title: Occurrence, fate and ecotoxicological assessment of pharmaceutically active compounds in wastewater and sludge from wastewater treatment plants in Chongqing, the Three Gorges Reservoir Area.
abstract: The occurrence, removal and ecotoxicological assessment of 21 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, antiepileptics, antilipidemics and antihypersensitives, were studied at four municipal wastewater treatment plants (WWTP) in Chongqing, the Three Gorges Reservoir Area. Individual treatment unit effluents, as well as primary and secondary sludge, were sampled and analyzed for the selected PhACs to evaluate their biodegradation, persistence and partitioning behaviors. PhACs were identified and quantified using high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. All the 21 analyzed PhACs were detected in wastewater and the target PhACs except acetaminophen, ibuprofen and gemfibrozil, were also found in sludge. The concentrations of the antibiotics and SVT were comparable to or even higher than those reported in developed countries, while the case of other target PhACs was opposite. The elimination of PhACs except acetaminophen was incomplete and a wide range of elimination efficiencies during the treatment were observed, i.e. from "negative removal" to 99.5%. The removal of PhACs was insignificant in primary and disinfection processes, and was mainly achieved during the biological treatment. Based on the mass balance analysis, biodegradation is believed to be the primary removal mechanism, whereas only about 1.5% of the total mass load of the target PhACs was removed by sorption. Experimentally estimated distribution coefficients (<500 L/kg, with a few exceptions) also indicate that biodegradation/transformation was responsible for the removal of the target PhACs. Ecotoxicological assessment indicated that the environment concentrations of single compounds (including sulfadiazine, sulfamethoxazole, ofloxacin, azithromycin and erythromycin-H2O) in effluent and sludge, as well as the mixture of the 21 detected PhACs in effluent, sludge and receiving water had a significant ecotoxicological risk to algae. Therefore, further control of PhACs in effluent and sludge is required before their discharge and application to prevent their introduction into the environment.
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China; College of Geography Science and Tourism, Chongqing Normal University, Chongqing 400047, PR China. Electronic address: qyan2005@hotmail.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China. Electronic address: gaoxu@cqu.edu.cn.
authors.forename: Xu
authors.initials: X
authors.lastname: Gao
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, PR China.
authors.forename: You-Peng
authors.initials: YP
authors.lastname: Chen
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China.
authors.forename: Xu-Ya
authors.initials: XY
authors.lastname: Peng
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China.
authors.forename: Yi-Xin
authors.initials: YX
authors.lastname: Zhang
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China.
authors.forename: Xiu-Mei
authors.initials: XM
authors.lastname: Gan
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China.
authors.forename: Cheng-Fang
authors.initials: CF
authors.lastname: Zi
authors.affiliation: Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045, PR China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, PR China.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Guo
mesh_terms: D001673:Biodegradation, Environmental; D002681:China; D004784:Environmental Monitoring; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D052616:Solid Phase Extraction; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D004364:Pharmaceutical Preparations; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Apparent solid-water partition coefficient; Ecotoxicological risk; Mass balance analysis; Pharmaceutically active compound (PhACs); Sludge; Treatment efficiency