Degradation of burazol blue ED by heterogeneous fenton process: simultaneous optimization by central composite design

Abstract

This work is an application of the response surface methodology (RSM) to determine the effects of operational parameters on the heterogeneous Fenton-type oxidation of the burazol blue ED (BB). The study was conducted using a Fe (III) sepiolite catalyst in the presence of hydrogen peroxide (H₂O₂) in a batch process. The effects of operational parameters such as the pH of the reaction, catalyst concentration, stirring speed, and reaction time were examined under the following conditions: a temperature of 25°C, 100 ppm initial dye concentration, and 0.5 mM H₂O₂ concentration. Because of the significant curvature effect, central composite design (CCD) was preferred to full-factorial experimental design for the simultaneous optimization of color and chemical oxygen demand (COD) removals. Optimized reaction conditions were established as pH 2, 1 g/250 mL catalyst dose, 250-rpm stirring speed, and 60-min reaction time. Contour plots and a desirability function were used to find the local points of optimization. After conformation, under the optimized reaction conditions, 96% color and 75% COD removals were obtained experimentally. These values were in the prediction interval and were in agreement with the quadratic polynomial model predictions.

Keywords:

• Central composite design
• Heterogeneous Fenton process
• Color removal
• COD removal
• burazol blue ED

Acknowledgements

This paper is a part of the results of project number 201215D13 funded by Eskisehir Osmangazi University. The authors wish to thank their university for all the support provided.