Swine effluents are among the high pollutants effluent generated by agro-industrial activities, and therefore, inappropriate discharge can initiate fatal processes, such as eutrophication, pollution, and asphyxia of the aquatic biota. In this regard, the anaerobic baffled reactor (ABR) is viewed as a potential bioreactor to handle swine effluents since the baffles play a key role in organic matter degradation. The ABR’s design and the optimization depend on the hydrodynamic knowledge, since it can determine the degree of mixing, the volumetric efficiency, the reactor geometry, and the exact model to be applied in order to determine the performance of the unit. Thus, the evaluation of the hydrodynamic behavior of ABR, set in pilot scale and continuously fed with liquid effluent from swine manure was carried out and lithium chlorine was injected under steady-state operational condition using stimulus response techniques. The ABR hydrodynamics parameters were determined using numerical methods in Matlab® 2009 software. The theoretical hydraulic retention time (HRT) adopted was 16 h. The average residence time (t) found was 24.5 h, the number of dispersion d= 0.13, and the flow pattern was characterized as plug-flow with great axial dispersion. The percentage of dead zones was about 26% and volumetric efficiency ranged from 35 to 100%.
Key words: Swine effluent, hydrodynamic, dispersion number, tracer studies, anaerobic baffled reactor (ABR).