Development and Experimental Validation of a Conceptual Model for Biotrickling Filtration of H_2S

摘要

A dynamic model that describes the behavior of high-performance hydrogen sulfide (H_2S)-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-liqnid-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_2S could be studied. Model outputs were compared with experimental data to determine the sensitivity of the system to selected parameters. At low H_2S concentration, diffusion of H_2S within the biofilm, and biofilm thickness were the major governing factors among nine considered model parameters. At higher H_2S 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_2S degrading biotrickling filters has not yet been reached.