Application of weak magnetic field coupling with zero-valent iron for remediation of groundwater and wastewater: A review

Abstract

Zero valent iron (ZVI) has been extensively used for remediation of contaminated groundwater and wastewater. The removal of contaminants by alone ZVI is significantly limited by its intrinsic passive layer and influenced by the precipitation of iron (hydr)oxides on the surface of ZVI, which affects the further reaction of ZVI with contaminants. The premagnetization of ZVI and the addition of weak magnetic field (WMF) were proposed to resolve these problems. The application of a WMF is considered to be a promising and cutting-edge technology to increase the corrosion of ZVI, rejuvenate or improve the reactivity of ZVI, expand the range of target contaminants, and improve the removal efficiency of ZVI system. This study summarized the latest advances of WMF coupling with ZVI and magnetic ZVI derivative technologies for sequestration of (a) heavy metals, (b) arsenic, (c) selenium, (d) antimony, and degradation of (e) chlorinated organic compounds, (f) nitroaromatic compounds, (g) dyes, and (h) others. The remediation performance and reaction mechanisms were discussed and summarized. The results showed that WMF-ZVI and magnetic ZVI derivative technologies were the mainstream technology and had excellent remediation performance for the above contaminants. Concerning the future development and application of WMF-ZVI and magnetic ZVI derivative technologies, some suggestions are put forward and some conclusions are drawn.