title: Effects of ozone and ozone/peroxide pretreatments on disinfection byproduct formation during subsequent chlorination and chloramination.
abstract: Ozone (O3) and ozone/hydrogen peroxide (O3/H2O2) can be used in water treatment facilities to remove many organic micropollutants with taste, odor, and color implications. The effects of O3 and O3/H2O2 on the formation of disinfection byproducts (DBPs) in subsequent chlorination and chloramination processes, however, are not well determined. In this study, we compared the yields of a series of regulated and emerging DBPs during sequenced O3-Cl2, O3/H2O2-Cl2, O3-NH2Cl, and O3/H2O2-NH2Cl oxidation of 11 samples, each with different hydrophobicity, bromide concentration, soluble microbial products, and humic substances. For most water, pretreatment with O3 and O3/H2O2 increased the formation of chloral hydrate (CH), trichloronitromethane (TCNM) and haloketones (HKs) but lowered the yields of haloacetonitriles (HANs) during chlorination processes. Compared with O3 alone, O3/H2O2 in combination generated more CH and HKs during chlorination, and their extents of formation appeared to depend on the O3 doses. In terms of chloramination, both O3 and O3/H2O2 reduced THM, HAA, and HAN formation significantly without increasing CH, TCNM, or HKs. These results suggest that O3 or O3/H2O2 pretreatments may provide some benefits for the chloramination process in controlling regulated and emerging DBPs in waters without high bromide content.
authors.affiliation: Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China. yangx36@mail.sysu.edu.cn
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Peng
authors.forename: Baiyang
authors.initials: B
authors.lastname: Chen
authors.forename: Wanhong
authors.initials: W
authors.lastname: Guo
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Liang
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
mesh_terms: D001966:Bromine / Q000737:chemistry; D002700:Chloramines / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry; D004203:Disinfection / Q000379:methods; D006861:Hydrogen Peroxide / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014876:Water Pollution / Q000517:prevention & control; D018508:Water Purification / Q000379:methods*
chemical_list: D002700:Chloramines; D009930:Organic Chemicals; D016877:Oxidants; D014874:Water Pollutants, Chemical; D002713:Chlorine; D010126:Ozone; D006861:Hydrogen Peroxide; D001966:Bromine