Heterogeneous photocatalysis and photo-Fenton of estradiol in wastewater

The European Directive 2000/60/CE stresses the need of adopting measures against water pollution in order to achieve a progressive reduction of pollutants and water reuse. Advanced Oxidation Processes (AOPs) are promising ways to perform the mineralization of pollutants. AOPs are characterized by the in situ production of hydroxyl radicals, which are highly reactive species capable of oxidizing organic materials in a non-selective way. The main objective of this to study was to compare the 17-β Estradiol (E2) degradation in wastewater by different AOPs including UV, UV+oxidant, UV-TiO2, photo-Fenton, UV-photosphere, UV-graphenesphere, UV-oxone (a photo-Fenton like process based on peroxymonopersulfate as oxidant). Homogeneous photo–Fenton like process using peroxymonopersulfate as oxidant and heterogeneous photocatalysis using TiO2 were the most effective technologies for the fast removal of estrogenic hormone. Both processes were very fast considering that 95% of E2 was removed in few minutes. Moreover, UV-oxone was more efficient than UV-TiO2 since with the first technology the complete mineralization of E2 was achieved within 2 minutes without the production of dangerous by-products.