Preparation of NH2-CTS/MZ composites and their adsorption behavior and mechanism on uranium ions

Using the waste basalt powder, ferric chloride (FeCl3·6H2O), ferrous sulfate (FeSO4·7H2O), 3-aminotrimethoxysilane (3-TMSPT) and Chitosan (CTS) as raw materials, through hydrothermal synthesis, in-situ synthesis, cross-linking and grafting methods, the amino-modified chitosan/magnetic zeolite composite (NH2-CTS/MZ) was prepared. The samples were characterized by SEM, XRD, VSM, BET, FTIR and XPS. The removal ability and adsorption mechanism of U(VI) in an aqueous solution by NH2-CTS/MZ were systematically studied. The results showed that under the conditions of 308 K and pH = 5, NH2-CTS/MZ reached adsorption equilibrium within 180 min, and the equilibrium adsorption capacity was 749.5 mg·g−1. The adsorption isotherm conforms to the Langmuir isotherm model (R2 = 0.998), and the adsorption kinetics conforms to the quasi-secondary kinetic model (R2 = 0.987). The adsorption behaviour is a spontaneous endothermic process. This study shows that NH2-CTS/MZ has a good application prospect in the removal of uranyl ions.