Removal of Reactive Black 5 dye using Fenton oxidation from aqueous solutions and optimization of response surface methodology

Abstract

In this study, optimum conditions of color removal from aqueous solution of anionic Reactive Black 5 (RB5) dye through the Fenton oxidation process were investigated. Central composite design (CCD) of response surface methodology (RSM) was used to optimize the Fenton process. The pH, dye concentration, Fe2+ dosage and H2O2 dosage were selected as independent variables of method, and design experiments were carried out. Intervals of independent variables were initial pH of solution pH (2.5-5.5), dye concentration (50-350 mg/L), Fe2+ dosage (25-55 mg/L) and H2O2 dosage (175- 425 mg/L) at a constant temperature of 30 degrees C. The color removal performance of Fenton reactive increased with decreasing pH value and dye concentration and increasing reactive amount. The experimental studies showed that the RB5 removal efficiency of Fenton oxidation was over 99%. The conditions of maximum removal were obtained as initial solution pH 2.5, dye concentration 120 mg/L, Fe2+ dosage 25 mg/L and H2O2 dosage 240 mg/L. A full quadratic model equation which interacts response variables with independent variables was developed. The model data agreed with experimental data very well. R-2 value confirming the reliability of the model equation was 96.19%.