RES³T - Rossendorf Expert System for Surface and Sorption Thermodynamics

MX-80 bentonite was detected using acid-based titration, XRD and FTIR in detail. The sorption behavior of ⁶³Ni(II) from aqueous solution to MX-80 bentonite was investigated as a function of solid content, ionic strength and pH by using batch technique. The experimental data of ⁶³Ni(II) sorption on MX-80 bentonite was obtained using the diffuse layer model (DLM) with the aid of FITEQL 3.1 program. The results indicated that the sorption of ⁶³Ni(II) on MX-80 bentonite was mainly dominated by surface complexation, and cation exchange also contributed partly to ⁶³Ni(II) sorption at low pH values. The sorption isotherms were simulated by Langmuir and Freundlich models, and the results indicated that Freundlich isotherm model fitted the sorption data better than the Langmuir isotherm model. The results are crucial to evaluate the sorption and migration of radionickel in MX-80 bentonite.