重庆生活饮用水二氧化氯消毒副产物水平及影响因素

Chlorine dioxide disinfection byproducts and influencing factors in drinking water in Chongqing

目的分析二氧化氯消毒副产物水平和影响因素。方法采集并检测2019—2020年重庆市6264份生活饮用水的亚氯酸盐和氯酸盐浓度,与水样类型、水源类型、消毒方式、耗氧量浓度和二氧化氯浓度进行相关性分析,对单因素相关因子进行回归分析。结果(1)氯酸盐检出率为79.49%(4979/6264),浓度为(0.264±0.672)mg/L;亚氯酸盐检出率为78.37%(4909/6264),浓度为(0.236±0.468)mg/L;出厂水氯酸盐浓度显著高于末梢水,差异有统计学意义(F=6.007,P<0.05)。(2)使用纯二氧化氯发生器的,氯酸盐和亚氯酸浓度均高于使用复合二氧化氯发生器,差异均有统计学意义(F=55.594、69.693,均P<0.05)。(3)以湖库塘地表水为水源的,氯酸盐和亚氯酸浓度均高于其他水源类型,差异均有统计学意义(F=9.574、3.896,均P<0.05)。(4)耗氧量、二氧化氯浓度与亚氯酸盐和氯酸盐浓度均成正相关,二氧化氯和耗氧量浓度对氯酸盐和亚氯酸盐浓度有正向影响,偏回归系数分别为0.440/0.364、0.075/0.059。(5)使用复合二氧化氯发生器较纯二氧化氯发生器可降低亚氯酸盐和氯酸盐浓度,偏回归系数分别为0.151和0.076。结论应综合分析水源水质状况,合理选择消毒设备并控制消毒剂余量,以控制饮用水二氧化氯消毒副产物水平。

Objective This paper aims to analyze the by-products of chlorine dioxide disinfection and the influencing factors.Methods The relativity analysis and regression analysis were conducted for chlorate and chlorite versus water sample,water source and disinfect generation types,as well as COD and chlorine dioxide concentration.Results(1)The detection rates of chlorate and chlorite were 79.49%(4979/6264)and 78.37%(4909/6264)respectively,and the concentration was(0.264±0.672)mg/L and(0.236±0.468)mg/L respectively.It was testified that chlorate concentration was significantly higher in treated water than that in tap water(F=6.007,P<0.05).(2)Water samples treated by pure chlorine dioxide generator were tested with significantly higher concentration of chlorate and chlorite than those treated by mixed chlorine dioxide generator(F=55.594、69.693,both P<0.05).(3)Water samples from lakes,reservoirs and ponds as a whole were tested with significantly higher concentration of chlorate and chlorite than those from other water sources(F=9.574、3.896,both P<0.05).(4)COD and chlorine dioxide concentration were both positively related to chlorate and chlorite,and their partial regression coefficients were 0.440/0.364 and 0.075/0.059 for chlorate and chlorite respectively.(5)Using mixed chlorine dioxide generator was helpful to lower the concentration of chlorine dioxide disinfection byproducts when compared to pure chlorine dioxide generator.The partial regression coefficients were 0.151 and 0.076.Conclusion Water source quality,disinfect generation technology are important for controlling chlorine dioxide disinfection byproducts concentration in drinking water.