Remoção de matéria orgânica e nitrogênio em reatores sequenciais em batelada com biomassa suspensa

Abstract

The choice of simple effluent treatment technologies with nutrient removal is necessary to avoid problems such as eutrophication and contamination of water bodies. Thus, the proposal of this work is to evaluate the performance of two sequential reactors in batches, being one anaerobic (RSBan) and one aerobic (RSBae). In both reactors, the biomass was suspended and the synthetic sewage substrate, with characteristics of domestic wastewater waters. The RSB were operated manually and the operation was divided into three stages, in which the nitrogen and solid series were evaluated, in addition to the chemical demand for oxygen (COD) and others. The reactors had a usable volume of 8 L and were operated in cycles of 24 h (step 1), and 12 h (steps 2 and 3). During step 1, the reactors operated independently, and results pointed to cod removals of 75.22 ± 16.75%, and 55.10 ± 17.44%, for the RSBae and RSBan, respectively. In step 2, the effluent from the aerobic reactor operated as post-treatment of the anaerobic effluent, presenting cod removal results of 92.63 ± 4.01% for the final effluent. In the last stage, the anaerobic reactor also acted in a third anoxic phase to promote denitrification, achieving overall efficiency of cod removal of 84.2% and total nitrogen of 60.5%, when the remaining cod of the anaerobic phase was used as a source of Carbon for denitrification; and removal of cod of 82.2%, and 79% of total nitrogen removal when using ethanol.