title: Effects of ozone pretreatment on the formation of disinfection by-products and its associated bromine substitution factors upon chlorination/chloramination of Tai Lake water.
abstract: This study investigated the effects of preozonation on disinfection by-products (DBPs) formation during chlorination and chloramination of the water collected from Tai Lake. Results showed that the high ozone dose (0.6-1.0 mg O₃/mg DOC) pretreatment reduced the yields of trihaloacetic acids (reduced 62-63% in chlorination), dihaloacetonitriles (reduced 53-55% and 14-26% in chlorination and chloramination, respectively) and trihaomethanes (reduced 19% in chloramination), but markedly increased the formation of halonitromethanes (increased 4.7-5.6 times in chlorination and 2.1-2.7 times in chloramination), haloketones (increased 4.8-7.1 times in chlorination and 2.5-2.9 times in chloramination) and dihaloacetic acids (increased 1.5-2.4 times in chlorination and 0.3-0.6 times in chloramination). Thus the high ozone dose pretreatment should be avoided during chlorination/chloramination of Tai Lake water. Also, chloramination (with and without preozonation) produced much lower DBPs yields as compared with chlorination (with and without preozonation), indicating that chloramine was a better choice to control the DBPs yields. Further analysis also revealed that the bromine substitution factors (BSFs) of DBPs varied with disinfection mode. In chlorinamination, the BSFs generally showed a decrease trend with the ozone dose, yet in chlorination, the BSFs mostly exhibited first an increase and then a decrease trend. Moreover, the BSFs of DBPs in chloramination (with or without preozonation) were dominantly lower than those in chlorination (with or without preozonation).
authors.affiliation: College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Wang
authors.affiliation: College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
authors.forename: Mengyong
authors.initials: M
authors.lastname: Ruan
authors.affiliation: College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Lin
authors.affiliation: College of Engineering, Zhejiang Normal University, Jinhua 321004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China. Electronic address: huachang2002@163.com.
authors.forename: Huachang
authors.initials: H
authors.lastname: Hong
authors.affiliation: College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China. Electronic address: zhouxiaoling@zjnu.cn.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Zhou
mesh_terms: D001966:Bromine / Q000737:chemistry*; D004202:Disinfectants / Q000737:chemistry*; D004203:Disinfection; D054879:Halogenation; D060106:Lakes / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D004202:Disinfectants; D014874:Water Pollutants, Chemical; D010126:Ozone; D001966:Bromine
keywords: Bromine substitution factor (BSF); Chloramination; Chlorination; Disinfection by-products (DBPs); Ozone; Tai Lake