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

ABSTRACT 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 ( ¹ O ₂ ) 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 ( k _obs = 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, ¹ O ₂ ‐driven antibiotic detoxification, reducing oxidant demand and secondary pollution while advancing scalable, sustainable treatment of antibiotic wastewaters.