Selective adsorption of mercury ion from water by a novel functionalized magnetic Ti based metal-organic framework composite

Jing Li; Guo Lin; Fangguan Tan; Likang Fu; Biao Zeng; Shixing Wang; Tu Hu; Libo Zhang

doi:10.1016/j.jcis.2023.08.022

Selective adsorption of mercury ion from water by a novel functionalized magnetic Ti based metal-organic framework composite

J Colloid Interface Sci. 2023 Dec:651:659-668. doi: 10.1016/j.jcis.2023.08.022. Epub 2023 Aug 6.

Authors

Jing Li¹, Guo Lin², Fangguan Tan³, Likang Fu³, Biao Zeng¹, Shixing Wang³, Tu Hu³, Libo Zhang³

Affiliations

¹ The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, PR China.
² State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China; The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, PR China. Electronic address: guolin@kust.edu.cn.
³ State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China.

PMID: 37562307
DOI: 10.1016/j.jcis.2023.08.022

Abstract

In the context of industrialization and severe wastewater pollution, mercury ions pose a major threat due to their high toxicity. However, traditional adsorbents and common metal-organic framework (MOF) materials have limited effectiveness. This study focuses on combining magnetic materials with functionalized titanium-based MOF composite (SNN-MIL-125(Ti)@Fe₃O₄) to improve mercury ion adsorption. Through comprehensive characterization and analysis, the adsorption performance and mechanism of the material were studied. The optimal adsorption of the material was achieved at pH 5, exhibiting a pseudo-second-order adsorption model and the Hill theoretical capacity of 668.98 mg/g. Hill and Tempkin models confirmed the presence of chemical and physical adsorption sites on the material surface. Thermodynamic experiments showed a spontaneous endothermic process. Despite the presence of interfering ions, the material exhibited high selectivity for mercury ions. After four cycles, adsorption performance decreased by only 8%, indicating excellent reusability. Nitrogen- and sulfur-containing functional groups played a key role in mercury ion adsorption. In conclusion, SNN-MIL-125(Ti)@Fe₃O₄, as a magnetic MOF adsorption material, showed potential for effective remediation of mercury-contaminated wastewater. This study contributes to the development of efficient adsorption materials and enhances the understanding of their mechanism.

Keywords: Adsorption; Magnetic MOF; Mercury; Selectivity; Wastewater.