Uranium adsorption on ferrihydrite - effects of phosphate and humic acid
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Date
1996-12-01
Journal Title
Journal ISSN
Volume Title
Publisher
De Gruyter
Abstract
Uranium adsorption on ferrihydrite was studied as a function of pH in systems equilibrated with air, in the presence and absence of added phosphate and humic acid (HA). The objective was to determine the influence of PO43- and HA on uranium uptake. Below pH 7, the sorption of UO22+ typically increases with increasing pH (the 'low pH sorption edge'), with a sharp decrease in sorption above this pH value (the 'high pH edge'). The presence of ΣPO43- of 10-4 mol/L moved the low pH edge to the left by approximately 0.8 pH units. The PO43- was strongly bound by the ferrihydrite surface, and the increased uptake of U was attributed to the formation of ternary surface complexes involving both UO22+ and PO43-. The addition of HA (9 mg/L) increased U uptake at pH values below 7, with little effect at higher pH values. The positions of the pH edges were also affected by the ionic strength and total U content. These experiments show that sorption interactions involving PO43 and HA must be considered in order to model the behavior of U in natural systems, in which these components are often present. © 1996 Oldenbourg Wissenschaftsverlag GmbH.
Description
Physical copy held by ANSTO Library at DDC: 577.277/46.
Keywords
Uranium, Phosphates, Humic acids, pH Value, Air, Sorption, Environmental effects, Carbon dioxide, Ferrite
Citation
Payne, Τ. E., Davis, J. A., & Waite, T. D. (1996). Uranium adsorption on ferrihydrite - effects of phosphate and humic acid. Paper presented to Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere, proceedings of the Fifth International Conference Saint-Malo (France), 10-15 September 1995. In Radiochimica Acta, 74(s1), 239–244. doi:10.1524/ract.1996.74.special-issue.239