TiO₂/Zeolite Composites for SMX Degradation under UV Irradiation

Sulfamethoxazole (SMX) is a common antibiotic that is considered an emerging pollutant of water bodies, as it is toxic for various aquatic species. TiO₂-based photocatalysis is a promising method for SMX degradation in water. In this work, TiO₂/zeolite (Z-45 loaded with TiO₂ labeled as TZ and ZSM-5 loaded with TiO₂ labeled as TZSM) composites were prepared by mechanical mixing and liquid impregnation methods, and the photocatalytic performance of these composites (200 mg·L⁻¹) was investigated toward the degradation of SMX (30 mg·L⁻¹) in water under UV light (365 nm). The pseudo-first-order reaction rate constant of the TZSM1450 composite was 0.501 min⁻¹, which was 2.08 times higher than that of TiO₂ (k = 0.241 min⁻¹). Complete SMX degradation was observed in 10 min using the UV/TZSM1450 system. The mineralization ability in terms of total organic carbon (TOC) removal was also assessed for all of the prepared composites. The results showed that 65% and 67% of SMX could be mineralized within 120 min of photocatalytic reaction by TZSM2600 and TZSM1450, respectively. The presence of (Formula presented.) and (Formula presented.) anions inhibited the degradation of SMX, while the presence of (Formula presented.) had almost no effect on the degradation efficiency of the UV/TZSM1450 system. The electrical energy per order estimated for the prepared composites was in the range of 68.53–946.48 kWh m⁻³ order⁻¹. The results obtained revealed that the TZSM1450 composite shows promising potential as a photocatalyst for both the degradation and mineralization of SMX.