Summary: | 碩士 === 臺灣大學 === 生物產業機電工程學研究所 === 98 === In this study, the performance of microbial fuel cells (MFCs) was investigated by applying immobilized cells entrapped treated anaerobic sludge with cellulose acetate at three different inoculum sizes (10 g, 20 g and 30 g) and five feeding pHs (4, 5, 6, 7, 9) , respectively. A mediatorless single air-cathode MFC was constructed where Carbon paper was used as anode electrode, Pt-Ti net as cathode and synthetic wastewater was the substrate.
When the feeding was pH 4, the optimum performance of power output and coulombic efficiency (CE) at inoculum sizes of 30 g were the highest at 14.97 mW/m2 and 6.33 %. But in the feeding of pH 5, they were 14.19 mW/m2 and 4.15 % when inoculum sizes was 20 g. In pH 6, there were no apparently differences between these three systems. However in feeding pH 7, the highest power output was observed in inoculum sizes of 10 g at 8.18 mW/m2. The power output and CE in inoculum sizes 30 g were the lowest in pH 9, they were 1.13 mW/m2 and 0.23 %, respectively. These results showed the performance of MFCs would be strongly affected by the feeding pH.
Besides, this study focused on the investigation of the pre-treatment of sludge. Two groups of immobilized cells with different sludge supplier but the same inoculum sizes of 30 g were made. One was produced by heat pre-treatment which means the sludge was boiled at 100oC for 15 min, and the other was no heat pre-treatment. The results showed the maximum power output in pre-treatment and un-treatment system were 3.17 mW/m2 and 2.43 mW/m2. The average COD removal efficiencies were 43.43±14.788 % and 34.81±3.947 %. According to these observations, we found heating pre-treatment was no apparently effects on the performance of MFCs. It is better to use another pre-treatment method or select different kinds of sludge to decrease the cost of MFC in real application.
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