聚乙烯亚胺修饰磁性碳纳米管对水中六价铬的吸附

摘要

Magnetic multi-walled carbon nano-tubes(MWCNTs@Fe3O4)have been prepared by solvothermal meth-od,and MWCNTs@Fe3O4/PEI obtained by surface-decorated polyethyleneimine(PEI). The adsorbent has been char-acterized,and the influences of pH,ionic intensity and natural organic matter on the adsorption of Cr(Ⅵ)from wa-ter,and the cyclic regeneration capability of adsorbents investigated. The results show that the optimum adsorption pH=3. The adsorption process complies with the pseudo-second order kinetic model and Langmuir isothermal ad-sorption model. The ionic intensity inhibits the adsorption of Cr(Ⅵ),but humic acid has little influence on the re-moval of Cr(Ⅵ). After six times of adsorption and analysis,the adsorbent still has pretty good adsorption perfor-mance.%采用溶剂热法制备磁性多壁碳纳米管(MWCNTs@Fe3O4),用聚乙烯亚胺(PEI)进行表面修饰,得到MWCNTs@Fe3O4/PEI.对吸附剂进行表征,研究pH、离子强度和天然有机物对水中铬(Ⅵ)的吸附及吸附剂的循环再生能力.结果表明,最佳吸附pH=3,吸附过程符合准二级动力学模型和Langmuir等温吸附模型,离子强度抑制Cr(Ⅵ)的吸附;腐殖酸对Cr(Ⅵ)的吸附影响不大.在6次吸附解吸后,吸附剂仍有良好的吸附性能.