title: Transformation of bisphenol A in water distribution systems: a pilot-scale study.
abstract: Halogenations of bisphenol A (BPA) in a pilot-scale water distribution system (WDS) of a cement-lined ductile cast iron pipe were investigated. The water in the pilot-scale WDS was chlorinated with a free chlorine concentration of 0.7 mg L(-1) using sodium hypochlorite, and with an initial BPA concentration of 100 μg L(-1) was spiked in the WDS. Halogenated compounds in the BPA experiments were identified using EI/GC/MS and GC. Several BPA congeners, including 2-chlorobisphenol A (MCBPA), dichlorobisphenol A (D2-CBPA), 2,2',6-trichlorobisphenol A (T3CBPA), 2,2',6,6'-tetrachlorobisphenol A (T4CBPA), 2-bromobisphenol A (MBBPA), and bromochlorobisphenol A (MBMCBPA) were found. Moreover, further halogenation yielded other reaction intermediates, including 2,4,6-trichlorophenol (T3CP), dichlorobisphenol A, bromodichlorophenol, and dibromochlorophenol. After halogenation for 120min, most of the abovementioned reaction intermediates disappeared and were replaced by trihalomethanes (THMs). Based on these experimental findings, the halogenation process of BPA oxidation in a WDS includes three stages: (1) halogenation on the aromatic ring; (2) chlorine or bromine substitution followed by cleavage of the α-C bond on the isopropyl moiety with a positive partial charge and a β'-C bond on the benzene moiety with a negative partial charge; and (3) THMs and a minor HAA formation from phenolic intermediates through the benzene ring opening with a chlorine and bromine substitution of the hydrogen on the carbon atoms. The oxidation mechanisms of the entire transformation from BPA to THM/HAA in the WDS were proposed.
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China.
authors.forename: Zilong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: U.S. EPA, National Risk Management Research Laboratory, Cincinnati, USA.
authors.forename: Y Jeffrey
authors.initials: YJ
authors.lastname: Yang
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China.
authors.forename: Jingqing
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Mao
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, China. Electronic address: zhangyan@zju.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D001559:Benzhydryl Compounds / Q000737:chemistry*; D001966:Bromine / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry; D002733:Chlorophenols / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D054879:Halogenation; D010636:Phenols / Q000737:chemistry*; D010865:Pilot Projects; D012973:Sodium Hypochlorite / Q000737:chemistry; D022882:Trihalomethanes / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D001966:Bromine; D002713:Chlorine; D002733:Chlorophenols; D010636:Phenols; D012973:Sodium Hypochlorite; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; C024564:2,4,6-trichlorophenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Bisphenol A; Halogenations; Mechanism; Water distribution system