Antibiotic pollution threatens aquatic ecosystems and water supplies, so analysis of ecofriendly remediation approaches like biochars with catalytic degradation abilities is a top priority. In this work, quinolone antibiotics were degraded by activating oxidants to generate transient radicals using the environmentally persistent free radicals (EPFRs) carried by biochar. The physical and chemical characterization confirmed that biochar is suitable for the removal of organic pollutants. By regulating biochar preparation parameters, it was found that EPFR generation peaked at 500 °C. As the temperature increased from 300 °C to 500 °C, the EPFRs changed from oxygen-centered radicals (g > 2.0040) to carbon-centered radicals (g < 2.0030). The catalytic degradation efficiencies of the EPFR activated oxidants from large to small were: peroxydisulfate (PDS), peroxymonosulfate (PMS), H2O2 and flowing O2. The combined actions of SO4•- and •OH effectively degraded antibiotics. The results showed that biochar activating persulfate is a promising technique for the degradation of antibiotics.
Keywords: Biochar; Catalytic degradation; Environmentally persistent free radicals; Quinolone antibiotics.
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