We compared two H2O2 oxidation methods for the treatment of industrial wastewater: oxidation using Fentons reagent [H2O2/Fe(II)] and microwave irradiation. Both methods were applied to the treatment of synthetic phenol solutions (100mgL1) and of an industrial effluent containing a mixture of ionic and non-ionic surfactants at high load (20gL1 of COD). The effects of initial pH, initial H2O2 concentration, Fenton catalyst amount and irradiation time were assessed. According to the oxidation of phenol, it has been found that the oxidation by Fentons reagent is dependent on the pH, contrary to the microwave system, which is not influenced by this parameter. For both systems, a limiting amount of oxidant has been found; above this point the oxidation of phenol is not improved by a further addition of peroxide. The oxidation of the industrial surfactant effluent has only been successful with the Fentons reagent. In this case, large amounts of ferrous ions are necessary for the precipitation of the ionic surfactants of the effluent, followed by the oxidation of the non-ionic constituents of the solution.