Study on the Adsorption Performance of a Novel Magnetic Graphene Oxide Adsorbent for Uranium

Background: The problem of nuclear water pollution is becoming serious worldwide. Uranium, as a metal substance with long half-life radioactivity, is commonly treated by various methods. Adsorption is considered to be one of the most promising methods for treating uraniumcontaining wastewater. Method: Magnetic nanoparticles MnFe2O4 were prepared via the coprecipitation method, followed by modification of silica using the improved Stöber method. Subsequently, amino was functionalized and grafted onto graphene oxide to prepare a novel magnetic graphene oxide composite MnFe2O4@SiO2-NH2@GO. Results: The highest adsorption rate of MnFe2O4@SiO2-NH2@GO for uranium can reach 97.27% in 1 mg·L-1 uranium solution, and the adsorption process conformed to the quasi-second-order kinetic model and Langmuir adsorption isotherm model, indicating that it was a monolayer adsorption dominated by chemisorption. The adsorption thermodynamic parameters demonstrated that the adsorption process was a spontaneous endothermic reaction. Conclusion: MnFe2O4@SiO2-NH2@GO had excellent adsorption properties for uranium, which has great application potential in the treatment of low-concentration uranium-containing wastewater.