Preparation and application of red mud-based heterogeneous Fenton catalyst

The zero-valent iron (ZVI) heterogeneous Fenton catalyst based on red mud (RM) was synthesized by direct reducing iron oxide in RM using H₂ at 800 °C (RMH-800). X-ray diffraction analysis showed that Fe₂O₃ in RM was reduced to Fe⁰. Brunauer -Emmett-Teller, scanning electron microscopy and high-resolution transmission electron microscopy show that RMH-800 is a ZVI-loaded porous material. The catalysts were characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Under the conditions of 2.86 mM H₂O₂, 100 mg/L Acid Red G (ARG) and 1 g/L RMH-800, 95 % of ARG was removed within 10 min. The RMH-800/H₂O₂ system also showed excellent degradability to antibiotics (Sulfamethoxazole, Ibuprofen and Primidone). •OH is the main species responsible for pollutants degradation. RMH-800 showed low iron leaching during the reaction process and excellent catalytic performance even after 6 repeats, indicating it a stable and low-cost material with great potential for wastewater treatment.