香蕉纤维-壳聚糖水凝胶的制备及其吸附重金属离子性能研究

Study on the Preparation and Heavy Metal Adsorption of Banana Fiber-Chitosan Hydrogels

以香蕉纤维、壳聚糖为原料,离子液体1-烯丙基-3-甲基咪唑氯盐[Amim]Cl为溶解系统,在香蕉纤维网状结构中引入壳聚糖亲水性大分子基团,构建香蕉纤维-壳聚糖复合水凝胶,分析其重金属吸附能力。结果表明:在香蕉纤维大分子骨架上引入-NH2亲水性基团,成功构筑香蕉纤维-壳聚糖复合水凝胶,且表面分布不规则空隙结构;香蕉纤维壳聚糖复合水凝胶在660min时失水率达到94.36%;当水凝胶的用量为5g/L时,对Cu^2+、Cd^2+、Pb^2+的去除率分别为98.35%、79.22%和77.3%,40min时可达吸附平衡;吸附过程用准二级动力学模型来描述更为适当,其对重金属离子的吸附作用以化学吸附为主;香蕉纤维-壳聚糖水凝胶具有良好的重金属吸附性能,对Cu^2+的吸附作用更为显著。

Banana fiber and chitosan were dissolved in lonic liquid [Amim]Cl for a clear and transparent solution. In the solution chitosan macromolecular group and banana fiber molecular chain unit were connected through each other to construct the complex hydrogel. The hydrogel structure were characterized and the heavy metal ion adsorption properties were analyzed in this paper. And the results were shown that: the composite hydrogel with banana fiber and chitosan was successfully prepared;The hydrophilic functional groups (-NH 2) from chitosan was leaded in the network structure of banana fiber;Irregular voids were distributed at the surface of the hydrogel. Driage of the composite hydrogel was 94.36% at 660 min. When the dosage of the hydrogel was 5 g/L, the removal rate of Cu^2+, Cd^2+ and Pb^2+ were 98.35%, 79.22% and 77.3% respectively, and attained adsorption equilibrium in 40 min. The adsorption mechanism is chemical adsorption based by level 2 adsorption kinetics model. The banana fiber and chitosan composite hydrogel has good adsorption properties for heavy metals ions and especially for Cu^2+.