Enhanced removal of uranium(VI) from aqueous solution by a novel Mg-MOF-74-derived porous MgO/carbon adsorbent.

The elimination and safe treatment of U(VI) from radioactive wastewater has attracted widespread attention with the development of the nuclear power industry. In this work, a MgO/carbon adsorbent was successfully prepared by one-step Mg-MOF-74 pyrolyzation and used for U(VI) removal from aqueous solution. Characteristic results indicated that the as-prepared composite was a typical porous structure. The adsorption performance of the MgO/carbon towards U(VI) was studied by batch experiments. The results indicated that the MgO/carbon can rapidly and effectively remove U(VI) and showed an excellent adsorption capacity (777.51 mg/g), which is much higher than other reported adsorbent materials. In addition, the intraparticle diffusion model provides a good explanation for each adsorption process. The adsorption capacity of the MgO/carbon towards U(VI) is greatly promoted by the large specific surface area and well-defined porous structure. Based on the zeta potential and XPS analysis, the possible mechanism for U(VI) removal involved the surface complexation and electrostatic attraction. The results indicate that the MgO/carbon can be regarded as an efficient adsorbent for U(VI) removal from wastewater, which has a very broad application prospect.