余氯对饮水再污染的消毒效果评价

Evaluation of the Disinfective Effects of Residual Chlorine for Controlling Post-treatment Pollution of Tap Water

为评价饮水中余氯对灭活再污染的细菌和病毒的效果,在自来水中加入一定量的余氯,观测再污染E.coli和f_2噬菌体在2小时内的灭活率。结果表明,自由性余氯0.3mg/L能在1分钟内杀死全部E.coli和f_2,但结合性余氯的效果较差,将剂量提高到1.5～2.0mg/L,可在30分钟内杀死全部E.coli,灭活f_2只有90％。水中维持一定量的余氯,也能控制反复污染。降低水温,提高水的pH值、浑浊度或有机物——甘氨酸,将降低余氯的灭活效果。

In order to evaluate the effects of residual chlorine in tap water to inactivate the bacteria and viruses introduced by post-treatment pollution, tap water with definite amount of residual chlorine Was challenged with E. coli or coliphage f2, and evaluated the inactivation rate within 2 hours. Experimental results indicated that free chlorine residual 0.3 mg/L could inactivate E. coli and f2 completely within 1 minute. Combined chlorine residual 0.3 mg/L was less effect, but increasing the dose of it up to 1.5-2.0 mg/L, E. coli were killed completely, but ft were inactivated about 90% in 30 minutes. Maintenance of definite amount of residual chlorine in tap water could controll repeated pollution too. Decreasing the water temperature, increasing the water pH, turbidity or the polluted indicator——glycine could decrease the inactivative efficiency of residual chlorine in water.