Pretreatment of cyanobacterial biomass for the production of biofuel in microbial fuel cells

The present study delves into phototrophic cyanobacterial biomass production by concomitant CO₂ sequestration, selecting an effective pretreatment condition followed by using this as feedstock for green fuel or bioelectricity production by Microbial Fuel Cells (MFC). The performance of the various photobioreactors were put up against Anabaena sp. PCC 7120 biomass production. Maximum microalgal biomass of 1.15 gL⁻¹ was attained in an airlift bioreactor for 9 days under a light intensity of 100 µEm⁻²s⁻¹. Pretreatment methods like sonication, HCl acid, and H₂O₂ treatment (2 % vv⁻¹) were applied to digest harvested biomass. Higher power output (6.76 Wm⁻³) was attained, and 73.5 % COD was eliminated using 2 % (vv⁻¹) acid pre-treated biomass. Better results were obtained using acid pre-treated biomass because the conductivity of the anolyte increased with the neutralization of acid-pre-treated biomass. The results demonstrate that cyanobacterial biomass could be employed successfully as a renewable resource for green fuel generation in MFCs.