Box-Behnken experimental design to optimize the degradation of methyl orange by β-cyclodextrin-assisted photo-Fenton

Abstract

Cyclodextrins (CDs) are cyclic oligosaccharides that form inclusion complexes with organic pollutants due to their hydrophobic cavities. This study focused on optimizing the conditions for the degradation process of Methyl Orange (MO) in a homogeneous aqueous medium through β-cyclodextrin (β-CD) assisted photo-Fenton. A Box-Behnken experimental design was implemented, and the response surface methodology (RSM) was applied to predict and optimize the optimal conditions for MO removal. The experimental data fit a statistically valid quadratic model according to an analysis of variance (ANOVA), yielding a determination coefficient of R2 = 0.9966, indicating a 95 % predictive accuracy. Optimization via RSM revealed that the ideal conditions to achieve a maximum removal of 96.4 % were: [β-CD] = 21 μM, [Fe2+] = 121 μM, [H2O2] = 7571 μM, and a pH of 4.2. Experimental verification of these conditions resulted in a degradation efficiency of 95.3 %, with a relative error of 1.15 %, demonstrating its proximity to the predicted value, highlighting the potential for scaling this approach to more complex systems. Thus, the methodology used proves to be an efficient and economically viable solution for the treatment of wastewater contaminated with dyes.