Heterogeneous Catalytic Ozonation of Sulfamethoxazole in Aqueous Solution over Composite Iron–Manganese Silicate Oxide

Composite iron–manganese silicate oxide (FMSO) was synthesized and used as a heterogeneous catalyst for the ozonation of sulfamethoxazole. Results showed that FMSO/O₃ process significantly increased the TOC removal efficiency from 27% (sole ozonation) to 79.8%. Generated intermediates exhibited much higher adsorption affinity on FMSO than sulfamethoxazole. Presence of FMSO could accelerate the mass transfer of ozone, adsorb a certain amount of ozone on its surface, and subsequently decompose ozone into hydroxyl radical. Neutral charge surface of FMSO was more favorable to interact with the ozone molecules. FMSO maintained a good catalytic activity after several repeated use and revealed low metal ion leaching during ozonation.