Nanoscale zero valent iron and bimetallic particles for contaminated site remediation

Since the late 1990s, the use of nano zero valent iron (nZVI) for groundwater remediation has been investigated for its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. nZVI shows tremendous promise in the environmental sector due to its high reactivity and as such, numerous laboratory and field studies have been performed to assess its effectiveness. This paper reviews the current knowledge of nZVI/bimetallic technology as it pertains to subsurface remediation of chlorinated solvents and heavy metals. The manuscript provides background on the technology, summarizing nZVI reactions with chlorinated solvents and metals, and examines the factors affecting nZVI reactivity. Studies on subsurface transport of bare and coated nZVI particles are also reviewed and challenges with field implementation are discussed. This manuscript offers a comprehensive review of nZVI technology and highlights the work still needed to optimize it for subsurface remediation. (C) 2012 Elsevier Ltd. All rights reserved.