微生物燃料電池處理含硫廢水及產電特性

Abstract

微生物燃料電池（Microbial fuel cell，MFC），可藉由微生物將有機廢水中的化學能直接轉變為電能，為一新興的廢水處理單元。本論文分別使用Pseudomonas sp. C27 及硫酸鹽還原菌 (Sulfate-reducing bacteria , SRB) 為微生物燃料電池陽極生物膜之菌源，探討MFC產電特性及廢水處理效果。 結果顯示，以Pseudomonas sp. C27啟動之MFC系統在處理含硫化物廢水時有較高輸出電壓 (140 mV) 及電流密度值 (240 mA/m2)，且當初始硫離子濃度為125.2 ppm時，硫離子去除率最高達98.4%，但長期運行下因受外來雜菌侵入導致產電效能下降。以SRB啟動之MFC在陽極培養液為乳酸和硫酸鹽時，具有較高輸出電壓 (308 mV) 和電流密度值 (513 mA/m2) ，最大功率密度為255 mW/m2，且在不同條件下，皆可維持80%以上硫酸鹽去除率。另外，SRB與C27複合電極型之生物燃料電池除了可增加總產電量，提升產電效率，亦可改善硫離子累積之缺點。

Microbial Fuel Cell (MFC) is a promising new technology which combines wastewater treatment with energy production. MFC uses bacteria as catalysts to convert chemical energy from organic matters in wastewater into electrical power. In this thesis, two different types of bacteria were used for the inoculation of MFCs’ anodes: Pseudomonas sp. C27, and Sulfate-reducing bacteria, SRB. The influence of different bacteria used on the MFC anode on the electricity generation characteristics and wastewater treatment performance of MFC were evaluated. The Pseudomonas sp. C27 MFC system produces its maximum voltage and current density at 140 mV and 240 mA/m2, when fed with sulfide only substrates; the sodium sulfide removal efficiency can reach as high as 98.4%. However, it is difficult to maintain a pure bacteria culture system under long operating time due to intrusion of other bacteria. The current generation of Pseudomonas sp. C27 MFC system drops over time. MFC systems inoculated with SRB and fed with lactate and sulfate has the maximum voltage at 308V, maximum current density at 513 mA/m2 and maximum power density at 254.84 mW/m2. Also, under different substrate conditions, sulfate removal efficiency can reach above 80%. Finally, the MFC system with both SRB and C27 can produce high voltage and electricity generation efficiency.