Retention profile and kinetics characteristics of the radionuclide 90-Sr(II) onto kaolinite

Abstract

The sorption of radionuclide 90-Sr(II) from aqueous solution onto kaolinite was studied by batch experiments under various experimental conditions. Kaolinite was characterized by XRD and FT-IR. The kinetic sorption process was well described by pseudo-second-order model. The sorption isotherms indicate that the sorption of 90-Sr(II) on kaolinite was better fitted by Langmuir than Freundlich and D–R models. The thermodynamic parameters (i.e., ΔH0, ΔS0 and ΔG0) suggest that the sorption was a spontaneous and endothermic process. The sorption of 90-Sr(II) on kaolinite was mainly dominated by ion exchange and outer-sphere surface complexation.