Aqueous speciation and pH effect on the sorption behavior of uranium by montmorillonite

  • H. Akçay
Letter to the Editor


Clay minerals occur widely in nature and play a very important role in agriculture, mineral recovery and chemical manufacturing. Among the many properties which affect clay behaviour, water binding and ion exchanging appear to be the most important. The study of the cation exchange capacity of soils is of great theoretical and practical importance since the CEC determines in many ways the behavior of nutrients, chemical amendments, and many toxic compounds entering the sols. Sorption interactions with montmorillonite and other clay minerals in soils are potantially important mechanisms for attenuating the mobility of heavy metal cations through the subsurface environment. In this work the cation exchange capacity (CEC) of montmorillonite from west Anatolia, and sorptions with montmorillonite for attenuating the mobility of uranium were studied. The CEC value was found to be 77 meq/100 g montmorillonite. The relative importance of test parameters e.g., contact time, particle size, pH and U(+6) aqueous speciation was determined. The results show that sorption on montmorillonite is a funtion of pH depending strongly on the aqueous U(+6) species. It reaches a maximum at near neutral pH(pH}7). At low and at high pH solutions the sorption values of uranium are poor. These sorption values were attributed to the formation of aqueous U(+6) carbonate complexes in alkaline conditions and the ionexchange process between UO2+2 species and interlayer cations on montmorillonite in acidic solutions.


Clay Uranium Montmorillonite Clay Mineral Cation Exchange Capacity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Z. Borovec, Chem. Geol., 32 (1981), 45–58.CrossRefGoogle Scholar
  2. 2.
    A. Tsunashima, G. W. Brindley, M. Bastovano, Clays Clay Miner., 29 (1981) 10.Google Scholar
  3. 3.
    L. L. Ames J. E. McGarrah, B. A. Walker, Clays Clay Miner., 31 (1983) 321.Google Scholar
  4. 4.
    C. A. Sikalidis, C. Alexiades, P. Misaelides, Toxicol. Environ. Chem., 20/21 (1989) 175.Google Scholar
  5. 5.
    J. M. Zachara, J. P. McKinley, Aquatic Sci., 55 (1993) 250.Google Scholar
  6. 6.
    H. Akçay, S. Kilinç, C. Karapire, J. Radioanal. Nucl. Chem. 214 (1996) 51.Google Scholar
  7. 7.
    B. Allard, G. W. Beall, T. Krajewski, J. Radioanal. Nucl. Chem., 200 (1995) 529.Google Scholar
  8. 8.
    J. P. McKinley, J. M. Zachara, S. C. Smith, G. D. Turner, Clay Miner., 43 (1995) 586.Google Scholar
  9. 9.
    R. T. Pabalan, D. R. Turner, Aquatic Geo., 2 (1997) 203.Google Scholar
  10. 10.
    C-K. Hsi, D. Langmuir, Geochim. Cosmochim. Acta, 51 (1987) 243.Google Scholar
  11. 11.
    A. Mehlich, Soil Sci., 66 (1948) 429.Google Scholar
  12. 12.
    Methodes d'Analyse, Presse Universitaire de France, Paris, 3 (1964) 134; 5 (1970) 260.Google Scholar
  13. 13.
    J. M. Zachara, S. C. Smith, Soil Sci. Soc. Amer., 58 (1994) 762.Google Scholar
  14. 14.
    D. R. Turner, S. A. Sassman, J. Contam. Hydrol., 21 (1996) 322.Google Scholar
  15. 15.
    J. D. Prikryl, R. T. Pabalan, D. R. Turner, B. W. Leslie, Radiochim. Acta, 66/67 (1994) 291.Google Scholar
  16. 16.
    M. Dozol, R. Hagemann, Pure Appl. Chem., 65 (1993) 1081.Google Scholar
  17. 17.
    T. D. Waite, J. A. Davis, T. E. Payne, G. A. Waychunas, N. Xu Geochim. Cosmochim, Acta, 58 (1994) 5465.CrossRefGoogle Scholar
  18. 18.
    H. Wanner, I. Forest, Chemical Thermodynamics of Uranium, North-Holland, Amsterdam, 1992.Google Scholar
  19. 19.
    H. Wanner, Y. Albinson, O. Karnl, E. Wieland, P. Wersin, L. Charlet, Radiochim. Acta, 66/67 (1994) 733.Google Scholar
  20. 20.
    J. D. Allison, D. S. Brown, K. J. Novo-Gradac, A Geochem. Assesment Model for Envir. Systems, EPA/600/3-91/021, 1991, Athens (USA).Google Scholar
  21. 21.
    J. P. Coetzee, Suid-Afrikaanse Tydskrif Vir Wetenskop, 84 (1988) 421.Google Scholar
  22. 22.
    D. W. Oscarson, R. L. Watson, H. G. Miller, App. Clay Sci., 2 (1987) 29.Google Scholar

Copyright information

© Akadémiai Kiadó 1998

Authors and Affiliations

  • H. Akçay
    • 1
  1. 1.Department of Chemistry, Buca Eĝitin FacultyDokuz Eylül UniversityBuca-IzmirTurkey

Personalised recommendations