Phthalate and alkyl phenol concentrations in soil following applications of inorganic fertiliser or sewage sludge to pasture and potential rates of ingestion by grazing ruminants

Soil concentrations of dioctyl phthalate (DOP) and the alkyl phenols, octyl phenol (OP) and nonyl phenol (NP), after repeated surface applications of sewage sludge to pastures, were investigated. Liquid sludge was applied at a rate of 2.25 tonnes dry matter (DM) per hectare to each of three treated (T) plots on three occasions during the summer and two occasions in the early spring over a period of 2.5 years. Control (C) plots were treated with inorganic fertiliser containing amounts of nitrogen equivalent to those applied to the treated plots. At between 69 and 81 days after the application of sludge, 15 separate soil samples were collected from one half of each of the plots (Experiment 1). Concentrations (microg g(-1)) of DOP were higher (P < 0.001) than those of NP, while those of OP were generally below detectable levels. Mean soil concentrations of DOP were not significantly different in T and C plots [0.233 vs. 0.155 microg g(-1); standard error of the difference (SED) = 0.046; not significant (NS)], partly because there was already a relatively large amount of DOP present. NP concentrations were, however, significantly higher in T than in C plots (0.021 vs. 0.013 microg g(-1) SED = 0.002; P < 0.05). There was no consistent change over time in the mean soil concentrations of these compounds when sampled at intervals of 3-6 months. Concentrations in soil samples collected at monthly intervals following sludge application indicated that the variation in concentrations of these endocrine-disrupting compounds (EDC) was unrelated to time since sludge application. Rates of soil ingestion, expressed as the percentage of DM intake represented by soil, were higher during the winter than the summer (5.40 vs. 1.17; SED = 0.360; P < 0.001) and estimated daily intakes of DOP and NP were up to 150 microg and 8 microg, respectively. It is concluded that the application of sewage sludge to pasture does not increase soil concentrations of phthalate (as DOP) or alkyl phenols. Thus, the risk of increased exposure to these EDC as a result of sludge application is small. However, the small effect of sludge application on soil concentrations may be largely a reflection of the relatively high concentrations of DOP already present in the soil, which may be biologically significant.     

Quantitative assessment of polycyclic aromatic hydrocarbons in sewage sludge from wastewater treatment plants in Qingdao, China

In this study, 16 polycyclic aromatic hydrocarbons (PAHs) were detected in sewage sludge samples from four wastewater treatment plants (WWTPs) in Qingdao, China. These WWTPs differ in the type of treatment used and in the origin of the wastewater. The total amounts of PAHs in digested sludges ranged from 1.9645 to 6.5752 mg/kg, which did not exceed the projected European Union cut-off limits (6 mg/kg) for sludge found in farmland, except for the Haibohe WWTP. Significant differences were observed in overall PAH values between WWTPs receiving domestic effluents and those receiving industrial effluents. The total amounts of PAHs in digested sludge from the Licunhe and Haibohe WWTPs, which mainly received industrial effluents, were markedly higher than those of the Tuandao and Huangdao WWTPs, which received only domestic effluents. The distribution of PAH compounds in digested sludges were analysed. At the Tuandao, Huangdao and Licunhe WWTPs, 2-, 3-, 4-benzene rings were predominant, accounting for 100%, 99.8% and 99.0% of the sum concentration of 16 PAHs (∑PAHs), respectively. At the Haibohe WWTP, a large number of high molecular weight PAHs (5-, 6-benzene rings) were observed, accounting for 30% of the ∑PAHs. The sum of seven carcinogenic PAHs (∑PAHs-c) ranged from 0.8694 to 3.0389 mg/kg in four WWTPs. The highest value was found in the Haibohe WWTP. Moreover, the PAH concentrations in sludges from the different treatment processes in the Licunhe and Tuandao WWTPs are discussed.     

