Applied Catalysis B: Environmental, Vol.248, 108-114, 2019
Effects of ultrasound irradiation on the electrochemical treatment of wastes containing micelles
This work focuses on the effect of the irradiation of ultrasound during the electrolysis of wastes polluted with micelles. To do this, synthetic wastewater (emulating the ones produced in cosmetic industry) was formulated and it underwent several electrochemical and sono-electrochemical, at low and high frequencies, oxidation assays. Processes were monitored paying attention not only to the changes observed in the organic soluble intermediates and final products, but also to the size of the micelles. Results demonstrate that the presence of surfactant in wastes may interfere on the degradation of pollutants due to the formation of micelles. Nevertheless, 90% of mineralization was achieved by the coupled process of electrolysis and low frequency ultrasound. Furthermore, ultrasound irradiation can contribute to faster turbidity and foam depletion and to retard the formation of perchlorates. Regarding the micelles, it was found that application of ultrasound directly affects the changes on particles size during their destruction which, in turn, influences on the performance of the electrochemical process. A simple phenomenological model is proposed to explain the influence of this irradiation.