Trinity strategy prepared high-performance biochar for peroxydisulfate activation to degrade tetracycline

Abstract

In this study, a novel high-performance biochar (BNC) was prepared using a trinity strategy of liquid templates, B/N co-doping, and one-step pyrolysis for activating peroxydisulfate (PDS) to degrade tetracycline (TC). The catalytic activity of BNC can be tuned by varying the boron doping ratio and pyrolysis temperature. Of these, the optimized product, BNC-2–900, degraded 80 % of TC (50 mg/L) in 30 min. The high degradation efficiency was attributed to the accelerated electron transfer originated by graphite N, CO, and B-N-C functional groups of BNC, in which the non-radical pathways containing electronic transfer and 1O2-mediated oxidation were indicated as the primary pathways for TC degradation. Furthermore, Box-Behnken design (BBD) was employed to optimize various operating parameters in the BNC/PDS system whereby optimal degradation conditions were determined: Initial TC concentration was 20 mg/L; PDS dosage was 64.57 mg; BNC dosage was 70.91 mg; Temperature was 50 °C; Initial pH was 8.3, where the TC degradation rate reached 100 %. This study provides a novel trinity strategy that combines stability, environmental friendliness, and facility for developing heteroatom-doped carbonaceous catalysts.