Hostname: page-component-745bb68f8f-grxwn Total loading time: 0 Render date: 2025-01-12T09:34:42.418Z Has data issue: false hasContentIssue false
  • English
  • Français

Uranyl Sorption Onto Alumina

Published online by Cambridge University Press:  03 September 2012

Anna-Maria M. Jacobsson  and
Robert S. Rundberg
Anna-Maria M. Jacobsson
Affiliation:
Department of Nuclear Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden
Robert S. Rundberg
Affiliation:
Los Alamos National Laboratory, MS-J514, Los Alamos, NM 87545, USA
Get access

Abstract

The mechanism for the adsorption of uranyl onto alumina from aqueous solution was studied experimentally and the data were modeled using a triple layer surface complexation model. The experiments were carried out at low uranium concentrations (9×10-11 - 5×10-8M) in a CO2 free environment at varying electrolyte concentrations (0.01 – 1 M) and pH (4.5 – 12). The first and second acid dissociation constants, pKal and pKa2, of the alumina surface were determined from potentiometric titrations to be 7.2 ± 0.6 and 11.2 ± 0.4, respectively. The adsorption of uranium was found to be independent of the electrolyte concentration. We therefore conclude that the uranium binds as an inner sphere complex. The results were modeled using the code FITEQL. Two reactions of uranium with the surface were needed to fit the data, one forming a uranyl complex with a single surface hydroxyl and the other forming a bridged or bidentate complex reacting with two surface hydroxyls of the alumina. There was no evidence from these experiments of site heterogeneity. The constants used for the reactions were based in part on predictions made utilizing the Hard Soft Acid Base, HSAB, theory, relating the surface complexation constants to the hydrolysis of the sorbing metal ion and the acid dissociation constants of the mineral oxide surface.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 465: Symposium II – Scienfific Basis for Nuclear Waste Management XX , 1996 , 797
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Cui, D., Thesis: Sorption Processes and Solubilities of Radionuclides in Deep Granite Fracture Systems, Royal Institute of Technology, Stockholm, Sweden, (1996).Google Scholar
2. Kirmiburgh, D. G., Jackson, M. L., and Syers, S. K., Soil Sci. Soc. Am. J., 40 796–799, (1976).Google Scholar
3. Dzombak, D. A. and Morel, F. M. M., Surface Complexation Modeling: Hydrous Ferrie Oxide, John Wiley and Sons, New York (1990).Google Scholar
4. Pearson, R. G., J. Chem. Ed. 45 (9) 581–587 (1968).Google Scholar
5. Schindler, P. W., Österreichische Chemie-Zeitschrift., 86 (6), 141–147 (1985).Google Scholar
6. Anderson, M. A. and Rubin, A. J. eds., Adsorption of Inorganics at Solid-Liquid Interfaces, pp. 203, Ann Arbor Science Publishers, Ann Arbor (1981).Google Scholar
7. Waite, T. D., Davis, J. A., Payne, T. E., Waychunas, G. A., Xu, N., Geochim. Cosmochim. Acta 58, 5465–5478 (1994)Google Scholar
8. Del Nero, M., Miura, T., Bontems, G., Duplâtre, G., Clément, A., extended abstract, 4th International conference Nuclear and Radiochemistry (1996).Google Scholar
9. Gran, G., Acta Chemica Scandinavica 4, 559–577 (1950).Google Scholar
10. Rundberg, R. S., unpublished work.Google Scholar
11. Baes, C. F. Jr. and Mesmer, R. E., The Hydrolysis of Cations, Krieger Publishing Company, Malabar Florida (1986).Google Scholar
12. Hayes, K. F., Roe, A. L., Brown, G. E. Jr., Hodgson, K. O., Leckie, J. O., and Parks, G. A., Science 238, 783–786 (1987).Google Scholar
13. Westall, J., Report 82–01 Dept. of Chemistry, Oregan State University, Corvallis Oregon (1982).Google Scholar
14. Grenthe, I. et al. Chemical Thermodynamics of Uranium. Elsevier, (1992).Google Scholar
15. Rundberg, R. S., Albinsson, Y., Vannerberg, K., Radiochim. Acta 66/67, 333–339 (1994).Google Scholar
16. Degueldre, C., Ulrich, H. J., and Silby, H., Radiochim. Acta 65, 173–179 (1994).Google Scholar
17. Motschi, H., Adsorption Sci. and Technol. 2, 39–54 (1985).Google Scholar
18. Hayes, K. F., Papelis, C., and Leckie, J. O., J. Colloid Interface Sci., 125 (2) 717–726 (1988).Google Scholar
19. Hsi, C-K. D. and Langmuir, D., Geochim. Cosmochim. Acta 49, 1931–1941 (1985).Google Scholar
20. Bradbury, M. H. and Baeyens, B., J. Colloid Interface Sci., 128 364–371 (1993).Google Scholar