Development and experimental validation of a conceptual model for biotrickling filtration of H 2 S

A dynamic model that describes the behavior of high‐performance hydrogen sulfide (H 2 S)‐degrading biotrickling filters for odor control was developed. The model attempts to accurately describe pollutant mass transfer in the biotrickling filter, i.e., external mass transfer resistances, and both direct gas‐biofilm and gas‐liquid‐biofilm mass transfer were considered. In order to calibrate the model, an innovative differential biotrickling filter was constructed in which the effect of air velocity on the removal of H 2 S could be studied. Model outputs were compared with experimental data to determine the sensitivity of the system to selected parameters. At low H 2 S concentration, diffusion of H 2 S within the biofilm, and biofilm thickness were the major governing factors among nine considered model parameters. At higher H 2 S concentrations and lower air flow rates, external mass transfer played a very important role. This new finding, confirmed experimentally, has important implications, as it proves that the performance limit of H 2 S degrading biotrickling filters has not yet been reached.