珠江水体中有机物分布、组成及与消毒副产物生成的关系

以珠江水体为研究对象,利用XAD树脂分离溶解性有机物(DOC)中的腐殖质及其他有机组分.考察了珠江中DOC的质量浓度、组成分布、SUVA254和三卤甲烷生成势(THMFP),并分析有机物的组成与三卤甲烷生成势(THMFP)之间的关系.结果表明,珠江水域在广东省内的DOC质量浓度为0.7～33.0 mg.L-1,THMFP为30.39～1 091.52μg.L-1,两者呈正比例线性相关.在空间分布上,各支流的DOC质量浓度和THMFP均沿下游方向逐渐增加,而腐殖质在DOC中所占的质量分数却沿下游方向逐渐递减.在加氯实验中,腐殖质是珠江中最主要的消毒副产物前驱物(产生了珠江中64.6%的三卤甲烷),其三卤甲烷生成活性(STHMFP)是其他有机组分的2倍以上.另一方面,SUVA254和腐殖质的质量分数呈正比例线性相关,说明SUVA254对珠江水中消毒副产物前驱物也有一定的指示作用.

Relationship Between Dissolved Organic Carbon and DBP in the Pearl River Water

Dissolved organic carbon(DOC) in the Pearl River system in Guangdong Province was fractioned by using XAD resins into humic substances and other fractions.The concentration and distribution of DOC,SUVA254,trihalomethanes formation potential(THMFP) and relationships between DOC and THMFP were analyzed.The 2-year study demonstrated that the DOC concentration of Pearl River ranged from 0.7 to 33.0 mg·L-1.On the other hand,the trihalomethanes formation potential(THMFP) in Pearl River was 30.39-1 091.52 μg·L-1,which showd a linear relationship with the DOC concentration.Spatially,the DOC concentration and THMFP increased downstream along each tributary;however,the humic substances mitigated to the opposite.During the chlorination,humic substances were the main precursors of disinfection by-products(generating 64.6% of THM) in Pearl River and the specific trihalomethanes formation potential(STHMFP) of humic substances was over 2 times higher as the other fractions.In addition,SUVA254 was proved to provide a reference indicator in testing the precursors of disinfection by-products.