Adsorption of uranium (VI) by a MgAl-DHBDC/LDH composite: kinetic, mechanistic and thermodynamic studies

A magnesium aluminum bimetallic organic framework derivative (MgAl-DHBDC/LDH composite) was prepared by etching MgAl bimetallic MOF template and used to remove U(VI) in aqueous solution. Compared to MgAl-DHBDC, the stability, dispersibility and removal ratio of U(VI) with MgAl-DHBDC/LDH were improved significantly over a wide pH range. The adsorption of uranium by MgAl-DHBDC/LDH was mainly multilayer physical adsorption, and the adsorption process was a spontaneous endothermic process. Moreover, the removal ratio of U(VI) by the MgAl-DHBDC/LDH composite remained above 90% after 4 cycles, indicating good regeneration performance. The MgAl-DHBDC/LDH composite shows great potential in the remediation of radionuclide uranium wastewater. Graphical abstract