复合卤代苯酚氧化脱卤诱导的Cl/Br分子间转移机制研究

Chlorophenols and bromophenols are among halogenated phenols (HPs) which are widely distributed and greatly affect human health and ecological environment. They are very likely to co-occur in contaminated environmental media, but their degradation pathways are unknown when they coexist. Chloride and bromide ions are not only dehalogenated products of chlorophenols and bromophenols, but also the potential chlorine/bromine pool for de novo formation of organohalogens. To couple oxidative dehalogenation of binary HPs and re-activation of chlorine/bromine together, using six typical chlorophenols and bromophenols as target pollutants and endogenous halogens pool, by applying kinetic modeling and transient substances monitoring, this project aims to center on Cl/Br intermolecular transfer mechanism induced by HPs dehalogenation using emerging sulfate-radical based advanced oxidation technology. This project will reveal their involved mechanisms in binary HPs degradation containing reactive halogen species, halogen radicals and potential halogen carriers (HPs and their byproducts) and the roles of transient intermediates in organohalogens polymerization and advanced dehalogenation. Therefore, this project is expected to provide important information for exploring new source and sink of organohalogens during combined HPs remediation.

氯酚和溴酚是分布广且对人类和生态环境影响较大的两类卤代苯酚。二者可能同时存在于被污染环境介质，但其共存时的氧化降解途径至今尚不明确。氯离子和溴离子是氯酚和溴酚脱卤产物，也可能是有机氯/溴代物二次生成的卤素来源。本项目拟将二元卤代苯酚氧化脱卤与氯/溴二次活化的耦合作用为主要研究目标，以6种典型氯酚和溴酚为研究对象和内源性卤素离子来源，结合动力学软件模拟研究和瞬态物种监测方法，以新兴的硫酸根自由基高级氧化技术降解二元卤代苯酚为反应模板，研究卤代苯酚氧化脱卤引发的氯/溴分子间转移机制。试图揭示活性卤物种和卤素自由基与潜在的卤素载体(卤代苯酚及其降解产物)的相互作用原理，以及非稳态中间体对于卤代物聚合与深度脱卤的作用机制，为阐明卤代苯酚复合污染治理时有机卤代物未知的“源”和“汇”提供重要线索。

氯离子和溴离子是氯酚和溴酚脱卤产物，也可能是有机氯/溴代物二次生成的卤素来源。本项目拟将二元卤代苯酚氧化脱卤与氯/溴二次活化的耦合作用为主要研究目标，构建了多种以空穴、超氧自由基、羟基自由基和硫酸根自由基、单线态氧等为主要氧化活性物种的高级氧化降解体系和新型耐盐氧化技术，深入研究了硫酸根自由基主导的有机物降解体系中典型氯酚或溴酚氧化降解动力学和降解途径，探讨了典型卤代污染物氧化降解中间体与外源卤素离子的耦合作用，揭示了溴、氯代苯酚氧化降解时氯、溴分子间转移动力学与反应机制。项目成果为探知卤代苯酚复合污染治理时有机卤代物未知的“源”和“汇”提供了科学参考。受项目资助共在 <Water Res.>, <Chem. Eng. J.>和<J. Hazard. Mater.>等国际环境化学期刊发表26篇SCI期刊论文, 参加国内外学术交流6次，培养博士研究生3名，培养硕士研究生6名。