| 聚乙烯亚胺改性氧化石墨对水中Cr(Ⅵ)的吸附 |
| Cr(Ⅵ) Adsorption on Polyethyleneimine Modified Graphite Oxide |
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| 摘要: 通过对石墨氧化、酯化,将聚乙烯亚胺耦合接枝到氧化石墨表面,制备聚乙烯亚胺改性氧化石墨(PEI-GO)。通过FTIR、XRD、TEM、RS和XPS等对合成材料进行表征,并研究了其对水中的Cr(Ⅵ)吸附和脱附性能。表征结果表明,聚乙烯亚胺成功嫁接到氧化石墨上,其氨基含量为4.36mmol·g-1。PEI-GO对水中Cr(Ⅵ)具有很好的吸附性能,吸附等温线符合Freundlich方程,吸附动力学可用拟二级动力学方程来描述。PEI-GO对水中Cr(Ⅵ)的吸附随pH的升高而降低。阴离子的存在降低吸附剂对Cr(Ⅵ)的吸附,不同阴离子的影响大小顺序为PO43- >SO42- >NO3- >Cl-。XPS结果表明,PEI-GO对Cr(Ⅵ)的去除是吸附-化学还原耦合作用的结果。经4次脱附再生循环,PEI-GO对Cr(VI)仍具有较高吸附量,表明该吸附剂再生性好,可循环使用。 |
| 关键词: 聚乙烯亚胺 改性氧化石墨 六价铬 吸附 脱附 |
| 基金项目: 国家自然科学基金(No.21107065)和污染控制与资源化国家重点实验室(南京大学)开放课题(No.PCRRF11012)资助项目。 |
| Abstract: Polyethyleneimine modified graphite oxide (PEI-GO) were prepared by grafting polyethyleneimine (PEI) on the surface of graphite after oxidation and esterification. The structure and surface properties of synthesized composites were characterized by Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), Rraman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS) analysis, and its adsorption and desorption capability for aqueous Cr(Ⅵ) was also conducted. Characterization results indicated that polyethyleneimine has been successfully grafted on the surface of graphite oxide, and the content of the amino groups of PEI-GOis 4.36 mmol·g-1. PEI-GOexhibits high adsorption capacity for aqueous Cr(Ⅵ). Adsorption isotherm of Cr(Ⅵ) onto PEI-GO could be described better by Freundlich model than Langmuir model. The pseudo-second-order kinetics followed the adsorption data very well. Adsorption amount of Cr(Ⅵ) onto PEI-GOdecreased with increasing pH. The presence of anions in solution resulted in the suppressed Cr(Ⅵ) adsorption, and the effect of different anions was in the order of PO43- > SO42- > NO3- > Cl-. XPSanalysis indicates that adsorption coupled chemical reduction mechanism contributes to enhanced Cr(Ⅵ) adsorption on PEI-GO. After four successive desorption-regeneration cycles, PEI-GO still possesses high adsorption capacity for Cr(Ⅵ), which indicates that the adsorbent has good regeneration capability and can be used repeatedly. |
| Keywords: polyethyleneimine modified graphite oxide hexavalent chromium adsorption desorption |
| 投稿时间：2014-12-29 修订日期：2015-04-13 |
| 摘要点击次数: 1898 |
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| 王家宏,尹小龙,吉艳芬.聚乙烯亚胺改性氧化石墨对水中Cr(Ⅵ)的吸附[J].无机化学学报,2015,31(6):1185-1193. |
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