ABSTRACT
Biofiltration employs the metabolic activity of microorganisms immobilized on a packing material to degrade gas phase pollutants which are the energy source for microbial growth. However, biomass accumulation is one of the most critical parameters that need to be controlled along the operation of biofilters and biotrickling filters in order to achieve stable performance for long term operation. The excess of biomass inside the bioreactor significantly increases pressure drop, which ultimately may lead to wash part of the biomass from the system or to force the replacement of the support media. Additionally, excess biomass implies an increased operation cost (due to pressure drop increases) coupled to a reduced removal efficiency due to reduced specific surface areas and porosities. In addition, potential channeling because of nonuniform biomass growth might occur. Moreover, most of dynamic mathematical models in biofiltration rarely incorporate biomass accumulation processes meaning that predicted results could differ significantly from experimental data in the case of high loads of pollutant.
