Zero-Valent Iron for Water Treatment

The use of zero-valent iron in the treatment of hazardous water contaminants is reviewed. The review concentrates on experimental procedures employed in the investigation of a range of applications for zero -valent iron and the efficacy of the processes. Investigations reviewed include those performed with halogenated aliphatic compounds, halogenated aromatic compounds, nitro-aromatic organic compounds, and high-valency toxic metals. Experiments employing bimetallic and cementation reductants as well as zero-valent iron alone are covered. The need for zero-valent iron technology is discussed, as is the need for more rigorous investigation of operational parameters. Despite a paucity of information from the literature it has been shown that efficacy is greatest for well-mixed batch or continuous column systems employing neutral to acidic pH and a high specific surface area of iron. The literature also reveals a need to focus future work on enhancing the chemical reaction taking place on the iron surface in order to enhance the rate of reductive remediation.