-sodium of this method was 0.375?×?10^?3 ng. The limit of quantification (LOQ) was 5.0 μg/kg for rice plant samples, 2.0 μg/kg for rice hull, 0.2 μg/kg for water, and 0.1 μg/kg for soil and husked rice samples. The average recoveries of bispyribac-sodium ranged from 74.7 to 108 %, with relative standard deviations less than 13 %. The half-lives of bispyribac-sodium in rice plant, water, and soil were in the range of 1.4–5.6 days. More than 90 % of bispyribac-sodium residue dissipated within 5 days. The final residues of bispyribac-sodium in rice were all below LOQ at harvest time.     

Perfluorooctane sulfonate (PFOS) distribution and effect factors in the water and sediment of the Yellow River Estuary, China

The distribution of perfluorooctane sulfonate (PFOS) was investigated in a total of 15 water and sediment samples from the Yellow River Estuary, China in April 2011. The results indicated that the concentrations of PFOS in the water and sediment samples averaged 157.5 ng/L and 198.8 ng/g and ranged from 82.30 to 261.8 ng/L and 75.48 to 457.0 ng/g, respectively. The concentrations of PFOS in the sediment column increased from 45.32 to 379.98 ng/g with the decrease of the sampling depth, which showed that the increased PFOS pollution in the sediment appeared in this region in over recent years. The distribution coefficient (K _d) of PFOS between water and sediment linearly increased from 0.37 to 4.80 L/g as the salinity (S‰) increased from 0.18 to 4.47. Correlation analysis revealed that K _d was significantly and positively correlated to the contents of total organic carbon and clay of the sediment, and salinity. Therefore, salinity was an important parameter in controlling the sediment–water interactions and the fate or transport of PFOS in the aquatic environment. The results of this study showed that the estuary was an important sink for PFOS and suggested that PFOS might be carried with the river water and transported for long distances before it reached to the sea and largely scavenged to the sediment in the estuaries due to the change in salinity.     

Assessment of organochlorine pesticides and plasticisers in the Selangor River basin and possible pollution sources

A study on the quality of water abstracted for potable use was conducted in the Selangor River basin from November 2008 to July 2009. Seven sampling sites representing the intake points of water treatment plants in the basin were selected to determine the occurrence and level of 15 organochlorine pesticides (OCPs), six phthalate esters (PAEs) and bisphenol A (BPA). Results indicated OCPs were still detected regularly in 66.1 % of the samples with the Σ₁₅OCPs ranging from 0.6–25.2 ng/L. The first data on PAEs contamination in the basin revealed Σ₆PAEs concentrations were between 39.0 and 1,096.6 ng/L with a median concentration of 186.0 ng/L while BPA concentration ranged from <1.2 to 120.0 ng/L. Although di-n-butyl phthalate was detected in all the samples, concentrations of di-ethyl(hexyl)phthalate were higher. Sampling sites located downstream recorded the highest concentrations, together with samples collected during the dry season. Comparison of the detected contaminants with the Department of Environment Water Quality Index (DOE-WQI) showed some agreement between the concentration and the current classification of stream water. While the results suggest that the sites were only slightly polluted and suitable to be used as drinking water source, its presence is cause for concern especially to the fragile firefly “Pteroptyx tener” ecosystem located further downstream.     

Preliminary occurrence studies of antibiotic residues in Hong Kong and Pearl River Delta

An improved liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was developed and validated to investigate the occurrence of selected antibiotic residues in Hong Kong and Pearl River Delta. LC and MS parameters were optimized to produce the maximum analytical responses for each compound. The established method targeted five groups of antibiotics, namely, macrolides, sulfonamides, tetracyclines, quinolones, and amphenicols. The method was validated for three types of environmental water matrices, namely, reservoir, river, and estuarine waters. Low detection limits of 0.17–0.18 ng/L for macrolides, 0.22–0.34 ng/L for quinolones, 0.67–1.65 ng/L for tetracyclines, and 0.27–0.56 ng/L for sulfonamides were obtained. No apparent interferences were observed in the chromatograms of all antibiotics groups. The developed method was preliminarily used to analyze water samples collected from Yuen Long River in New Territories, Hong Kong and four sites along the Pearl River Delta. Results showed that high level of tetracycline was found among the groups tested in the local river samples. In Pearl River Delta, we identified significant levels of erythromycin, roxithromycin, and sulfadiazine in Shenzhen Reservoir.     

