Advanced process of microbiological control of wastewater in combined system of disinfection with UV radiation

摘要

The purpose of this study was to present a methodology with superior efficiency for inactivatingnpathogenic indicators commonly found in domestic sewage. The adopted method was basednon synergistic effect resulting from the introduction of a UV radiation pre-disinfection stagenof sewage followed by secondary treatment. A pilot unit was installed in the sewage treatmentnplant of the University of Sa˜ o Paulo to simulate the combined system in full-scale operationalnconditions. Its performance was evaluated through microbiological examinations for determiningnEscherichia coli, total coliforms and coliphages. The application of UV radiation at 5.1mW/cm2 forn10 s of exposure in the first disinfection stage was enough to reduce the surviving number ofnE. coli around 100 times, in comparison to the conventional method. Therefore, based onnexperimental data, it is possible to conclude that combining treatment and pre-disinfection stagenis an effective potential technique to produce effluents with lower degree of contamination bynpathogenic organisms.