A comparative study of the effect of desferrioxamine B, oxalic acid, and Na-alginate on the desorption of U(VI) from goethite at pH 6 and 25°C

GEOC 27

Domenik Wolf-Boenisch, dwolf@ucmerced.edu, Sierra Nevada Research Institute, Sierra Nevada Research Institute, University of California, Merced, Merced, CA 95344 and Samuel J. Traina, sam.traina@ucop.edu, Sierra Nevada Research Institute, University of California, Merced, P.O. Box 2039, Merced, CA 95344.
Batch desorption experiments on goethite particles reveal the extent of uranyl desorption and hence bioavailability with different organic acids. Desorption increases in the order: background electrolyte < Na-alginate < desferrioxamine B (DFO-B) < oxalate. A compilation of DFO-B surface excesses on goethite from our experiments together with literature values reveal that DFO-B adsorbs only a constant ~3% to the goethite surface. Oxalate displays higher surface concentrations but still lower than the determined uranyl surface excess. In the case of alginate, desorption is weak and adsorbed alginate hampers any considerable detachment of U(VI) in the presence of the more potent ligands, DFO-B and oxalate.
 

Physical Chemistry of Soil and Aquifer Systems: A Symposium in Honor of Garrison Sposito
1:30 PM-5:10 PM, Sunday, 10 September 2006 Moscone Center -- Room 256, Oral

Division of Geochemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006