山东省主要河流中抗生素污染组成及空间分布特征

采用固相萃取-液相色谱/串联质谱法研究了山东省境内四大流域主要河流中抗生素污染组成及空间分布特征,涉及我国用量最大的6类共20种抗生素。结果表明:20种抗生素均有检出,且大环内酯类、喹诺酮类和四环素类抗生素整体检出浓度较高。就流域而言,半岛诸河流域抗生素污染较小,平均总质量浓度61.4 ng/L;海河流域、小清河流域和淮河流域相对较为严重,平均总质量浓度分别为232、175、118 ng/L。抗生素空间分布呈现一定的规律,检出浓度较高的点位主要集中在人口密集区下游,抗生素污染与周边生活污水、养殖企业废水和城市污水处理厂排水密切相关,而且抗生素组成可从一定程度上反映出污染来源。     

Residue levels of organochlorine pesticides in some ecosystem components of Manzala Lake

To evaluate the organochlorine pesticide (OCP) contamination of Manzala Lake, its ecosystem was investigated during the winter season (December to March). The studied ecosystem components were water, sediment, aquatic weeds, and fishes in four locations. The samples were analyzed by gas chromatography with electron capture detector. Pollutant levels of total OCPs showed significantly high levels in the water areas of Round road (46.253 ng/ml), Port-Said Damietta road (19.301 ng/ml), followed by Bughas El-Rasoah (5.539 ng/ml), then Ashtoum El Gamel (natural reserve area now) (0.289 ng/ml). Organochlorines were detected in sediment only in Round road (3.359 μg/kg) and Port-Said Damietta road (0.171 μg/kg) by significant order while they were undetectable in Ashtoum El Gamel and Bughas El-Rasoah. Total OCPs in aquatic weeds ranged between 0.194 μg/kg in Port-Said Damietta and 0.026 μg/kg in Ashtoum El Gamel. While OCPs were 0.160 and 0.153 μg/kg in Round road and Bughas El-Rasoah, respectively. Concerning fish muscles OCPs were significantly higher in the Round road area (0.397 μg/kg) followed by the Port-Said Damietta road (0.258 μg/kg), and finally, Ashtoum El Gamel samples (0.126 μg/kg). The results revealed the direct relation for the accumulation of OCPs between studied ecosystem parameters at the Manzala Lake during the winter season. Results also demonstrated that fish samples collected from the Manzala Lake in the studied areas were contaminated with levels of organochlorines, not higher than the maximum permissible level recorded by FAO/WHO, and that the public is not at risk with fish consumption.     

Determination of micropollutants in combined sewer overflows and their removal in a wastewater treatment plant (Seoul,South Korea)

The present study investigated the occurrence of 29 selected micropollutants such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs) in surface waters and wastewaters in Seoul (South Korea) during both dry and wet weather conditions. The study area was selected based on the lack of available information regarding the suspected contamination of rivers/creeks by EDCs and PPCPs in the Seoul region and the presence of a wastewater treatment plant (WWTP), which serves approximately 4.1 million inhabitants and has a design capacity of 1,297?×?10³ m³/day. Many target compounds (83 %) were detected in samples collected from wastewater treatment influent/effluent, creek water, and combined sewer overflow (CSO). The total EDC/PPCP concentrations were as follows: WWTP influent (69,903 ng/L)?>?WWTP effluent (50,175 ng/L) >3 creek samples (16,035–44,446 ng/L) during dry weather, and WWTP influent (53,795 ng/L)?>?WWTP bypass (38,653 ng/L) >5 creek samples (15,260–29,113 ng/L) >2 CSO samples (11,109–11,498 ng/L) during wet weather. EDCs and PPCPs were found to be present at high daily loads (65.1 and 69.8 kg/day during dry and wet weather, respectively) in the WWTP effluent. Compound removal by the WWTP varied significantly by compound: caffeine, diclofenac, ibuprofen, naproxen, and propylparaben (>90 %), and acesulfame, DEET, iohexol, iopromide, and iopamidol (<5 %). These findings and literature information support the hypothesis that the efficiency of removal of EDCs and PPCPs is strongly dependent on both removal mechanism (e.g., biodegradation, adsorption to sludge, and oxidation by chlorine) and compound physicochemical properties (e.g., pK _a and hydrophobicity).     

Occurrence of aflatoxin M1 in UHT milk and infant formula samples consumed in Burdur,Turkey

Aflatoxins are toxic fungal metabolites found in foods and feeds. Aflatoxin M₁ (AFM₁), a metabolite of the potent carcinogen aflatoxin B₁ (AFB₁), occurs in milk from animals consuming feed contaminated with AFB₁. The aim of this study was to investigate the occurrence and levels of AFM₁ in ultra-high temperature (UHT) milk and infant formula samples consumed in Burdur City. During 2011, 41 samples of UHT milk and 33 samples of infant formula were randomly collected from different supermarkets and drug stores. The occurrence and contamination levels of AFM₁ in the samples were investigated using the competitive enzyme-linked immunoabsorbent assay (ELISA) method. AFM₁ was detected in 30 samples (73.2 %) in concentrations ranging from 6.42 to 71.33 ng/L (mean level, 17.76 ng/L). Altogether, only three (7.3 %) samples of UHT milk were contaminated at levels above the Turkish legal limit (50 ng/L). However, AFM₁ was not detected in all infant formula samples. It is concluded that despite the widespread occurrence of AFM₁ in UHT milk samples, the contamination levels were not serious for public health.     

