APPLICATION OF A DYNAMIC BIOFILTRATION MODEL TO A TWO-STAGE BIOFILTER THAT TREATS HYDROGEN SULFIDE AND ORGANIC SULFUR COMPOUNDS

摘要

A dynamic biofiltration model for odor control was calibrated and validated usingrnhydrogen sulfide (H2S) and methyl mercaptan (MeSH) data obtained from a two-stagernbiofilter that was packed with 15% compost and 85% wood chips. The model isrnincorporated into a user-friendly software called BiofilterTM. BiofilterTM comes with arndetailed user’s manual and can be used to support design and optimization of biofiltersrnand biotrickling filters used for treatment of odorous air emissions and VOCs. Althoughrnthe model has been evaluated with H2S data obtained from lava rock biofilters previously,rnthis is the first time that a model of this complexity was evaluated with odor-causingrnorganic sulfur compound data obtained from a biofilter packed with an organic medium.rnThe effects of the gas residence time and pH on MeSH removal efficiency are discussedrnbased on model simulations. It was found that increasing the gas residence time wasrnimportant for increasing the MeSH removal efficiency and control of pH was critical forrnimproving the performance of biofiltration of MeSH. For example, at pH 2.6, thernsimulated removal efficiency of MeSH was 76% with a residence time of up to 50rnseconds; but at pH 6.4, the simulated removal of MeSH was 97% with a residence time ofrnonly 20 seconds. These modeling results suggest that control of pH is critical if onernwishes to improve the performance of MeSH removal during biofiltration. In addition,rnthe performance of a biofilter packed with a mixture of wood chips and compost and arnbiofilter packed with lava rock were compared for H2S removal efficiency and modelingrnresults showed that biofilter packed with lava rock was more efficient than the biofilterrnpacked with wood chips and compost.