Design of 3D alumina-doped magnesium oxide aerogels with a high efficiency removal of uranium(VI) from wastewater

Herein, 3D alumina-doped magnesium oxide (Al2O3/MgO) aerogels were successfully prepared by a simple lyophilization–calcination method for the uranium (U(VI)) elimination from wastewater. Various batch experiments were used to testify that Al2O3/MgO aerogels exhibited remarkable removal performance for U(VI), especially Al2O3/MgO aerogels with Al2O3/MgO molar ratios of 1 : 1 (Al/Mg-3). Results showed that Al/Mg-3 could quickly reach the adsorption equilibrium within the contact time of 100 min, while the adsorption capacity of Al/Mg-3 for U(VI) could reach as high as 1046.9 mg g−1 at pH 6.0. The selectivity of Al/Mg-3 for U(VI) proved that Al/Mg-3 could be used to remove U(VI) from wastewater. The adsorption efficiency of Al/Mg-3 for U(VI) could still retain more than 92.5% after five cycles. Furthermore, the continuous U(VI) separation test results showed that the adsorption equilibrium time and adsorption efficiency of Al/Mg-3 could decrease to 40 min and increase to 99.7%, respectively. This work demonstrated that the remarkable U(VI) removal performance of Al/Mg-3 could make it an effective and reusable material for the adsorption of U(VI) from U(VI)-contained wastewater.