The use of full factorial design for modeling the effects of process parameters on decolorization of Reactive Yellow 15 by using Fe/ZrO2 catalyst

Abstract

This study is an application of full factorial design to determine the effects of operational parameters on heterogeneous Fenton oxidation of Reactive Yellow 15 (RY15). Fenton oxidation was conducted using a Fe/ZrO2 catalyst in the presence of hydrogen peroxide (H2O2) in a batch process. The effects of pH of the reaction, catalyst concentration and reaction time were examined under the following conditions: 28 degrees C of temperature, 50 ppm initial dye concentration, 6% Fe and 50 mM H2O2 concentration. The factors and levels used during experiments were as follows: initial pH (2.0 and 6.0), catalyst concentration (0.1 and 0.3 g/25 mL), contact time (60, 120 min). The significance of the effects was investigated by the analysis of variance (ANOVA) with a confidence level of 95%. After the statistical procedure, analysis of variance, studentized t-test, and residual analysis, the regression model equation was obtained for RY15 decolorization. The ANOVA results showed that the catalyst concentration (B) had the greatest positive effect on RY15 removal, followed by pH (A) with a negative effect and contact time (C) with a positive effect. When the initial pH was 2, catalyst concentration was 0.3 g/25 mL, and the contact time was 120 min, the maximum RY15 removal efficiency was obtained as 94.89%.