GEOCHEMICAL AND MINERALOGICAL CONTROLS ON THE OXIDATION OF BIOGENIC URANINITE BY FERRIHYDRITE

摘要

Uranium contamination of ground and surface waters has been detected at numerous sites throughout the world, including agricultural evaporation ponds, U.S. Department of Energy nuclear weapons manufacturing areas and mine tailings sites. Uranium is generally found in the hexavalent oxidation state in oxic systems and is quite mobile. Conversely, U(IV) forms sparingly soluble solids, even in the presence of common groundwater ligands, such as carbonate, and, thus, tends to be relatively immobile. Therefore, the oxidation state of uranium will play an important role in determining its environmental mobility.