Impacts of Bromide Ion on N-nitrosodimethylamine Formation during Chlorination/Chloramination
N-nitrosodimethylamine (NDMA), a probable human carcinogen, has recently been observed in drinking water and wastewater treated for eventual recycle at levels of concern. Our current investigations on NDMA formation influencing factors suggest that there might be a link between NDMA formation and the bromide ion presence. With low bromide (0.88 μ M) existed, more NDMA formed during chlorination, the reactive bromide-containing intermediate should be response for the formation increased. But after most HOCl was transferred to HOBr, less NDMA would be formed via nitrosation pathway which was possibly caused by the decreased nitrite concentration. In the presence of ammonia, the yield of NDMA formation could increase nearly fivefold. NDMA formation varied with different reagent (chlorine, ammonia and dimethylamine)addition orders, the minimum yield reached when ammonia was the last reagent added to the water.During chloramination by preformed mono-chloroamine (NH2Cl), NDMA/NDEA (N-nitrosodiethylamine) formation increased while bromide increased. The phenomenon was possible caused by the formation of high reactive bromoamine and other halamines. But NDMA formation was limited by bromide when tertiary aliphatic amine with dimethylamine group as the precursor, which indirectly proved that tertiary amine may have a different pathway to form nitrosamines.
N-nitrosodimethylamine bromide disinfection by product chlorination chloramination
Lei Yang Zhonglin Chen Shuqing Zhao An Li Haoyu Li
State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
国际会议
The 12th Asian Pacific Confederation of Chemical Engineering Congress(第十二届亚太化工联盟大会暨化工展览会)
大连
英文
2008-08-04（万方平台首次上网日期，不代表论文的发表时间）