Preparation of composite hydrogel (PCG) and its adsorption performance for uranium(VI)

In this work, a novel composite hydrogel (PCG) was constructed by mixing amidoxime polyacrylonitrile, chitosan and graphene oxide. The structure characterization of PCG was successfully investigated by FTIR, SEM. The effects of the pH, initial concentration of metal ion and contact time were conducted by a batch of experiments. PCG showed higher adsorption selectivity for U(VI) and its maximum adsorption capacity can reach up 247 mg/g. PCG can be completely separate from the aqueous solution and displayed excellent regeneration ability which would not cause secondary pollution to water bodies. The sorption kinetics of PCG for U(VI) followed pseudo-second order model well and Langmuir model were used to describe the equilibrium data well, which indicated that a monolayer adsorption occurred on PCG and the chemisorption was the main rate-limiting step. This work proved that PCG could be considered as the effective and promising material for removal of U(VI) from aqueous solution. (C) 2020 Elsevier B.V. All rights reserved.