College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Chemosphere. 2017 Jul;178:73-79. doi: 10.1016/j.chemosphere.2017.03.039. Epub 2017 Mar 14.
The kinetics and mechanisms of 17β-estradiol (E2) chlorination in water distribution systems (WDS) were studied. We examined the impacts of different factors, including pH, temperature, humic acid concentration and type, and flow velocity. The experimental results showed that the rate constants in beaker tests and WDS were described by a pseudo-first-order model. pH had the greatest impact on E2 chlorination in the beaker tests. However, temperature had the greatest impact on E2 chlorination in WDS. Mechanistic analysis of E2 chlorination showed that chlorine attacked E2 in three stages: 1) halogenation of the aromatic ring, 2) cleavage of the benzene moiety and chlorine or bromine substitution formation, and 3) formation of trihalomethanes (THMs) and halogenated acetic acids (HAAs) from phenolic intermediates through benzene ring opening with chlorine and/or bromine substitution of hydrogen on the carbon atoms. In the third stage, the concentrations of THMs and HAAs increased rapidly.
研究了 17β-雌二醇（E2）在给水系统（WDS）中氯化的动力学和机制。考察了不同因素，包括 pH 值、温度、腐殖酸浓度和类型以及流速的影响。实验结果表明，烧杯试验和 WDS 中的速率常数符合假一级动力学模型。pH 值对烧杯试验中 E2 的氯化影响最大。然而，温度对 WDS 中 E2 的氯化影响最大。E2 氯化的机理分析表明，氯气分三个阶段攻击 E2：1）芳环卤化，2）苯部分的断裂和氯或溴取代形成，以及 3）通过苯环开环形成三卤甲烷（THMs）和卤代乙酸（HAAs），其中酚类中间体与氯和/或溴取代碳原子上的氢。在第三阶段，THMs 和 HAAs 的浓度迅速增加。
