Preparation and adsorption properties for Cs⁺ of modified diatomite-supported copper hexacyanoferrate composite

Herein, aluminum chloride was used as the aluminum source to modify diatomite (De) by hydrothermal method. Copper hexacyanoferrate (KCuHCF) nanoparticles were loaded onto the surface of modified De by the impregnation method, and two composite adsorbents, gamma-AlOOH/De-KCuHCF and gamma-Al2O3/De-KCuHCF, were prepared. The prepared materials were characterized and used for Cs+ adsorption. The results showed that the prepared adsorbents had better adsorption performance for Cs+. The maximum adsorption capacity can reach 75.44 and 84.02 mg.g(-1), respectively. The desorption rate of gamma-Al2O3/De-KCuHCF can reach 81.88% after three consecutive desorption with 3 mol.L-1 NH4NO3 as the desorption solution and the Cs+ adsorption rate of gamma-Al2O3/De-KCuHCF in simulated brines was as high as 97.55%. After five adsorption-desorption cycles the adsorption capacity remained high. The adsorption kinetic process and adsorption isotherm model of the prepared adsorbent were also analyzed. The