Co-doped Fe3O4/α-FeOOH for highly efficient peroxymonosulfate activation to degrade trimethoprim: Occurrence of hybrid non-radical and radical pathways. (1st January 2023)

• Record Type: Journal Article
• Authors: Xu, Junge; Zhang, Ziwei; Hong, Junxian; Wang, Dong; Fan, Gongduan; Zhou, Jian; Wang, Yingmu
• Is Part Of: Journal of environmental management. Volume 325:Part A(2023)
• Publication Date: 2023-01-01
• Subjects: Advanced oxidation process -- PMS activation -- Antibiotic -- Magnetic recovery -- Degradation pathways; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.116459
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Trimethoprim (TMP), as a widely used chemotherapeutic antibiotic agent, has caused potential risks to the aquatic environment. In this study, magnetic Co-doped Fe3 O4 /α-FeOOH was fabricated by a facile one-step ageing method and used for activation of peroxymonosulfate (PMS) in TMP degradation. It was found that low catalyst (0.5 g/L) and PMS addition (0.2 mM) led to the high degradation efficiency of TMP (97.2%, k obs = 0.11211 min −1 ) over a wide range of pH. The oxidation of active radical (SO4 · − ) and non-radical singlet oxygen ( 1 O2 ) co-acted on TMP degradation. Besides, PMS was activated through the cycles between Co(II)/Co(III) and Fe(II)/Fe(III). Fifteen degradation intermediates of TMP were identified by LC-MS, and three possible degradation pathways including hydroxylation, demethylation, and cleavage were proposed. The recovered catalysts exhibited high stability and reusability, maintaining 80% TMP removal efficiency with inappreciable metal leaching (0.012 mg/L of Co, 0.113 mg/L of Fe) after six cycles. Besides, the Co–Fe3 O4 /α-FeOOH/PMS system was highly tolerant to inorganic anions and actual water bodies (river water, lake water, tap water, and sewage plant effluent). Overall, this work provided a promising way to the potential application of Fe-based binary metal oxide for PMS activation. Graphical abstract: Image 1 Highlights: Co-doped Fe3 O4 /α-FeOOH exhibited excellent catalytic activity for PMS activation. The superparamagnetism of the catalyst significantly enhanced the reusability. Cycles between Co(II)/Co(III) and Fe(II)/Fe(III) played crucial roles in PMS activation. Hybrid non-radical and radical pathways contributed to efficient trimethoprim degradation. TMP degradation pathways include hydroxylation, demethylation, and cleavage.