Removal of emerging pollutants in aqueous phase by heterogeneous Fenton and photo-Fenton with Fe2O3-TiO2-clay heterostructures

Fe2O3-TiO2-clay heterostructures have been prepared using an organo-bentonite as support, which organophilic character favored the fixation of TiO2. Furthermore, Fe2O3 was successfully anchored by wet impregnation. The resulting materials are characterized by a disordered layered structure and a mesoporous texture. The heterostructures were employed as catalysts for the removal of two pharmaceuticals, acetaminophen (ACE) and antipyrine (ANT), by heterogeneous Fenton and photo-Fenton processes. ACE removal under different operation conditions was studied in detail to establish structure-performance relationships, being the TiO2 formation and the developed texture the main factors controlling the activity. ANT showed a higher refractory behavior in oxidation by Fenton. Among the technologies studied, heterogeneous photo-Fenton achieved the best catalytic performance and higher kinetic rate and mineralization degree. Iron leaching was very low, lower than 5% of the initial iron load in all cases. This work demonstrates the potential application of these heterostructures for the removal of emerging pollutants of different nature.