Adsorption of Radionuclides from Aqueous Solutions by Inorganic Adsorbents

Abstract

Radionuclides such as ¹³⁷Cs and ⁸⁵Sr were removed from dilute aqueous solutions by means of inorganic adsorbents, MS-13X and chabazite. Adsorption data of radionuclides on the inorganic adsorbents were satisfactorily correlated by the Dubinin-Astakov (DA) equation. Gaussian-type distributions of adsorption energies were obtained from the parameters of the DA equation by applying the condensation approach. A surface diffusion model was applied to estimate the intraparticle mass transfer of radionuclides. The range of surface diffusion coefficients estimated was 3.2 × 10⁻¹² to 3.5 × 10⁻¹¹ m²/s. The adsorption model, which describes the surface diffusion mechanism with the DA equation, satisfactorily simulated the adsorption behavior of radionuclides on zeolites in batch adsorbers.