Cu^(2+)印迹壳聚糖/Al_2O_3的制备及动态吸附性能

Preparation and dynamic adsorption performance of copper( Ⅱ)-imprinted chitosan /Al_2O_3 composite material

以表面接枝和表面印迹技术为基础,采用正硅酸乙酯改性的Al2O3为载体,壳聚糖为功能单体,制备了一种新型Cu2+印迹壳聚糖/Al2O3复合材料(IIP/Al2O3),以傅里叶变换红外表征了IIP/Al2O3,发现Cu2+印迹壳聚糖被有效接枝到Al2O3表面。考察填充柱入口Cu2+质量浓度、柱高、流速和pH值对IIP/Al2O3柱动态吸附性能的影响,研究动态吸附模型,结果表明:当填充柱入口Cu2+质量浓度为100 mg/L、柱高为37.25 mm、流速为1.0 mL/min和pH值为5时,IIP/Al2O3柱穿透吸附量和平衡吸附量分别为4.03和15.68 mg/g,吸附平衡时间为215 min,穿透时间为31 min,吸附行为符合Thomas模型,理论平衡吸附量为15.76 mg/g,Thomas常数为0.342 9×10-3L/(mg·min)。研究IIP/Al2O3柱的选择性分离特性和稳定性,发现IIP/Al2O3柱对Cu2+吸附率远高于竞争离子Ni2+和Zn2+,经5次吸附-洗脱后,穿透吸附量及平衡吸附量仅分别下降5.2%和3.0%。

Taking Al2 O3 modified with tetraethylorthosilicate as carrier material, and chitosan as functional monomer,a novel copper ion imprinted chitosan/aluminium oxide （IIP/Al2 O3 ）was prepared based on the surface-grafted and surface imprinting technologies.The IIP/Al2 O3 was characterized by using the Fourier transform infrared spectroscopy.The results show that copper ion imprinted chitosan is grafted successfully on the surface of Al2 O3 .The effects of Cu2＋inlet mass concentration,column height,flow rate and pH value on the dynamic adsorption of Cu2＋on IIP/Al2 O3 were investigated.The model for dynamic adsorption of Cu2＋on IIP/Al2 O3 was studied.The results indicate that when Cu2＋inlet mass concentration is 100 mg/L,column height is 37.25 mm, flow rate is 1 .0 mL/min and pH value is 5 ,the breakthrough capacity and dynamic adsorption capacity of the IIP/Al2O3 are 4.03 mg/g and 15.68 mg/g,respectively,and equilibrium time and breakthrough time are 215 min and 3 1 min,respectively.Thomas model is suitable for the description of dynamic adsorption of the IIP/Al2 O3 .The theoretical adsorption capacity of the IIP/Al2O3 is 15.76 mg/g,and Thomas constant is 0.342 9 ＆#215;10 -3 L/（mg＆#183; min）.The selectivity and stability of IIP/Al2 O3 were studied further.The IIP/Al2 O3 showed good characteristics, such as high selectivity and good reusability.The adsorption percentage of Cu2＋on IIP/Al2 O3 was higher than that of Ni2＋or Zn2＋on IIP/Al2 O3 .After the adsorption-desorption cycles were repeated 5 times,the breakthrough capacity and dynamic adsorption capacity were decreased only by 5 .2% and 3 .0%,respectively.