title: Occurrence and fate of pharmaceutically active compounds in the largest municipal wastewater treatment plant in Southwest China: mass balance analysis and consumption back-calculated model.
abstract: The occurrence and fate of twenty-one pharmaceutically active compounds (PhACs) were investigated in different steps of the largest wastewater treatment plant (WWTP) in Southwest China. Concentrations of these PhACs were determined in both wastewater and sludge phases by a high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Results showed that 21 target PhACs were present in wastewater and 18 in sludge. The calculated total mass load of PhACs per capita to the influent, the receiving water and sludge were 4.95mgd(-1)person(-1), 889.94μgd(-1)person(-1) and 78.57μgd(-1)person(-1), respectively. The overall removal efficiency of the individual PhACs ranged from "negative removal" to almost complete removal. Mass balance analysis revealed that biodegradation is believed to be the predominant removal mechanism, and sorption onto sludge was a relevant removal pathway for quinolone antibiotics, azithromycin and simvastatin, accounting for 9.35-26.96% of the initial loadings. However, the sorption of the other selected PhACs was negligible. The overall pharmaceutical consumption in Chongqing, China, was back-calculated based on influent concentration by considering the pharmacokinetics of PhACs in humans. The back-estimated usage was in good agreement with usage of ofloxacin (agreement ratio: 72.5%). However, the back-estimated usage of PhACs requires further verification. Generally, the average influent mass loads and back-calculated annual per capita consumption of the selected antibiotics were comparable to or higher than those reported in developed countries, while the case of other target PhACs was opposite.
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.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Chongqing Water Group, Co., Ltd., Chongqing 400015, PR China. Electronic address: hughgao@outlook.com.
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.
authors.forename: Lei
authors.initials: L
authors.lastname: Huang
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: 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; 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; 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; D006801:Humans; D008956:Models, Chemical; D015242:Ofloxacin / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D015242:Ofloxacin; D004364:Pharmaceutical Preparations; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: China; Mass balance analysis; Pharmaceutical consumption back-calculated model; Pharmaceutically active compound; Sludge; Wastewater