Environ. Sci. Technol. 1998, 32, 3366-3373
Reductive Precipitation of Uranium(VI) by Zero-Valent Iron B . G U , * ,† L . L I A N G , ‡ M . J . D I C K E Y , † X. YIN,† AND S. DAI§ Environmental Sciences Division and Chemical Technology Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, and Department of Earth Sciences, University of Wales, Cardiff, P.O. Box 914, Cardiff, CF1 3YE, U.K.
This study was undertaken to determine the effectiveness of zero-valent iron (Fe0) and several adsorbent materials in removing uranium (U) from contaminated groundwater and to investigate the rates and mechanisms that are involved in the reactions. Fe0 filings were used as reductants, and the adsorbents included peat materials, iron oxides, and a carbon-based sorbent (Cercona Bone-Char). Results indicate that Fe0 filings are much more effective than the adsorbents in removing uranyl (UO22+) from the aqueous solution. Nearly 100% of U was removed through reactions with Fe0 at an initial concentration up to 76 mM (or 18 000 mg of U/L). Results from the batch adsorption and desorption and from spectroscopic studies indicate that reductive precipitation of U on Fe0 is the major reaction pathway. Only a small percentage (