Concentrations of Cu, Fe, Mn, and Zn in tropical soils amended with sewage sludge and composted sewage sludge

Sewage sludge may be used as an agricultural fertilizer, but the practice has been criticized because sludge may contain trace elements and pathogens. The aim of this study was to compare the effectiveness of total and pseudototal extractants of Cu, Fe, Mn, and Zn, and to compare the results with the bioavailable concentrations of these elements to maize and sugarcane in a soil that was amended with sewage sludge for 13 consecutive years and in a separate soil that was amended a single time with sewage sludge and composted sewage sludge. The 13-year amendment experiment involved 3 rates of sludge (5, 10, and 20 t ha^?1). The one-time amendment experiment involved treatments reflecting 50, 100, and 200 % of values stipulated by current legislation. The metal concentrations extracted by aqua regia (AR) were more similar to those obtained by Environmental Protection Agency (EPA) 3052 than to those obtained by EPA3051, and the strongest correlation was observed between pseudo(total) concentrations extracted by AR and EPA3052 and bioavailable concentrations obtained by Mehlich III. An effect of sewage sludge amendment on the concentrations of heavy metals was only observed in samples from the 13-year experiment.     

Multi-residue determination of pharmaceuticals in sludge and sludge enriched soils using pressurized liquid extraction, solid phase extraction and liquid chromatography with tandem mass spectrometry

An analytical method to determine a selection of 27 frequently prescribed and consumed pharmaceuticals in biosolid enriched soils and digested sludges is presented. Using a combination of pressurized liquid extraction, solid phase extraction and liquid chromatography with tandem mass spectrometry, it was possible to detect all analytes in each sample type at the low-sub ng g(-1) level. Solid phase extraction efficiencies were compared for 6 different sorbent types and it was found that Waters Oasis HLB cartridges offered enhanced selectivities with 20 analytes showing final method recoveries > or =60% in both soils and digested sludges. The method was validated for linearity, range, precision and limits of detection in both sample matrices. All analytes were then determined in sludge enriched soils as well as the precursor thermally dried sludge fertilizer produced from a primary wastewater treatment plant. Levels of the antibacterial agent triclosan were found to exceed 20 microg g(-1) in digested sludge and 5 microg g(-1) in thermally dried sludge cake. Significant traces of carbamazepine and warfarin were also detected in the above samples.     

Organic contaminants in the Firth of Clyde following the cessation of sewage sludge dumping

To assess contaminant concentrations in the Firth of Clyde in relation to the former sewage sludge dump site at Garroch Head, and investigate any temporal changes, fish have been sampled annually since 1992 and sediment since 1999. In addition, a further four locations in the Clyde (Holy Loch, Hunterston, Skelmorlie and Irvine Bay) have been sampled for fish and sediment since 1999. Chlorobiphenyls (CBs) were measured in fish samples and polycyclic aromatic hydrocarbons (PAHs) and CBs in sediment. Since sampling was initiated the concentration for the summation operatorICES7 CBs in fish liver has been consistently >500 microg kg(-1) lipid weight at Garroch Head and the other Clyde sites and lower at the reference sites (Pladda, Colonsay, Broad Bay). Although the lowest CB concentrations of the eleven year period in plaice liver from Garroch Head were found in 2002, CB concentrations were found not to have decreased significantly since sewage sludge dumping ceased in 1998. However, a change in CB profile was observed with fish liver collected between 1992 and 1998 from Garroch Head showing a lower proportion of the less chlorinated CBs compared to the 1999-2002 liver samples. Highest CB and PAH concentrations in sediment were found at Garroch Head and Holy Loch with concentrations at these sites being significantly higher than at all other sites.     

Occurrence and distribution of organophosphorus flame retardants and plasticizers in anthropogenically affected groundwater

Occurrence and distribution of chlorinated and non-chlorinated organophosphates in 72 groundwater samples from Germany under different recharge/infiltration conditions were investigated. Tris(2-chloro-1-methylethyl) phosphate (TCPP) and tris(2-chloroethyl) phosphate (TCEP) were the most frequently detected organophosphates in groundwater samples. Highest individual organophosphate concentrations (>0.1 μg L(-1)) were determined in groundwater polluted by infiltrating leachate and groundwater recharged via riverbank filtration of organophosphate-loaded recipients. In samples from springs and deep groundwater monitoring wells that are not affected by surface waters, organophosphate concentrations were mostly below the limit of detection. The occurrence (3-9 ng L(-1)) of TCPP and TCEP in samples from aquifers with groundwater ages between 20 and 45 years indicates the persistence of both compounds within the aquifer. At urban sites organophosphate-loaded precipitation, surface runoff, and leakage of wastewater influenced groundwater quality. For rural sites, where groundwater recharge is only influenced by precipitation, organophosphates were very rarely detectable in groundwater.     

