Evaluation Of Activated Sludge Treatment And The Efficiency Of The Disinfection Of Giardia Species Cysts And Cryptosporidium Oocysts By Uv At A Sludge Treatment Plant In Campinas, South-east Brazil

Among many waterborne disease the giardiasis and cryptosporidiosis are of particular public health interest, because Giardia cysts and Cryptosporidium oocysts can persist for long periods in the environment, and both pathogenic protozoa have been implicated as the cause of many outbreaks of gastroenteritis in the last 25 years. In order to evaluate the efficiency of cysts and oocysts' removal by the activated sludge process, and by UV reactor in inactivating cysts and oocysts in one wastewater treatment plant (WWTP) of Campinas, three sampling points were selected for study: (1) influent. (2) treated effluent without UV disinfection and (3) treated effluent with UV disinfection, Giardia spp. cysts prevailed with higher density in the three different sample types. Cryptosporidium spp. oocysts were observed in only two samples of influent and just one sample of treated sewage with UV disinfection. 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