Screening and quantification of emerging contaminants in Periyar River,Kerala (India) by using high-resolution mass spectrometry (LC-Q-ToF-MS)

The presence of emerging contaminants (ECs) in different aquatic systems may contribute to hazardous effects on aquatic organisms and subsequently on human health. In the present work, liquid chromatography coupled to a quadrupole time of flight mass spectrometer (LC-Q-ToF-MS) was used to identify and quantify a series of ECs in Periyar River in Aluva region, Kerala, India. The water samples were pre concentrated using solid-phase extraction (SPE) prior to analysis. The compounds were probed in both positive and negative ionization mode using electro spray ionization (ESI). Method validations were performed for linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision (intraday and inter day). The ECs were quantified using standard calibration curve. The identified nine ECs include pharmaceuticals, personal care products, steroids, surfactants, and phthalate. A relatively high concentration was observed in the case of 2-dodecyl benzene sulfonic acid (1012 ng/l) and low concentration was observed for lignocaine (4.3 ng/l; since this is below LOQ, the value is only approximate). In addition, we have identified another 28 organic compounds using the technique of non-target analysis out of which seven compounds fall in the category of surfactants. Being the first report on ECs in Periyar River, the data is very important as this river is one of the biggest and important rivers of Kerala having several purification units for drinking water in the province.     

Pharmaceuticals as emerging organic contaminants in Umgeni River water system,KwaZulu-Natal,South Africa

The occurrences of pharmaceuticals and personal care products as emerging organic contaminants (EOCs) have been reported in several countries of the world except from African countries. This study was therefore conducted to investigate the occurrence of nine antibiotics, five antipyretics, atenolol, bezafibrate, and caffeine in wastewater and surface water samples from the Umgeni River. The water samples were extracted with solid-phase extraction using hydrophilic-lipophilic balance (HLB) and C-18 cartridges for the acidic and neutral drugs, respectively. The quantification was carried out with high-performance liquid chromatography-diode array detector (HPLC-DAD) using the standard addition method. The method limits of detections were in the range of 0.14–0.97 μg/L while the recoveries were between 53.8 and 108.1 %. The wastewater had 100 % occurrence of the analytes studied, with caffeine having the highest concentration at 61?±?5 μg/L and nalidixic acid being the most observed antibiotic at 31?±?3 μg/L. The waste treatment process reduced the influent concentrations by 43.0–94.2 % before discharge except for atenolol removal that is lower. The concentrations of the analytes were lower in the surface water with most compounds having concentrations below 10 μg/L except acetaminophen and atenolol. The estuary mouth and Blue Lagoon had the highest concentrations of some of the compounds in surface water which depict downstream load. The factors governing the fate and mobility of these compounds in this environment are not fully understood yet and will require further studies.     

DDT, DDE, and 1-hydroxypyrene levels in children (in blood and urine samples) from Chiapas and Oaxaca, Mexico

The aim of this study was to evaluate the DDT, DDE, and 1-hydroxypyrene exposure levels of children living in communities located in southeastern Mexico. The study communities were Lacanja and Victoria in Chiapas state and Ventanilla in Oaxaca state. Children living in Lacanja had total blood DDT levels (mean?±?SD, 29,039.6?±?11,261.4 ng/g lipid) that were significantly higher than those of children in Victoria (10,220.5?±?7,893.1 ng/g lipid) and Ventanilla (11,659.7?±?6,683.7 ng/g lipid). With respect to the 1-hydroxypyrene levels in urine samples, the levels in Lacanja (4.8?±?4.1 μg/L or 4.5?±?3.9 μmol/mol creatinine) and Victoria (4.6?±?3.8 μg/L or 3.9?±?3.0 μmol/mol Cr) were significantly higher than levels found in Ventanilla (3.6?±?1.4 μg/L or 2.5?±?0.5 μmol/mol Cr). In conclusion, our data indicate high levels of exposure in children living in the communities studied in this work. The evidence found in this study could be further used as a trigger to revisit local policies on environmental exposures.     

