title: Formation of disinfection by-products after pre-oxidation with chlorine dioxide or ferrate.
abstract: The effect of pre-oxidation with chlorine dioxide (ClO2) or ferrate (Fe(VI)) on the formation of disinfection by-products (DBPs) during chlorination or chloramination was tested with natural waters from 12 sources (9 surface waters, 1 groundwater, and 2 wastewater effluents). DBPs investigated included trihalomethanes (THM), chloral hydrate (CH), haloketones (HK), haloacetonitriles (HAN) and trichloronitromethane (TCNM), chlorite and chlorate. Chlorite and chlorate were found in the ClO2-treated waters. Application of 1 mg/L ClO2 ahead of chlorination reduced the formation potential for THM by up to 45% and the formation of HK, HAN and TCNM in most of the samples. The CH formation results were mixed. The formation of CH and HK was enhanced with low doses of Fe(VI) (1 mg/L as Fe), but was greatly reduced at higher doses (20 mg/L Fe). Fe(VI) reduced the formation of THM, HAN and TCNM in most of the samples. Reduced potential for the formation of NDMA was observed in most of the samples after both ClO2 and Fe(VI) pre-oxidation.
authors.affiliation: SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET) School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, China. Electronic address: yangx36@mail.sysu.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Wanhong
authors.initials: W
authors.lastname: Guo
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Tingjin
authors.initials: T
authors.lastname: Ye
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
mesh_terms: D017606:Chlorine Compounds / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D017606:Chlorine Compounds; D010087:Oxides; C017311:ferrate ion; C025109:chlorine dioxide; D007501:Iron
keywords: Chloramination; Chlorination; Chlorine dioxide; Disinfection by-products; Ferrate; Pre-oxidation