title: Precursors and factors affecting formation of haloacetonitriles and chloropicrin during chlor(am)ination of nitrogenous organic compounds in drinking water.
abstract: This study investigated the precursors and factors affecting formation of haloacetonitriles (HANs) and chloropicrin (TCNM) during chlorination/chloramination of eight amino acids in the effluent water of V-type clarifying filtration from a drinking water treatment plant. The yields of trichloroacetonitrile (TCAN), dichloroacetonitrile (DCAN) and TCNM were higher during chlorination than during chloramination. Tyrosine and tryptophan produced the greatest amount of DCAN and also generated a small amount of TCAN during chlorination process. Besides, the yields of DCAN were higher than TCNM during chlorination/chloramination. Contact time, Cl2:org-N molar ratios, pH, temperature and bromide ion affected nitrogenous disinfection by-products (N-DBPs) formation during chlorination of tryptophan in different degrees. TCAN, DCAN and TCNM formation showed the increasing and then decreasing with prolonged contact time. Higher Cl2:org-N molar ratios improved N-DBPs formation within a certain range. The pH affected N-DBPs formation differently. HANs increased with increasing pH from 5 to 6 and decreased with increasing pH from 6 to 9, while TCNM increased with increasing pH from 5 to 9. Higher temperatures enhanced TCNM formation, but reduced the formation of TCAN and DCAN. The presence of bromide ions improved the yields of HANs and TCNM and shifted N-DBPs to more brominated ones.
authors: School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors: Aiyin
authors: A
authors: Jia
authors: School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, Guangzhou 510006, PR China. Electronic address: ppchdwu@scut.edu.cn.
authors: Chunde
authors: C
authors: Wu
authors: School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors: Yan
authors: Y
authors: Duan
mesh_terms: D000097:Acetonitriles / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry; D001965:Bromides / Q000737:chemistry; D002700:Chloramines / Q000737:chemistry*; D004203:Disinfection; D060766:Drinking Water / Q000032:analysis; D054879:Halogenation; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D000097:Acetonitriles; D000596:Amino Acids; D001965:Bromides; D002700:Chloramines; D060766:Drinking Water; D006843:Hydrocarbons, Chlorinated; D014874:Water Pollutants, Chemical; C029549:trichloroacetonitrile; C100187:chloropicrin; C051716:dichloroacetonitrile
keywords: Amino acid; Chloramination; Chlorination; Chloropicrin; Haloacetonitriles