Application of response surface method to carbamazepine removal in photo-ozonation reaction under alkaline condition

In this study, the photo-ozonation reaction for carbamazepine (CBZ) removal was investigated under alkaline conditions. Response surface methodology based on a central composite design was used to obtain the optimum experimental conditions, and examine both main and interaction effects of the photo-ozonation reaction variables such as O₃ concentration, H₂O₂ concentration and UV intensity. The level of O₃ concentration significantly influenced CBZ removal (p < 0.001). CBZ removal increased with increasing both O₃ and H₂O₂ concentration up to a certain level, whereas further increase in O₃ and H₂O₂ concentration resulted in an adverse effect due to the hydroxyl radical scavenging effect. The optimum conditions for complete CBZ removal at pH 9 were found to be 0.89 mg of O₃ l⁻¹, 4.85 mg of H₂O₂ l⁻¹ and 3.18 mW of UV intensity cm⁻², respectively.