重庆市涪陵区城乡饮用水中微囊藻毒素的污染

目的 探讨重庆市涪陵区城乡居民饮用水中微囊藻毒素LR(MC-LR)污染现状.方法 在涪陵区市政水源水(长江水)、管网水、二次供水系统设立采样点;同时,抽取水源和水处理工艺完全相同的4个乡镇水厂,选择其水源水、管网水;在上述4个乡镇分别选择3～4个农村居民饮用水井.于2004年6-11月,采集各采样点水样.采用酶联免疫试剂盒测定MC-LR含量,采用氯化亚锡分光光度法测定水样中总磷含量,采用紫外分光光度法测定水样中总氮含量.结果 6-11月市政水源水(长江水)、管网水以及6月市政二次供水、乡镇水厂水源水、管网水、农村居民饮用水井水水样中均未检出MC-LR.7-11月乡镇水厂水源水中MC-LR含量为(0.63±0.27)μg/L,高于管网水[(0.57±0.25)μg/L],差异无统计学意义(t=1.188,P＞0.05).农村井水中MC-LR含量以8、9、10月最高,7、11月次之.市政水厂水源水、管网水水样中总磷、总氮的含量均符合GB3838-2002《地表水环境质量标准》中地面水三级卫生标准要求;7、11月二次供水水样中总磷、总氮的含量高于8、9、10月.乡镇水厂水源水、管网水所有水样中总磷、总氮含量均超过国家地面水三级卫生标准.7-11月农村饮用井水水样中总磷、总氮含量略低于乡镇水厂水源水、管网水.7-11月氮磷比为6.56～13.13,其中8、9、10月氮磷比约为7.2,适合各种藻类生长且是水体中MC-LR形成的高峰期.结论 本次调查的涪陵区城乡饮用水不同程度地受到MC-LR污染.在今后的改水工程中,应增加去除MC-LR的设施和加强消毒处理.

Investigation of Drinking Water Pollution by Microcystin in City and Countryside of Fuling District,China

Objective To understand the microcystin(MC-LR)pollution in drinking water in the city and countryside of Fuling District,Sichuan,China.Methods In 2004,285 water samples were collected from different types of water in Fuling district in different season and the concentration of LR(MC-LR),total phosphorus and total nitrogen in water were determined respectively.Results From July to November in 2004,no LR(MC-LR)was detected and the total phosphorus and total nitrogen did not exceed the national standard limits in the drinking water in the city,but in the secondary water supply in the city,the MC-LR was detected,the total phosphorus and total nitrogen exceed the standard limits.In the countryside,the MC-LR was detected,the total phosphorus and total nitrogen exceed the standard limits.Conclusion In the countryside of Fuling District,Sichuan,China,the drinking water,water source and tap water,was seriously contaminated by microcystin,the total phosphorus and total nitrogen exceed the national standard limits.