title: Production of trihalomethanes, haloacetaldehydes and haloacetonitriles during chlorination of microcystin-LR and impacts of pre-oxidation on their formation.
abstract: Microcystins (MCs) in drinking water have gained much attention due to their adverse health effects. However, little is known about the impact of pre-oxidation in the formation of disinfection by-products (DBPs) during the downstream chlorination of MCs. The present study examined the formation of both carbonaceous and nitrogenous DBPs from chlorination of MC-LR (the most abundant MC species) and evaluated the impact of permanganate (PM), hydrogen peroxide (H2O2) and chlorine dioxide (ClO2) pre-oxidation on the DBP formation in chlorination. Higher yields of chloroform (CF) (maximum 43.0%) were observed from chlorination of MC-LR than free amino acids which are included in MC-LR structure. Chloral hydrate (CH) and dichloroacetonitrile (DCAN) were also produced from the chlorination of MC-LR, and the latter one was formed probably due to the chlorination of peptide bonds. A high pH favored the production of CF and CH, but inhibited the formation of DCAN. In the presence of bromide, bromo-DBPs could be produced to pose a threat. For example, 0.58μg/L of tribromoacetaldehyde was produced from the chlorination of MC-LR at Br-=200μg/L. PM and ClO2pre-oxidation could both reduce the DBP formation from MC-LR. In contrast, H2O2appeared not to significantly control the DBP formation.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. Electronic address: feedwater@126.com.
authors.forename: Wenhai
authors.initials: W
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Dechang
authors.initials: D
authors.lastname: Yao
authors.affiliation: Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Minghao
authors.initials: M
authors.lastname: Sui
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Naiyun
authors.initials: N
authors.lastname: Gao
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives / Q000737:chemistry*; D000097:Acetonitriles / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry; D017606:Chlorine Compounds; D002725:Chloroform / Q000737:chemistry; D060766:Drinking Water; D054879:Halogenation; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D017895:Manganese Compounds; D008387:Marine Toxins; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry*; D052998:Microcystins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides
chemical_list: D000097:Acetonitriles; D000596:Amino Acids; D017606:Chlorine Compounds; D060766:Drinking Water; D006846:Hydrocarbons, Halogenated; D017895:Manganese Compounds; D008387:Marine Toxins; D052998:Microcystins; D010087:Oxides; C048856:permanganic acid; D002725:Chloroform; C025109:chlorine dioxide; D006861:Hydrogen Peroxide; C057862:cyanoginosin LR; D000079:Acetaldehyde; D008697:Methane
keywords: Chlorine dioxide; Disinfection by-products; Haloacetaldehydes; Hydrogen peroxide; Microcystin-LR; Permanganate