Research on the Activation of Persulfate for Antibiotic Degradation by Iron–Nitrogen Doped Biochar

Carbamazepine (CBZ), a poorly biodegradable antibiotic, is widely detected in aquatic environments, posing potential threats to ecosystems and human health. There is an urgent need to develop efficient water treatment technologies. This study successfully prepared nitrogen-doped biochar composite materials loaded with zero-valent iron (Fe0@CN) via a one-pot calcination method for activating peroxymonosulfate (PMS) to degrade CBZ. The material was systematically characterized using multiple analytical techniques. Results indicate that Fe0@CN-1.5 exhibits a high specific surface area (482.65 m2/g) and an abundant mesoporous structure, with nitrogen doping promoting graphitic structure formation and the uniform dispersion of zero-valent iron. Under conditions of a 0.3 g/L catalyst loading, a 15 mM PMS concentration, and an initial pH of 5.5, 30 mg/L of CBZ achieved 97% degradation within 30 min. Radical quenching experiments and electrochemical analysis indicate that ·SO4− and ·OH are the primary active species in this system, alongside non-radical electron transfer processes. The material demonstrates excellent degradation performance and cycling stability across various real-world water bodies and pollutant systems. This study provides a carbon-based catalytic material with application potential and a theoretical basis for the efficient treatment of antibiotic wastewater.