Photocatalytic inactivation of E. faecalis in secondary wastewater plant effluents

摘要

Photocatalytic inactivation of Enterococcus faecalis using TiO2 suspensions was investigatednand compared to the inactivation of the most commonly used faecal indicator strainnEscherichia coli. In contrast to the inactivation in pure deionized water, disinfection of effluentsnfrom the biological process of an urban wastewater plant showed a longer initial lag phasenand higher survival fractions after several hours of irradiation. Moreover, the fluctuation ofnthe composition of the effluents strongly affects the overall inactivation rate, not directlynrelated to changes in the values of organic matter content. Additionally, it was found thatnE. faecalis seems to be more resistant than E.coli towards the photocatalytic treatment.nThese results could be related to the differences in the cell wall structure of bothnmicroorganisms. The main conclusion of this work is that attention must be paid whenntransferring results obtained for model organism to real bacteria consortia and from laboratorynexperiments with deionized water to effluents from sewage plants.