Levels and distribution of PCDD/Fs, dl-PCBs, and organochlorine pesticides in sediments from the lower reaches of the Haihe River basin, China

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and organochlorine pesticides (OCPs) in surface sediments from the lower reaches of the Haihe River basin, northern China, were determined by high-resolution gas chromatograph–high-resolution mass spectrometer. The concentrations of 2,3,7,8-substituted PCDD/Fs, dl-PCBs, and total OCPs [sum of hexachlorobenzene, hexachlorocyclohexanes, and dichlorodiphenyltrichloroethane (DDTs)] in 17 sediment samples were in the ranges of 11.6–1,180,924 pg/g dry weight (dw), 18.7–50,017 pg/g dw, and 1.7–35,280 ng/g dw, respectively. The contamination levels in the samples varied significantly between the different sites. Abnormally high concentrations of PCDD/Fs, dl-PCBs, and some OCPs were found in sediments from the lower reaches of the main channel of the Haihe River and the Dagu Drainage River, which were attributed to the historical production of pentachlorophenol and other pesticides near these locations. High levels of DDTs were detected in the Yongding New River sediment, which were likely to have originated from the discharge of wastewater from a dicofol factory upstream. In samples taken from other sites, the concentrations of these pollutants were at levels comparable to those documented in other areas of China. This preliminary investigation suggests that historical pesticide production in the Haihe River basin has contributed significantly to the contamination of this aquatic ecosystem and that further attention to this issue is warranted.     

Occurrence of naproxen,ibuprofen, and diclofenac residues in wastewater and river water of KwaZulu-Natal Province in South Africa

The present paper reports a detailed study that is based on the monitoring of naproxen, ibuprofen, and diclofenac in Mbokodweni River and wastewater treatment plants (WWTPs) located around the city of Durban in KwaZulu-Natal Province of South Africa. Target compounds were extracted from water samples using a multi-template molecularly imprinted solid-phase extraction prior to separation and quantification on a high-performance liquid chromatography equipped with photo diode array detector. The analytical method yielded the detection limits of 0.15, 1.00, and 0.63 μg/L for naproxen, ibuprofen, and diclofenac, respectively. Solid-phase extraction method was evaluated for its performance using deionized water samples that were spiked with 5 and 50 μg/L of target compounds. Recoveries were greater than 80% for all target compounds with RSD values in the range of 4.1 to 10%. Target compounds were detected in most wastewater and river water samples with ibuprofen being the most frequently detected pharmaceutical. Maximum concentrations detected in river water for naproxen, ibuprofen, and diclofenac were 6.84, 19.2, and 9.69 μg/L, respectively. The concentrations of target compounds found in effluent and river water samples compared well with some studies. The analytical method employed in this work is fast, selective, sensitive, and affordable; therefore, it can be used routinely to evaluate the occurrence of acidic pharmaceuticals in South African water resources.     

Occurrence of selected pharmaceuticals in river water in Japan and assessment of their environmental risk

The existence of pharmaceuticals in the water environment is thought to be a potential problem for aquatic organisms. In this study, we conducted a nationwide survey to clarify the occurrence of 24 selected pharmaceuticals in major Japanese rivers and evaluated their environmental risk to aquatic organisms. We found a total of 22 substances in river waters at concentrations from several nanograms per liter to several micrograms per liter. We found the highest, which was 2.4 μg/L of caffeine, followed by 1.5 μg/L of crotamiton and 1.4 μg/L of sulpiride. We conducted an environmental risk assessment of the 22 pharmaceuticals detected in river water, for which predicted no-effect concentration (PNEC) values for crustacea and algae had been obtained. The measured environmental concentration/PNEC values of four substances, caffeine, carbamazepine, clarithromycin, and ketoprofen, exceeded 0.1 with the maximum value of 9.0 for clarithromycin. As clarithromycin exhibits a high environmental risk to aquatic organisms, particular attention is required.     

Characterization of domestic wastewater treatment in Oman from three different regions and current implications of treated effluents

Treated effluents become one of the most significant sources for irrigation and other activities in arid and semi arid countries such as Oman. This study focuses on characterizing the quality of domestic wastewater in chosen three regions: Muscat, Sohar, and Salalah. The knowledge on treatment processes, quality, and proper management of domestic wastewater reuse for various purposes is essential. Wastewater samples were collected from six different sewage treatment plants (STPs) over a period of 1 year in 2009 on a monthly basis. The raw sewage (RS) and treated effluent (TEs) samples were collected from different sampling points in each STP. Both types of samples were analyzed for physicochemical and microbiological assessment. All tests were conducted according to the standard method for the examination of water and wastewater. The results revealed that the TEs electrical conductivity, biological oxygen demand, chemical oxygen demand, heavy metals, sodium, potassium, and total dissolved solids values were found within Omani Standards (OS). The RS in all STPs was categorized as high strength concentration and samples exceeded the acceptable range for ammonia in most of the selected plants except Sohar and Salalah. Nitrate values in RS were also observed in higher concentrations. In general, the produced TEs have met most of regulatory limits stated by OS except for nitrate, Escherichia coli and total suspended solids (TSS). Furthermore, it should be noted that the performance of Salalah and Darsayt STPs can be classified as the best compared to the other four STPs studied in Oman.