Integrated electro-Fenton system based on embedded U-tube GDE for efficient degradation of ibuprofen

Kaiqiang Shi; Yi Wang; Anlin Xu; Hongwei Zhu; Liankai Gu; Xiaodong Liu; Jinyou Shen; Weiqing Han; Kajia Wei

doi:10.1016/j.chemosphere.2022.137196

Integrated electro-Fenton system based on embedded U-tube GDE for efficient degradation of ibuprofen

Chemosphere. 2023 Jan;311(Pt 2):137196. doi: 10.1016/j.chemosphere.2022.137196. Epub 2022 Nov 9.

Authors

Kaiqiang Shi¹, Yi Wang¹, Anlin Xu², Hongwei Zhu¹, Liankai Gu¹, Xiaodong Liu¹, Jinyou Shen¹, Weiqing Han¹, Kajia Wei³

Affiliations

¹ Key Laboratory of Jiangsu Province for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China.
² Nanjing Tech University, School of Environmental Science and Engineering, Nanjing 211816, Jiangsu, China. Electronic address: annie01183@163.com.
³ Key Laboratory of Jiangsu Province for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China. Electronic address: kajiaw@njust.edu.cn.

PMID: 36370765
DOI: 10.1016/j.chemosphere.2022.137196

Abstract

Ibuprofen (IBP) is a carcinogenic non-steroidal anti-inflammatory drug (NSAID). It is of certain hazard to aquatic animals and may cause potential harm to human health. As traditional methods cannot effectively remove such a pollutant, many advanced oxidation processes (AOPs) have been developed for its degradation. The electro-Fenton process has the advantages of strong oxidative ability, a synergistic effect of various degradation processes, and a wide application range. This study developed a high-performance gas diffusion electrode (GDE) for electrochemical hydrogen peroxide (H₂O₂) production. The optimum system performance was found at the current density of 10 mA cm^-2, pH of 7.0, and air flow rate at 0.6 L min^-1, where the accumulation of H₂O₂ could reach as high as 769.82 mg L^-1. The computational fluid dynamics (CFD) simulation results revealed a fast mass-transfer property in this electro-Fenton system with U-tube GDEs, which resulted in a deep-level degradation (∼100%) of the pollutant (IBP) and a low-concentration degradation of 10 mg L^-1 within a 120-min reaction period. The high-performance liquid chromatography-mass spectrometry (LC-MS) studies demonstrated that the hydroxyl radicals were the primary active species in the electro-Fenton system and that the degradation intermediates of IBP were mainly 1-(4-isobutylphenyl) ethanol and 2-hydroxy-2-(4-isobutyl phenyl) propanoic acid through four probable electro-Fenton degradation pathways. This report provides a facile and efficient way to construct a high-performance electro-Fenton reactor, which could be effectively used in advanced oxidation processes (AOPs) to remove emerging contaminants in wastewater and natural water.

Keywords: Electro-fenton; Gas diffusion electrode; Ibuprofen; Reaction mechanisms.