Efficient removal of U(VI) by an environmental-friendly amidoxime matrix microspheres: Batch experiments and mechanism investigation

As a strategic resource, the safe management and recovery of uranium (U(VI)) is of great significance for environmental protection and resource recycling. To address it, the effective capture of U(VI) from wastewater is necessary but still challenging. In this work, an environmental-friendly adsorbent amidoxime and carboxyl functionalized microspheres (ACBs) were successfully prepared, characterized and evaluated for U(VI) adsorption. The ACBs exhibited outstanding adsorption abilities for U(VI) with high adsorption capacity, fast kinetics, good selectivity and excellent reusability. The U(VI) adsorption mechanism onto ACBs was synthetically investigated by various characterizations and DFT calculations, suggesting that the amidoxime and carboxyl groups coordinated with U(VI) by & pi; and & sigma; bonds. Further investigation in actual water samples and degradation experiments suggested that the ACBs can not only effectively remove U(VI) from wastewater, but also it can be completely degraded to achieve waste-free goals after the adsorption-desorption process. This work provides new insight into the significance of designing efficient and environmental-friendly adsorbent material for U(VI) removal from wastewater.