Formation of brominated disinfection by-products and bromate in cobalt catalyzed peroxymonosulfate oxidation of phenol
Formation of brominated disinfection by-products and bromate in cobalt catalyzed peroxymonosulfate oxidation of phenol
复制标题
DOI：
10.1016/j.watres.2015.07.015
复制
发表时间：
2015-11-01
期刊：
影响因子：
12.8
通讯作者：
Ji, Yuefei
中科院分区：
文献类型：
--
作者：
Liu, Kuo;Lu, Junhe;Ji, Yuefei
近年来，硫酸盐自由基（SO4中心点）氧化过程中卤化消毒副产物（DBPs）的形成引起了人们的广泛关注。然而，潜在的反应途径尚未得到很好的探索。研究了钴活化过氧单硫酸盐（Co2+/PMS）氧化过程中Br-的转化。以苯酚为模型化合物，模拟天然有机物质（NOM）的反应活性。结果表明，在Co2+/PMS体系中，Br-可有效转化为活性溴（RBS），包括游离溴和溴自由基（Br-中心点、Br-2（中心点-）等）。SO4中心点在此过程中起主要作用。由此产生的RBS导致苯酚的溴化，形成溴化DBPs (Br-DBPs)，包括溴仿和溴乙酸，在此过程中检测到溴化苯酚作为中间体。Br-DBPs被过量的SO4中心点进一步降解，最终转化为溴酸盐。在没有Co2+的情况下也形成了游离溴，这表明Br-本身可以被PMS氧化。游离溴也与苯酚结合，依次生成br - dbp。而在SO4中心点-缺失的情况下，Br-DBPs无法进一步转化。本研究首次阐明了PMS氧化体系中Br-的综合转化图，在实际应用PMS消除污染时应考虑到这一点。(C) 2015 Elsevier Ltd.版权所有。
Formation of halogenated disinfection by-products (DBPs) in sulfate radical (SO4 center dot-) based oxidation processes attracted considerable attention recently. However, the underlying reaction pathways have not been well explored. This study focused on the transformation of Br- in cobalt activated peroxymonosulfate (Co2+/PMS) oxidation process. Phenol was added as a model compound to mimic the reactivity of natural organic matter (NOM). It was revealed that Br- was efficiently transformed to reactive bromine species (RBS) including free bromine and bromine radicals (Br-center dot, Br-2(center dot-), etc.) in Co2+/PMS system. SO4 center dot- played a principal role during this process. RBS thus generated resulted in the bromination of phenol and formation brominated DBPs (Br-DBPs) including bromoform and bromoacetic acids, during which brominated phenols were detected as the intermediates. Br-DBPs were further degraded by excessive SO4 center dot- and transformed to bromate ultimately. Free bromine was also formed in the absence of Co2+, suggesting Br- could be oxidized by PMS per se. Free bromine was incorporated to phenol sequentially leading to Br-DBPs as well. However, Br-DBPs could not be further transformed in the absence of SO4 center dot-. This is the first study that elucidated the comprehensive transformation map of Br- in PMS oxidation systems, which should be taken into consideration when PMS was applied to eliminate contamination in real practice. (C) 2015 Elsevier Ltd. All rights reserved.