Oxygen-deficient MnCO3 based on waste alkaline Zn-MnO2 battery as an enhanced activator for peroxymonosulfate removing Oxytetracycline hydrochloride

In this study, manganese from the cathodes for waste batteries (WBCs) was recovered by hydrometallurgical method as a raw material for the peroxymonosulfate (PMS) activator MnCO 3 , which was successfully synthesized by a simple and environmentally friendly process. MnCO 3 had a good degradation properties for oxytetracycline hydrochloride (OTC-HCl). Under the best conditions through the BoxBehnken Design (BBD), the MnCO 3 /PMS system effectively decomposed 91.3 % of OTC-HCl (initial concentration of 60 mg/L), and the Total Organic Carbon (TOC) removal rate was 63.6 % within just 10 min. Moreover, the system exhibits effectiveness over a wide pH range, with its degradation rate remaining largely unaffected by the presence of inorganic anions. Reactive species, including sulfate radicals (SO 4 ·− ), hydroxyl radicals (･OH), superoxide radicals (O 2 ·− ), and singlet oxygen ( 1 O 2 ), are generated by the degradation system. A series of experiments and characterizations demonstrated that 1 O 2 plays a significant role in the degradation system. This study paves the way for the recycling of spent zinc‐manganese batteries and establishes an efficient multi-mechanism degradation system for treating recalcitrant organic wastewater.