Nutrient transfer by runoff from sewage sludge amended soil under simulated rainfall

Wastewater sludges are used in agriculture as soil amendment and fertilizer, with regard to their organic matter and nutrient content. However, availability of nitrogen and phosphorus from sludge-amended soils and their transfer in runoff may lead to eutrophication of downstream surface water. The aim of this study is to establish and compare the effect of two different sludges on these transfers: an anaerobically digested and thermically stabilised sludge (Seine-Aval treatment plant, sludge no. 1), and a limed sludge (Saint-Quentin treatment plant, sludge no. 2). Experiments were performed on 12 sloping micro-plots (1 m × 1 m) submitted to sludge spreading and controlled rainfall simulation. Runoff water was sampled and analysed for concentrations in nitrogen species and phosphorus. Results show that spreading of sludge no. 1 increased both ammonium nitrogen (mean of 1.1 mg L^–1 N-NH₄ vs. 0.2 mg L^–1 N-NH₄ for control micro-plots) and particulate phosphorus concentrations (mean of 2 mg L^–1 P vs. 1.1 mg L^–1 P for control micro-plots) in runoff water. On the other hand, sludge no. 2 did not induce any significant effect on nutrient concentrations in runoff. These results are related to chemical composition and physical treatment of sludges. This study underlines the existence of a short-term risk of nutrient mobilisation by runoff after sludge spreading on soil, and the need to check precisely the impact of this practice on water quality.     

Determination of six anti-infectives in wastewater using tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry

A rugged and specific method based on tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry for the determination of anti-infectives in raw sewage and wastewater plant effluents was developed. Analyte recoveries from spiked effluents ranged from 68 to 104%. Two specific selected reaction monitoring transitions and their peak area ratios were used to avoid false positives and confirm the presence of the targeted substances. Detection limits allowed low nanogram per litre detection (0.3-22 ng L(-1)). The method was successfully applied to real samples from the Montréal wastewater treatment plant. All the studied anti-infectives were found in the wastewater samples in concentrations ranging from 39 to 276 ng L(-1). Mean flows of anti-infectives were estimated from effluent concentrations and it was found that large amounts (>118 g day(-1) up to 830 g day(-1)) are discharged in the receiving waters of the St Lawrence River.     

Occurrence and fate of androgens, estrogens, glucocorticoids and progestagens in two different types of municipal wastewater treatment plants

The occurrence and fate of fourteen androgens, four estrogens, five glucocorticoids and five progestagens were investigated in two different types of wastewater treatment plants (Plant A: activated sludge with chlorination, and Plant B: oxidation ditch with UV) of Guangdong province, China. 14, 14, and 10 of 28 target compounds were detected in the influent, effluent and dewatered sludge samples with the concentrations ranging from below 1.2 ± 0.0 ng L(-1) (stanozolol) to 1368 ± 283 ng L(-1) (epi-androsterone), below 1.0 ± 0.0 ng L(-1) (progesterone) to 23.1 ± 1.0 ng L(-1) (5α-dihydrotestosterone), 1.0 ± 0.1 ng g(-1) (estrone) to 460 ± 4.4 ng g(-1) (5α-dihydrotestosterone), respectively. The concentrations of total androgens (1554-1778 ng L(-1) in influent, 13.3-47.8 ng L(-1) in effluent, 377-923 ng g(-1) in dewatered sludge) were much higher than those of total estrogens (41.5-60.2 ng L(-1) in influent, 5.6-13.5 ng L(-1) in effluent, 13.9-57.8 ng g(-1) in dewatered sludge), glucocorticoids (171-192 ng L(-1) in influent, 2.2-6.3 ng L(-1) in effluent, N.D.-4.4 ng g(-1) in dewatered sludge), and progestagens (39.6-40.5 ng L(-1) in influent, 6.9-12.1 ng L(-1) in effluent, N.D. in dewatered sludge) in these two WWTPs. According to mass balance analysis, the removal rates of most target steroids in Plant A had exceeded 90%, while those in Plant B for nearly half of detected target steroids were lower than 80%. It is obvious that the treatment capacity of the activated sludge system (Plant A) is superior to the oxidation ditch (Plant B) in the degradation of steroids in sewage treatment systems. Androgens, estrogens and progestagens were mainly removed by sorption and degradation, while the reduction of glucocorticoids was primarily due to degradation.     

