Electricity Generation from MFCs Using Differently
Grown Anode-Attached Bacteria |
Joo-Youn Nam1, Hyun-Woo Kim2†, Kyeong-Ho Lim3, and Hang-Sik Shin4 |
1Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA 16802, USA 2Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, 1001 S. McAllister, Tempe, AZ 85287, USA 3Deparatment of Civil and Environmental Engineering, Kongju National University, 275 Budae-dong, Seobukgu, Cheonan, Chungnam, 330-717, Republic of Korea 4Department of Civil and Environmental Engineering, KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea |
Corresponding Author:
Hyun-Woo Kim ,Tel: +1-480-294-4534, Fax: +1-480-727-0889, Email: hyunwoo.kim.1@asu.edu |
Received: December 1, 2009; Accepted: February 22, 2010. |
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ABSTRACT |
To understand the effects of acclimation schemes on the formation of anode biofilms, different electrical performances are characterized
in this study, with the roles of suspended and attached bacteria in single-chamber microbial fuel cells (MFCs). The results show
that the generation of current in single-chamber MFCs is significantly affected by the development of a biofilm matrix on the anode
surface containing abundant immobilized microorganisms. The long-term operation with suspended microorganisms was demonstrated
to form a dense biofilm matrix that was able to reduce the activation loss in MFCs. Also, a Pt-coated anode was not favorable for
the initial or long-term bacterial attachment due to its high hydrophobicity (contact angle = 124°), which promotes easy detachment of
the biofilm from the anode surface. Maximum power (655.0 mW/m2) was obtained at a current density of 3,358.8 mA/m2 in the MFCs
with longer acclimation periods. It was found that a dense biofilm was able to enhance the charge transfer rates due to the complex development
of a biofilm matrix anchoring the electrochemically active microorganisms together on the anode surface. Among the major
components of the extracellular polymeric substance, carbohydrates (85.7 mg/m2anode
) and proteins (81.0 mg/m2anode
) in the dense anode
biofilm accounted for 17 and 19%, respectively, which are greater than those in the sparse anode biofilm. |
Keywords:
Anode biofilm | Electrochemical impedance spectroscopy | Extracellular polymeric substance | Power density | Single-chamber
microbial fuel cell |
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