Harvest of electrical energy from fermented microalgal residue using a microbial fuel cell

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>The application of microalgal biomass for fermentation has been highlighted as a means of producing a range of value-added biofuels and chemicals. On the other hand, the microalgal residue from the fermentation process still contains as much as 50% organic contaminants, which can be a valuable substrate for further bioenergy recovery. In this study, a microbial fuel cell and automatic external load control by maximum power point tracking (MPPT) were implemented to harvest the electrical energy from waste fermented microalgal residue (FMR). The MFC with MPPT produced the highest amount of energy (1.82 kJ/L) compared to the other MFCs with fixed resistances: 0.98 (1000 Ω), 1.16 (500 Ω), and 1.17 kJ/L (300 Ω). The MFC with MPPT also showed the highest maximum power density (88.6 mW/m<SUP>2</SUP>) and COD removal efficiency (620.0 mg COD/L removal with 85% removal efficiency). The implementation of MPPT gained an approximate 12.9% energy yield compared to the previous fermentation stage. These results suggest that FMR can be an appropriate feedstock for electrical energy recovery using MFCs, and the combined fermentation and MFC system improves significantly the energy recovery and treatment efficiency from FMR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The combination of fermentation and MFC improves energy recovery. </LI> <LI> Fermented microalgal residue (FMR) was used as the feedstock for MFCs. </LI> <LI> Automatic load control with maximum power point tracking (MPPT) was implemented. </LI> <LI> The MPPT-MFC showed the highest energy production (1.82 kJ/L) with a 12.9% yield. </LI> <LI> The combined system enhanced the energy recovery and treatment efficiency. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>