预氧化消毒方式对三卤甲烷控制的生产性试验

Productive Test of Trihalomethanes Control by Different Preoxidation Disinfection Processes

以高温高藻期原水为处理对象,在天津某净水厂选择预臭氧—紫外线加单点加氯消毒、预臭氧—紫外线加两点加氯消毒、预加氯—紫外线加两点加氯消毒3种不同预氧化消毒方式进行生产性试验,考察3种工况下滤后水、出厂水及管网水中三卤甲烷(THMs)生成量、余氯、浊度等相关水质指标。结果表明,控制出厂水和管网水THMs最低的最佳预氧化消毒方式为预臭氧—紫外线加两点加氯消毒,在每年7月—9月采用预臭氧—紫外线加两点加氯的预氧化消毒方式,预加氯—紫外线加单点加氯的预氧化消毒方式可用于7月—9月之外的时段,当7月—9月之间在应急情况下必须启动预加氯时,必须采取两点加氯的消毒方式。

A productive test was carried out in a water treatment plant in Tianjin, in which raw water with high temperature and high algae concentration was treated by three preoxidation disinfection processes, namely preozonation/UV and single-point chlorine, preozonation/UV and two-points chlorine and prechlorination/UV and two-points chlorine. Production of trihalomethanes(THMs), residual chlorine and turbidity in filtered water, effluent and pipe network water under three different treatment conditions were investigated and analyzed. The optimal preoxidation disinfection process to obtain minimum THMs in the effluent and pipe network water was preozonation/UV and two-points chlorine disinfection process. The process was advised to be applied between July and September each year, while preozonation/UV and single-point chlorine disinfection process could be applied in the periods except July to September. When prechlorination must be applied between July and September in an emergency situation, the two-point chlorination process must be adopted.