Chemical oxidation of methylene blue using a Fenton-like reaction

Oxidation by Fenton-like reactions is proven and economically feasible process for destruction of a variety of hazardous pollutants in wastewater. We report herein the oxidation of methylene blue, a basic dye of thiazine series using a Fenton-Like reaction at normal laboratory temperature and at atmospheric pressure. The effects of different parameters like the initial concentrations of dye, Fe2+, and H2O2, PH of the solution, reaction temperature, and added electrolytes on the oxidation of the dye present in dilute aqueous solution in the concentration range (3.13-9.39) x 10(-5) mol dm(-3) (10-30 mg l(-1))have been assessed. The results indicate that the dye can be most effectively oxidized in aqueous solution at dye:Fe2+:H2O2 molar ratio of 1:1.15.14.1. More than 98% removal of the dye could be achieved in 1 h in the pH range 2.2-2.6 at 299 K which corresponds to about 81% reduction of the initial GOD. The results will be useful for designing the treatment systems of various dye-containing wastewaters. (C) 2001 Elsevier Science B.V. All rights reserved.