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Impact of initial biofilm growth on the anode impedance of microbial fuel cells.
Biotechnol Bioeng. 2008 Sep 01; 101(1):101-8.BB

Abstract

Electrochemical impedance spectroscopy (EIS) was used to study the behavior of a microbial fuel cell (MFC) during initial biofilm growth in an acetate-fed, two-chamber MFC system with ferricyanide in the cathode. EIS experiments were performed both on the full cell (between cathode and anode) as well as on individual electrodes. The Nyquist plots of the EIS data were fitted with an equivalent electrical circuit to estimate the contributions of various intrinsic resistances to the overall internal MFC impedance. During initial development of the anode biofilm, the anode polarization resistance was found to decrease by over 70% at open circuit and by over 45% at 27 microA/cm(2), and a simultaneous increase in power density by about 120% was observed. The exchange current density for the bio-electrochemical reaction on the anode was estimated to be in the range of 40-60 nA/cm(2) for an immature biofilm after 5 days of closed circuit operation, which increased to around 182 nA/cm(2) after more than 3 weeks of operation and stable performance in an identical parallel system. The polarization resistance of the anode was 30-40 times higher than that of the ferricyanide cathode for the conditions tested, even with an established biofilm. For a two-chamber MFC system with a Nafion 117 membrane and an inter-electrode spacing of 15 cm, the membrane and electrolyte solution dominate the ohmic resistance and contribute to over 95% of the MFC internal impedance. Detailed EIS analyses provide new insights into the dominant kinetic resistance of the anode bio-electrochemical reaction and its influence on the overall power output of the MFC system, even in the high internal resistance system used in this study. These results suggest that new strategies to address this kinetic constraint of the anode bio-electrochemical reactions are needed to complement the reduction of ohmic resistance in modern designs.

Authors+Show Affiliations

Fuel Cell Dynamics and Diagnostics Laboratory, Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. rur14@psu.eduNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

18646217

Citation

Ramasamy, Ramaraja P., et al. "Impact of Initial Biofilm Growth On the Anode Impedance of Microbial Fuel Cells." Biotechnology and Bioengineering, vol. 101, no. 1, 2008, pp. 101-8.
Ramasamy RP, Ren Z, Mench MM, et al. Impact of initial biofilm growth on the anode impedance of microbial fuel cells. Biotechnol Bioeng. 2008;101(1):101-8.
Ramasamy, R. P., Ren, Z., Mench, M. M., & Regan, J. M. (2008). Impact of initial biofilm growth on the anode impedance of microbial fuel cells. Biotechnology and Bioengineering, 101(1), 101-8. https://doi.org/10.1002/bit.21878
Ramasamy RP, et al. Impact of Initial Biofilm Growth On the Anode Impedance of Microbial Fuel Cells. Biotechnol Bioeng. 2008 Sep 1;101(1):101-8. PubMed PMID: 18646217.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Impact of initial biofilm growth on the anode impedance of microbial fuel cells. AU - Ramasamy,Ramaraja P, AU - Ren,Zhiyong, AU - Mench,Matthew M, AU - Regan,John M, PY - 2008/7/23/pubmed PY - 2008/9/30/medline PY - 2008/7/23/entrez SP - 101 EP - 8 JF - Biotechnology and bioengineering JO - Biotechnol. Bioeng. VL - 101 IS - 1 N2 - Electrochemical impedance spectroscopy (EIS) was used to study the behavior of a microbial fuel cell (MFC) during initial biofilm growth in an acetate-fed, two-chamber MFC system with ferricyanide in the cathode. EIS experiments were performed both on the full cell (between cathode and anode) as well as on individual electrodes. The Nyquist plots of the EIS data were fitted with an equivalent electrical circuit to estimate the contributions of various intrinsic resistances to the overall internal MFC impedance. During initial development of the anode biofilm, the anode polarization resistance was found to decrease by over 70% at open circuit and by over 45% at 27 microA/cm(2), and a simultaneous increase in power density by about 120% was observed. The exchange current density for the bio-electrochemical reaction on the anode was estimated to be in the range of 40-60 nA/cm(2) for an immature biofilm after 5 days of closed circuit operation, which increased to around 182 nA/cm(2) after more than 3 weeks of operation and stable performance in an identical parallel system. The polarization resistance of the anode was 30-40 times higher than that of the ferricyanide cathode for the conditions tested, even with an established biofilm. For a two-chamber MFC system with a Nafion 117 membrane and an inter-electrode spacing of 15 cm, the membrane and electrolyte solution dominate the ohmic resistance and contribute to over 95% of the MFC internal impedance. Detailed EIS analyses provide new insights into the dominant kinetic resistance of the anode bio-electrochemical reaction and its influence on the overall power output of the MFC system, even in the high internal resistance system used in this study. These results suggest that new strategies to address this kinetic constraint of the anode bio-electrochemical reactions are needed to complement the reduction of ohmic resistance in modern designs. SN - 1097-0290 UR - https://www.unboundmedicine.com/medline/citation/18646217/Impact_of_initial_biofilm_growth_on_the_anode_impedance_of_microbial_fuel_cells_ L2 - https://doi.org/10.1002/bit.21878 DB - PRIME DP - Unbound Medicine ER -