Institute of Environmental Research at Greater Bay, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China.
Department of Building and Environmental Engineering, Shenzhen Polytechnic, Shenzhen, 518055, China.
Chemosphere. 2019 Dec;237:124521. doi: 10.1016/j.chemosphere.2019.124521. Epub 2019 Aug 5.
Chemical oxidation processes have been extensively utilized in disinfection and removal of emerging organic contaminants in recent decades. Some undesired byproducts, however, are produced in these processes. Of them, bromate has attracted the most intensive attention. It was previously regarded as a byproduct that typically occurred in ozone-based oxidation processes. However, for the past decade, bromate formation has been detected in other oxidation processes such as CuO-catalyzed chlorination, SO-based oxidation, and ferrate oxidation processes. This review summarizes the occurrences, mechanisms, influencing factors, risk assessment, and control strategies of bromate formation in the four oxidation processes, i.e., ozone-based oxidation, chlorine-based oxidation, SO-based oxidation, and ferrate oxidation. Besides, some unresolved issues for future studies are provided: (1) Clarification of the relative contributions of SO and Br to the oxidation of bromine for bromate formation in SO-based oxidation processes; (2) evaluation of the role of different reactive species in the bromate formation in the process of UV/HOCl; (3) quantification of the dual role of alkalinity in bromate formation during ozonation; (4) assessment of the risks of bromate formation in SO-based oxidation processes for practical applications; and (5) exploration of strategies for inhibiting bromate formation in SO-based oxidation, UV/chlorine, and metal oxide-catalyzed chlorination processes.
近几十年来，化学氧化工艺在消毒和去除新兴有机污染物方面得到了广泛应用。然而，这些工艺会产生一些不理想的副产物。其中，溴酸盐受到了最广泛的关注。它曾被认为是臭氧氧化工艺中典型的副产物。然而，在过去十年中，溴酸盐的形成已在其他氧化工艺中被检测到，如氧化铜催化氯化、基于 SO 的氧化和高铁酸盐氧化工艺。
本综述总结了四种氧化工艺（臭氧氧化、氯氧化、基于 SO 的氧化和高铁酸盐氧化）中溴酸盐形成的发生、机制、影响因素、风险评估和控制策略。此外，还提供了一些未来研究中尚未解决的问题：（1）澄清基于 SO 的氧化过程中 SO 和 Br 对溴氧化生成溴酸盐的相对贡献；（2）评估不同活性物质在 UV/HOCl 过程中溴酸盐形成中的作用；（3）定量研究臭氧氧化过程中碱度对溴酸盐形成的双重作用；（4）评估基于 SO 的氧化过程中溴酸盐形成的风险，以应用于实际；（5）探索抑制基于 SO 的氧化、UV/氯和金属氧化物催化氯化过程中溴酸盐形成的策略。
