Facile synthesis of robust polyethyleneimine incorporated chitosan composite hydrogel for efficient enrichment of uranium(VI) in aqueous solution

The development of polymer hydrogel with abundant ion diffusion paths is needed to address sustainable energy supply and ecological security. Herein, a robust chitosan-based polymer hydrogel with superior structural stability and sufficient active sites was fabricated by incorporating polyethyleneimine into chitosan for efficient enrichment of uranium(VI). The as-prepared chitosan-based polymer hydrogel has a maximum uranium adsorption capacity of 291.75 mg-U/g at pH= 6, together with relatively good selectivity to uranium(VI). The adsorption process was described well with the pseudo-second-order kinetic model and Langmuir isotherm model. The main adsorption mechanism was related to the complexation of uranyl ions with the amino and hydroxyl groups. The chitosan-based polymer hydrogel, with the merits of facile preparation, easy solid-liquid separation, eco-friendliness and cyclic utilization highlights its promising application in uranium removal and recovery from uranium-containing wastewater.