Determinação de parâmetros cinéticos em sistema de lodo ativado empregado no pós-tratamento de reatores UASB com o uso da respirometria

Abstract

The modern anaerobic reactors, featuring the UASB reactor, in regions of tropical weather, enable the removal of significant part of sewage organic matter at a low cost. Nevertheless, these reactors’ effluents often require a post-treatment for a complementary removal of the organic matter, what has been successfully attained, for instance, in activated sludge systems. In this case, however, there may be changes in the kinetics of degradation, in comparison to other classic activated sludge systems, since the organic matter available in the anaerobic reactor effluent is usually less absorbed by the heterotrophic bacteria than the one from raw sewage. Therefore, this work’s goal was to determine the kinetic parameters of the heterotrophic sludge originated from an activated sludge system used in the post-treatment of UASB reactors. A series of tests was performed to determine the kinetic parameters of the bacteria mass: Specific Oxygen Uptake Rate (SOUR), substrate utilization constant (K_ms) and the maximum specific growth constant (μ_m), utilizing respirometry to determine them. Moreover, the fractions of organic matter consumed in the catabolism and anabolism were calculated as well. The parameters obtained differ from the ones specified on the literature for the sewage treatment plant configuration on this work, being close to the values found in activated sludge systems not preceded of anaerobic unit.