Avaliação de um fotorreator simplificado de radiação UV utilizado na inativação de coliformes e ovos de helmintos em esgotos tratados

Abstract

This research evaluated the applicability of a simplified ultraviolet radiation photoreactor, for the inactivation of total coliforms, Escherichia coli and Ascaris lumbricoides eggs, present in effluents from a UASB reactor and a Biological Percolator Filter. The photoreactor, with a volume of 2.2 L and made of PVC pipe with a diameter of 100 mm, was equipped with an immersed lamp, with low mercury pressure, with a power of 15 W. The photoreactor was tested for the disinfection of wastewater a biological percolating filter and a UASB reactor, both fed with domestic sewage from the sewage interceptor of the Arrudas stream, in the city of Belo Horizonte. The results obtained demonstrated the applicability of photoreactors for the disinfection of treated sewage, with high average inactivation efficiencies of total coliforms and E. coli being observed, in the range between 4 and 5 logarithmic units, for doses ranging between 13.6 and 102 .43 mW.s/cm2. Exposure to ultraviolet radiation significantly affected the development of Ascaris eggs, with the best results being obtained for doses between 13.6 and 20.3 mW.s/cm2, when only around 10% of the eggs completed development. until the larval stage. The results obtained show the applicability of ultraviolet radiation as post-treatment of UASB/Biological Filter systems.