2016年定西市生活饮用水水质卫生监测分析

Surveillance of sanitary conditions of drinking water in Dingxi city, 2016

目的分析2016年甘肃省定西市生活饮用水水质卫生状况及其影响因素,为有关部门制定改水措施提供科学依据。方法调查全市集中式供水水厂和部分分散式供水监测点水处理工艺、水源类型和供水方式等卫生现状,检测枯水期和丰水期出厂水、末梢水及二次供水样品,按照《生活饮用水卫生标准》GB 5749-2006进行评价,检测结果录入EXCEL建立数据库,用SPSS 19.0进行统计分析。结果全市2 955 839人中62.95%饮用集中式供水,37.05%饮用分散式供水,共监测水样704份,合格水样449份、合格率63.78%,单项指标合格率较低的为浑浊度(83.52%)、总大肠菌群(83.66%)和菌落总数(86.79%)水样合格率城市水(84.33%)高于农村水(58.95%,χ2=30.254,P<0.05),集中式供水(69.70%)高于分散式供水(12.33%,χ2=93.323,P<0.05);影响微生物、感官性状和一般化学物指标的因素主要为供水方式、水样类型和水源类型。结论定西市饮用水安全问题比较严重,总体水质合格率和农村自来水普及率低,影响水质合格率的主要指标为微生物、感官性状和一般化学物指标;市(县)政府应加大改水力度,重点向农村地区倾斜。

Objective To analyze the sanitary conditions of drinking water and understand their influencing factors in Dingxi city of Gansu province in 2016, and provide scientific basis for the policy of water improvement formulated by the relevant departments. Methods The water treatment process, water type, mode of water supply, population covered and the application of sterilizing equipment were investigated in the monitoring points of centralized water supply facilities and part of the decentralized water supply facilities in the city. The finished water, tap water and the water secondary supplied in dry season and wet season were tested in the laboratory and evaluated according to the Hygienic Standard for Drinking Water（GB 5749-2006）. The results were entered into EXCEL for statistical analysis with SPSS 19.0 software. Results Among2 955 839 residents in Dingxi city, there were 62.95% of people drinking the water supplied by the centralized water supply facilities and 37.05% of people drinking the water supplied by the decentralized water supply facilities. Totally 704 water samples were tested and 449 samples were qualified with the qualified rate of 63.78%. The single indexes with the lowest qualified rate were turbidity（83.52%）, total coliform（83.66%） and total colony（86.79%）. The qualified rate of water samples was higher in urban area（84.33%） than in rural area（58.95%, χ2=30.254, P〈0.05）, and the qualified rate of centralized water supply（69.73%） was higher than that of the decentralized water supply（12.33%, χ2=93.323, P〈0.05）. The influencing factors of the indexes of microorganisms, sensory attributes and general chemicals were mainly mode of water supply, type and source of water. Conclusions The water safety is serious in Dingxi city due to the low general qualified rate of water and the popularity of tap water in rural area. The main factors influencing the qualified rate of water are microorganism, sensory attributes and general chemicals. The government should increase the intensity of water improvement and focus on rural area.