Tratamento de águas residuárias em sistema biológico combinado: reator anóxico seguido de reator aeróbio com meio suporte imobilizado

Abstract

The population growth associated with urban development, which is often disordered, has been increasing the quantity of wastewater in the cities. This has been causing a series of environmental impacts, such as contamination of rivers. Consequently, eutrophication of waters, soil contamination and direct impacts on public health. Therefore, the use of combined systems for wastewater biological treatment is currently a widespread reality as an alternative in the removal of matter and nutrients. In this way, the present research aimed at the biological treatment of domestic and sanitary wastewater in a combined system of anoxic reactor followed by an aerobic reactor with immobilized submerged support medium. In order to produce effluent with low concentrations of carbonaceous material and nutrients, as well how to investigate the production of biomass in both systems and the study of microbial kinetics. The system operated in two phases, the first being composed with domestic wastewater (phase I) and the second phase being composed with sanitary wastewater (phase II). Both phases had an operating time of 90 days, operating with a daily flow of 13.5 L and 8-hour TDH. The operational configuration of the system proved to be efficient for domestic and sanitary wastewater treatment, with the best results being in phase II. In percentage terms, the system of phase I showed removal efficiency of 81%, 88% and 70% for COD, SST and NT, respectively. In a phase II were 90%, 91% and 87% for COD, SST and NT, respectively. The results of the mass balance showed the organic and nitrogenous fractions that were removed from the system. The results of the kinetic constants for metabolism of heterotrophic and autotrophic bacteria showed values close to those described in the literature.