Elimination of mass transfer and kinetic limited organic pollutants in biofilters: A review

- Mass transfer and kinetic limitations are two main limitations in biofiltration.
- Pollutants were categorized in 2 groups as mass transfer and kinetic limited.
- Parameters for the elimination of the 2 groups in biofilters were reviewed.
- Biofiltration of the two groups in a mixture were investigated.
- Improved biofilter's configurations to enhance the limitations were discussed.

Mass transfer and kinetic limitations are two obstacles to the removal of a pollutant from the gas phase in a biofilter (BF) or a biotrickling filter (BTF). The issue becomes more challenging when mass transfer and kinetic limitations are present especially for treatment of pollutants in mixtures. In the present study, the most common organic pollutants which may have mass transfer or kinetic limitations in BFs and BTFs are described. Accordingly, the recent studies of mass transfer limited and kinetic limited organic pollutants elimination in BFs and BTFs are reviewed. Subsequently, the most effective operating parameters for each sort of limitations are discussed. Finally, some improved bioprocesses like two liquid phase biotrickling filters, step feeding and hybrid biofilters to overcome the limitations of mass transfer and kinetic limited organic pollutants are discussed.