Abstract: The performance of a novel cross-linked magnetic chitosan(TTG-MCTS),which is coated with magnetic fluids and cross-linked with glutaraldehyde and thiourea,is investigated for the adsorption of U(Ⅵ) from aqueous solutions. Infrared spectra of chitosan before and after modification show that the coating is successful and the cross-linking process is effective. The energy dispersive spectroscopy（EDS） analysis before and after adsorption indicates that U(Ⅵ) is adsorbed successfully onto the TTG-MCTS. The influences of the pH of solution,the initial concentration of U(Ⅵ) ions and the contact time on the adsorption amounts are discussed,and appropriate process conditions for the adsorption of U(Ⅵ) are obtained. Experimental equilibrium data are obtained and modeled using classical Freundlich and Langmuir adsorption isotherms. The data fits to the Langmuir isotherm better,and the uptake of U(Ⅵ) is 161.3 mg·g^-1. Two simplified models including pseudo-first order and pseudo-second order equations are selected to follow the adsorption process. The experimental data for the kinetics of adsorption are correlated well with the pseudo-second order equation.

Key words: cross-linked magnetic chitosan, uranium, adsorption capacity, isotherms