2022年绵阳市生活饮用水亚氯酸盐的水平和影响因素

Level and influencing factors of chlorite in domestic drinking water in Mianyang City in 2022

目的分析绵阳市生活饮用水消毒副产物亚氯酸盐的水平以及影响因素,评价水质状况,以有针对性地制定降低亚氯酸盐水平的有效措施。方法2022年绵阳市共检测生活饮用水样本2044份,对其检测的亚氯酸盐浓度与水样采样时期、消毒方式、水源类型、二氧化氯浓度以及菌落总数采用t检验和方差分析进行组间比较,并对相关因素进行回归分析。结果1080份水样检出亚氯酸盐,超标水样40份,检出率为52.84%,超标率为1.96%,平均浓度为0.168mg/L。地下水亚氯酸盐浓度高于地表水,差异有统计学意义(F=14.498,P<0.05);农村水亚氯酸盐浓度高于城市水,差异有统计学意义(F=5.791,P<0.05);湖库塘水源类型水样中高纯二氧化氯和复合二氧化氯的亚氯酸盐检出率显著高于江河溪和地下水,差异有统计学意义(F=11.870,P<0.05)。二氧化氯和耗氧量的偏回归系数为0.421和0.073,对亚氯酸盐浓度有正向影响,差异有统计学意义(t=4.603、6.083,P<0.05),氨氮的偏回归系数为-0.381,对亚氯酸盐浓度有负向影响,差异有统计学意义(t=-2.921,P<0.05)。结论绵阳市农村饮用水存在较严重的消毒副产物亚氯酸盐超标情况,需要进一步控制消毒剂在一个合理的水平。

Objective To analyze the level and influencing factors of chlorite,a disinfection by-product of drinking water in Mianyang City,and to evaluate the water quality condition in order to formulate targeted and effective measures to reduce the level of chlorite.Methods A total of 2044 samples of domestic drinking water were detected in Mianyang City in 2022.The detected chlorite concentration was compared with the water sampling period,disinfection method,water source type,chlorine dioxide concentration,and the total counts of colonies using t-test and variance analysis to compare the groups,and regression analysis was performed on the related factors.Results Chlorite was detected in 1080 water samples,with 40 water samples exceeding the standard.The detection rate was 52.84%,the exceeding rate was 1.96%,and the average concentration was 0.168mg/L.The concentration of chlorite in groundwater was higher than that in surface water,and the difference was statistically significant(F=14.498,P<0.05).The concentration of chlorite in rural water was higher than that in urban water,and the difference was statistically significant(F=5.791,P<0.05).The detection rates of chlorite in high-purity chlorine dioxide and composite chlorine dioxide in water samples from lake,reservoir,and pond source types were significantly higher than those in rivers,streams,and groundwater,and the difference was statistically significant(F=11.870,P<0.05).The partial regression coefficients of chlorine dioxide and oxygen consumption were 0.421 and 0.073,which had a positive impact on chlorite concentration,with statistically significant differences(t=4.603,6.083,P<0.05).The partial regression coefficient of ammonia nitrogen was-0.381,which had a negative impact on chlorite concentration,and the difference was statistically significant(t=-2.921,P<0.05).Conclusion There is a serious situation of excessive chlorite,a disinfection by-product,in rural drinking water in Mianyang City,and it is necessary to further control the disinfectant at a reasonable level.