- 學位論文
汽油水溶液於微生物燃料電池中降解及產電效率研究
Gasoline Degradation and Electricity Generation in Microbial Fuel Cell
摘要
本研究旨在利用生物燃料電池於不同操作條件下分別分解汽油與醋酸鈉水溶液以產生電流。當以醋酸鈉為基質時，改變外電阻大小對產電的影響遠超過改變電解質組成、陰極曝氣流量及初始基質濃度高低。當電阻由100提高到1000歐姆時，雖然電壓由130提高到331 mV，但是電流與電功率分別下降74與32 %，且庫倫效率由27 % 降至4 %，半飽合常數由277 降至147 mg/L COD。當醋酸鈉基質中混入甲苯/甲基第三丁基，不會提高最大穩定電壓，但卻可以延長其時間，顯示混入的甲苯/甲基第三丁基可以在MFC中被分解，也能有效產出電能。當MFC以汽油水溶液為基質時，雖然可以被微生物分解，但是產生的最大電壓為1.3 mＶ，產電效能遠低於以先前以醋酸鈉為基質。汽油中各成分的分解速率大小為乙苯>對二甲苯>甲苯>苯>鄰二甲苯>甲基第三丁醇。汽油中再添加醋酸鈉作為輔助基質可以提高產出的電壓及庫倫效率，但汽油的降解速率受醋酸鈉的競爭作用也減緩。添加中性紅（Neutral red）作為電子梭可以提高產出的電壓與庫倫效率，但不會提高基質的降解速率。
並列摘要
Gasoline and sodium acetate aqueous solution were used in microbial fuel cells (MFCs) under several different operating conditions for electricity generation. Though variations in electrolyte composition, cathode air flow rate and substrate concentrations would affect the electricity generation, but they were not as significant as the variations in external resistance. For experiments using sodium acetate as the electron donor, the maximum stable potential was raised from 130 to 331 mV when the external resistance was switched from 100 Ω to 1000 Ω; however, the corresponding current and power densities were decreased 74 and 32 %, respectively. The Columbic Efficiency (CE) was decreased from 27 to 4 %, and the half-saturation constant was also reduced from 277 to 147 mg/L COD. Adding the mixture of toluene/MTBE as the co-substrate of sodium acetate did not raise the maximum stable potential, but prolonged the period of that and enhanced the electricity generation. For MFCs using gasoline aqueous solution as the substrate, the performance of electricity generation was much worse than previous MFCs using sodium acetate. It was only 1.3 mV generated despite the gasoline was degraded. The degradation rate of components in gasoline was ethyl benzene > p-xylene > toluene > benzene > o-xylene > MTBE. The addition of sodium acetate as the co-substrate or neutral red as the electron shuttle both did raise the electricity generation.