聚乙烯亚胺改性磁性膨润土对Pb2 和Cu2 的吸附性能

Adsorption properties of polyethyleneimine modified magnetic bentonite for Pb2 and Cu2

摘要:

在磁性膨润土(MB)表面接枝聚乙烯亚胺(PEI)制备聚乙烯亚胺改性磁性膨润土(PEI/MB)，对其进行了FTIR、VSM、XRD、TGA、SEM和EDS表征与分析，研究其对水溶液中Pb2 和Cu2 的吸附性能。结果表明：聚乙烯亚胺成功接枝于磁性膨润土表面并有效提高其对Pb2 和Cu2 吸附量；溶液初始pH对吸附量影响较大，随pH增大，吸附量增加。在pH=5,溶液初始浓度为300mg/L，PEI/MB对Pb2 和Cu2 吸附量分别为96.21mg/g和61.08 mg/g；吸附过程更符合准二级动力学模型，吸附行为更符合Langmuir吸附等温模型，为自发吸热过程。经过5次循环利用后，吸附容量保持为原来60%以上，表明PEI/MB具有一定的重复利用性。研究表明，聚乙烯亚胺改性磁性膨润土是一种具有良好应用前景的重金属废水吸附剂。

Abstract:

Polyethyleneimine-modified magnetic bentonite(PEI/MB) was prepared by grafting polyethyleneimine(PEI) on the surface of magnetic bentonite(MB), characterized by FTIR、VSM、XRD、TGA、SEM and EDS, its adsorption performance of Pb2 and Cu2 in aqueous solution was studied. The results showed that polyethyleneimine was successfully grafted onto the surface of magnetic bentonite and effectively increased its adsorption capacity for Pb2 and Cu2 ; the initial pH of the solution has a great influence on the adsorption capacity, and as the pH increase, the adsorption capacity increase. At pH=5, the initial concentration of the solution is 300mg/L, and the actual adsorption capacity of PEI/MB for Pb2 and Cu2 is 96.21mg/g and 61.08mg/g respectively; The adsorption process is more in line with the quasi-second-order kinetic model, and the adsorption behavior is more in line with the Langmuir adsorption isotherm model,which is a spontaneous endothermic process.After 5 cycles of recycling, the adsorption capacity remaine above 60%, indicating that PEI/MB has certain reusability. Studies have shown that polyethyleneimine-modified magnetic bentonite is a potential adsorbent for the removal of heavy metals from wastewater.