Electrochemical-enhanced Fe3O4/biochar activates peroxymonosulfate (E/nano-Fe3O4/BC/PMS) for degradation of oxytetracycline. (December 2022)

• Record Type: Journal Article
• Authors: Jiang, Haotian; Qi, Zehuan; Wang, Zhenjun
• Is Part Of: Chemosphere. Volume 308:Part 1(2022)
• Publication Date: 2022-12
• Subjects: PMS -- Oxidative degradation -- OTC -- Fe3O4; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.136148
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: To find cost-effective and environmentally friendly free radical activators to stimulate peroxymonosulfate (PMS) oxidative degradation of organic pollutants, nano-Fe3 O4 /biochar (BC) composites were prepared and characterized in this work to examine their effectiveness in stimulating PMS oxidative degradation of Oxytetracycline (OTC) in water enhanced with electrochemical degradation. When the mass ratio of nano-Fe3 O4 to BC is 1:1, the catalyst nano-Fe3 O4 /BC exhibits the most obvious degradation effect on OTC. After 4 h of degradation, the OTC concentrations were reduced from 20 to 2.65 mg L −1, while treated with a single nano-Fe3 O4 and a single BC are reduced by only 67.7% and 61.8%. Anions HCO 3 − and H 2 PO 4 − significantly inhibit OTC degradation, and HCO 3 − has a stronger inhibitory effect than H 2 PO 4 −, while Cl − and NO 3 − can promote OTC degradation. Quenching test and electron spin paramagnetic resonance (EPR) detection showed that singlet oxygen ( 1 O2 ) was the main active species in the degradation process, followed by hydroxyl radical (·OH). When reused for the third time, the removal rate of OTC by nano-Fe3 O4 /BC composites with mass ratios of 1:4, 1:2 and 1:1 was still more than 70%. Therefore, the nano-Fe3 O4 /BC composite is a promising PMS activator, which can realize the rapid oxidative degradation of OTC. Graphical abstract: Image 1 Highlights: Catalyst nano-Fe3 O4 /BC (1:1) exhibits the most obvious degradation effect on OTC. 1 O2 is the main active species in the degradation process. Nano-Fe3 O4 /BC composite is proved to be a promising PMS activator.