کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1695863 | 1011878 | 2010 | 7 صفحه PDF | دانلود رایگان |
In the geological disposal system with stable colloidal particles, the influence of the colloidal particles on the migration of radionuclides has to be evaluated. Not only the distribution coefficient, which is a measure for adsorption of radionuclides on colloidal particles, but also the reversibility of adsorption should be determined. In this study, adsorption and desorption of Cs+ ions on colloidal montmorillonite particles were investigated in the wide range of the initial Cs+ concentrations. A rapid, almost linear and reversible adsorption of Cs+ on montmorillonite was observed at basic condition, indicating that the adsorption of Cs+ on montmorillonite was mostly dominated by ion exchange. The size of the montmorillonite particles slightly affected the distribution coefficients at lower Cs+ concentrations, suggesting the contribution of surface complexation. The ion exchange and surface complexation model reproduced the adsorption and desorption behavior of Cs+. To explain the fixation of Cs+, montmorillonite was conditioned with the solutions of various Cs+ concentrations and the basal spacing was measured by X-ray diffraction (XRD). Conditioning montmorillonite at higher Cs+ concentrations > 5 × 10− 3 M decreased the basal spacing which may result in the fixation of Cs+ in the interlayer space. Since the adsorption experiments were carried out at lower Cs+ concentration < 10− 4 M, Cs+ adsorption was reversible.
Journal: Applied Clay Science - Volume 49, Issue 3, July 2010, Pages 262–268