Stability performance analysis of Fe based MOFs for peroxydisulfates activation to effectively degrade ciprofloxacin

Fang-Lan Geng; Hai-Yuan Chi; Hua-Chao Zhao; Jin-Quan Wan; Jian Sun

doi:10.3389/fbioe.2023.1205911

Stability performance analysis of Fe based MOFs for peroxydisulfates activation to effectively degrade ciprofloxacin

Front Bioeng Biotechnol. 2023 Jul 28:11:1205911. doi: 10.3389/fbioe.2023.1205911. eCollection 2023.

Authors

Fang-Lan Geng¹, Hai-Yuan Chi², Hua-Chao Zhao¹, Jin-Quan Wan³, Jian Sun³

Affiliations

¹ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
² Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, China.
³ College of Environment and Energy, South China University of Technology, Guangzhou, China.

Abstract

Fe-based metal-organic frameworks (MOFs) show high activity toward the activation of peroxodisulfate (PDS) for the removal of organic micropollutants (OMPs) in wastewater treatment. However, there is a phenomenon of Fe ion dissolution in the Fe-based MOFs' active PDS system, and the reasons and influencing factors that cause Fe ion dissolution are poorly understood. In this study, we synthesized four types of Fe-based MOFs and confirmed their crystal structure through characterization. All types of Fe-based MOFs were found to activate PDS and form sulfate radicals (SO₄ ^-), which effectively remove OMPs in wastewater. During the process of Fe-based MOFs activating PDS for CIP removal, activated species, oxidant reagent, and pH negatively impact the stability performance of the MOFs' structure. The coordination bond between Fe atom and O atom can be attacked by water molecules, free radicals, and H⁺, causing damage to the crystal structure of MOFs. Additionally, Fe (II)-MOFs exhibit the best stability performance, due to the enhanced bond energy of the coordination bond in MOFs by the F ligands. This study summarizes the influencing factors of Fe-based MOFs' damage during PDS activation processes, providing new insights for the future development of Fe-based MOFs.

Keywords: Fe-based metal-organic frameworks; crystal structure; organic micropollutants; peroxodisulfate; stability performance.

Grants and funding

This work was supported by the National Natural Science Foundation of China (22076032, 21707158, 22006025, and 22106026), the introduced innovative R&D team project under the “The Pearl River Talent Recruitment Program” of Guangdong Province (2019ZT08L387), and the China Postdoctoral Science Foundation (2020M682654).