Kelp-derived N-doped biochar activated peroxymonosulfate for ofloxacin degradation

N-doped carbon materials have been proven to be effective catalysts for activating peroxymonosulfate (PMS). Marine algae biomass is rich in nitrogenous substances, which can reduce the cost of N-doping process and can obtain excellent N-doped catalysts cheaply and easily. In this study, kelp biomass was selected to prepare N-doped kelp biochar (KB) materials. The high defect degree, high specific surface area, and participation of graphite N make KB have excellent catalytic degradation ability. The KB degraded 40 mg/L ofloxacin (OFL) close to 100% within 60 min, applied with PMS. Through quenching experiments and electron paramagnetic resonance spectroscopy, the degradation process dominated by non-radical pathways was determined. At the same time, O-2(center dot-) and O-1(2) were closely related, and a significant impact of quenching O-2(center dot-) on the reaction was observed. The non-radical approach made the system excellent performance over a wide pH range and in the presence of multiple anions. The experiments of reusability confirmed the stability of the material. Its catalytic performance was restored after low-temperature pyrolysis. This research supports the use of endogenous nitrogen in biomass. It provides more options for advanced oxidation process application and marine resource development. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, N-doped kelp biochar (KB) materials were prepared from kelp biomass, showing excellent catalytic degradation ability under the influence of PMS. The non-radical pathways dominated the degradation process, allowing the system to perform well over a wide pH range. Reusability experiments confirmed the stability of the material, which could restore its catalytic performance through low-temperature pyrolysis.