Activated carbon-supported nano zero-valent iron (nZVI@AC) for enhanced peracetic acid activation in Fenton-like degradation of sulfamethoxazole

This study presented a novel nano zero-valent iron anchored on activated carbon (nZVI@AC) catalyst, designed to overcome the inherent aggregation and oxidation limitations of bare nZVI. The nZVI@AC composite exhibited high catalytic activity for peracetic acid (PAA) activation, achieving complete degradation of sulfamethoxazole (SMX) within 10 min (k_obs = 0.3171 min^-1). Characterizations confirmed that the AC support significantly enhanced electron transfer and increased the electron-donating capacity. This maximized exposure of active Fe²⁺ species, which was crucial for efficient PAA activation and reactive oxygen species (ROS) generation. Radical quenching, electron paramagnetic resonance, and probe experiments identified hydroxyl radicals, singlet oxygen (¹O₂), and acetylperoxyl radicals as the primary ROS, with ¹O₂ playing the dominant role. The nZVI@AC/PAA system demonstrated remarkable stability and practical viability. This work established nZVI@AC as an efficient, stable, and versatile catalyst for PAA-based advanced oxidation processes, offering promising potential for water remediation applications.