Kinetic Study of Catalytic Oxidation of Sodium Dodecylsulphate by Fenton’s Reagent in Aqueous Solution

This work describes the application of Fentonʹs reagent (H2O2/Fe2+) to the kinetic study of the degradation of anionic surfactants. The surfactant considered here is the anionic sodium dodecylsulphate (SDS), largely used in many industrial applications and particularly in formulations of detergents and cosmetics. Two series of experiments was achieved in the solutions at pH 3, with ferrous sulphate and at ambient temperature (about 35°C) during 120 minutes of time of reaction. An initial SDS concentration of 3.47x10-5 mol.L"1 (or 10 mg.L-1) was selected. The evolution of oxidation reactions permitted to follow the effect of initial H2O2 concentrations on the disappearance of SDS in the treated solution. A detailed kinetics study of the anionic surfactant degradation was achieved, following which a kinetic model of 5/3 order was proposed (based on 1 order for SDS and 2/3 for Fentonʹs reagent)