Photocatalytic oxidation of 17 -Ethinylestradiol by UV-activated TiO2 in batch and continuous-flow reactor

Abstract

In this study, the photocatalytic oxidation by UV-activated TiO2 was investigated for the degradation of a 15 mgL-1 solution of 17 α-ethinylestradiol (EE2) in an ultra-pure water matrix. The TiO2 adsorption, solution pH and catalyst TiO2 concentration were evaluated. Operating as a batch reactor, the system showed a 90% removal, with a 40-min retention time, a pH value of 8 a TiO2 concentration of 0.1 gL-1, and a rate constant of 0.13 min-1 for this experiment. The adsorption was negligible in 2 h at pH 7. As a continuous-flow reactor, the operation achieved an 87% removal with a TiO2 concentration of 0.025 gL-1 at pH 7. Ultraviolet-C (UVC) photolysis presented a removal of 40% in 2 h at pH 7 with the system operating in batch mode. Operating as a sequencing batch, the reactor showed remarkable efficiency in the removal of EE2 in a short period. Key words: Photocatalysis, 17 α-ethinylestradiol, UV-activated TiO2, sequencing batch reactor, continuous flow reactor.