GEOC 179 |
| Sofie P. Pasilis and Jeanne E. Pemberton. Department of Chemistry, University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721 |
| Accurate prediction of contaminant mobility and development of remediation strategies for soils and groundwaters contaminated by uranium is made difficult by the complexity of uranyl(VI) speciation behavior in the presence of organic chelating agents. Here we use ATR-FTIR spectroscopy to investigate the adsorption behavior of UO22+ on Al2O3 in the presence of citrate. We examine the adsorption of the uranyl-citrate complexes using isotherms developed by plotting the νs(COO–) peak areas of adsorbed citrate species versus solution citrate concentration, and use νas(UO2) as a probe to examine the coordination environment of adsorbed UO22+. Uranyl-citrate species appear to be adsorbed as ternary surface complexes and Al2O3-citrate interactions to be stronger than those of citrate with UO22+, resulting in a structural transformation of the UO22+-citrate complex upon adsorption. We also show that the uranyl-citrate complexes can interact strongly with adsorbed citrate. |
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Vibrational Spectroscopy in the Earth and Environmental Sciences
1:30 PM-4:50 PM, Thursday, April 1, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |