Long-term effect of set potential on biocathodes in microbial fuel cells: electrochemical and phylogenetic characterization.
The long-term effect of set potential on oxygen reducing biocathodes was investigated in terms of electrochemical and biological characteristics. Three biocathodes were poised at 200, 60 and -100 mV vs. saturated calomel electrode (SCE) for 110 days, including the first 17 days for startup. Electrochemical analyses showed that 60 mV was the optimum potential during long-term operation. The performance of all the biocathodes kept increasing after startup, suggesting a period longer than startup time needed to make potential regulation more effective. The inherent characteristics without oxygen transfer limitation were studied. Different from short-term regulation, the amounts of biomass were similar while the specific electrochemical activity was significantly influenced by potential. Moreover, potential showed a strong selection for cathode bacteria. Clones 98% similar with an uncultured Bacteroidetes bacterium clone CG84 accounted for 75% to 80% of the sequences on the biocathodes that showed higher electrochemical activity (60 and -100 mV).
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
Xue
X
Xia
Yanmei
Y
Sun
Peng
P
Liang
Xia
X
Huang
D000332:Aerobiosis; D001419:Bacteria / Q000235:genetics* / Q000254:growth & development; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development; D018533:Biomass; D004560:Electricity; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D008969:Molecular Sequence Data; D010100:Oxygen / Q000032:analysis; D010802:Phylogeny; D012995:Solubility; D013997:Time Factors
D010100:Oxygen