Simultaneous removal of estrogens and pathogens from secondary treated wastewater by solar photocatalytic treatment

Recently, the fate of emerging compounds in environmentally relevant samples has attracted considerable attention. Solar semiconductor photocatalysis may offer an appealing methodology to treat such contaminants. At the same time the use of solar photocatalysis for water and wastewater disinfection is a topic well-documented in the literature. In this respect, the simultaneous degradation of synthetic estrogen 17α-ethynylestradiol (EE2) and Escherichia coli removal employing simulated solar radiation and TiO2 as the photocatalyst was investigated. In general, the more complex the water matrix is the slower E. coli removal becomes, while the presence of E. coli in the reaction mixture did not obstruct EE2 removal. Although EE2 removal occurred relatively fast, overall estrogenic activity was only partially removed. This implies that other species inherently present in the effluent and/or some photocatalytic transformation by-products may be proportionately more estrogenic than EE2. Overall, the use of solar radiation can constitute an advantageous treatment strategy for the simultaneous removal of micro-pollutants and pathogens from secondary treated effluent.