配水管网细菌活性影响因素

为研究配水管网水中细菌活性的变化规律,以北方某市试验室模拟配水管网为对象,应用荧光显微镜对经吖啶橙染色的细菌进行直接镜检并计数,以更准确地对细菌活性进行定量分析.以活菌数占细菌总数的比值来表征整体细菌活性,并研究多种因素对配水管网水中细菌活性的影响.结果表明,吖啶橙染色荧光显微镜直接镜检应用于管网水中细菌计数能够快速得到较稳定的结果,计数结果重现性好.试验水样中的活菌数10~3~10~4cells·m L~(-1),细菌总数10~4~10~5cells·m L~(-1).管网水中整体细菌活性与水温、浊度和流速都存在正相关关系;与运行稳定后的水中余氯存在负相关关系.模拟配水管网水中常见形态的细菌对次氯酸钠消毒剂的耐受能力依次为:短杆形菌球形菌长杆形菌弧形菌,并且杆形菌恢复活性和再繁殖的能力较强.夏季水样中短杆形菌多于冬季.

Influencing Factors of Bacterial Activity in Water Distribution Networks

In order to study the variation patterns of bacterial activity in water distributed networks, this paper studied a simulated water distribution network in a northern China city. Microscopic examination and bacterial counts were conducted on acridine orange-stained bacteria using fluorenscence microscopy to ensure precise quantitative analysis. The ratio of viable bacterial count to total bacterial count was used to characterize the overall bacterial activity in the drinking water distribution network,as well as to study the impacts imposed by various factors. As indicated, this method was proved to be rapid,reliable and repeatable in bacterial counts. Populations of viable bacteria and total bacteria in water samples were 10³-10⁴ cells·mL^-1 and 10⁴-10⁵ cells·mL^-1, respectively. There was a positive correlation between the bacterial activity and water temperature, turbidity, and flow velocity. There was also a negative correlation between bacterial activity and residual chlorine after the operation stabilized. The capacity of different forms of bacteria in the simulated water distribution networks with tolerance of sodium hypochlorite was in the following order:long-rod-shaped, spherical-shaped, short-rod-shaped, and curved-shaped. The reactivation and reproduction capability of rod-shaped bacteria was stronger. There were more short-rod-shaped bacteria in summer water samples than in winter.