长江沿线城市水源氯(胺)化消毒副产物生成潜能研究

以长江上游重庆、中游武汉、下游上海等大城市的长江饮用水源为研究对象,在对溶解性有机物分子量和亲疏水性分离的基础上,分别采用氯和氯胺两种方式消毒,对比分析了相同时期沿江这些城市原水中氯(胺)化常规和新兴含氮消毒副产物生成潜能的分子组成规律.研究表明,重庆、武汉、上海三地的溶解性有机物均以小分子前体物为主,主要分布在<1kDa的区间内,且以强疏水性成分和亲水性成分为主,原水经氯(胺)化可产生三卤甲烷、卤乙酸、卤乙腈、三氯硝基甲烷等类型的消毒副产物;三地的氯(胺)化主要的含碳消毒副产物(C-DBPs)和含氮消毒副产物(N-DBPs)生成潜能均在<1kDa的区间内最大,从上游到下游,在<1kDa的区间内的生成潜能占各自总潜能比例逐渐增加.三地的氯(胺)化的C-DBPs和N-DBPs生成潜能均以强疏水性组分或亲水性组分为主,且氯胺化可导致亲水性组分C-DBPs和N-DBPs生成潜能所占总量比例增加.

Distribution of disinfection by-product formation potential by chlor(am)ination in three megalopolis along Yangtze river

Dissolved organic matter (DOM) in raw water from upper Yangtze River in Chongqing, middle Yangtze River in Wuhan, lower Yangtze River in Shanghai was isolated into fractions with different hydrophobicity and molecular weight (MW) by resin adsorption and ultra-filtration, respectively, to investigate and regulate emerging disinfection byproducts formation potential during chlorination and chloramination for each fraction. Research showted that DOM from Chongqing, Wuhan and Shanghai was mainly constituted of MW<1kDa organic compounds, hydrophilic and hydrophobic fractions. Trihalometheanes, haloketones, haloacetic acids, haloacetonitriles and chloropicrin were formed after chlorination and chloramination. Among three cities, MW<1kDa fractions gave the highest yield of carbonaceous disinfection byproducts (C-DBPs) and nitrogenous disinfection byproducts (N-DBPs), and the proportion of MW<1kDa formation potential tended to ascend from the upper Yangtze River to lower Yangtze River; Among all three megalopolis, hydrophobic fraction and hydrophilic fraction produced more C-DBPs and N-DBPs, the proportion of hydrophilic fraction C-DBPs and N-DBPs formation potential tended to ascend during chloramination.