EDTA functionalized Fe₃O₄/graphene oxide for efficient removal of U(VI) from aqueous solutions

In this study, a regenerable magnetic ligand material (EDTA-mGO) was fabricated by binding chelating groups (EDTA) onto Fe₃O₄/graphene oxide and applied to remove U(VI) from aqueous solution. The sorption experiments were investigated under different experimental conditions, such as temperature, contact time and pH. EDTA-mGO showed fast removal capacity for U(VI) (<1.5 h) with high sorption ability (277.43 mg/g). The removal mechanisms mainly attributed to the metal-binding organic ligand (EDTA) and the electrostatic attractions between U(VI) and oxygenic functional groups. In addition, the as-prepared EDTA-mGO dispersed in water could be easily collected after the sorption by the external magnetic field within 10 s. The removal of U(VI) by EDTA-mGO followed the pseudo-second-order rate better than the pseudo-first-order. The thermodynamic data indicated the endothermic and the spontaneous nature of U(VI) sorption. Furthermore, the reproducibility studies suggested that EDTA-mGO has a good reusability and a high stability.