碩士 / 國立雲林科技大學 / 環境與安全衛生工程系碩士班 / 99 / Microbial fuel cell (MFC) systems degrade organic pollutants in water using microorganisms in the anode chamber, and are used to generate electricity. Hence, the MFC is a green technology for both pollutant treatment and renewable energy. The MFC system can use many materials as the terminal electron acceptor (TEA); oxygen with its high reduction potential and superior persistence is one of the best TEAs. However, oxygen is consumed continuously by the reduction reaction in the cathode during MFC system operation. If reduction relies only on atmospheric oxygen, the reaction will be limited by the air transfer rate, thereby decreasing reduction reaction performance. In this study, Spirulina was added into the cathode chamber to produce oxygen by photosynthesis, and the generated oxygen served as the TEA to maintain the oxidation-reduction reaction in the MFC system.
This study used a cube-type MFC (C-MFC) made from an acrylic sheet. The C-MFC, with anode and cathode chamber volumes of 250 ml, was separated by a proton exchange membrane (PEM) with a surface area of 100 cm2. Carbon cloths, used as electrodes in both the anode and cathode chambers, were connected by copper wires and a 1-kΩ resistor to form a circuit. The phosphate buffer solution, the electrolyte, was added into both chambers. The BTEX-degrading mixed culture was added into the anode chamber. Two operating conditions, with Spirulina and without Spirulina in the cathode chamber, were utilized to determine the effects of dissolved oxygen (DO) on electricity generation.
Experimental results were as follows. (1) Under limited oxygen in the cathode chamber, oxygen was consumed continually as organic compounds were degraded in the anode chamber. (2) With no oxygen in the cathode chamber, no electricity was generated, which is attributable to the prolongation of microorganisms in degrading organic compounds. (3) Electricity generation was enhanced significantly with sufficient oxygen as the TEA in the C-MFC system. Oxygen was provided via photosynthesis with Spirulina in the cathode chamber. (4) The electricity generated by the C-MFC with Spirulina under an all-light condition was greater than under alternating light and dark, likely due to oxygen diffusion from the anode chamber to cathode chamber, thereby reducing the degree of electron transfer. (5) The DO was depleted rapidly under darkness with Spirulina in the cathode chamber. However, the C-MFC still produced electricity, likely due to the presence of a TEA other than oxygen in the cathode chamber. (6) The presence of a mediator was observed during toluene degradation via cyclic voltammetry (CV) analysis.
| Identifer | oai:union.ndltd.org:TW/099YUNT5633040 |
| Date | January 2011 |
| Creators | Yu-Cheng Hsieh, 謝雨澄 |
| Contributors | Chi-Wen Lin, 林啟文 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 116 |
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