Engineered biochar derived from food waste digestate for activation of peroxymonosulfate to remove organic pollutants

The anaerobic digestion of food waste, can result in large amounts of solid waste digestate, often without methods of disposal. In this study, a biochar was prepared from food waste digestate (FWD) by pyrolysis, and its potential to activate peroxymonosulfate (PMS) for the removal of pollutants from a simulated textile wastewater was evaluated. The results showed that the addition of biochar (0.5 g/L) and PMS (1 mM) to wastewater could remove >99% of a representative azo dye pollutant (reactive brilliant red X-3B, 1 g/L) within 10 min. The efficiency of this removal process was attributed to the catalytic sites in the biochar (graphitic carbon and nitrogen, pyridinium nitrogen and CO structures) which could activate PMS to produce reactive oxygen species (¹O₂, O₂^-, OH and SO₄^-). The results obtained in this study confirmed the activation potential of the biochar derived from FWD on PMS, providing an alternative utilization strategy for anaerobic FWD.