title: Effect of bromide on the transformation and genotoxicity of octyl-dimethyl-p-aminobenzoic acid during chlorination.
abstract: Octyl-dimethyl-p-aminobenzoic acid (ODPABA), one of the most commonly used organic UV filters, can undergo considerable transformation in water when entering into the disinfection process. The impacts of bromide on degradation kinetics, formation and speciation of transformation products, regulated disinfection by-products (DBPs) as well as genotoxicity changes during ODPABA chlorination were investigated in this study. Results indicated that the reaction of ODPABA with chlorine followed pseudo-first-order and second-order kinetics. Adding bromide noticeably enhanced the degradation rate of ODPABA, but reduced the impact of chlorine dose. Four halogenated transformation products (Cl-ODPABA, Br-ODPABA, Cl-Br-ODPABA and Br2-ODPABA) were detected by LC-MS/MS. Mono-halogenated products were stable during 24-h chlorination, while di-halogenated products constantly increased. The total yields of trihalomethanes (THMs) and haloacetic acids (HAAs) were both low, but predominated by bromine substitution at high levels of bromide. In addition, SOS/umu tests showed that genotoxicity was generated after ODPABA chlorination, which was increased at least 1.5 times in the presence of bromine. Whereas, no significant genotoxicity variation was observed following bromide concentration change.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Qiwan
authors.initials: Q
authors.lastname: Chai
authors.affiliation: International Publishing Center, China National Knowledge Infrastructure, Beijing 100192, China.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaomao
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: yanghw@tsinghua.edu.cn.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Yang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Environmental Engineering Programs, The Pennsylvania State University, Middletown, PA 17057, USA.
authors.forename: Yuefeng F
authors.initials: YF
authors.lastname: Xie
mesh_terms: D001965:Bromides / Q000737:chemistry*; D004202:Disinfectants / Q000737:chemistry*; D004203:Disinfection; D054879:Halogenation; D009152:Mutagenicity Tests; D009153:Mutagens / Q000737:chemistry* / Q000633:toxicity; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D013473:Sunscreening Agents / Q000737:chemistry* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity; D018508:Water Purification / Q000379:methods; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity
chemical_list: D001965:Bromides; D004202:Disinfectants; D009153:Mutagens; D013473:Sunscreening Agents; D014874:Water Pollutants, Chemical; C508310:octyl-dimethylaminobenzoate; D004124:p-Dimethylaminoazobenzene
keywords: Bromide; Chlorination; Genotoxicity; Octyl-dimethyl-p-aminobenzoic acid; Transformation products