title: Fate and removal of various antibiotic resistance genes in typical pharmaceutical wastewater treatment systems.
abstract: The high levels of antibiotic residues in pharmaceutical wastewater treatment plants (PWWTPs) make these plants the hotspots for the proliferation of antibiotic resistance genes (ARGs). This study investigated the fate and removal of 11 ARG subtypes for sulfonamide, tetracycline, β-lactam, and macrolide resistance in each processing stage of two full-scale PWWTPs in northern China. The levels of typical ARG subtypes in the final effluents ranged from (2.56 ± 0.13) × 10(1) to (2.36 ± 0.11) × 10(7) copies/ml. The absolute abundance of ARGs in effluents accounted for only 0.03-78.1 % of influents of the two PWWTPs, while the majority of the ARGs were transported to the dewatered sludge with concentrations from (2.65 ± 0.43) × 10(5) to (4.27 ± 0.03) × 10(10) copies/g dry weight (dw). The total loads of ARGs discharged through dewatered sludge plus effluent was 1.01-14.09-fold higher than that in the raw influents, suggesting the proliferation of ARGs occurred in the wastewater treatment. The proliferation of ARGs mainly occurs in biological treatment process, such as aeration tank, anoxic tank, sequencing batch reactor (SBR), and bio-contact oxidation, facilitates the proliferation of various ARGs, implying significant replication of certain ARG subtypes may be attributable to microbial growth. Chemical oxidation seems promising to remove ARGs, with removal efficiency ranged from 29.3 to 85.7 %, while the partial correlation analysis showed significant correlations between antibiotic concentration and ARG removal. Thus, the high antibiotic residues within the PWWTPs may have an influence on the proliferation, fate, and removal of the associated ARG subtypes.
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China.|Shandong Provincial Solid Waste and Hazardous Chemical Pollution Prevention and Control Center, Jinan, 250117, China.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Zhai
authors.affiliation: College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Yang
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China. mao@tju.edu.cn.
authors.forename: Daqing
authors.initials: D
authors.lastname: Mao
authors.affiliation: College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China. luoy@nankai.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis; D002681:China; D004345:Drug Industry; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D007220:Industrial Waste; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D007220:Industrial Waste; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Activated sludge; Antibiotic resistance genes; Antibiotics; Bio-contact oxidation; Pharmaceutical wastewater treatment plant; Sequencing batch reactor