Enhanced degradation of diclofenac via H2O2-assisted photocatalysis in a submerged membrane reactor using N-doped TiO2

Abstract This study presents an in-depth investigation of hydrogen peroxide (H 2 O 2 )-assisted photocatalytic degradation of diclofenac (DCF) using N-doped TiO 2 (N-TiO 2 ) in a submerged membrane photocatalytic reactor (SMPR) under visible light. The technical achievements of this work include optimizing critical parameters such as solution pH, catalyst concentration, DCF concentration, and H 2 O 2 concentration to maximize degradation efficiency. The results indicate that the optimal conditions for DCF removal were achieved at pH 6.5, N-TiO 2 of 1.0 g l −1 , DCF concentration of 20 mg l −1 , and H 2 O 2 concentration of 21.75 mg l −1 . Under these conditions, DCF removal efficiency significantly improved from 42.21% in the absence of H 2 O 2 to 79.55% with the addition of H 2 O 2 . This demonstrates the crucial role of H 2 O 2 in enhancing photocatalytic degradation performance. Comparative analysis with other studies using UV light further emphasizes the efficacy of this visible light-driven process, which achieved competitive removal rates, demonstrating the potential of visible light and N-TiO 2 as a sustainable solution for DCF degradation in wastewater. This research provides valuable insights into optimizing conditions for DCF degradation using N-TiO 2 under visible light, offering potential applications for this photocatalytic process.