羧甲基-β-环糊精/磁性介孔硅对Pb2+的吸附研究

Adsorption of Pb2+ by Carboxymethyl-β-Cyclodextrin/Magnetic Mesoporous Silica

采用羧甲基-β-环糊精(CM-β-CD)和磁性介孔二氧化硅制得CM-β-CD/磁性介孔二氧化硅复合吸附剂(Fe3O4@SiO2@mSiO2-CM-β-CD),并应用于水体中Pb^2+的去除。通过SEM、EDS、FTIR、XRD等现代技术表征所得复合材料。研究表明:Fe3O4@SiO2@mSiO2-CM-β-CD对Pb^2+的吸附遵循伪二级模型,符合Langmuir模型。在298 K时,Pb2+的理论饱和吸附量为60.8 mg/g。此外,热力学参数表明吸附过程是自发的。最后,Fe3O4@SiO2@mSiO2-CM-β-CD表现出优异的磁分离性能,此外还证明在强酸性条件下具有良好的稳定性。经5次再生循环作用后,Fe3O4@SiO2@mSiO2-CM-β-CD对Pb^2+仍保持较高的吸附容量。

CM-β-CD/magnetic mesoporous silica composite adsorbent(Fe3O4@SiO2@mSiO2-CM-CD)was prepared by using carboxymethyl-β-cyclodextrin(CM-β-CD)and magnetic mesoporous silica,and applied to the removal of Pb^2+ in water.The resulting composite was characterized by modern techniques such as SEM,EDS,FTIR,XRD.The results show that the adsorption of Pb^2+ by Fe3O4@SiO2@mSiO2-CM-β-CD follows the pseudo-secondary model and conforms to the Langmuir model.At 298 K,the theoretical saturated adsorption capacity of Pb^2+ is 60.8 mg/g.In addition,thermodynamic parameters indicate that the adsorption process is spontaneous.Finally,Fe3O4@SiO2@mSiO2-CM-β-CD exhibits excellent magnetic separation properties,and also demonstrates good stability under strong acidic conditions.After 5 cycles of regeneration,Fe3O4@SiO2@mSiO2-CM-β-CD still maintains a high adsorption capacity for Pb^2+.