HR: 1340h
AN: B53C-1003    [Abstracts]
TI: Structural analysis of solids formed by reacting U(VI) with Fe(0)
AU: * SharmaSarkar, S
EM: ssharmasarkar@ucmerced.edu
AF: University of California, P.O. Box 2039, Merced, CA 95344 United States
AB: Structural elucidation of uranium associated with iron is critical in understanding the chemistry of the passivity layers. Uranyl (VI) solutions were reacted with zerovalent iron (0) powder as a function of molality and pH, and the resulting solids were characterized using SEM and EXAFS techniques. Lower pH (3-5) favored up to 99 percent solid formation from the solution U. The solid phase formation appeared to be a combination of partial reduction, adsorption and precipitation processes, depending on the pH condition. Schoepite at different hydration levels and also alpha- and beta- oxides were the predominant U solids. The morphology and structural coordination of the solids varied as a function of the boundary conditions. Results of these studies can be utilized in optimizing an efficient decontamination design of the corroded steels.
DE: 1000 GEOCHEMISTRY (New field, replaces Rock Chemistry)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting