CATALYTIC DEGRADATION OF AZO-DYES BY USING FENTON REACTION IN AQEOUS SOLUTION

Abstract

To establish cost-efficient operating conditions for potential application of Fenton and photo-Fenton oxidation process to treat wastewater containing different types of dyes such as methyl orange (MO), methylene blue (MB), ponceau 3R (P3R), eriochrome black T (EBT) and congo red (CR). The oxidation with Fenton and photo-Fenton reaction in homogeneous and heterogeneous system is an effective technology for destruction of a large number of the dyes which are considered from the important sources of environmental contamination and cause damage to both aquatic life and human beings due to their toxic, carcinogenic and mutagenic effects. The effects of different parameters like the concentration of H2O2, the concentration of FeSO4 in homogeneous system or the weight of Fe2O3 in heterogeneous system, the initial concentration of the dye and the pH of the solution were carried out on the degradation of each dye to investigate the optimal conditions with the best results at low cost. In heterogeneous system ferric oxide was characterized by X-ray diffraction (XRD) analysis, infrared spectroscopy (IR), transmission electron microscopy (TEM), surface area Abstract xvi measurements (BET), differential thermal analysis (DTA) and thermo gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) techniques. The three kinetic models (zero-order, First-order and second-order equations) were studied. From regression coefficients (R2), the fit is better with the second-order equation than that with zero-order and first-order equations. So the kinetic study indicated that the degradation kinetics of the studied dyes followed the second-order kinetics.