生活饮用水相关指标与细菌总数的相关性研究

Study on the correlation between the related indicators of drinking water and the total number of bacteria

目的探讨生活饮用水相关指标与细菌总数的关系。方法于2017年3~11月对上饶市广丰区水厂、某居民小区生活饮用水进行取样,取样点包括水厂出水口、小区管网入口、网管沿程点与网管末梢点。检测每个取样点水样的细菌总数、混浊度、总铁、自由余氯、溶解性总固体、总硬度等指标。余氯通过便携式余氯仪测定,细菌总数通过平皿计数法测定。将这些指标与细菌总数进行相关性分析,探究这些指标对细菌总数的影响。结果饮用水浑浊度与细菌总数成显著正相关(r=0.87,P<0.05);饮用水中总铁含量与细菌总数成正相关(r=0.41,P<0.05);饮用水自由余氯量与细菌总数成显著负相关(r=-0.92,P<0.05);饮用水溶解性总固体与细菌总数无相关性(r=0.17,P>0.05);饮用水总硬度与细菌总数无相关性(r=0.05,P>0.05)。结论影响生活饮用水中细菌总数的因素很多,主要受混浊度、含铁量、自由余氯量和溶解性固体影响,总硬度对细菌总数影响不大。因此,应该综合多种因素考虑,从多方面采取合理措施,保障居民用水安全。

Objective To investigate the relationship between the related indicators of drinking water and the total number of bacteria. Methods From March to November 2017, the drinking water samples from the water plants and a residential area in Guangfeng district of Shangrao city were sampled. The sampling points included the water outlet of the water plants, the entrance of the pipe network of the communities, the point of the network pipe and the tip of the network pipe. The total number of bacteria, turbidity, total iron, free residual chlorine, dissolved total solids, total hardness and other indicators of water samples at each sampling point were measured. The residual chlorine was determined by a portable residual chlorine meter, and the total number of bacteria was determined by the plate counting method. A correlation analysis was performed between these indicators and the total number of bacteria to explore the effect of these indicators on the total number of bacteria. Results There was a significant positive correlation between the turbidity of drinking water and the total number of bacteria (r=0.87, P<0.05). There was a positive correlation between total iron content in drinking water and the total number of bacteria (r=0.41, P<0.05). There was a significant negative correlation between the amount of free chlorine in water and the total number of bacteria (r=-0.92, P<0.05). There was no correlation between the dissolved total solids in drinking water and the total number of bacteria (r=0.17, P>0.05). There was no correlation between total hardness and the total number of bacteria (r=0.05, P>0.05). Conclusion There are many factors affecting the total number of bacteria in drinking water. It is mainly affected by turbidity, iron content, free residual chlorine and dissolved solids. The total hardness has little effect on the total number of bacteria. Therefore, a variety of factors should be considered and reasonable measures from various aspects should be taken to ensure the safety of residents.