南水北调中线工程总干渠河南段原水中消毒副产物前体物变化规律

Water Quality in the Henan Intake Area of the South-to-North Water Diversion Project

以取自南水北调中线总干渠河南段沿线10个分水口门的原水为研究对象,探究了原水中有机物的相对分子质量分布和亲疏水性分布规律;并且研究了原水在氯化和氯胺化条件下消毒副产物生成潜能的变化规律.分离实验结果表明,南水北调沿程原水中的有机物以小分子和强疏水性为主,<1×103区间的溶解性有机碳(DOC)所占的比例最大,质量分数约为57%,强疏水性组分的DOC含量最高,占到总量的50%左右;氯化及氯胺化消毒副产物生成潜能分析实验结果表明,氯化及氯胺化后主要生成了两种含碳消毒副产物(三氯甲烷和一溴二氯甲烷)和两种含氮消毒副产物(二氯乙腈和三氯硝基甲烷).氯化三氯甲烷生成潜能约为120μg·L-1,与氯化生成潜能相比,氯胺化三氯甲烷生成潜能减少了90%左右,一溴二氯甲烷减少了84.9%左右,生成的两种含氮消毒副产物增加了,其中二氯乙腈的生成量增加了约2.3倍,但总含氮消毒副产物生成潜能仍旧较低,均小于6μg·L-1.本研究成果可为南水北调中线工程河南段沿线城市的水厂工艺选择和优化提供有效的理论和技术支持.

The molecular weights,as well as the hydrophobicity composition of natural organic matter（NOM） in raw water,were investigated in the Henan intake area of the South-to-North Water Diversion Project. This study also discusses the formation of carbonaceous disinfection by-products and nitrogenous disinfection by-products during chlorination and chloramination of raw water in this area. Most of the NOM in raw water were small molecules and hydrophobic fractions. The molecular weight fractions of 1 × 10^3 were the most abundant,accounting for 57% of the NOM. The hydrophobic fractions were the most abundant and accounted for 50% of the NOM. Two kinds of C-DBPs（CF and DCBM） and two kinds of N-DBPs（DCAN and TCNM） were mainly produced after chlorination and chloramination,and the formation potential of CF was about 120 μg·L^-1 after chlorination. Results of chloramination showed that the productions of CF and DCBM by this process were about 90% and 84. 9% lower than that by chlorination. However,the amount of N-DBPs increased,and among them the amount of DCAN increased by about 2. 3 times,but the overall N-DBPs formation potential was still low and less than 6 μg·L^-1. The results of this study can provide theoretical and technical support for the process selection and optimization of the waterworks in the Henan intake area of the South-to-North Water Diversion Project.