Removal of Endocrine-Disrupting Compounds, Estrogenic Activity,and Escherichia coliform from Secondary Effluents in a TiO2-Coated Photocatalytic Reactor

摘要

This study investigated the photocatalytic removal of endocrine-disrupting compounds (EDCs), estrogenicnactivity, and Escherichia coliform (E. coli) in secondary effluents from a wastewater treatment plant in a cylindricalnphotocatalytic reactor. Its application for advanced wastewater treatment processes was evaluated. Estrone, 17aestradiol,nestriol, nonylphenol, and bisphenol A were chosen as target EDCs because of their high prevalence innwastewater. EDCs, estrogenic activity, and E. coli in the secondary effluent were rapidly removed within 100 minnof TiO2 photocatalysis. Reactor performance was enhanced significantly by TiO2 photocatalysis compared withnUV photolysis. Filtration was evaluated as a pretreatment method in TiO2 photocatalysis by comparing thenreduction rate of estrogenic activity and E. coli in filtered samples with unfiltered wastewater samples. Theninactivation rate of E. coli increased significantly after filtration, whereas the estrogenic activity reduction ratenonly slightly increased. This could be attributed to the partial impeding effects of suspended solids on photosensitivenreactions induced by humic acid during photocatalysis. TiO2 photocatalysis with filtration pretreatmentncan be an effective method for advanced wastewater treatment. This is the first report on the removal ofnEDCs and E. coli from secondary effluents using TiO2 photocatalysis as an advanced wastewater treatmentnprocess.