Electricity generation and microalgae cultivation in microbial fuel cell using microalgae-enriched anode and bio-cathode

• Electricity generation and microalgae cultivation was done simultaneously.
• Microalgae biomass was used as a substrate at anode.
• Freshwater microalgae were grown at cathode.
• The maximum power output of 1926 ± 21.4 mW/m2 was achieved.
• Microalgae produced biomass up to 1247 ± 52 mg/L.

In this study, a microbial fuel cell (MFC) was developed to treat waste, produce electricity and to grow microalgae simultaneously. Dead microalgae biomass (a potential pollution vector in streams) was used as a substrate at anode. CO2 generated at anode was used to grow freshwater microalgae at cathode. The performance of microalgae-fed MFC was compared with acetate-fed MFC. The maximum power density of 1926 ± 21.4 mW/m2 (8.67 ± 0.10 W/m3, at Rext = 100 Ω) and Coulombic efficiency (CE) of 6.3 ± 0.2% were obtained at 2500 mg COD/L of microalgae powder (0.5 g/L). Microalgae captured CO2 (5–14%, v/v) to produce a biomass concentration of 1247 ± 52 mg/L. However, microalgae could not grow in acetate-fed (0.5 g/L) MFC (acetate-control) and without anodic CO2 supplying MFC (CO2-control).