聚乙烯亚胺修饰磁性碳纳米管对水中六价铬的吸附

Adsorption of Cr(Ⅵ) from water by polyethyleneimine decorated magnetic carbon nano-tubes

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p H、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p H=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。

Magnetic multi-walled carbon nano-tubes（MWCNTs@Fe3 O4）have been prepared by solvothermal meth-od,and MWCNTs@Fe3 O4/PEI obtained by surface-decorated polyethyleneimine（PEI）. The adsorbent has been char-acterized,and the influences of p H,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 adsorptionp H=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.