Highly Effective Removal of Sulfamethoxazole Through Photocatalysis and Adsorption Using Surfactant‐Coated <scp> TiO ₂ </scp> Nanomaterials

ABSTRACT Antibiotic residue in water is a serious problem as it may accelerate development of antibiotic resistant bacteria. The present study investigated the removal of sulfamethoxazole (SMX) antibiotic through adsorption and photocatalysis techniques using titania nanoparticles (TiO 2 ‐NPs) with cetyltrimethylammonium bromide (CTAB) cationic surfactant surface coating. The SMX removal efficiencies by CTAB coated TiO 2 ‐NPs (CCTN) were much higher using adsorption combined with photocatalysis than using individual techniques. The maximum removal efficiency reached 80.3% under the selected conditions of pH 3, contact time 150 min and 5 mg/mL CCTN dosage. Adsorption isotherms and kinetics of SMX on CCTN followed Freundlich and pseudo‐second‐order models, respectively. The removal mechanisms of SMX using CCTN by both adsorption and photocatalysis are discussed in detail based on the change in functional groups and surface charge before and after SMX treatment. Our results demonstrate that CCTN is a high performance material for removing SMX from water using both adsorption and photocatalysis.