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

摘要： 采用纳米Fe₃O₄作为磁流体包埋、戊二醛和硫脲进行交联壳聚糖，制备磁性交联壳聚糖（TTG-MCTS）。红外光谱（FTIR）和X射线能谱（EDS）分析结果表明，壳聚糖改性后，吸附能力得到提高，铀(Ⅵ)成功地被吸附在TTG-MCTS上。系统研究了溶液pH值、铀(Ⅵ)初始浓度及振荡时间对吸附容量的影响，继而得到最佳工艺条件。吸附过程用Langmuir等温式拟合优于用Freundlich等温式，最大吸附容量为161.3 mg·g^-1。较之拟一级动力学模型，拟二级动力学模型能更好地拟合实验数据。