目的研究3-氯-4-二氯甲基-5-羟基-2(5氢)-呋喃酮(MX)和总有机碳(TOC)浓度以及非挥发性有机提取物致突变性在饮用水常规处理工艺过程中的变化,为城市给水处理工艺优化提供依据。方法采集某自来水厂饮用水常规处理工艺过程中的源水、预加氯后的混凝沉淀水、沉淀水、过滤水、加氯消毒后的出厂水和管网末梢水。采用气相色谱/质谱联用(GC/MS)和TOC分析仪分别检测水样MX浓度和TOC浓度,Ames试验检测水样非挥发性有机提取物的致突变性,同时检测水样的浊度和pH值。结果常规处理工艺过程中不同工艺段水样MX和TOC浓度的变化趋势一致,与源水比较,均表现为预加氯和加氯消毒后二者浓度上升,经过沉淀处理后二者浓度下降;水中MX的生成量与TOC浓度呈显著正相关,而与水的浊度和pH值无相关关系;加氯消毒后的出厂水和管网末梢水致突变活性也有所增加。结论在饮用水常规处理工艺过程中,加氯和沉淀工艺是影响MX和TOC浓度的重要环节;加氯可增加饮用水中MX的生成量和致突变活性,影响饮水安全。
Objective To study the effect of routine water treatment technology on contents of 3-cloro-4- (dichloromethyl)-5-hydroxy-2(SH)-furanone(MX) and total organic carbon(TOC) in drinking water, as well as mutagenicity of the non-volatile organic extracts from drinking water for providing scientific bases for optimization of the drinking water treatment technology. Methods Water samples including raw water, water from treatment steps of coagulative precipitation after prechlorination, precipitation, filtration and chlorination disinfection, and tap water were collected. GC/MS and TOC- Analyse were used to determine the concentrations of MX and TOC. The pH value and turbidity of water were also determined. The mutagenicity of non-volatile organic extracts from water samples was evaluated by means of Ames test. Results MX and TOC concentrations showed the same variation during the process of drinking water treatment. Compared to raw water, MX and TOC levels in water were increased after prechlorination and chlorination disinfection and decreased after precipitation. MX levels were signinficantly correlated with TOC levels, but not with pH value and turbidity. There were higher mutagenic activities of water after chlorination disinfection and tap water than that of raw water. Conclusion For drinking water treatment technology, chlorination and precipitation were important procedures affecting concentrations of MX and TOC. Chlorination enhances formation of MX and mutagenic activity of drinking water.