Abstract:Cobalt-magnesium composite materials (Co-Mg LDH) were prepared by co-precipitation method and characterized by SEM, XRD, FTIR and XPS characterization methods. The effects of removal time, pH value of solution, ion strengths, initial concentration of U(Ⅵ), solid-to-liquid ratio, and reaction temperature of Co-Mg LDH on removing of U(Ⅵ) were investigated. The results show that Co-Mg LDH has the best removal capability on U(Ⅵ) in solution under the conditions including removal time of 30 min, pH value of solution of 4, dosage of Co-Mg LDH of 6 g/L, and reaction temperature of 75 ℃, the removal rate is about 100%. The results of isothermal adsorption, kinetics, and thermodynamics studies have shown that the adsorption process conforms to the Freundlich isotherm adsorption model and quasi second order adsorption kinetics model, which is a spontaneous and irreversible endothermic reaction process. According to the optimal adsorption conditions, Co-Mg LDH has been applied to the removal of U(Ⅵ) from the actual wastewater of an associated radioactive mine in Guangdong Province. The results show that the removal rate of U(Ⅵ) is 98.1%, and the uranium content of the treated wastewater meets the discharge standard of Rare Earth Industry Pollutants (GB 26451—2011). The composite material has a good application prospect in the treatment of uranium containing acidic wastewater from associated radioactive ore.