宝安区家用净水器过滤水中亚硝酸盐含量及细菌总数调查分析

目的 调查经净水器净化后水中亚硝酸盐、菌落总数和总大肠菌群与未经净化的水之间的结果差异,以考察净化器对管网自来水的净化效果及家用净水器的卫生状况。 方法 随机选取使用净水器的135户家庭作为研究对象,采集每户家庭经净水器过滤的水和该家庭的自来水,检测亚硝酸盐、菌落总数和总大肠菌群三个指标,对结果进行统计学分析。同时比较不同净水器品牌间结果的差异。 结果 经净水器流出水中亚硝酸盐含量最高为0.821 mg/L,均符合标准限量要求(生活饮用水亚硝酸盐限量标准为1 mg/L),26份水样菌落总数高于标准限值(100 cfu/ml),超标率为19.26%(26/135),其中最大值为46 000 cfu/ml。135份自来水水样的菌落总数和亚硝酸盐测定结果均为合格。自来水经净水器净化后,水中的亚硝酸盐含量和菌落总数超标率均有增高,与自来水测定结果比较差异均有统计学意义(P<0.001);水中亚硝酸盐含量与菌落总数结果之间呈正相关(P<0.001);不同品牌净水机的饮用水中所含亚硝酸盐的含量及菌落总数差异有统计学意义(P<0.05)。 结论 宝安区居民使用家用净水器存在一定的卫生安全隐患,民众对净水器的使用维护知识亟须提高,对家用净水器的卫生监管应该加强。

Nitrite content and total number of bacterial colonies in water treated with household water purifier in Bao'an District

Objective To investigate the differences in the detection results of nitrite, total number of colonies and total coliform bacteria in purified water treated by household water purifier and unpurified water so as to survey the purification effect of purifier on tap water and the sanitary condition of household water purifier. Methods One hundred and thirty-five households with home water purifier were randomly selected as the subjects. Samples of water from household water purifier and tap water were collected from each household, and the nitrite content, total number of colonies and total coliform bacteria were detected. The detection results were statistically analyzed. The hygienic status of different brands of water purifiers was compared. Results The highest nitrite content of water treated by household water purifier was 0.821 mg/L, which met the national drinking water standard (the limit standard of nitrite in drinking water was 1 mg/L). The total number of bacterial colonies in 26 water samples was higher than the standard limit of drinking water (100 cfu/ml), and the maximum value was 46,000 cfu/ml. The over-standard rate of total number of bacterial colonies was 19.26% (26/135). The detection results regarding total number of bacterial colonies and nitrite in 135 tap water samples were qualified. The over-standard rates of nitrite content and total number of colonies in tap water purified by water purifier increased, showing statistically significant differences in the detection results of tap water and purified tap water (P<0.001). There was a positive correlation between nitrite content and total number of colonies (P<0.001). There were statistically significant differences in the nitrite content and total number of colonies in drinking water from different brands of water purifiers (P<0.05). Conclusion There are hidden troubles of sanitary safety in residents' household water purifiers in Bao'an District; and hence, the public's knowledge regarding the proper use and maintenance of water purifiers needs to be improved urgently, andsanitary supervision on household water purifiers should be strengthened.