Zerovalent iron (ZVI) has drawn intense interest as an effective and inexpensive tool to enhance degradation of various environmental contaminants. Reduction of Cr(VI) to Cr(III) by ZVI merits environmental concern as a hazardous species is transformed into a non-hazardous one. Objectives of this research were to assess kinetics and capacity of Cr(VI) reduction by different sources of ZVIs, of which chemical parameters can base in situ application of ZVI to treat Cr(VI) contaminated water. Reduction kinetics were first-order and rapid showing that 50% of the initial Cr(VI) was reduced within 7.0 to 347 min depending on Cr(VI) concentration, temperature and ZVI source. The reduction rates were increased with decreasing the initial Cr(VI) concentrations and increasing the reaction temperatures. The J ZVI (Shinyo Pure Chemical Co., Japan) was more effective in Cr(VI) reduction than PU (Peerless Metal Powders, USA). The maximum reduction capacities of J and PU ZVIs at 25 oC were 0.045 and 0.042 mmol g.1 Fe0, respectively. A relatively higher value of the net reaction energy (Ea) indicated that Cr(VI) reduction by ZVI was temperature dependent and controlled by surface properties of ZVI. Chemical parameters involved in the Cr(VI) reduction by ZVI such as temperature quotient, kinetic rates, and stoichiometry indicated that the ZVI might be effective for in situ treatment of the Cr(VI) containing wastewater.
Sparks DL, Environmental soil chemistry, Academic Press, USA, 1995
Yang JE, Kim JS, Ok YS, Yoo KY, In press, 2006
Yang JE, Kim JS, Ok YS, Yoo KY, Korean J. Environ. Agric., 24, 203, 2005
Yang JE, Kim YK, Kim JH, Park YH, Environmental impacts and management strategies of trace metals in soil and groundwater in the republic of Korea, In: Soil and Groundwater Pollution and Remediation, P. M. Huang and I. K. Iskander, eds., CRC Press, New York, 2000
Yang JE, Skogley EO, Soil Sci. Soc. Am. J., 56, 408, 1992