Effective Degradation of Metronidazole through Electrochemical Activation of Peroxymonosulfate: Mechanistic Insights and Implications

Haicen Liao; Jingkai Fang; Jiahao Wang; Xianhu Long; Igor Ying Zhang; Rongfu Huang

doi:10.3390/en17071750

Energies (Apr 2024)

Effective Degradation of Metronidazole through Electrochemical Activation of Peroxymonosulfate: Mechanistic Insights and Implications

Haicen Liao,
Jingkai Fang,
Jiahao Wang,
Xianhu Long,
Igor Ying Zhang,
Rongfu Huang

Affiliations

Haicen Liao: Sichuan Provincial Key Laboratory of Universities on Environmental Science and Engineering, MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Jingkai Fang: Sichuan Provincial Key Laboratory of Universities on Environmental Science and Engineering, MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Jiahao Wang: Sichuan Provincial Key Laboratory of Universities on Environmental Science and Engineering, MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Xianhu Long: Sichuan Provincial Key Laboratory of Universities on Environmental Science and Engineering, MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Igor Ying Zhang: Collaborative Innovation Centre of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovation Materials, MOE Laboratory for Computational Physical Science, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Chemistry, Fudan University, Shanghai 200433, China
Rongfu Huang: Sichuan Provincial Key Laboratory of Universities on Environmental Science and Engineering, MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China

DOI: https://doi.org/10.3390/en17071750
Journal volume & issue: Vol. 17, no. 7
p. 1750

Abstract

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The investigation into the degradation of metronidazole (MNZ), a frequently employed antibiotic, through the electrochemical activation of peroxymonosulfate (PMS) utilizing either boron-doped diamond (BDD) or dimensional stable anode (DSA) as the anode, was conducted in a systematic manner. The enhancement of MNZ removal was observed with increasing current density, PMS dosage, and initial pH. Response surface methodology (RSM), based on a Box–Benken design, was utilized to evaluate the efficiency of MNZ elimination concerning current density (ranging from 11.1 to 33.3 mA/cm2), initial pH (ranging from 3 to 9), PMS dosage (ranging from 1 to 5 mmol·L−1), and reaction time (ranging from 25 to 45 min). The optimal operational conditions for MNZ removal were determined as follows: a current density of 13.3 mA/cm2, a pH of 3.7, a PMS dosage of 2.4 mmol·L−1, and a reaction time of 40 min. Electron paramagnetic resonance (EPR), quenching experiments, and chemical probe experiments confirmed the involvement of •OH, SO4•− and 1O2 radicals as the primary reactive species in MNZ degradation. The presence of HCO3− and H2PO4− hindered MNZ removal, whereas the presence of Cl− accelerated it. The degradation pathways of MNZ were elucidated by identifying intermediates and assessing their toxicity. Additionally, the removal efficiencies of other organic pollutants, such as sulfamethoxazole (SMX), carbamazepine (CBZ), and nitrobenzene (NB), were compared. This study contributes to a comprehensive understanding of MNZ degradation efficiency, mechanisms, and pathways through electrochemical activation of PMS employing BDD or DSA anodes, thereby offering valuable insights for the selection of wastewater treatment systems.

Published in Energies

ISSN: 1996-1073 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology
Website: http://www.mdpi.com/journal/energies

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