LAUSR

Abstract In this study, several scenarios have been evaluated based on Advanced Oxidation Processes (AOPs) in order to develop a combined process that permits to explore the possible synergistic effect of photo and electro-based processes for degrading stable pollutants. To achieve this objective, the selection of a suitable heterogeneous catalyst and reactor configuration to implement different AOPs combinations, was accomplished. In order to determine the efficiency of the degradation process, the ionic liquid 1-butyl-2,3-dimethylimidazolium chloride was selected as stable model pollutant. Several catalysts were synthetized by adsorption of Fe and TiO2 on expanded perlite, which has great floatability due to its light mass, enhancing the direct above irradiation of the prepared catalyst. In addition, a scarcely reported bifunctional floating catalyst, which combines a mixture of Fe and TiO2, was also synthetized for its application on combined AOPs working at natural pH. A cyclic and sequential two-cell-reactor was configured, so the photo-based reactions took place in one cell and the electrolytic reactions in another one. This reactor allowed the ample illumination of the catalyst, without the impediment of the electric devices, as both processes occur in different cells connected by a peristaltic pump. After the comparison of different AOPs, the best performance was achieved using a new Fe-TiO2 bifunctional floating catalyst during the photoelectro-Fenton-like process. Using 2.77 g/L of this catalyst, complete pollutant removal and approximately 80% of TOC and COD degradation were achieved after 4 h. The prepared catalyst demonstrated its reusability after five consecutive treatments. Moreover, the good performance of the developed system was confirmed by the treatment of a real wastewater matrix.