硫化零价铁去除水中污染物的效能及交互机制

Performances and Interactions of Contaminants Removal from Water by Sulfidated Zerovalent Iron

如何同步提升零价铁去除水中污染物的反应速率和电子选择性已成为近年研究热点。基于无氧体系下硫化能通过抑制零价铁与水之间的副反应而改善体系还原除污染物效能,系统概括了不同硫化方式、硫化药剂和硫化程度合成的硫化零价铁理化特征,并揭示了其与硫化零价铁在不同水氧环境下去除不同污染物反应活性和电子选择性的交互机制。硫化能够主要通过调控界面亲疏水和导电性能而实现改善零价铁除污染的效能,其提升表现主要依赖于硫化程度,而与硫化方式、硫化药剂相关性较低。最后,展望了基于硫化零价铁的水污染控制技术在地下水修复和工业废水处理的应用前景。

In recent years,synchronously mediating the reactivity and electron selectivity(ES)of zerovalent iron(ZVI)toward target contaminant has been of great interest but challenging to researchers.Sulfidation can suppress the side reaction of ZVI with water under anaerobic conditions and thus improve the ES toward target contaminants.As such,this review systematically summarizes the physicochemical characteristics of sulfidated ZVI(S-ZVI)as function of the sulfidation approaches,reagents and extents.Then,this work analyzes the interactions of contaminants removal by S-ZVI.Typically,the sulfidation can tune the electrical conductivity and/or hydrophobicity of ZVI,thereby enhancing the reactivity and ES toward target contaminants under aerobic or anaerobic conditions,which is strongly dependent on S/Fe molar ratio but without regard to the approaches and reagents of sulfidation.Finally,the application potentials of S-ZVI for groundwater remediation and wastewater treatment are also outlooked.