芳香类有机物在饮用水消毒过程中的氯化反应活性研究

Chlorination reaction activity of the aromatic organic compounds in the disinfection of drinking water

在试验水样中分别加入几种代表性的芳香类有机物进行氯化试验,研究芳香类有机物在饮用水消毒过程中的氯化反应活性,并使用气相色谱仪(ECD检测器)测定消毒副产物三卤甲烷和卤乙酸的生成量。结果表明:1)各受试物质氯化生成消毒副产物的活性(生成量和生成速度)从大到小依次为间苯二酚、对苯二酚、邻苯二酚、苯酚、苯胺、苯甲酸、硝基苯;2)芳香类有机物氯化反应生成消毒副产物的活性取决于苯环上官能团的性质、数量和位置等;3)苯甲酸的氯化反应可分为快速反应和慢速反应两个阶段。

The present paper intends to introduce our study results on the chlorination reaction activity of the aromatic organic compounds in the disinfection of drinking water. As is known, humie acid and aromatic organic compounds usually generally detected in the source wa- ter. But recently it was found to be able to react to chlorine in drinking water treatment process so as to generate disinfection by-products （DBPs）, such as trihalomethanes （THMs） and haloacetic acids （HAAs）. The concentrations of THMs and HAAs can be measured by using gas chromatograph （ECD）. Some representative aromatic organic compounds were studied and found to have chemical structure similar as humie acid including 1,2-benzenediol, 1,3-benzenediol, 1,4-benzenediol, phenol, aniline, benzoic acid and nitrobenzene were selected as the research objects. These six representative aro- matic organic compounds can then be added to water sample and used to conduct chlorination test in order to study the chlorination reaction activity of aromatic organic compounds during the disinfection of drinking water. The results indicate that： （1） The orders of THMs and HAAs formation activity （formation and reaction rate ） in the chlorination reactions of the aromatic organic compounds can be shown as 1,3-benzenediol 〉 1,4-benzenediol 〉 1,2-benzenediol 〉 phenol 〉 aniline 〉 benzoic acid 〉 nitrobenzene; （2） The characteristics, number and location of the functional groups on the benzene ring may have effect on the DBPs formation activities of chlo- rination reactions of aromatic organic compounds ; （3） The chlorination reaction of phenol included two reaction stages： the rapid initial and the slower consumption stage. The estimated k value was 1 × 10^-5 s^- 1 for the reaction of phenol with aqueous chlorine during the rapid initial consumption stage, and the value of was 3 L· mol^-1· min^-1 for the reaction of phenol with aqueous chlorine at the slower consumption stage. The above said results can be used to provide valuable information for the effective control of the disinfection by-products in treating the drinking water.