Mixotrophic operation of photo-bioelectrocatalytic fuel cell under anoxygenic microenvironment enhances the light dependent bioelectrogenic activity

Electrogenic activity of photo-bioelectrocatalytic /photo-biological fuel cell (PhFC) was evaluated in a mixotrophic mode under anoxygenic microenvironment using photosynthetic consortia as biocatalyst. An acetate rich wastewater was used as anolyte for harnessing energy along with additional treatment. Mixotrophic operation facilitated good electrogenic activity and wastewater treatment associated with biomass growth. PhFC operation documented feasible microenvironment for the growth of photosynthetic bacteria compared to algae which was supported by pigment (total chlorophyll and bacteriochlorophyll) and diversity analysis. Pigment data also illustrated the association between bacterial and algal species. The synergistic interaction between anoxygenic and oxygenic photosynthesis was found to be suitable for PhFC operation. Light dependent deposition of electrons at electrode was relatively higher compared to dark dependent electron deposition under anoxygenic condition. PhFC documented for good volatile fatty acids removal by utilizing them as electron donor. Bioelectrochemical behavior of PhFC was evaluated by voltammetric and chronoamperometry analysis.

► Syntrophic association of photosynthetic bacteria and micro algae for power generation was studied.
► Microaerophilic conditions and mixotrophic mode showed good electrogenic activity.
► Acetate rich wastewater as anolyte in PhFC facilitated harnessing bioelectricity along with treatment.