Identification of surfactant degradation products as toxic organic compounds present in sewage sludge

A cost-effective strategy combining chemical analysis and bioassays for the identification of polar toxic compounds in sewage sludge is reported. ToxAlert 100 bioluminescence inhibition assay was used in combination with chemical analysis involving extraction, clean-up, chromatographic separation and mass spectrometry detection. This methodology was applied to real samples of sludge from three wastewater treatment plants (WWTP) located in Catalonia (Spain) during a 3 month period. In the first step, sewage sludge was lyophilized, treated by sonication with a mixture of methanol and chloroform and finally cleaned up using a sequential solid phase extraction (SSPE) with an octadecylsilica cartridge (C18) in series with a polymeric Lichrolut EN cartridge (Lic EN). In the second step, the toxicity of each fraction of the sludge sample was investigated using the ToxAlert 100. The unequivocal identification and quantification of polar organic cytotoxic substances present in the fractionated extracts were determined by liquid chromatography-mass spectrometry (LC-MS). Major toxic compounds identified were: non-ionic polyethoxylated surfactants (nonylphenol polyethoxylates, alcohol polyethoxylates), their intermediates (polyethylene glycol polyethoxylated, nonylphenol carboxylates and polyethoxylated alcohol carboxylates), linear alkylbenzenesulfonates and heavy metals. The toxic response (in terms of bioluminescence inhibition using ToxAlert 100), defined by the 50% effective concentration (EC50), and the toxicity units (TU) for every standard non-ionic surfactant were calculated. The results provided the identification of polar cytotoxic compounds as well as the evaluation of their contribution to the total toxicity observed in sewage sludge.     

Polycyclic musks in the Ruhr catchment area--transport, discharges of waste water, and transformations of HHCB, AHTN and HHCB-lactone

The polycyclic musk fragrance compounds HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran; trade name, e.g. galaxolide) and AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene, trade name, e.g. tonalide) and the transformation product of HHCB (HHCB-lactone) were analysed in surface water samples and sewage treatment plants (STP) effluents in the Ruhr megalopolis. The STPs were the dominant source for these pollutants. In the part of the river where the drinking water is extracted from the river, about 60 ng L(-1) HHCB, 10 ng L(-1) AHTN and 20-30 ng L(-1) HHCB-lactone were found as typical riverine concentrations, while none of the compounds were detected near the spring of the river. On the other hand sewage treatment plant effluents exhibited concentrations up to 600 ng L(-1). The STP's effluent resulted in elevated concentrations in some parts of the river and in the lakes into which they discharge. As some of the plants emit HHCB-lactone with a significantly changed enantiomeric pattern, biotransformation of HHCB to HHCB-lactone occurs in some waste water treatment plants operating with activated sludge. In those parts of the river where no relevant discharges of waste water or fresh water takes place neither the concentration nor the pattern changes significantly. This holds true especially for the HHCB versus HHCB-lactone ratios which indicates degradation less than 15% of the HHCB inventory in the river Ruhr itself. In other rivers, such as the Rhine, higher levels of HHCB-lactone in comparison to HHCB were detected (ratio 1 : 1).     

Transport and fate of organochlorine pesticides in the River Wuchuan,southeast China

Persistent organic pollutants (POPs) such as chlorinated pesticides are of global concern due to their widespread occurrence, persistence, bioaccumulation and toxicity to animals and human. This paper summarises recent research on 18 chlorinated pesticides in an important catchment in China, by determining their concentrations and behaviour in water, sediment, soil and plants. The concentrations of the total pesticides were in the ranges 187-893 ng l(-1) in river water, 8.53-210 ng g(-1) dry weight in soil, 2.66-13.45 ng g(-1) dry weight in river sediment, and 651-2823 ng g(-1) dry weight in plants. The predominance of beta-HCH as the major isomer of HCHs in all water, soil, sediment and plant samples was clearly observed, due to beta-HCH's resistance to biodegradation. On average beta-HCH accounted for 44%, 53%, 50%, and 46% of the total HCH concentration in water, soil, sediment and plant, respectively. Of the DDTs, DDE accounted for 48%, 43%, 53%, 55% of the total DDT, which suggested that DDT had been transformed to its metabolites, DDE and DDD, of which DDE was the more stable. The chlorinated pesticide levels in the River Wuchuan were generally below the guideline values in China, but some sites displayed levels in excess of EC Environmental Quality Standards for HCHs and DDTs. The results therefore provide important information on the current contamination status of a key agricultural watershed in China, and point to the need for urgent actions to evaluate the long-term fate and toxicity of such persistent compounds and an appropriate remediation strategy.     

