北京市西城区2009-2011年生活饮用水水质卫生状况分析

目的了解西城区生活饮用水水质卫生状况，为加强辖区生活饮用水卫生监督管理，保障水质的卫生安全提供依据。方法于2009--2011年抽样检测西城区生活饮用水供水单位855家，采集二次供水水样l188份，管网水水样135份。按照标准检验方法，对样品进行采集与保存，根据标准检验方法对19项指标进行检验分析，依据卫生标准对检测结果进行评价。结果西城区2009--2011年生活饮用水总体合格率93．4％，且各年水质合格率差异不存在统计学意义（P大于0．05），同一供水类型3年中水质合格率差异不存在统计学意义（P大于O．05），其中各指标合格率均高于95％。浑浊度、色度、铁、锌、细菌总数5项指标，二次供水合格率均高于管网水，差异存在统计学意义（P小于0．05）。二次供水夏季水质合格率低于冬季和春秋季，其中浑浊度、细菌总数、大肠菌群合格率低于其它季节，差异存在统计学意义（P小于0．05）。结论2009--2011年西城区生活饮用水水质良好，且水质状况稳定。变频调速式和无负压无吸程式供水系统的广泛应用和有效的监督管理，有效地保障了水质安全。夏季应加强对水质的消毒处理。

Sanitary Status of Drinking Water in Xicheng District of Beijing in 2009--2011

Objectives To investigate the sanitary quality of drinking water in Xicheng district of Beijing in order to strengthen the sanitary supervision and management as well as to provide scientific standard for the security of drinking water supply. Methods All procedures for collecting, reserving, examining and evaluating samples were conducted according to the methods in GB/T 5750 - 2006 and GB 5749 - 2006. Results The sanitary quality of drinking water was relatively high and stable in 2009--2011. The qualification rate of turbidity, chromaticity, Fe, Zn, total bacteria counts in water samples from secondary water supplies were higher than that from pipe networks. The qualification rate of water samples from secondary water supply in summer was worse than that in winter, spring and fall, especially turbidity, total bacteria counts and coliform bacteria. Conclusions The quality of drinking water was good and stable in Xicheng district in 2009--2011. The wide use of frequency conversion and speed adjustment facilities and non-negative pressure automatic facilities in secondary water supply system and effective supervision and management could protect the security of water quality. The disinfection of drinking water in summer should be strengthened.