Towards an understanding of the sorption of U(VI) and Se(IV) on sodium bentonite

K. A. Boult, M. M. Cowper, T. G. Heath, H. Sato, T. Shibutani, M. Yui

Research output: Contribution to journalConference article

63 Citations (Scopus)

Abstract

The sorption behaviour of uranium(VI) and selenium(IV) on a purified bentonite sample has been investigated and the results compared with those for sorption onto the unpurified material and goethite. Batch sorption data for U(VI) on purified bentonite show strong sorption in the pH range 5 to 8 (R(d)>104 cm3 g-1). Outside this range the sorption decreases although the R(d) remains above 103 cm3 g-1 across the pH range studied. U(VI) sorption was also found to decrease rapidly with increasing carbonate concentration. Thermodynamic modelling of the data indicates that sorption at low pH may be due to an ion-exchange process, whereas above pH 5 surface complexation dominates. The sorption of Se(IV) on purified bentonite was found to be significant only below pH 7. Sorption of Se(IV) on goethite showed a strong dependency on pH; with strong sorption below pH 8, and a sharp decrease in sorption above pH 8. Sorption of Se(IV) onto the smectite component of impure bentonite is therefore only likely to be significant at low pH and sorption is dominated by a goethite-like surface of an iron constituent mineral above pH 5. Copyright (C) 1998 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)141-150
Number of pages10
JournalJournal of Contaminant Hydrology
Volume35
Issue number1-3
DOIs
Publication statusPublished - Dec 15 1998
Externally publishedYes
EventProceedings of the 1997 6th International Conference on the Chemistry and Migration Behavior of Actinides and Fission Products in the Geosphere - Sendai, Jpn
Duration: Oct 26 1997Oct 31 1997

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Keywords

  • Bentonite
  • Montmorillonite
  • Radionuclides
  • Selenium
  • Sorption
  • Uranium

ASJC Scopus subject areas

  • Environmental Chemistry
  • Water Science and Technology

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