上海市某区管道直饮水水质危险因素研究

Study on Risk Factors of Piped Drinking Water Quality in a District of Shanghai

目的探讨影响管道直饮水水质的危险因素。方法于2008年8月和12月分别对上海市某区辖内14个居民小区的管道直饮水系统进行水质检测并调查潜在的危险因素,以典型水质指标实测值和全部指标的综合指数值为应变量拟合多元线性逐步回归模型。结果管道直饮水综合水质可能与投入使用时间、用户开通率、消毒工艺等有关。投入使用时间每增加1年,综合指数平均下降约0.05;用户开通率每增加10%,综合指数平均下降约0.03;消毒工艺由微电解和紫外线组合消毒变为单独臭氧消毒时,综合指数平均下降约0.28。四氯化碳、铁、菌落总数、耗氧量、浑浊度、亚硝酸盐、pH值、三氯甲烷、UV254、电导率和溶解性总固体的多元回归模型均具有统计学意义。结论影响管道直饮水综合水质的主要危险因素为投入使用时间、用户开通率和水质消毒工艺,个别指标还受膜处理工艺和管网分布远近的影响。

Objective To explore the risk factors of piped drinking water quality.Methods The water quality of piped drinking system in a district of Shanghai was detected in August and December of 2008 and potential risk factors of water quality were investigated.Multiple linear stepwise regression models were constructed to fit the measured values of specific indices and the evaluation value of comprehensive index with various potential risk factors.Results The integrate water quality of piped drinking water may be associated with time of use,frequency of use and disinfection process.The comprehensive index value decreased 0.05 corresponding to an increment of one year in time of use,0.03 corresponding to 10% increase of frequency of use,and 0.28 corresponding to a change of disinfection process from,a combination of micro-electrolysis and UV disinfection to single ozone method.Multiple linear stepwise regression models fitted to the measured values of specific indices including carbon tetrachloride,Fe,total number of colonies,COD,turbidity,nitrite,pH value,chloroform,UV254,conductivity and TDS were all statistically significant.Conclusion The time of use,frequency of use and disinfection process can be considered as the major potential risk factors for the integrate water quality of piped drinking system.Some specific water index may also be influenced by membrane treatment techniques and the net distribution of piped water system.