Preliminary assessment of polybrominated diphenyl ethers (PBDEs) in the Scottish aquatic environment, including the Firth of Clyde

This paper presents preliminary data on polybrominated diphenyl ethers (PBDEs) in the Scottish aquatic environment. Sediment and biota (fish liver, fish muscle and mussels) from a number of locations around Scotland were analysed for PBDEs with samples being from both remote and from potentially contaminated areas such as the former sewage sludge dump site at Garroch Head in the Clyde. PBDEs were measured in both cultivated, rope grown mussels and wild mussels collected from 5 sites around Scotland in 2006. Total PBDE concentrations (sum of tri- to hepta-BDEs) ranged from 相似文献   

Environmental risk assessment of heavy metal extractability in a biosludge from the biological wastewater treatment plant of a pulp and paper mill

A five-stage sequential extraction procedure was used to fractionate heavy metals (Cd, Cu, Pb, Cr, Zn, Fe, Mn, Ni, Co, As, V and Ba) in a biosludge from the biological wastewater treatment plant of Stora Enso Oyj Veitsiluoto Mills at Kemi, Northern Finland, into the following fractions: (1) water-soluble fraction, (2) exchangeable fraction, (3) easily reduced fraction, (4) oxidizable fraction, and (5) residual fraction. The biosludge investigated in this study is a combination of sludge from the primary and secondary clarifiers at the biological wastewater treatment plant. Extraction stages (2)–(4) follow the protocol proposed by the Measurements and Testing Program (formerly BCR Programme) of the European Commission, which is based on acetic acid extraction (stage 2), hydroxylamine hydrochloride extraction (stage 3), and hydrogen peroxide digestion following the ammonium acetate extraction (stage 4). The residual fraction (stage 5) was based on digestion of the residue from stage 4 in a mixture of HF + HNO₃ + HCl. Although metals were extractable in all fractions, the highest concentrations of most of the metals occurred in the residual fraction. From the environmental point of view, it was notable that the total heavy metal concentrations in the biosludge did not exceed the maximal allowable heavy metal concentrations for sewage sludge used in agriculture, set on the basis of environmental protection of soil by European Union Directive 86/278/EEC, and by the Finnish legislation. The Ca (98.6 g kg⁻¹; dry weight) and Mg (2.2 g kg⁻¹; dry weight) concentrations in the biosludge were 62 and 11 times higher than the typical values of 1.6 and of 0.2 g kg⁻¹ (dry weight), respectively, in arable land in Central Finland. The biosludge had a slightly alkaline pH (∼8.30), a high loss-on-ignition value (∼78%) and a liming effect of 10.3% expressed as Ca equivalents (dry weight). This indicates its potential as a soil conditioner and improvement agent, as well as a pH buffer.     

Quantitative analyses of selected polychlorinated biphenyl (PCB) congeners in water,soil, and sediment during winter and spring seasons from Msunduzi River,South Africa

