JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY, vol.211, no.2, pp.435-442, 1996 (Journal Indexed in SCI Expanded)
The sorption behavior of cesium on montmorillonite type clay was studied by using radioactivity measurements. Concentrations of Cs+ ions ranged from 10−6 to 10−2M. Cesium retention reduced with increasing salt concentration which was varied between 10−4 and 10−1M. Selectivity coefficients KCs−Na for the exchange between Cs and Na were calculated for different equivalent fractions of Cs on the solid phase. Using theK Cs−Na values, free energy change was found to be 7.8 kJ/mol. The data could be fitted to a Freundlich isotherm, and empirical Freundlich parameters enabled the generation of a site distribution function. By fitting the data to the Dubinin-Radushkevich (D-R) isotherm, a mean energy of sorption of 8.6 kJ/mole was calculated which corresponds to the energy of ion exchange reactions. The values of energy changes calculated by using two different methods were in good agreement.