多水源供水管网中消毒副产物风险分析

通过调研北方某大型城市多水源供水格局下管网水中三卤甲烷(THMs)和卤乙酸(HAAs)这2类消毒副产物(DBPs)的质量浓度水平,对管网中各类DBPs的超标风险、风险点的时空分布及影响因素进行了分析,从确定管网指示性DBPs、检测频率及管网采样点布设3个方面提出了关于管网DBPs风险分析方法的建议.研究结果表明,该市D...

Risk analysis of disinfection by-products in multi-source drinking water distribution system

This study monitored the trihalomethanes (THMs) and halogen acids (HAAs) concentrations of tap water in a large city of northern China with multi-source water supply and analyzed the violation risk, time-space distribution and influencing factors of DBPs. A risk analysis methodology for DBPs in tap water is put forward, which included three aspects, namely, selection of indicative DBPs, monitoring frequency and the layout of sampling points. It was found that the overall risk of DBPs exceeding standard limits in the city is relatively low. However, the risk of HAAs in tap water is significantly higher than that of THMs, thus could serve as an indicator of DBPs in tap water. The areas with relatively high DBPs risks in multi-source DWDS are as follows: areas with mixed water supply from both groundwater and surface water and the far-ends of the pipe network; time periods with water temperature below 20 ℃, dissolved organic carbon (DOC) concentration higher than 1.7 mg·L−1 and free chlorine residual concentration is higher than 0.5 mg·L−1; areas with significant turbidity fluctuation due to unstable hydraulic conditions and the presence of pipe sediments. Sampling frequency and the sampling points should be increased accordingly during the periods/in the areas with relatively high DBPs risk.