Engineered Fe-doped activated carbon from industry waste for peroxymonosulfate activation: Performance and mechanism

Efficient and low-cost catalysts are important for contaminant remediation in peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs). In this study, a solid waste, generated by the polyferric chloride coagulation of the phenol-saturated powder activated carbon from an industrial wastewater treatment plant, was used to prepare metal/carbon composites under different pyrolysis temperatures (650-950 degrees C). The catalyst pyrolyzed at 950 degrees C (FeAC-950) exhibited the highest reactive activity for PMS activation as demonstrated by a series of electrochemical techniques. Nearly complete BPA elimination can be achieved within 60 min by 0.1 g L-1 FeAC950 and 0.5 mM PMS. The results of electron paramagnetic resonance (EPR), chemical quenching and open circuit potential (OCPT) experiments demonstrate a combined radical and non-radical oxidation mechanism in the FeAC-950/PMS process and BPA was removed dominantly through radical pathway. Various persistent organic pollutants can be efficiently eliminated in the FeAC-950/PMS system. In addition, the present system showed good tolerance to natural organic matter as well as some common anions such as chloride and nitrate. This study dedicated a simple method to prepare an efficient solid waste-based catalyst in environmental catalysis. The outcomes will not only provide a value-added reuse approach for waste management but also facilitate the FeAC-950 applications in wastewater remediation technologies.