| Summary: | 碩士 === 康寧大學 === 休閒資源暨綠色產業研究所 === 99 === In this study, a new fixed-film microbial fuelcell (FFMFC) was developed to generate electricity. The reticulated vitreous carbon (RVC) and bio-catalytic metal ions of Fe3+, Mn4+, Co3+, and Ni2+ coated on RVC was selected as anode test materials. A new proton-permeable porcelain membrane were compared with Nafion 117. The RVC, Fe3+-RVC (Fe3+ coated on the surface of RVC), carbon paper, carbon felt, graphite-kaolin felt, Fe3+-graphite-kaolin felt were used as the testing materials for cathode. By using different combinations of electrodes materials and structure, the MFC performance parameters, including power density, coulombic efficiency, COD (chemical oxygen demand) removal efficiency, and concentration of metabolic intermediates VFAs (volatile fatty acids), were measured.
The results were as follows:
1) When RVC was used as a cathode material, a maximal power density (PDmax) of 158.3 mW/m2 together with a minimal internal resistance (Rint) of 204.6 Ω was found to be coupled with the Ni2+-RVC anode;
2) This study’s optimal material combination was Co3+-RVC of anode and Fe3+-RVC of cathode, which PDmax was increased to 232.2 mW/m2 and Rint was lowered to 93.7 Ω;
3) When Fe3+-graphite-kaolin felt containing a proton-permeable porcelain layer used as a cathode material and the cell structure was air-cathode, the maximum power density of the FFMFC was 121.6 mW/m2;
4) When the anode of bio-catalytic metal ions coated on the surface of RVC was applied, the COD removal efficiency was higher and the VFAs concentrations were lower than that of the one without coating. This indicated that the bio-catalytic metal ions imposed effects on the anaerobes’ metabolism.
Furthermore, the electrical production rate of the former system was also higher than the latter one. This can be shown by when the metal ion was coated, its affinity to the electron was enhanced. As well, it helped the electron pass through the cell-membrane barrier to the anode to form water via reacting proton and dissolved oxygen. Therefore its internal resistance would be lowered and its electrical production rate was improved.
|
|---|