The lack of information and the need for knowledge on the organic pollutants within the area of KwaZulu-Natal together with the global problem of water supply have prompted our investigation into the analyses of eight polychlorinated biphenyl (PCB) congeners in the Msunduzi River of KwaZulu-Natal, South Africa. Soil, sediment, and water samples were collected at ten different sites along the river during winter and spring seasons. Soil and sediment samples were extracted using ultra sonication with dichloromethane while water samples were liquid-liquid extracted using dichloromethane. All sample extracts were cleaned-up using a multi-layer silica gel column and analyzed with gas chromatography-mass spectrometry. Quality assurance measures were also determined. The percentage recoveries for water were 53–128 for all the PCBs analyzed, while sediment recoveries ranged between 69 and 105%. The highest total concentrations of the PCBs in sediment were 214.21–610.45 ng/g dw at the Du Toit sampling site and 30.86–444.43 ng/g dw basis at the wastewater treatment inlet for winter and spring, respectively. Soil PCB concentrations were 76.53–397.75 ng/g dw at the Msunduzi Town sampling site and 20.84–443.49 ng/g (dry weight) at the Du Toit sampling site for winter and spring, respectively. In addition, high PCB concentrations were found in effluent of the wastewater treatment inlet compared to other sampling sites, which ranged between 0.68–22.37 and 2.53–35.69 ng/mL for winter and spring seasons, respectively. In all the sampling sites selected for this study, Du Toit afforded the highest PCB concentration levels and the lowest was after chlorination at the Darvill wastewater treatment plant. The results presented are new and it is the first study of organic pollutants such as PCBs that has been carried out on this river.     

Use of sequential extraction to assess the influence of sewage sludge amendment on metal mobility in Chilean soils

In Chile, the increasing number of plants for the treatment of wastewater has brought about an increase in the generation of sludge. One way of sludge disposal is its application on land; this, however involves some problems, some of them being heavy metal accumulation and the increase in organic matter and other components from sewage sludge which may change the distribution and mobility of heavy metals. The purpose of the present study was to determine the effect of sewage sludge application on the distribution of Cr, Ni, Cu, Zn and Pb in agricultural soils in Chile. Three different soils, two Mollisols and one Alfisol, were sampled from an agricultural area in Central Chile. The soils were treated with sewage sludge at the rates of 0 and 30 ton ha(-1), and were incubated at 25 degrees C for 45 days. Before and after incubation, the soils were sequentially extracted to obtain labile (exchangeable and sodium acetate-soluble), potentially labile (soluble in moderately reducing conditions, K4P2O7-soluble and soluble in reducing conditions) and inert (soluble in strong acid oxidizing conditions) fractions. A two-level factored design was used to assess the effect of sludge application rate, incubation time and their interaction on the mobility of the elements under study. Among the metals determined in the sludge, zinc has the highest concentration. However, with the exception of Ni, the total content of metals was lower than the recommended limit values in sewage sludge as stated by Chilean regulations. Although 23% of zinc in sludge was in more mobile forms, the residual fraction of all metals was the predominant form in soils and sludge. The content of zinc only was significantly increased in two of the soils by sewage sludge application. On the other hand, with the exception of copper, the metals were redistributed in the first four fractions of amended soils. The effect of sludge application rate, incubation time and their interaction depended on the metal or soil type. In most cases an increase in more mobile forms of metals in soils was observed as the final effect.     

Distribution pattern, behavior, and fate of antibacterials in urban aquatic environments in South China

Occurrence, behavior and fate of several groups of antibacterials were investigated in municipal wastewater, sewage sludge, and urban river water in China. Fluoroquinolones (e.g., ciprofloxacin, norfloxacin, and ofloxacin), macrolides (dehydroerythromycin, roxithromycin, and clarithromycin), sulfonamides (sulfamethoxazole and sulfamethazine) and trimethoprim were ubiquitously detected in the wastewater in China. Fluoroquinolones were generally the most abundant in the raw sewage, with a maximum concentration of up to 6415 ng L(-1) observed for norfloxacin. Sulfonamides and macrolides transported predominantly in the aqueous phase. A median percentage of 67% of sulfonamides and 86% of macrolides remained in the final effluent after treatment in sewage treatment plants. On the contrary, sorption played a significant role in transport of fluoroquinolones and approximately half of the fluoroquinolones finally ended up and persisted in the dewatered sludge. In the urban section of the Pearl River at Guangzhou, sulfonamides, trimethoprim, and macrolides were widely present at median concentrations of 22-735 ng L(-1), whereas fluoroquinolones were only occasionally detected at 2-152 ng L(-1), probably due to their strong tendency of partition to sediment and/or photodegradability. The result of principal components analysis suggests input of non-sewage derived sulfamethazine in the Pearl River. Seasonal variations of the antibacterials distribution in the wastewater are mainly ascribed to different consumption. Dilution effect by precipitation, however, also plays an important role in seasonal distribution of the antibacterials in the Pearl River.     

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.