RESUMO
Photocatalysis has shown the ability to inactivate a wide range of harmful microorganisms with traditional use of chlorination. Photocatalysis combined with applied bias potential (photoelectrocatalysis) increases the efficiency of photocatalysis and decreases the charge recombination. This work examines the inactivation of fecal coliform bacteria present in real urban wastewater by photoelectrocatalysis using nanoparticulated films of TiO2 and TiO2/Ag (4%w/w) under UV light irradiation. The catalysts were prepared with different thicknesses by the sol-gel method and calcined at 400°C and 600°C. The urban wastewater samples were collected from the sedimentation tank effluent of the university sewage treatment facility. The rate of bacteria inactivation increases with increasing the applied potential and film thicknesses; also, the presence of silver on the catalyst surface annealed at 400°C shows better inactivation than that at 600°C. Finally, a structural cell damage of Escherichia coli (DH5α), inoculated in water, is observed during the photoelectrocatalytic process.
