Avaliação Hidrodinâmica de um Reator Biológico de Leito Empacotado.

Abstract

The effluent generation increase requires compact and efficient units to comply with quality discharge standards. The biological packed bed reactors offer support for biomass and the establishment of oxygen gradients to foment the simultaneous growth of nitrifiers and denitrifiers bacteria for nitrogen removal. The reactor performance does not only rely on microbial and enzymatic kinetics but also the physical process involved. The packed bed creates an uneven flow, fomenting anomalies in the system. The present study aimed to evaluate the hydrodynamic of a packed bed reactor in distinct operational conditions. The upflow cylindrical reactor with a volume of 10.08 L was filled with Mini Biobob® media and operated in hydraulic retention times (HRT) of 8 h, 14 h, and 20 h, with recirculation ratios R0, R1, and R2, with/without aeration. The flow pattern was defined as close to a complete mix, it was verified mixture increases with the HRT reduction for the non-aerated operation, and no influence was observed for the aerated period. The experiments revealed that the mean HRT was lower than the theoretical stipulated due to anomalies. The impact on the mixture was not noticed for both operations when varying the recirculation ratio, not influencing the boundary layer thickness and mass transfer. A mean dead volume of 23.17% and 22.53% were found for the aerated and non-aerated operations, respectively. A significant statistical correlation was not found for the studied variables' parameters.