Desempenho de Sistema Combinado Anaeróbio-Aeróbio na Remoção de Nitrogênio no Tratamento de Esgoto Sanitário

Abstract

This paper describes the evaluation of the performance of an anaerobic-aerobic system, consisting of anaerobic filter (AF) followed by biological aerated filter (BAF), operated with and without recirculation of treated effluent to mitigate the adverse effects of organic concentrations on nitrification and promote the removal of Total Nitrogen in anoxic ambient. In the first two steps, the application of the organic loading rate (OLR) on BAF ranged from 0.49 ± 0.27 and 0.31 ± 0.08 kg BOD m-3 d-1 due to the reduction of surface application rate of 60 to 44 m3 m-2 d-1. In the third stage, with recirculation, OLR and surface application rate were 0.29 ± 0.02 kg BOD m-3 d-1 and 65.8 m3 m-2 d-1, allowing the system to reduce 43 ± 10% of average initial concentration of 72 mg L-1 Total Nitrogen. The application of organic loading rates in BAS, more than 0.30 kg BOD m-3 d-1 inhibited nitrification due to competition for oxygen.