应用零价铁基材料还原和催化氧化降解多溴联苯醚

Reductive Debromination and Advanced Oxidation of Polybrominated Diphenyl Ethers (PBDEs) Using Zero-Valent Iron (ZVI) Based Materials

多溴联苯醚(PBDEs)是一类新型的持久性有机污染物(POPs),由于不合理的使用和处置,在多种环境介质中均存在不同程度的污染。环境中PBDEs的降解技术已成为近年来的研究热点。大量的研究表明,零价铁(ZVI)还原脱溴降解PBDEs是一种高效快速且经济可行的治理技术。本文在总结国内外关于ZVI基材料降解PBDEs研究的基础上,分析了ZVI还原降解PBDEs的机理、动力学、影响因素及降解路径。从总体上看,ZVI作为高活性电子供体虽然能将高溴代PBDEs迅速降解为低溴代产物,但产生的低溴代PBDEs往往具有更大的环境风险,需进一步降解处理。近年来的研究表明,利用ZVI作为间接电子供体,通过催化活化H_2O_2或过硫酸盐产生高活性自由基,能够实现开环降解低溴代PBDEs。基于以上分析,通过构建一套先还原-后氧化的降解体系,有望实现高溴代PBDEs的彻底降解。最后,本文对ZVI降解PBDEs技术的后续研究进行了讨论和展望。

Polybrominated diphenyl ethers （PBDEs） are a group of persistent organic pollutants which have attracted a lot of concern because of their unreasonable use and disposal. Efforts have been paid to developing techniques to rapidly degrade PBDEs, among which the application of zero-valent iron （ZVI） has been found effective because of the reducibility and the ability of activating advanced oxidation processes （AOPs）. In this paper, the research on degradation of PBDEs by ZVI are summarized, and the mechanism, kinetics, influencing factors and degradation pathways are reviewed. Although ZVI can be effectively used as direct electron donors for debromination of highly-brominated DEs, the resultant lower brominated DEs are more toxic and generally need further treatment. On the other hand, recent studies indicate ZVI could be used as indirect electron donors by inducing heterogeneous Fenton systems or persulfate （PS） systems to produce reactive oxygen species （ROS）, which could degrade lower brominated DEs through ring opening. Therefore, the integration of ZVI and Fenton systems or persulfate systems by constituting two-stage reduction/subsequent oxidation treatment may be a solution for complete ring-opening degradation of highly-brominated DEs. Besides, further research on PBDEs degradation based on ZVI technology is