Evaluation of biocathodes in freshwater and brackish sediment microbial fuel cells.
Biofilms on biocathodes can catalyze the cathodic oxygen reduction and accordingly guarantee high cathode redox potentials. The present research assessed the use of biocathodes in full-sediment microbial fuel cells. Carbon felt-based biocathodes were evaluated in freshwater systems, and an extension of their application to brackish systems and/or stainless steel webs as base material was considered. Efficient biocathodes could be developed within days through inoculation with active microorganisms. Carbon felt was found most suited for the biocathodes in freshwater with increased performance at salinities around 80-250 mM. Maximum long-term performance reached 12.3 microW cm(-2) cathode. The relative benefit of stainless steel seemed to increase with increasing salinity. A combination of stainless steel cathodes with biofilms could, however, also result in decreased electrical performance. In an efficiently catalyzing cathodic biofilm, an enrichment with an uncultured Proteobacterium--previously correlated with steel waste--was observed.
De Schamphelaire
Liesje
L
Laboratory of Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
Boeckx
Pascal
P
Verstraete
Willy
W
D001674:Bioelectric Energy Sources; D018441:Biofilms / Q000254:growth & development*; D002244:Carbon / Q000378:metabolism; D004566:Electrodes / Q000382:microbiology*; D005618:Fresh Water / Q000382:microbiology*; D008969:Molecular Sequence Data; D020560:Proteobacteria / Q000254:growth & development* / Q000378:metabolism*; D013193:Stainless Steel
D013193:Stainless Steel; D002244:Carbon