La-SIIPs对镧离子的吸附性能研究

Adsorption Properties of La-SIIPs for Lanthanum Ions

采用离子印迹技术,以聚乙烯醇-明胶交联复合物为基质,4-氨基苯硫酚为螯合剂,戊二醛为交联剂,La(Ⅲ)为模板进行交联聚合制备了La(Ⅲ)表面印迹聚合物(La-SIIPs)。通过红外光谱、扫描电镜进行表征,吸附实验考察了La(Ⅲ)初始浓度、吸附时间、吸附体系pH值等因素对La-SIIPs吸附性能的影响。结果表明,La-SIIPs在浓度60 mg/L时出现拐点、120 min达到吸附平衡、在pH=5的酸性环境中表现出良好的吸附性能;在La(Ⅲ)与共存离子Al(Ⅲ)、Mg(Ⅱ)、Ca(Ⅱ)、Zn(Ⅱ)组成的混合吸附体系中,La-SIIPs对La(Ⅲ)具有较好的识别作用,呈现出良好的吸附选择性。La-SIIPs对La(Ⅲ)吸附过程符合Langmuer等温吸附模型和二级动力学吸附模型,以化学吸附为主。

La(Ⅲ)surface imprinted polymers(La-SIIPs)were prepared by ion imprinting technique with the conjugated complex of polyvinyl alcohol and gelatin particles as matrix,4-Aminothiophenol as chelating agent and glutaraldehyde as crosslinking agent.It was characterized by scanning electron microscopy and infrared spectroscopy.The equilibrium adsorption experiment of La-SIIPs was carried out to investigate the adsorption performance of La-SIIPs for La(Ⅲ),and the adsorption process parameters were optimized.The results showed that adsorption performance of La-SIIPs was good when the inflection point appeared at the concentration of 60 mg/L,the adsorption equilibrium was reached at 120 min,the optimal adsorption was obtained at 25℃in acidic environment with pH=5.In the mixed adsorption system composed of La(Ⅲ)and co-existing ions Al(Ⅲ),Mg(Ⅱ),Ca(Ⅱ)and Zn(Ⅱ),La-SIIPs has a good recognition effect on La(Ⅲ),and has a certain selective adsorption performance.The adsorption process of La(Ⅲ)by La-SIIPs conforms to the Langmuer isothermal adsorption model and second-order kinetic adsorption model.