摘要
The nonlinear heterogeneous adsorption behaviors of niobium (Nb) on clay rocks (bentonite and argillite) and granite in synthetic groundwater and seawater systems were evaluated by adsorption experiments, applying two heterogeneity-based isotherm models: the Langmuir–Freundlich (LF) and generalized-Freundlich (GF) models. According to the root mean square error (RMSE) between the experimental results and numerical simulation, the two heterogeneous sorption models (LF and GF), which correspond to a different heterogenous constant ( β ), were more adequate than Langmuir models for characterizing the Nb adsorption mechanism. The fitting results demonstrated that the sorption of Nb on granite, bentonite, and argillite exhibited a different adsorption affinity spectrum as a result of the heterogeneous mineral surface. Consequently, the Nb sorption capacity of bentonite and argillite was higher than that of granite and was estimated at 9.24E-01 mmol/g for bentonite, 8.44E-01 mmol/g for argillite, and 2.33E-02 mol/kg for granite.