Purification of uranium-containing wastewater by adsorption: a review of research on resin materials

Nuclear energy has been developed and used on a large scale as a clean energy source. Since the increasing growth of the worldwide nuclear industry, the pollution of wastewater by radionuclides and toxic metals is a major environmental issue. The extraction method had some advantages such as simple operation, fast kinetics, wide applicability, high-cost performance as well as no secondary pollution, and was widely used for uranium treatment in aqueous solution. A review of the material types used in the treatment of uranium(VI) contaminated radioactive water, synthesis methods, and adsorption mechanisms was presented in this paper from the point of view of the importance of uranium(VI) contaminated radioactive water purification. We divided the contents into three major groups: ion exchange resins, chelate resins, and natural product modified chelate resins. The adsorption of U(VI) was further improved by changing the structures and properties of the materials by physical/chemical methods. These efforts have resulted in improved adsorption qualities, which were primarily ascribed to electrostatic interactions, chelation, and ion exchange processes. Based on our present knowledge, further efforts are needed such as improving selectivity, enhancing chemical stability for multiple reuses and adsorption conditions to improve adsorption rates, etc.