咸潮对氯消毒中三卤甲烷的影响

受咸潮影响的出厂水三卤甲烷比非咸潮时高5倍,其中三溴甲烷增加10~4倍,远远大于三氯甲烷,4种THM8含量顺序发生了倒置,即CHBr_3>CHBr_2Cl>CHBrCl_2>CHCl_3。在管网中咸潮污染的出厂水和未污染水混合,加之余氯的作用,使得管网水中三卤甲烷(THMs)的种类分配再次发生变化。结合国内外的资料,综合评述了咸潮中溴化物与氯的反应及Br-THMs形成的机理,并提出了在咸潮期间控制饮用水中氯化消毒产物的思路。

The Effect of the Surface Water Intruded by Saline Water on Trihalomethanes During Chlorination

The amount of Trihalomethanes(THMs)formed in disinfection of the surface water intruded by saline water in a city of China was five higher than that observed in disinfection of natural water.Moreover,the concentration of CHBr_3 observed when surface water intruded by saline water was 10~4 higher than that observed when nor did water,but no significant amount of CHCl_3 was observed.In the time of saline water intrusion,the most predominant species among the four THMs formed was CHBr_3,followed by CHClBr_2,CHCl_2Br,and CHCl_3 in the decreasing order.This is opposite to the order observed in other times.However,the product distribution of THMs in water distribution system changed,since the produced water contaminated by saline water combined with water non-contaminated,and the precursor of water reacted with free chlorine in pipeline.According to the research at home and abroad,a comprehensive review regarding the reaction of bromide with chlorine,as well as mechanisms of brominated THMs.In addition,the corresponding countermeasures for controlling disinfection in drinking water in the time of saline water intrusion were also presented.