Construction of CDS/TIO2/HGS Composite Materials and Photocatalytic Reduction of Hexavalent Uranium in Wastewater

The separation and recovery of uranium from uranium-containing wastewater is important from the perspective of environmental protection and uranium recycling. CdS/TiO2/HGS composite materials were prepared by hydrothermal synthesis using hollow glass microspheres (HGS) as carrier. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy spectrum analysis (EDS). The activities were evaluated in the photocatalytic reduction of U(VI) in wastewater under visible light irradiation. The results indicate that CdS/TiO2/HGS materials are consisted of anatase type TiO2, cubic crystal type CdS and hollow glass microspheres. CdS/TiO2/HGS materials show good photocatalytic activity and their reduction reaction conform to the reaction dynamics characteristics of the proposed quasi-first-order. For a tailing pond wastewater with U(VI) concentration of 0.52 mg/L and pH = 6.40, the photocatalytic reduction rate of U(VI) by CdS/TiO2/HGS materials is 91.66% when the conditions of 1.5 g/L material dosage and irradiating for 120 min. The national wastewater discharge standard can be reached. The results have potential application value for the efficient and rapid treatment of radioactive wastewater.