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目的对德保县2008—2012年农村安全饮水工程供水系统水质进行分析,针对所存在问题提出改进建议。方法以2005年以后水利部门建成的国债项目的农村安全饮水工程为监测对象,按照分层随机原则,每年按东西南北中5个方位随机抽取5个乡(镇),根据农村安全饮水工程的水源类型、水处理工艺、供水规模及其覆盖人口等再进行分层,每个乡(镇)随机抽取3~4个农村安全饮水工程为监测点,分枯水期、丰水期2次采集出厂水和末梢水各1份进行水质监测,检测项目包括色度、浑浊度、臭和味、肉眼可见物、pH、铁、锰、氯化物、硫酸盐、溶解性总固体、总硬度、耗氧量、氨氮、砷、氟化物、硝酸盐、菌落总数、总大肠菌群、耐热大肠菌群等19个指标。根据GB 5749—2006《生活饮用水卫生标准》规定,检测结果全部符合标准的规定为合格。结果 5年共抽取92个监测点364份水样,其中合格水样116份,合格率为31.87%,枯水期、丰水期合格率分别为32.78%(59/180)、30.98%(57/184),出厂水、末梢水合格率均为31.87%(58/182),丰水期与枯水期、出厂水与末梢水间水质合格率差异均无统计学意义(均P>0.05)。水源水为地面水、地下水的合格率分别为22.73%(40/176)、40.43%(76/188),其中丰水期以地面水和地下水为水源的水质合格率分别为18.89%(17/90)和42.55%(40/94),两者差异具有统计学意义(P<0.01)。完全处理、仅消毒处理和未处理3种供水方式的水质合格率分别为100.00%(4/4)、48.30%(85/176)、14.67%(27/184),不同处理方式的水质合格率差异有统计学意义(P<0.01)。不合格指标中总大肠菌群、耐热大肠菌群和菌落总数的合格率分别为31.86%(116/364)、37.08%(135/364)、78.02%(284/364),浑浊度为76.65%(279/364),肉眼可见物为96.70%(362/364),pH为99.73%(363/364),其他各项均为100.00%。结论德保县农村安全饮水工程水质合格率较低,主要是微生物污染严重,提示应加强饮水安全工程的工艺处理和消毒,以保障饮水安全。
Objective To analyze the quality of water supply system of rural safe drinking water project in Dabao County from 2008 to 2012, and put forward suggestions for improvement according to the existing problems. Methods According to the principle of stratified randomization, five townships (towns) were randomly selected from five directions in east, west, south and north in each year according to the rural safe drinking water project of the national debt project built by the water conservancy department after 2005. According to the water source of rural safe drinking water project Type, water treatment process, water supply scale and its population coverage, and then stratified. Each township (town) randomly selected 3-4 rural drinking water projects as monitoring points, sub-dry period, Water quality monitoring was carried out for 1 part of peripheral water. The testing items included color, turbidity, odor and smell, macroscopic matter, pH, iron, manganese, chloride, sulfate, total dissolved solids, total hardness, oxygen consumption, Ammonia nitrogen, arsenic, fluoride, nitrate, total number of colonies, total coliforms, heat-resistant coliforms and other 19 indicators. According to GB 5749-2006 “drinking water health standards” provisions of the test results all meet the standards for the pass. Results A total of 364 water samples were collected from 92 monitoring sites over the five years, of which 116 were qualified and the pass rate was 31.87%. The pass rates in dry and wet periods were 32.78% (59/180) and 30.98% (57/184) respectively ), The passing rate of the ex-factory water and the extremity water were both 31.87% (58/182). There was no significant difference in passing rate between the ex-factory water and the terminal water during the wet and dry periods (all P> 0.05). The qualified rates of groundwater and groundwater were 22.73% (40/176) and 40.43% (76/188), respectively. The qualified rate of water quality with groundwater and groundwater as the source during the wet season was 18.89% (17 / 90) and 42.55% (40/94), respectively, with statistical significance (P <0.01). The pass rates of water quality of three kinds of water supply systems that were completely treated, disinfected and untreated were 100.00% (4/4), 48.30% (85/176) and 14.67% (27/184), respectively. The passing rate of water quality of different treatment methods The difference was statistically significant (P <0.01). The pass rates of total coliforms, heat-resistant coliform bacteria and colony in the unqualified indicators were 31.86% (116/364), 37.08% (135/364), 78.02% (284/364), respectively, and the turbidity was 76.65 % (279/364), 96.70% (362/364) macroscopic, pH was 99.73% (363/364), and all others were 100.00%. Conclusion The qualified rate of water quality of rural safe drinking water project in Deba County is relatively low, which is mainly due to the serious microbial pollution. It suggests that the treatment and disinfection of drinking water safety projects should be strengthened to ensure drinking water safety.