Magnetic MgFe2O4/biochar derived from pomelo peel as a persulfate activator for levofloxacin degradation: Effects and mechanistic consideration

• Published in: Bioresource technology Vol. 346; p. 126547
• Main Authors: Yao, Bin, Luo, Zirui, Du, Shizhi, Yang, Jian, Zhi, Dan, Zhou, Yaoyu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2022
• Subjects: Antibiotics; biochar; catalysts; catalytic activity; citrus peels; electrochemistry; electron paramagnetic resonance spectroscopy; Electron-transfer; levofloxacin; Magnetic biochar; magnetism; Non-radical pathway; oxidation; Persulfate; technology; Magnetic biochar; Antibiotics; Electron-transfer; Persulfate; Non-radical pathway
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2021.126547

[Display omitted] •MgFe2O4/biochar exhibited high performance for persulfate (PS) activation.•Satisfactory levofloxacin (LFX) degradation was achieved by MMB700/PS system.•Non-radial and electron-transfer mechanisms were involved in MMB700/PS system.•O2•− acted as the dominant active species in LFX degradation.•Possible degradation pathway of LFX was proposed. Biochar (BC) has been demonstrated the potential to activate persulfate (PS), but the limited catalytic efficiencies hindered their further application. Herein, an innovative magnetic MgFe2O4/BC (MMB) derived from pomelo peel was prepared for persulfate-based advanced oxidation process (PS-AOPs). Benefitting from the extraordinary properties, levofloxacin (LFX) was efficiently removed in the MMB/PS system. MMB700 exhibited the best catalytic activity, 87.87% of LFX was removed in the MMB700/PS system. In addition, it could maintain 67.90% of LFX degradation efficiency after 3 times of reuse. Quenching experiments, electron spin resonance (ESR) detection, and electrochemical test results indicated that both non-radical pathway and direct electron-transfer pathway advanced LFX degradation. LFX was oxidized by O2·− and 1O2, O2·− acted as the dominant active species. PS activation was induced by the active sites of MMB700. This work not only developed a promising magnetic biochar PS catalyst for antibiotics elimination, but also facilitated insights PS activation mechanisms.