A comparative assessment of the performance of fungal-bacterial and fungal biofilters for methane abatement

Methane is an important contributor to global warming and especially for dilute emissions, its oxidation to carbon dioxide can be difficult and expensive. Methane abatement was studied in a biofilter inoculated solely with the filamentous fungus Fusarium solani and compared to a biofilter inoculated with a consortium of methanotrophic bacteria (Methylomicrobium album and Methylocystis sp.) and F. solani. Results showed that F. solani degrade methane as the sole carbon source, achieving a maximum elimination capacity of 42.2 g m-3 h-1, nearly half of the maximum elimination capacity of the fungal-bacterial consortium. The second Damköhler number indicates that under the prevailing operational conditions, the fungal biofilter performance was bioreaction limited meanwhile external mass transport limitation was found on the fungal/methanotrophic bacteria biofilter. Results support the hypothesis that the beneficial effect of F. solani during CH4 biofiltration is mediated by biomass hydrophobicity rather than by an increase in the mass transfer area.