| More and more attention is focusing on the safty of drinking water suply. In this paper, firstly, chloramine formation and the characteristics and kinetics of monochloramine autodecomposition were studied. Secondly, considering the high concentration of ammonia and the complication of organic matters in Shanghai Huangpu River, formation characteristics and rules of disinfection byproducts (DBPs) were reviewed during the breakpoint chlorination process, and on the basis of grading and clssification of organisms, the control effects of chloramination on DBPs formation were studied. Finally, the formation rules of 2-monochlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol from phenol chlorination were investigated, and related influencing factors and kinetics were analysed. This series of studies provide certain theory support for safe disinfection of drinking water.The theory chlorination curve showed that, the peak of total chlorine was at the point of Cl/N ratio (mass ratio) of 5:1, and the breakpoint was at the point of Cl/N ratio of 8:1. while chloramine was the oxidant, the appropriate Cl/N ratio was 3:1 4:1, which made monochloramine the major part. Second-order reaction kinetics was observed for monochloramine autodecomposition. Cl/N ratio had the greatest impact on the autodecomposition, follwed by pH value. Kinetics model was built for this reaction.The results of study on formation characteristics of chlorination byproducts showed that, chloramine disinfection could reduce the formation of DBPs effectively, but the control effects were different for different kinds of organisims. Viewing from hydrophilia and hydrophobicity of organisims, the formation of CHCl2Br and CHClBr2 were mainly controlled by chloramine disinfection for the hydrophilia and strong hydrophobicity organic matters. For the weak hydrophobicity organic matters, formation of DBAA and CHCl3 were mainly reduced. Besides, viewing from the organic matters of different molecular weight, chloramine disinfection controlled the THMs and HAAs formation of the organisims whose molecular were less than 10KDa, and the control effect was weakened at some certain extent with the increase of molecular weight. In addition, breakpoint chlorination indicated that the formation concentrations of TTHM and THAA were increased substantially while free chlorine disinfection replaced chloramine disinfection.Phenol chlorination was a typical complicated complex reaction, and its kinetics characteristics were that phenol concentration decreased with the reaction time, and 2,4,6-trichlorophenol concentration increased at all the time, but 2-monochlorophenol and 2,4-dichlorophenol concentrations decreased afer increasing to one extremum point. This complex reaction was phenolic electronic substitution reaction, so reaction rate was related with the positive electricity of pro-electronic reagent, as well as the form of aromatic hydrocarbons. Rates of chlorination of phenol and 2-monochlorophenol were faster in alkaline water than that in weak acid water, so 2,4-dichlorophenol and 2,4,6-trichlorophenol formation concentrations increased with the reaction time.The existence of organic matters reduced phenol chloriantion rate slightly, and formation of 2-monochlorophenol and 2,4-dichlorophenol increased slightly with the increase of UV254, so formation of 2,4,6-trichlorophenol decreased. The growing Br-content also increased formation of 2,4-dichlorophenol, but reduced that of 2-monochlorophenol and 2,4,6-trichlorophenol. NH3-N would change the reaction from chlorination to chloramination, which controlled the formation of 2,4-dichlorophenol and 2,4,6-trichlorophenol effectively, and also reduced formation of 2-monochlorophenol. In addition, theory kinetics of the chlorophenols formation was analysed and a kinetics model was built for 2-monochlorophenol.
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