2015—2019年绵阳市生活饮用水水质监测结果分析

Analysis on monitoring results of drinking water quality in Mianyang City from 2015-2019

目的分析2015—2019年绵阳市水质监测数据,了解近年来绵阳地区生活饮用水卫生状况,发现风险指标,保障饮水安全。方法对6 939份水样按GB/T 5750—2006《生活饮用水标准检验方法》进行检测,GB 5749—2006《生活饮用水卫生标准》进行结果评价。结果 2015—2019年检测的6 939份水样总体合格率为71.06%。城市与农村生活饮用水合格率分别为96.11%和66.32%,差异有统计学意义(χ2=400.398,P<0.05);不同类型水样合格率差异有统计学意义(χ2=61.181,P<0.05);不同供水方式饮用水合格率差异有统计学意义(χ2=400.491,P<0.05);2015—2019年各年度生活饮用水合格率差异有统计学意义(χ2=37.307,P<0.05);农村供水大型工程和小型工程水样合格率分别为75.58%和64.43%,差异有统计学意义(χ2=45.927,P<0.05);农村饮用水耐热大肠菌群、总大肠菌群、大肠埃希菌、二氧化氯和游离氯合格率低。结论 2015—2019年绵阳市饮用水合格率城市明显优于农村,农村集中式供水大型工程合格率优于小型工程,连续5年水质合格率2017年最高,2015年最低。微生物和消毒指标是饮用水监测的关键指标。

Objective To analyze the monitoring data of drinking water quality in Mianyang City from 2015-2019, understand the sanitary status of drinking water in Mianyang area in the recent years, find out the risk indicators, and ensure the safety of public drinking. Methods Totally 6 939 samples of drinking water were tested according to the Standard test methods for drinking water(GB/T 5750-2006), and the results were evaluated according to the Sanitary standard for drinking water(GB 5749-2006).Results From 2015-2019, 6 939 samples were detected with the qualified rate was 71.06%. The qualified rate of urban and rural drinking water samples was 96.11% and 66.32% respectively, and the difference was statistically significant (χ2=400.398,P<0.05). The difference in the qualified rate was statistically significant among water samples with different types (χ2=61.181,P <0.05), and the difference in the qualified rate was statistically significant among water samples from different ways of water supply(χ2=400.491, P<0.05). There was statistically significant difference in the annual qualified rate of drinking water in 2015-2019(χ2=37.307, P<0.05). The qualified rate of water samples from large and small projects of the rural centralized water supply was75.58% and 64.43% respectively, and the difference was statistically significant (χ2=45.927, P<0.05). The qualified rates of thermotolerant coliform, total coliform, Escherichia coli, chlorine dioxide and free chlorine were lower in rural drinking water.Conclusion From 2015-2019, the qualified rate of drinking water in urban area of Mianyang City is significantly better than that in rural area. The qualified rate of large-scale centralized water supply projects in rural areas is better than that of small-scale projects. The qualified rate of drinking water is the highest in 2017 and the lowest in 2015. Microorganism and disinfection indexes are the key indexes of drinking water monitoring.