Preparation of magnetic chitosan composites and their adsorption properties on uranium

For the difficult recycling problem of chitosan, composite nanoparticles with core-shell structure were constructed by introducing magnetic zinc ferrate particles. Two different functional groups were further introduced and grafted onto the chitosan-coated magnetic zinc ferrate/silica nanoparticles to prepare novel, highly selective, acid-resistant and reusable two functionalized magnetic chitosan-based composites (ZSC-P and ZSC-D). The adsorption properties of the composites were investigated by adjusting the solution pH, adsorption time, initial concentration of uranium solution, and adsorption temperature; and the uranium adsorption process of the composites was investigated by kinetic and thermodynamic modelling.The maximum adsorption capacity of the composites was reached by the adsorbent of ZSC-P at 122.16 mg/g for pH=4, and that of ZSC-D was reached by the adsorbent of ZSC-D at 122.76 mg/g for pH=5. The adsorption processes of both adsorbent materials are as follows. The adsorption processes of the two adsorbent materials were in accordance with the quasi-secondary kinetic model and the Freundlich model, and both ZSC-P and ZSC-D materials showed good selective adsorption and regeneration properties for uranyl ions.