Upcycled Manganese Slag Enables Self‐Regenerating Pyrrole‐N Catalysis for Precision, Singlet Oxygen‐Driven Antibiotic Detoxification by Peroxydisulfate Activation

Antibiotic-laden wastewaters and vast stocks of electrolytic manganese slag residue (EMSR >130 Mt) pose coupled environmental risks. Conventional radical-centered persulfate oxidation is oxidant-intensive and nonselective, often generating toxic by-products and catalyst deactivation. Here, we upcycle EMSR via low-temperature anaerobic pyrolysis (200°C) to a pyrrolic-nitrogen (N)-rich carbon (L-EMSR) that forms metastable pyrrolic-N-peroxydisulfate (PDS) complexes, channeling electron/energy transfer to sustained selective singlet-oxygen (¹O₂) production through a reversible pyrrolic-N ↔ graphitic-N cycle. This selectivity edits toxicity-determining motifs in tetracycline (TC)-C2 deamination and C6 dehydroxylation with controlled D-ring oxidation/opening-abolishing antibacterial activity while retaining biodegradability. L-EMSR/PDS removes 10 mg·L⁻¹ TC within 25 min (kobs = 0.103 min⁻¹), achieves 57.5% Chemical oxygen demand (COD) removal in pharmaceutical wastewater, maintains >80% efficiency over eight cycles with negligible metal leaching, and is regenerable by 200°C re-pyrolysis. Life-cycle assessment (LCA) indicates low energy and environmental burdens with favorable specific energy and cost. This waste-to-resource, self-regenerating N-carbon platform enables precise, ¹O₂-driven antibiotic detoxification, reducing oxidant demand and secondary pollution while advancing scalable, sustainable treatment of antibiotic wastewaters.