Effect of environmental conditions on the sorption of uranium on Fe3O4@MnO2 hollow spheres

• Published in: Journal of molecular liquids Vol. 223; pp. 534 - 540
• Main Authors: Zhang, Jian, Guo, Zhiqiang, Li, Yuan, Pan, Shuhao, Chen, Xinlei, Xu, Jinzhang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2016
• Subjects: Fe3O4@MnO2 hollow spheres; Removal performance; Sorption isotherms; U(VI); U(VI); Removal performance; Fe3O4@MnO2 hollow spheres; Sorption isotherms
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2016.07.136

Herein, the hydrothermal method was adopted to synthesize Fe3O4@MnO2 hollow spheres for the removal of U(VI) from aqueous solution. The effects of contact time, pH, ionic strength, solid content and temperature were investigated by using a batch technique. The sorption of U(VI) was dependent on ionic strength at pH<7, suggesting that electrostatic interaction and/or outer-sphere surface complexation was the predominant sequestration mechanism within this pH range. In contrast, the ignorable effect of ionic strength on the sorption behaviors at pH>7 pointed to the occurrence of inner-sphere surface complexation. Typical sorption isotherms (Langmuir, Freundlich, Dubinin-Raduskevich) were determined for the mechanism of sorption process. The maximum sorption amount of U(VI) on Fe3O4@MnO2 hollow spheres reached to 13.95mg/g at 293K. The thermo-dynamic parameters were calculated from the temperature isotherms, and the results suggested that U(VI) sorption on Fe3O4@MnO2 hollow spheres was a spontaneous and endothermic process. The results might be important for the application for U(VI) pollution management.
•The Fe3O4@MnO2 hollow spheres were synthesized.•The sorption of U(VI) on Fe3O4@MnO2 hollow spheres is spontaneous and endothermic.•The sorption of U(VI) on Fe3O4@MnO2 hollow spheres is dependent on ionic strength.•Fe3O4@MnO2 hollow spheres can be used as cost-effective material for U(VI) removal.