Resource utilization of piggery sludge to prepare recyclable magnetic biochar for highly efficient degradation of tetracycline through peroxymonosulfate activation

Advanced oxidation processes based on persulfate activation can produce strong reactive oxygen species, which can effectively degrade a variety of organic pollutants. However, finding cost-effective activation methods and materials have become the key in the research process of this oxidation technology. With the discovery of the catalytic activity of biochar, the application of carbonaceous materials in persulfate activation has recently emerged. In this study, recyclable magnetic biochar was prepared from dewatered piggery sludge, and was used to activate peroxymonosulfate to degrade antibiotic tetracycline. Results showed that the catalytic activity of magnetic biochar was stronger than that of unmagnetized sludge biochar, and magnetic biochar showed better separation and sustainability in recovery and reuse. Neutral pH condition was also favorable for biochar and magnetic biochar to activate peroxymonosulfate. Peroxymonosulfate activation using magnetic biochar is an economical, efficient and environmentally friendly method for organic pollutants degradation.