调查了采用预氯化消毒工艺的某自来水厂不同工艺单元出水(沉淀出水、过滤出水和出厂水)中3种典型含氮消毒副产物(N—DI坤s)卤乙腈(HANs):二氯乙腈(DCAN)、溴氯乙腈(BCAN)、二溴乙腈(DBAN)的质量浓度随季节变化关系.研究发现,三种HANs的质量浓度水平在夏季和初秋时节最高,BCAN与DBAN的质量浓度还受到原水中Br质量浓度的影响.沉淀和过滤出水中DCAN质量浓度与溶解性有机氮DON值存在明显的线性关系(沉淀水:R。一0.893;过滤水:R。一0.892),与IX)C值之间的线性关系并不明显.BCAN、DBAN质量浓度与DON之间的线性关系较弱,与IXX2之间未存在明显的线性关系.咸潮期HANs的溴分布系数相对较高,对咸潮期溴代N-DBPs的控制应引起重视.
The concentration distributions of three kinds of typical nitrogenous disinfection by-products (N-DBPs) haloacetonitriles ( HANs ) : dichloroacetonitrile ( DCAN ), bromochloroacetonitrile ( BCAN ), dibromoacetonitrile (DBAN) in water after sedimentation, filtration and finished water with the seasons were surveyed. The results show that 3 HANs levels maximized in summer and early autumn, and the concentrations of DBAN and BCAN were influenced by the concentration variation of Br- in raw water. Significant linearrelationships between raw water DON and DCAN concentration in water after sedimentation and filtration were found (water after sedimentation: Rz = 0. 893; water after filtration: R2 = 0. 892); while no obvious liner relationship between DCAN concentration and raw water DOC was obtained. The linear relationships between BCAN concentration and raw water DON, DBAN concentration and raw water DON were weaker relatively, and relationships between their concentrations and DOC were not obvious. Bromine distribution coefficient (nBr) of HANs was higher in the saltwater tide period. The control of brominated N-DBPs in this period should be taken seriously.