流式细胞仪测定一氯胺对给水管网中氨氧化菌的消毒特性

Monochloramine disinfection characteristics of AOB in drinking water distribution systems by flow cytometry method

给水管网中氨氧化菌的生长是造成氯胺消毒给水管网硝化作用的一个根本原因,研究一氯胺对氨氧化菌的消毒灭活特性,对于控制氨氧化菌的生长从而控制硝化作用具有重要意义。运用流式细胞仪结合荧光染色的方法研究了一氯胺消毒作用下,温度、pH和有机物等水质因素对氨氧化菌消毒效果的影响并以消毒动力学模型对消毒特性进行总结。结果表明,一氯胺对氨氧化菌的消毒灭活效果随着温度的上升而提高,35℃时一氯胺灭活氨氧化菌的Ct3log比8℃时减少了54%;一氯胺对氨氧化菌的消毒灭活效果随着pH的下降而提高,pH=6.0时的Ct3log比pH=8.7时减少了67%;大分子有机物腐殖酸对一氯胺的消耗大于小分子有机物甘氨酸;在及时补充消毒剂的情况下,这两种有机物对一氯胺灭活氨氧化菌的影响较小,Ct3log变化幅度均在5%以内。根据流式检测结果探究了一氯胺对氨氧化菌的消毒灭活机理,结果表明一氯胺对细菌的灭活是一个缓慢的过程,且其对细菌细胞膜的破坏力较弱,不能迅速彻底地破坏细菌细胞膜从而使之失活。

A main cause of nitrification in drink water distribution system is the growth of ammonia oxidizing bacteria （AOB） , so the research on monochloramine disinfection characteristics of AOB has important significance for controlling the growth of AOB and further curtailing the incidence of nitrification in drinking water distribution systems. The monoehloramine effect of pH, temperature and organic matters on inactivated of AOB （Nitrosomonas europaea, ATCC19718） were studied by fluorescence staining and flow cytometry （FCM） method. The results showed that the inactivation rate increased with the temperature rising and pH decreasing. Ctalog values for monochloramine decreased by 54% when temperature increased from 8℃ to 35 ℃, whereas the Ct3log values decreased by 67% when pHdecreased from 8.7 to 6.0. The macro-molecular organic matter, humic acid had greater promoting effects on chloramine decay than the micro-molecular organics, glycin. But the both type organic matters had little influence on the inactivation rate when monochloramine was promptly added to maintain the disinfectant concentration. Furthermore, monochloramine disinfection mechanism of AOB was explored according to FCM results, it was found that monochloramine disinfection on AOB was a slow process with weak destruction for the cell membrane of bacteria.