A novel Corchorus olitorius-derived biochar/BiOCl photocatalyst for decontamination of antibiotic wastewater containing tetracycline under natural visible light.

Herein, a novel composite of Corchorus olitorius-derived biochar and BiOCl was fabricated and utilized for the degradation of tetracycline (TC) in a solar photo-oxidation reactor. The morphology, chemical composition, and interaction between the composite components were studied using various analyses. The biochar showed a TC removal of 52.7% and COD mineralization of 59.6% using 150 mg/L of the biochar at a pH of 4.7 ± 0.5, initial TC concentration of 163 mg/L, and initial COD of 1244 mg/L. The degradation efficiency of TC increased to 63% and the mineralization ratio to 64.7% using 150 mg/L of bare BiOCl at a pH of 4.7 ± 0.5, initial TC concentration of 178 mg/L, and COD of 1034 mg/L. In the case of biochar/BiOCl composite, the degradation efficiency of TC and COD mineralization ratio improved to 85.8% and 77.7% due to the potential of biochar to accept electrons which retarded the recombination of electrons and holes. The synthesized composite exhibited high stability over four succeeding cycles. According to the generated intermediates, TC could be degraded to caprylic acid and pentanedioic acid via the frequent attack by the reactive species. The prepared composite is a promising photocatalyst and can be applied in large-scale systems due to its high degradation and mineralization performance in a short time besides its low cost and stability.