Integrated Modeling of Anaerobic Fluidized Bed Bioreactor for Deicing Waste Treatment. II: Simulation and Experimental Studies

This paper examines the influence of bed segregation on the performance of an anaerobic fluidized bed bioreactor (AFBR) using both an integrated mathematical model previously described in Part I of this study, and experimental data obtained from a laboratory-scale AFBR continuous flow system and batch serum vial tests. Local hydrodynamics within the bed are shown to determine mixing intensities and patterns of bioparticles thereby controlling biofilm thickness and composition along the bed height. Results of the model simulations and the experimental data indicate that shallow biofilms that allow full substrate penetration are dominantly populated with faster growing micro-organisms. The internal mass transfer resistance in thicker biofilm significantly influences population distribution resulting in the increase of population of slower growing micro-organisms in a deeper layer of the biofilm. The serum bottle tests also confirm that microbial distribution inside a multispecies biofilm is determined by the hydrodynamic condition of the reactor. This study illustrates the importance of hydrodynamic regimes in the AFBR, and demonstrates the impact of bed segregation on bioparticle properties and total system performance.