title: [Reaction of free chlorine transforms into chloramines in microorganism inactivation experiment].
abstract: Due to organic N exiting in the pure bacterial cultures, when using free chlorine to inactivate microorganisms, freest chlorine transforms into organic N-chloramines which are no use in disinfection process. This reaction happens in E. coli, Pseudomonas aeruginosa inactivation experiments. Added 2 mg x L(-1) free chlorine to inactivate E. coli of 10(8) CFU x mL(-1), free chlorine exhausts in 5 min while chloramines and dichloramines become 0.92 mg x L(-1) and 0.4 mg x L(-1). E. coli is used as test microorganism in following inactivation experiments. E. coli suspension is purified by centrifugal and membrane filtration, but the purification can't help to separate the organic N from E. coli suspension, which indicating that the source of organic N may be from bacterium cells. Dilution is worked when E. coli concentrations are diluted under 10(5) CFU/mL. This result should be regarded in related researches in future.
authors.affiliation: Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. liujing99@mails.tsinghua.edu.cn
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: Xiao-Jian
authors.initials: XJ
authors.lastname: Zhang
authors.forename: Che-Qiong
authors.initials: CQ
authors.lastname: Zhang
mesh_terms: D002700:Chloramines / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry* / Q000494:pharmacology; D004202:Disinfectants / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000378:metabolism
chemical_list: D002700:Chloramines; D004202:Disinfectants; D002713:Chlorine; D009584:Nitrogen