The Kinetic Model for Decolourization of Commercial Direct Blue 2 Azo Dye Aqueous Solution by the Fenton Process and the Effect of Inorganic Salts

The study of Fenton’s oxidation and degradation of Direct Blue 2 (DB2) as the commercial azo dye in synthetic aqueous solution has been accomplished. The optimum oxidative degradation reaction conditions were achieved as follows: pH = 3.50, [H2O2] = 1.1×10-3 M, [Fe2+] = 1.0×10-4 M for [DB 2] = 1.0×10-4 M. Under optimal conditions, 80% of decolouration efficiency was carried out within 15 min of reaction. An engagement between the kinetics of the colour removal rates (ln k2) versus Lazo bond was carried out at the different pH levels. The colour removal rate was increased with decreasing of Lazo bond, in the order of pH: 3.5 > 5.0 > 2.5. The second-order kinetic model provided the best correlation of the data. Effects of various inorganic anions (such as Cl–, SO42-, CO32-, etc.) was studied to enhance the oxidation efficiency of Fenton reaction. Advanced oxidation technologies were developed in this study especially with dealing with contaminated textile wastewater over the use of chemical treatment.