title: Inactivation of antibiotic resistance genes in municipal wastewater by chlorination, ultraviolet, and ozonation disinfection.
abstract: This study investigated the inactivation of two antibiotic resistance genes (ARGs)-sul1 and tetG, and the integrase gene of class 1 integrons-intI1 by chlorination, ultraviolet (UV), and ozonation disinfection. Inactivation of sul1, tetG, and intI1 underwent increased doses of three disinfectors, and chlorine disinfection achieved more inactivation of ARGs and intI1 genes (chlorine dose of 160 mg/L with contact time of 120 min for 2.98-3.24 log reductions of ARGs) than UV irradiation (UV dose of 12,477 mJ/cm(2) for 2.48-2.74 log reductions of ARGs) and ozonation disinfection (ozonation dose of 177.6 mg/L for 1.68-2.55 log reductions of ARGs). The 16S rDNA was more efficiently removed than ARGs by ozone disinfection. The relative abundance of selected genes (normalized to 16S rDNA) increased during ozonation and with low doses of UV and chlorine disinfection. Inactivation of sul1 and tetG showed strong positive correlations with the inactivation of intI1 genes (for sul1, R (2)  = 0.929 with p < 0.01; for tetG, R (2)  = 0.885 with p < 0.01). Compared to other technologies (ultraviolet disinfection, ozonation disinfection, Fenton oxidation, and coagulation), chlorination is an alternative method to remove ARGs from wastewater effluents. At a chlorine dose of 40 mg/L with 60 min contact time, the selected genes inactivation efficiency could reach 1.65-2.28 log, and the cost was estimated at 0.041 yuan/m(3).
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, Jiangsu, People's Republic of China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhuang
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Ren
authors.forename: Jinju
authors.initials: J
authors.lastname: Geng
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lili
authors.initials: L
authors.lastname: Ding
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D002713:Chlorine / Q000494:pharmacology; D002947:Cities; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000379:methods; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000528:radiation effects*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects / Q000528:radiation effects; D010126:Ozone; D014466:Ultraviolet Rays; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D002713:Chlorine; D004202:Disinfectants; D010126:Ozone; D062065:Wastewater