聚乙烯亚胺/Fe_3O_4杂化磁性纳米吸附剂去除甲基橙

Removal of Methyl Orange by polyethylenimine / Fe_3O_4 hybrid magnetic nanoadsorbents

采用戊二醛共价交联法制备出了聚乙烯亚胺/Fe3O4杂化磁性纳米吸附剂(PEI-Fe3O4)。通过TEM、XRD、FTIR、VSM和TGA等手段表征了材料的结构和性质。以甲基橙(MO)为吸附质,系统考察了p H值、吸附时间和染料初始浓度等因素对吸附材料性能的影响。结果表明,MO在PEI-Fe3O4上的吸附具有强烈的p H依赖性,p H为3时吸附量最大;吸附平衡仅需20 min,吸附过程符合准二级动力学模型;等温吸附过程更符合Langmuir模型,MO的最大吸附量为242.4 mg/g。重复实验表明,吸附剂经过15次吸附/解吸附循环后仍可维持最初的吸附性能,显示出良好的机械和化学稳定性。因此,该杂化吸附剂在染料废水中MO的去除方面具有良好的应用前景。

Polyethylenimine / Fe3O4 hybrid magnetic nanoadsorbents（ PEI-Fe3O4） were prepared by a covalent cross-linking reaction using glutaraldehyde. The structures and properties of the hybrid materials were characterized by TEM,XRD,FT-IR,VSM,TGA,and other methods. By using methyl orange（ MO） as an adsorbate,the parameters likely to affect the adsorption behavior of the adsorbent,such as solution pH,adsorption time,and initial dye concentration,were systematically investigated. The results showed that the adsorption of MO by PEI-Fe3O4 was pH-sensitive and the maximum adsorption capacity was achieved at pH 3. The adsorption equilibrium could be reached within 20 min and the pseudo-second-order kinetics model offered a good description of the adsorption process; the adsorption isotherms matched well with the Langmuir model and the qmaxof MO was 242. 4 mg / g. The repeatability testing demonstrated that the adsorbent can retain its original adsorption capacity even after a run of 15 adsorption / desorption cycles,showing excellent mechanical and chemical stabilities. Therefore,the hybrid adsorbent could be used as a promising adsorbent for the removal of methyl orange from dye-bearing wastewater.