| Summary: | 碩士 === 國立臺灣海洋大學 === 河海工程學系 === 104 === Ammonia nitrogen, a major pollutant in domestic wastewater, usually caused oxygen drop in the water body, which should be effectively removed before the wastewater is discharged to a receiving water body. Using phototrophic microbial fuel cell (Photo-MFC) to treat domestic wastewater containing ammonia is promising because Photo-MFC not only can remove the pollutant but also recover bioenergy. An experimental Photo-MFC (termed as MFC-P) was employed in this study, loaded with 1000 Ω external resistance, operated at diurnal illumination of 12 h light/12 h dark (L/D) cycles. Real sewerage effluent containing ammonia nitrogen (NH4+-N) amended with ammonia chloride (covering 25, 50, and 150 mg/L) was continuously fed into the anodic chamber of MFC-P at flow rate of 1.5 L/day. After 170 days of operation, the electricity generation in MFC-P was founded decreased as ammonia concentration increased. The maximum power output of 76 mW/m3 was founded at 25 mg NH4+-N/L, while the oxygen supply by microalgae reached 126 mg/d which was adequate for nitrification. The ammonia concentration also affects ammonia removal efficiency, contribution of suspended growth in removing ammonia, and chlorophyll a production. Specifically, when influent ammonia concentration increased from 25 to 150 mg NH4+-N /L, the ammonia removal efficiency decrease from 99 % to 9%, the contribution of suspended grown in removing ammonia decreased from 28 % to 7 %, and chlorophyll a concentration from cathode chamber decreased from 446 μg/L to 1.8 μg/L. In addition, the effect of light on Photo-MFC performance was significant, for example, from light to dark periods, the electricity generation decreased from 0.19 mW to 0.08 mW and dissolved oxygen decreased from 1.3 mg/L to 0.1 mg/L. This study demonstrated that influent ammonia concentration is an important process parameter to Photo-MFC, in which the ammonia loading rate should be carefully designed in order to achieve optimal operation in pollutant removal and bioenergy recovery.
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