壳聚糖Pb2+螯合吸附剂的性能表征

用先印迹和后印迹方法制备了2种壳聚糖Pb2+螯合吸附剂(Pb-TMCS和TMCS-Pb),考察了吸附剂对 Pb2+的吸附性能。利用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)和X 射线能谱仪 (EDS)对吸附前后的Pb-TMCS,TMCS-Pb及壳聚糖(CS)分别进行形貌、结构及组成的表征。结果表明, 与TMCS-Pb和CS相比,先印迹方法制备的Pb-TMCS对Pb2+的吸附容量最大,可达45.38 mg/g;表面更加粗糙;包覆了磁性物质Fe3O4,具有磁性,能够迅速从吸附后的溶液中分离出来;对Pb2+的吸附机理是—NH2、—OH和CS与Pb2+发生了螯合反应;先印迹能留下更多印迹空穴,对Pb2+的吸附选择性更好。

Characterization of lead ions imprinting chitosan chelating adsorbents

Two lead ions imprinting chitosan chelating adsorbents(Pb-TMCS and TMCS-Pb)were prepared by imprinting lead ions before and after modifieding magnetic crosslinking chitosan. Adsorption capacity of lead ions onto adsorbents were studied. The morphology,structure and chemical composition characteristics of Pb-TMCS/TMCS-Pb/CS before and after adsorption of Pb2+ were characterized by Scan electron microscopy (SEM), X-ray diffraction(XRD), Fourier-transformed infrared spectroscopy (FTIR) and X-ray energy dispersive spectroscopy(EDS). Results showed that compared with TMCS-Pb and CS,Pb-TMCS showed higher adsorption capacity(45.38 mg/g). The rough surface of Pb-TMCS increased the specific surface. —NH2 groups, —OH groups and CS groups of Pb-TMCS participated in the chelating reaction. Imprinting lead ions at first led more imprinting cavities and had more selective adsorption ability.