次氯酸钠代替液氯消毒对自来水厂供水水质的影响

Effect of Sodium Hypochlorite Instead of Liquid Chlorine Disinfection on Water Quality in Waterworks

对使用同一水源的两条相同制水工艺分别采用次氯酸钠和液氯消毒,对比研究了两种消毒剂的消毒效果及消毒副产物的生成特性。结果表明,两种消毒剂对菌落总数和异养菌的去除效果都较好,出厂水的菌落总数和异养菌数都未超过100 CFU/mL,微生物安全性可以得到保障。两种消毒剂对三氯甲烷和四氯化碳含量的控制水平均可达到《生活饮用水卫生标准》(GB5749—2006)的要求。液氯消毒出水中的三氯甲烷和卤乙酸含量比次氯酸钠消毒出水中的略高,四氯化碳含量基本相同。采用次氯酸钠替代液氯消毒可有效降低水厂生产安全风险,同时在保证消毒效果的前提下有利于降低水中消毒副产物的生成水平。

Sodium hypochlorite and liquid chlorine were used for disinfection in two same water treatment processes using a common water source. Their specific disinfection efficiency and production of disinfection by-products were compared. The results showed that both disinfection processes could effi- ciently disinfect total bacteria and heterotrophic bacteria to below 100 CFU/mL. Microbial safety was guaranteed by the two disinfectants. Trichloromethane and carbon tetrachloride in the finished water satis- fied the requirement of the Standards for Drinking Water Quality （ GB 5749 - 2006）. The concentration of trichloromethane and haloacetic acid in the finished water from the liquid chlorine disinfection process was a little higher than that from the sodium hypochlorite disinfection process. The output concentration of carbon tetrachloride was the same. Sodium hypochlorite disinfection, compared to liquid chlorine disin- fection, effectively reduces production safety risk and the formation of disinfection by-products in water- works.