Abstract:
In this work, glycerol-modified Ni/Al hydrotalcite(GMH) was successfully prepared by hydrothermal synthesis method, and the batch technique and static adsorption method were used to study the adsorption behavior as a function of solid-to-liquid ratio, pH value, ionic strength, humic acid, contact time and temperature. The characterizations of SEM, FTIR and XRD were used to analyze the materials before and after adsorption, and the adsorption mechanism was discussed by adsorption kinetics and thermodynamic model. The results show that the pH value of the solution has a significant effect on the adsorption behavior of Eu(Ⅲ) and U(Ⅵ) on GMH, and the adsorption percentages reaches the maximum at pH=7.0. The pseudo-second-order kinetic model and the Langmuir isotherm model can well describe the adsorption process of Eu(Ⅲ) and U(Ⅵ) on GMH, and the adsorption process is spontaneous and endothermic. Under the experimental conditions, the maximum theoretical adsorption capacities for Eu(Ⅲ) and U(Ⅵ) onto GMH are 511 mg/g and 441 mg/g in solution, respectively. The adsorption of Eu(Ⅲ) by GMH in solution is mainly dominated by electrostatic interaction,inner-sphere surface complexation and ion exchange, while the adsorption of U(Ⅵ) is mainly achieved by electrostatic interaction and inner-sphere surface complexation. Experiment results show that the synthetic material has a great application prospect in the effective purification and repair of low-level radioactive wastewater.