A comprehensive kinetic model for the process of electrochemical peroxidation and its application for the degradation of trifluralin

The aim of this manuscript was to investigate indirectly the kinetics of formation of hydroxyl/hydroperoxyl radicals responsible for the degradation of persistent pollutants by electrochemical peroxidation. Experiments involving iron electrodes with and without H2O2 were initially carried out in a batch reactor at 0.2-0.6 A and 25 degrees C in the absence of any pollutants. Concentrations of Fe2+, H2O2, Fe3+, and H+ were determined experimentally as a function of time, and from them a detailed kinetic model comprising 25 electrolysis, dissociation, flotation and Fenton reactions was established. The tuned parameters were only the Faradaic yields for the reactions on the anode, the rate constant for the forward reaction of water dissociation, and flotation of Fe3+. A set of three kinetic experiments of electroperoxidation of trifluralin performed at 0.2 to 0.6 A and 25 degrees C was correctly described by the already presented subset of reactions, plus two others involving trifluralin and hydroxyl/hydroperoxyl radicals. (C) 2020 Elsevier B.V. All rights reserved.