A recycled polymetallic catalyst derived from acid mine drainage(AMD) for efficient tetracycline removal via peroxymonosulfate activation

Catalysts are critical components in advanced oxidation processes (AOPs) for removing recalcitrant antibiotics from water. The preparation of metal catalysts through waste conversion has gradually received growing attention owing to their sustainability and low-cost. Herein, acid mine drainage (AMD) as wastewater offers a tantalizing resource to be harnessed due to its high concentration of metal ions. To reduce the continuous consumption of metallic resources and prevent environmental pollution by heavy metals. This study, utilizing the abundance of transition metal ions in AMD, devises a straightforward methodology for adept transformation into persulfate catalysts—metal sulfides(MS) for antibiotic removal, enabling the MS/PMS system to sustainably degrade tetracycline(TC) over a wide pH range (2.0–10.0). Notably, it recycled more than 97 % of the transition metals in AMD; the removal of TC (30 mg/L) by adsorption and advanced oxidation was as high as 92 %, and MS can achieve 99.5 % removal of TC (10 mg/L) at low concentrations. Transition metal elements such as manganese and iron in the recovered catalytic material dispersed on MS played an indelible role in activating the PMS, and the non-radical pathway dominated by singlet oxygen led to the degradation of the TC. Overall, MS prepared based on the concept of treating pollution with waste had excellent TC removal capability, providing an innovative approach for the reduction of recalcitrant antibiotics (TC) and the resourceization of AMD.