Selective adsorption of uranium(VI) from aqueous solutions using the ion-imprinted magnetic chitosan resins.
Selective adsorption of uranium(VI) from aqueous solutions using the ion-imprinted magnetic chitosan resins.
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DOI：
10.1016/j.jcis.2011.09.069
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发表时间：
2012-01
影响因子：
9.9
通讯作者：
Liming Zhou;C. Shang;Zhi-rong Liu;Guolin Huang;A. Adesina
中科院分区：
文献类型：
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作者：
Liming Zhou;C. Shang;Zhi-rong Liu;Guolin Huang;A. Adesina
以U（VI）为模板，戊二醛为交联剂制备的离子印迹磁性壳聚糖树脂（IMCR）对U（VI）离子的吸附能力和选择性均优于无模板的非印迹磁性壳聚糖树脂（NIMCR）。结果表明，磁性壳聚糖树脂对U（VI）的吸附受初始pH值、初始U（VI）浓度和温度的影响。估计了吸附过程的动力学和热力学参数。这些数据表明，一个放热自发吸附过程动力学上遵循二级吸附过程。对Langmuir、Freundlich和Dubinin-Radushkevich吸附等温线模型进行了拟合，结果表明，Langmuir等温线方程与吸附等温线方程拟合良好。在pH 5.0、温度298K、吸附剂剂量50mg、接触时间3h条件下，IMCR的单层吸附容量为187.26mg/g， NIMCR的单层吸附容量为160.77mg/g，非常接近最大吸附容量。铀酰离子和其他金属离子在IMCR上的选择性系数表明，铀酰离子总体上优先于金属离子。此外，用0.5M hno3溶液对U（VI）离子进行解吸后，IMCR可再生，并可重复吸附。
The ion-imprinted magnetic chitosan resins (IMCR) prepared using U(VI) as a template and glutaraldehyde as a cross-linker showed higher adsorption capacity and selectivity for the U(VI) ions compared with the non-imprinted magnetic chitosan resins (NIMCR) without a template. The results showed that the adsorption of U(VI) on the magnetic chitosan resins was affected by the initial pH value, the initial U(VI) concentration, as well as the temperature. Both kinetics and thermodynamic parameters of the adsorption process were estimated. These data indicated an exothermic spontaneous adsorption process that kinetically followed the second-order adsorption process. Equilibrium experiments were fitted in Langmuir, Freundlich, and Dubinin–Radushkevich adsorption isotherm models to show very good fits with the Langmuir isotherm equation for the monolayer adsorption process. The monolayer adsorption capacity values of 187.26mg/g for IMCR and 160.77mg/g for NIMCR were very close to the maximum capacity values obtained at pH 5.0, temperature 298K, adsorbent dose 50mg, and contact time 3h. The selectivity coefficient of uranyl ions and other metal ions on IMCR indicated an overall preference for uranyl ions. Furthermore, the IMCR could be regenerated through the desorption of the U(VI) ions using 0.5M HNO3solution and could be reused to adsorb again.