Removal of Mercury (II) by EDTA-Functionalized Magnetic CoFe2O4@SiO2 Nanomaterial with Core-Shell Structure

Kai Xia; Yongfu Guo; Qijun Shao; Qu Zan; Renbi Bai

doi:10.3390/nano9111532

Removal of Mercury (II) by EDTA-Functionalized Magnetic CoFe₂O₄@SiO₂ Nanomaterial with Core-Shell Structure

Nanomaterials (Basel). 2019 Oct 29;9(11):1532. doi: 10.3390/nano9111532.

Authors

Kai Xia¹, Yongfu Guo^{2

3}, Qijun Shao⁴, Qu Zan^{5

6}, Renbi Bai⁷

Affiliations

¹ Center for Separation and Purification Materials &Technologies, Suzhou University of Science and Technology, Suzhou 215009, China. 1713022009@post.usts.edu.cn.
² Center for Separation and Purification Materials &Technologies, Suzhou University of Science and Technology, Suzhou 215009, China. yongfuguo@mail.usts.edu.cn.
³ Jiangsu Provincial Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China. yongfuguo@mail.usts.edu.cn.
⁴ Department of Fundamental Courses, Wuxi Institute of Technology, Wuxi 214121, China. shaoqj@wxit.edu.cn.
⁵ Jiangsu Provincial Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China. quzan@sjtu.edu.cn.
⁶ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. quzan@sjtu.edu.cn.
⁷ Center for Separation and Purification Materials &Technologies, Suzhou University of Science and Technology, Suzhou 215009, China. ceebairb@live.com.

Abstract

In order to reduce the difficulty and risk of operation, decrease the preparation time and improve the adsorption performance of magnetic nano-silicon adsorbent with core-shell structure, a carboxylated CoFe₂O₄@SiO₂ was prepared by EDTA-functionalized method using a safe, mild and simple hydrothermal method. The results show that the prepared material of CoFe₂O₄@SiO₂-EDTA has a maximum adsorption capacity of 103.3 mg/g for mercury ions (Hg(II)) at pH = 7. The adsorption process of Hg(II) is a chemical reaction involving chelation and single-layer adsorption, and follows the pseudo-second-order kinetic and Langmuir adsorption isotherm models. Moreover, the removal of Hg(II) is a spontaneous and exothermic reaction. The material characterization, before and after adsorption, shows that CoFe₂O₄@SiO₂-EDTA has excellent recyclability, hydrothermal stability and fully biodegradable properties. To summarize, it is a potential adsorption material for removing heavy metals from aqueous solutions in practical applications.

Keywords: EDTA functionalization; adsorption; heavy metal; magnetic material; mercury.

Abstract

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