Wastewater sludge in bioelectricity generation using microbial fuel cells

Ömeroğlu, Seçil
Today, the majority of world’s energy is provided by fossil fuels which soon will be exploited. This pressure forces countries to investigate renewable energy technologies like microbial fuel cells (MFCs). MFCs can convert chemical energy in organic matter into electricity via microbial activity. The objective of this study was to investigate the operational parameters and interactions within the MFCs to overcome the challenges that limit their full scale applications. This study started with optimization experiments by testing the type of materials. However, the power density (PD) values (~5.5 mW/m2) showed that performance depends on microbial degradation and electron transfer. Then, the system was redesigned considering electron losses, membrane fouling and internal resistance (IR). The maximum PD was calculated as 464 mW/m2. Following optimization experiments, the system was fed with different sludges (municipal, poultry, beverage, petrochemical and textile) to test the suitability of MFCs. The PD decreased to 205.93 mW/m2 with municipal sludge, since the sludge contains numerous ions, increasing IR. Applying 10 and 20 min sonication increased PD to 225.23 mW/m2 and 281.54 mW/m2, respectively. PD dropped to 45.88 mW/m2 when poultry sludge was fed. Beverage sludge, on the other, increased the PD to 360.91 mW/m2, while PD was calculated as 21.17 mW/m2 and 31.44 mW/m2 for petrochemical and textile sludge, respectively. One final objective was to operate a laboratory scale anaerobic digester to compare the performance of two competing bioenergy technologies. MFCs did not require additional heating even if the output was comparably small with more rapid organic conversion.
Citation Formats
S. Ömeroğlu, “Wastewater sludge in bioelectricity generation using microbial fuel cells,” Ph.D. - Doctoral Program, Middle East Technical University, 2019.