Degradation of chlortoluron during UV irradiation and UV/chlorine processes and formation of disinfection by-products in sequential chlorination
Degradation of chlortoluron during UV irradiation and UV/chlorine processes and formation of disinfection by-products in sequential chlorination
复制标题
紫外线照射和紫外线/氯过程中绿麦隆的降解以及连续氯化中消毒副产物的形成
DOI：
10.1016/j.cej.2015.07.074
复制
发表时间：
2016-01-01
影响因子：
15.1
通讯作者：
Gao, Nai-Yun
中科院分区：
文献类型：
--
作者：
Guo, Zi-Bo;Lin, Yi-Li;Gao, Nai-Yun
本研究考察了绿麦隆在紫外线（UV）照射、UV/氯工艺中的降解动力学与途径，以及后续氯化消毒后消毒副产物（DBPs）的生成情况。计算得出绿麦隆的量子产率为0.0258 mol/Einstein⁻¹，且在UV照射过程中，溶液pH值的影响可忽略不计。另一方面，在酸性条件、高氯剂量和高UV强度下，UV/氯工艺中绿麦隆的降解速率显著提升。绿麦隆在UV照射和UV/氯化过程均遵循准一级反应动力学，但UV/氯工艺比UV照射更高效，绿麦隆与羟基自由基（·OH）之间的反应速率常数测定为（2.18 ± 0.83）×10⁹ M⁻¹ s⁻¹ 。在UV/氯工艺中，随着氯剂量的增加和pH值的降低，绿麦隆的矿化程度显著提高。根据鉴定出的中间产物，提出了绿麦隆在UV照射和UV/氯工艺中的降解途径。同时，还研究了直接氯化消毒以及UV照射和UV/氯工艺后续氯化消毒过程中碳质消毒副产物（C - DBPs）和含氮消毒副产物（N - DBPs）的生成情况。与直接氯化消毒和UV照射相比，UV/氯工艺中生成了更多的消毒副产物前体，这在饮用水处理过程中值得广泛关注。（C）2015爱思唯尔出版社保留所有权利。
The degradation kinetics and pathways of chlortoluron during UV irradiation and UV/chlorine process as well as the formation of disinfection by-products (DBPs) after post-chlorination were investigated in this study. The quantum yield of chlortoluron was calculated as 0.0258 mol einstein(-1) and the effect of solution pH was negligible during UV irradiation. On the other hand, the degradation rate of chlortoluron during UV/chlorine process was significantly promoted at acidic conditions as well as high chlorine doses and UV intensity. UV irradiation and UV/chlorination of chlortoluron both followed the pseudo-first order reaction kinetics, but UV/chlorine process is more efficient than UV irradiation with the reaction rate constant between chlortoluron and OH radicals determined as (2.18 +/- 0.83) x 10(9) M-1 s(-1). The mineralization of chlortoluron was considerably increased with increasing chlorine dose and decreasing pH during UV/chlorine process. The degradation pathways of chlortoluron during UV irradiation and UV/chlorine processes were proposed according to the identified intermediates. The formation of carbonaceous DBPs (C-DBPs) and nitrogenous DBPs (N-DBPs) during direct chlorination and post chlorination of UV irradiation and UV/chlorine processes were investigated as well. More DBP precursors were formed during UV/chlorine process compared to direct chlorination and UV irradiation, which deserves extensive concerns in drinking water treatment processes. (C) 2015 Elsevier B.V. All rights reserved.