Enhancing and modeling the biofiltration of dimethyl sulfide under dynamic methanol addition

Recent research has shown that there is significant enhancement (up to 11-fold) of the biofiltration of dimethyl sulfide (DMS) in the presence of methanol (MeOH). The objectives of this study were to explore the potential to optimize DMS removal with MeOH addition and to develop and experimentally validate a mathematical model describing the biofiltration of DMS under dynamic MeOH addition. A dynamic model incorporating the competitive and activation effects of MeOH on DMS biodegradation was developed to describe both steady-state and transient-state behavior of inorganic biofilters treating DMS with MeOH addition less than 50g/m3h. The proposed model included the effect of substrates (e.g., MeOH) on biomass growth rate to take account for biofilm growth in biofilters over time. In the model, the biofilm was considered to have variable density along the biofilter column as a function of MeOH concentration in the air stream. At steady state, the modeled results on DMS removal were in close agreement with the experimental data. The transient-state behavior of the biofilters during periodic MeOH addition periods was also effectively predicted with the model. Our results support the proposed mechanism of MeOH effects on the biofiltration of DMS. A MeOH feeding strategy (pulse feeding) that enhanced DMS treatment by 35% was experimentally demonstrated and simulated by the model.