2002～2006年无棣县二次供水水质卫生状况分析

[目的]探讨无棣县二次供水系统中蓄水池、蓄水箱等蓄水设施对水质的影响状况。[方法]对2002~2006年无棣县内直接供水与二次供水不质进行检测。检测方法按GB 5750-85《生活饮用水标准检验方法》,评价依据按GB5749-85《生活饮用水卫生标准》。检测指标包括总铁、细菌总数、大肠菌群、氨氮、亚硝酸盐氮、硝酸盐氮等。[结果]二次供水合格率为18.7%,城市管网末梢水合格率为61.5%,差异有统计学意义(P<0.01)。其中,浑浊度、细菌总数、铁的合格率分别为20.8%、52.1%和75.0%,城市管网末梢水的合格率75.0%、86.1%和100.0%比较,差异均有统计学意义;大肠菌群二次供水合格率83.3%,略低于末梢水(84.6%);氨氮和硝酸盐氮,二次供水分别为0.30 mg/L和1.93mg/L,高于直接供水(0.16 mg/L和1.42 mg/L)。[结论]蓄水池的设计欠合理,蓄水量偏大,水在蓄水池内滞留时间偏长,又没有二次加氯消毒,造成浑浊度增高和细菌指标增高;铁质设施陈旧,总铁含量逐年增高,无棣县二次供水污染严重,应引起高度重视。

Quality Analysis of Secondary Water Supply in Wudi County from 2002 to 2006

[Objective]To research the affects of pool and other water secondary supply system instruments on water quality.[Methods]Twenty two indexes were analyzed on direct water supply and secondary water systems in Wudi county,Shandong,from 2002 to 2006.Analysis was applied with according to GB 5750-85 and GB 5749-85.The indexes included total Fe,Escherichia coli,NH3-N,NO2-N and NO3-N etc.[Results]The yield rate of secondary water supply quality was only 18.7%,much lower than that of the direct supply water.Turbidity and total bacterial count and Fe were 20.8%,52.1% and 75.0%,respectively,compared to 75.0%,86.1% and 100% of civic tip water,and difference was statistically significant;The yield rate of escherichia coli of secondary water supply quality was 83.3%,a little lower than that of tip water(84.6%);The rates of NH3-N and NO3-N were 0.30mg/l and 1.93mg/l,respectively,higher than those of direct water supply quality(0.16mg/l and 1.42 mg/l).[Conclusion]The unreasonable design of water reservoir made water higher turbidity and total bacterial count and no secondary Chlorine disinfection made water quality even worse.Total sidero-contents slowly increased per year because of the out-of-date sidero-facilities.It is vital recognition to the severe pollutions of the secondary water supply quality in Wudi County,Shandong.