GEOC 18 |
| Uranium is an element of significant geochemical and environmental significance due to its use in dating rocks and contamination of soils and aquifers. Uranium chemistry is complicated because it complexes with a wide variety of ligands in aqueous solution and on mineral surfaces. Understanding this complicated chemistry is critical for managing and remediating U-contaminated sites, so this study has focused on calculating structures and energetics of various U-complexes thought to be important in the environment. Methods included molecular clusters using Gaussian 03 and periodic mineral surfaces using VASP. Calculations on U(VI), U(V), and U(IV) aqueous species were the starting point for this investigation. Inorganic complexes such as U-carbonates (with and without Ca(II)) and U-phosphates were modeled. In addition, organic ligands such as oxalate, catecholate and organophosphoryl groups were compared. Lastly, bonding of U-carbonate to alumina and hematite surfaces were modeled and compared to experimental data. |
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Frontiers in Geochemistry: Commemorating the 25th Anniversary of the ACS-Geochemistry Division
1:30 PM-4:50 PM, Sunday, 10 September 2006 Moscone Center -- Room 262, Oral
Division of Geochemistry |