Yeast-derived biochar to load CoFe2O4: Degradation of tetracycline hydrochloride by heterogeneous activation of peroxymonosulfate

The development of high-efficiency catalysts is essential for activating peroxymonosulfate (PMS) to degrade organic pollutants. In this study, yeast-derived biochar (YBC) supported cobalt ferrite composite catalyst (CoFe2O4/YBC) was successfully synthesized, which can heterogeneous activate PMS to degrade tetracycline hydrochloride (TCH). The results showed that CoFe2O4/YBC could activate PMS effectively and stably owing to the synergistic effect of YBC and CoFe2O4. The degradation rate of TCH was nearly 95% under the optimal conditions, and it was still more than 90% after four cycles. Furthermore, according to quenching tests and electron paramagnetic resonance (EPR) detection, it was confirmed that ·OH, SO4·-, O2·-, and 1O2 were involved in TCH degradation, and 1O2 played a key role. After identifying the intermediates produced by TCH's degradation, two potential TCH degradation pathways were suggested. Further ECOSAR (2.0) software analysis revealed that the ecotoxicity of the final degradation products of TCH was small. This study demonstrates that the as-prepared CoFe2O4/YBC is an efficient and environmentally friendly PMS activation catalyst with great potential for application in the remediation of polluted aquatic environments.