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过程工程学报 ›› 2022, Vol. 22 ›› Issue (11): 1504-1511.DOI: 10.12034/j.issn.1009-606X.221431

• 研究论文 • 上一篇    下一篇

超重力法制备CNT负载MnFe2O4纳米材料及吸附Pb(II)应用

高雨松， 祁贵生*， 闫文超， 郭达， 刘有智
  

  1. 1. 中北大学山西省超重力化工工程技术研究中心
    2. 中北大学超重力化工过程山西省重点实验室
  • 收稿日期:2021-12-22 修回日期:2022-01-23 出版日期:2022-11-28 发布日期:2022-11-28
  • 通讯作者: 祁贵生 zbdxqgs@126.com
  • 作者简介:高雨松(1997-)，男，湖北省松滋市人，硕士研究生，研究方向为重金属废水处理，E-mail: 18071292072@163.com；通讯联系人，祁贵生，E-mail: zbdxqgs@126.com.
  • 基金资助:
    国家自然科学基金国际（地区）合作与交流项目;山西省应用基础研究计划

Preparation of CNT supported MnFe2O4 nanomaterial based on high-gravity technology and its application for the adsorption of Pb(II)

Yusong GAO,  Guisheng QI*,  Wenchao YAN,  Da GUO,  Youzhi LIU   

  1. Research Center of Shanxi Province for High Gravity Chemical Engineering and Technology, College of Chemical Engineering and Technology, North University of China, Taiyuan, Shanxi 030051, China
  • Received:2021-12-22 Revised:2022-01-23 Online:2022-11-28 Published:2022-11-28
  • Contact: QI Gui-sheng zbdxqgs@126.com

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摘要： 为改善MnFe2O4纳米颗粒在实际应用中的团聚问题，结合多壁碳纳米管(CNT)原位负载，提出超重力法制备CNT负载MnFe2O4纳米材料(MnFe2O4/CNT)。以典型的重金属污染Pb(II)作为研究对象，对其吸附性能进行研究。首先考察了MnFe2O4负载量对Pb(II)吸附容量的影响，确定最佳MnFe2O4负载量为83.3wt%。采用XRD, SEM, N2吸附-脱附比表面分析仪和VSM对最佳MnFe2O4负载量条件下的MnFe2O4/CNT进行表征。MnFe2O4/CNT展现出优异的磁性，其饱和磁化强度为35.85 emu/g，因而可应用于水体中污染物的磁性分离。吸附实验结果表明在初始Pb(II)浓度300 mg/L和溶液pH=6的条件下，Pb(II)在MnFe2O4/CNT上180 min达到吸附平衡，吸附平衡容量为80.7 mg/g，远高于单独的CNT (28.4 mg/g)。动力学研究表明Pb(II)在MnFe2O4/CNT上的吸附符合Elvoch动力学模型，说明吸附机理中存在化学吸附。Freundlich等温线模型能够很好地描述Pb(II)在MnFe2O4/CNT上的吸附过程，其代表发生在非均匀表面的多分子层吸附。另外，吸附等温线实验中获得的MnFe2O4/CNT最大吸附容量为106.2 mg/g，展现出了对重金属Pb(II)优异的吸附性能，在去除溶液中重金属中具有较大的应用潜力。根据X射线光电子能谱分析，表明吸附机理涉及到Pb(II)与MnFe2O4表面羟基的络合。

关键词: 超重力技术, MnFe2O4, 多壁碳纳米管, 重金属

Abstract: In order to overcome the agglomeration problem of MnFe2O4 nanoparticles in practical applications, the high-gravity technology combining with the in?situ support of multiwalled carbon nanotubes (CNT) is proposed to prepare the CNT supported MnFe2O4 nano-material (MnFe2O4/CNT). The typical heavy metal pollution Pb(II) is selected as the research object to study the adsorption performance of MnFe2O4/CNT. First, the effects of different MnFe2O4 loads on the adsorption capacity toward Pb(II) are investigated, and the optimal MnFe2O4 load is determined to be 83.3wt%. The obtained MnFe2O4/CNT in the optimal MnFe2O4 load is charactered by XRD, SEM, N2 adsorption-desorption specific surface analyzer and VSM, and which exhibits an excellent magnetic property with a high saturation magnetization of 35.85 emu/g. Thus, the obtained MnFe2O4/CNT can be applied for the magnetic separation of pollutants in water. The results of adsorption experiments show that under the conditions of initial Pb(II) 300 mg/L and solution pH=6, the adsorption of Pb(II) on MnFe2O4/CNT in solution reached equilibrium after 180 min, and the adsorption equilibrium capacity is 80.7 mg/g, which is much higher than pure CNT (28.4 mg/g). The kinetic study demonstrates that the adsorption behavior of Pb(II) on MnFe2O4/CNT is most consistent with the Elvoch kinetic model,which suggests there exists a chemical adsorption in the adsorption mechanisms. Freundlich isotherm model describes well the adsorption process of Pb(II) on MnFe2O4/CNT, which represents a multilayer adsorption process on heterogeneous surfaces. In addition, the maximum adsorption capacity of MnFe2O4/CNT obtained from adsorption isotherm experiment is 106.2 mg/g, which displays excellent adsorption performance for Pb(II) and has a great potential in heavy metals removal in solution. According to the X-ray photoelectron spectroscopy analysis, it can be concluded that the adsorption mechanisms involve the complexation between Pb(II) and the hydroxyl groups on the surface of MnFe2O4.

Key words: high-gravity technology, MnFe2O4, multiwalled carbon nanotube, heavy metal