Development of an electroactive aerobic biocathode for microbial fuel cell applications.

Priyadharshini Mani,Chandra T S,Godfrey Kyazze,Taj Keshavarz,Fidal V T,Kyle Bowman

doi:10.1111/1758-2229.12871

Abstract

Microbial biocathodes are gaining interest due to their low cost, environmental friendliness and sustainable nature. In this study, a microbial consortium was enriched from activated sludge obtained from a common textile effluent treatment plant in the absence of organic carbon source to produce an electroactive biofilm. Chronoamperometry method of enrichment was carried out for over 70 days to select for electroactive bacteria that could be used as a cathode catalyst in microbial fuel cells (MFC). The resultant biofilm produced an average peak current of -0.7 mA during the enrichment and produced a maximum power density of 64.6 ± 3.5 mW m-2 compared to platinum (72.7 ± 1.2 mW m-2 ) in a Shewanella-based MFC. Microbial community analysis of the initial sludge sample and enriched samples, based on 16S rRNA gene sequencing, revealed the selection of chemolithotrophs with the most dominant phylum being Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria and Acidobacteria in the enriched samples. A variety of CO2 fixing and nitrate-reducing bacteria was present in the resultant biofilm on the cathode. This study suggests that microbial consortia are capable of replacing expensive platinum as a cathode catalyst in MFCs.

Highlights

SummaryMicrobial biocathodes are gaining interest due to their low cost, environmental friendliness and sustainable nature
To make microbial fuel cell technology cost-effective, there is currently a lot of research to develop microbialRabaey and co-workers compared the efficiency of the mixed microbial population with that of individual isolates for reducing oxygen in an microbial fuel cells (MFC)
A stable current is defined by a phase where there is no sharp increase in current on replacement of the catholyte

Summary

Microbial biocathodes are gaining interest due to their low cost, environmental friendliness and sustainable nature. A microbial consortium was enriched from activated sludge obtained from a common textile effluent treatment plant in the absence of organic carbon source to produce an electroactive biofilm. Chronoamperometry method of enrichment was carried out for over 70 days to select for electroactive bacteria that could be used as a cathode catalyst in microbial fuel cells (MFC). The resultant biofilm produced an average peak current of −0.7 mA during the enrichment and produced a maximum power density of 64.6 ± 3.5 mW m−2 compared to platinum (72.7 ± 1.2 mW m−2) in a Shewanella-based MFC.

Introduction

Results and discussion

Conclusion