Decolorization of Sunzol Black DN conc. in aqueous solution by Fenton oxidation process: effect of system parameters and kinetic study

The decolorization of Sunzol Black DN conc. (SBDN) in aqueous solution by Fenton oxidation process was studied. The effects of different reaction parameters such as initial hydrogen peroxide concentration ([H2O2]o), initial Fe2+ concentration ([Fe2+]o), pH, temperature and the initial SBDN concentration ([SBDN]o) on the decolorization of the SBDN dye have been investigated. The optimal reaction conditions were experimentally determined and it was found to be [H2O2]o = 4 mM, [Fe2+]o = 0.05 mM, pH = 3.5 and [SBDN]o = 100 mg/l at temperature 30oC. Under optimal condition, 94.5% decolorization efficiency of dye in aqueous solution was achieved within 90 min of reaction. The decolorization kinetics of SBDN by Fenton oxidation process followed the second-order reaction kinetics, and the apparent activation energy, was found to be 38.582 kJ/mol.