Biofilter Model Research Articles

Development, experimental validation and dynamic analysis of a general transient biofilter model

In this study, a general transient biofiltration model, which incorporates general mixing phenomena, oxygen limitation effects, adsorption phenomena and general biodegradation reaction kinetics, is developed. Solutions are presented with and without the assumption of pseudo-steady state for the biofilm leading to approximate and general models, respectively. Solutions of the model are presented and validated with experimental transient data of benzene and toluene. Significant improvement in the model prediction is observed in comparison to earlier simplified models. However, the general model predictions seem to be better and it is superior to the approximate model as it does not require any correlations for film thickness or effectiveness factors. Dynamic analysis of the model is performed and compared with experimental data from the literature. Transient behavior during shut-down and restart-up are also well predicted by the model and the transient period does not seem to be long. Model predictions show that the biofilter is able to withstand extreme practical conditions such as random variations in the inlet concentration and gas flow rate. Theoretical analysis shows that the assumption of excess oxygen availability is not a good one, specially at high inlet concentration levels. Sensitivity studies show that mixing in the gas phase is an important phenomenon which should not be neglected and that some parameters need to be accurately estimated.

Analysis and comparison of biofilter models

Realistic mathematical models are essential for the scaling-up or the design of biofilters. However, the mathematical models which describe the steady-state and the transient operation of biofilters are very limited. Although some of these models are based on restrictive assumptions, they have been widely used in industry for designing actual biofilter units. This study gives detailed analysis and comparison between these models. The asymptotic behavior of recent models are presented. The results show that diffusion is an important phenomenon which should not be neglected in developing biofilter models, and that neglecting oxygen transport and its effects on growth kinetics will give unrealistic values for the effective as well as the actual film thickness.

Analysis and comparison of biofilter models

Realistic mathematical models are essential for the scaling-up or the design of biofilters. However, the mathematical models which describe the steady-state and the transient operation of biofilters are very limited. Although some of these models are based on restrictive assumptions, they have been widely used in industry for designing actual biofilter units. This study gives detailed analysis and comparison between these models. The asymptotic behavior of recent models are presented. The results show that diffusion is an important phenomenon which should not be neglected in developing biofilter models, and that neglecting oxygen transport and its effects on growth kinetics will give unrealistic values for the effective as well as the actual film thickness.