Simulation of non-linear heterogeneity-based isotherms for characterizing anaerobic and aerobic sorption of Se and Cs on various clay rocks

Thermodynamic sorption experiments of Se and Cs under aerobic/anaerobic conditions on granite, mudrock and MX-80 were conducted in synthetic groundwater/seawater medium. The batch experimental results were under the simulation of the two non-linear heterogeneity-based isotherm models, Langmuir–Freundlich (LF) and Generalized-Freundlich (GF) to evaluate the sorption characteristics of the Se and Cs. The results indicated that the LF and GF models could fit the experimental data more perfectly than the Langmuir one. Moreover, the affinity spectrum quantitatively demonstrated the discrepancy of heterogeneous sorption for the Se and Cs and its results demonstrated that the sorption mechanism between Se and Cs was quite different.