Magnetic pyro-hydrochar derived from waste cartons as an efficient activator of peroxymonosulfate for antibiotic dissipation

• Published in: Separation and purification technology Vol. 311; p. 123288
• Main Authors: Wu, Yang, Xu, Hai-yuan, Li, Zhi-hao, Zhu, Jing-ying, Bai, Jia-wen, Shao, Yi-fan, Lin, Chia-Cheng, Guan, Chung-Yu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2023
• Subjects: Antibiotics dissipation; Catalyzation; Mineralization; Pyro-hydrochar; Valorization; Waste cartons; Antibiotics dissipation; Catalyzation; Waste cartons; Mineralization; Valorization; Pyro-hydrochar
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.123288

[Display omitted] •Fe@N-PHC was synthesized to activate PMS and dissipate OFX/OTC.•The dissipation of OFX/OTC in the segmented phase resulted in higher TOC removal.•Nonradicals (1O2) play an essential role in OFX/OTC dissipation.•The Fe@N-PHC exhibited satisfactory separation performance and reusability.•Lignocellulose-bearing waste biomass is promising for environmental catalysis. Owing to the current emphasis of achieving carbon neutrality, the valorization of waste biomass has drawn global attention. Using sequential hydrothermal and pyrolytic procedures, we synthesized a magnetic pyro-hydrochar catalyst doped with Fe and nitrogen (Fe@N-PHC) from waste cartons. The characterization results revealed that Fe@N-PHC had a specific surface area of up to 220 m2/g, a defect structure with an abundance of functional groups, and good magnetic properties. Fe@N-PHC exhibited good adsorption capability and could effectively activate peroxymonosulfate to remove ofloxacin (OFX) and oxytetracycline (OTC) over a broad pH range. Specifically, the segmented phase removed OFX at varied pH levels at ∼ 85 % and OTC at ∼ 96 % during 105 min, with the highest iron exudation concentration not exceeding ∼ 0.35 mg/L. Furthermore, the magnetic separation of Fe@N-PHC is feasible and could be reused multiple times. Possible transformation products and ecotoxicity were predicted using LC-MS/MS and the ecological structure–activity relationship (ECOSAR) predictive model software. In addition, the removal of total organic carbon from the system was assessed. According to radical quenching experiments and electron paramagnetic resonance investigations, the catalytic dissipation process involves the formation of both radicals (SO4–, HO, and O2–) and a nonradical species (1O2). This exploratory study reconsiders the environmental value of waste cartons as part of a “waste into treasure” strategy. However, ongoing efforts should be made to optimize pyro-hydrochar modification and improve its catalytic capacity to remove various classes of emerging pollutants.