Chitosan modified molybdenum disulfide composites as adsorbents for the simultaneous removal of U(VI), Eu(III), and Cr(VI) from aqueous solutions

The potential coexistence of radionuclides and toxic metal ions is threatening the ecological environment. In this study, the chitosan modified molybdenum disulfide (CS/MoS2) was prepared by hydrothermal method for the simultaneous removal of U(VI), Eu(III), and Cr(VI). The removal capacities of CS/MoS2 in the single system were 0.71 mmol/g for U(VI), 0.86 mmol/g for Eu(III), and 3.04 mmol/g for Cr(VI) at pH 5.0. The simultaneous adsorption results indicated that the existence of U(VI) or Eu(III) could effectively improve the removal efficiency of Cr(VI). The trapping of Eu(III) decreased obviously in the presence of U(VI) or Cr(VI). The presence of Cr(VI) was beneficial to the retention of U(VI), while the presence of Eu(III) led to the decrease adsorption of U(VI). Based on the XPS characterization results, the retention of U(VI), Eu(III), and Cr(VI) on CS/MoS2 was mainly ascribed to the electrostatic attraction along with the hydroxyl and amidogen groups. The results revealed that CS/MoS2 composites were versatile and highly efficient for multiple pollutants elimination, which can be used for environmental pollution cleanup.