Photoautotrophic microalgae Scenedesmus obliquus attached on a cathode as oxygen producers for microbial fuel cell (MFC) operation

Enhanced performance of an air–cathode microbial fuel cell with oxygen supply from an externally connected algal bioreactor

“…Such a small increase in reduction current with use of pure oxygen (99.99 %) could be due to saturation of cathode catalytic ability at increased oxygen concentration. This phenomenon was also observed in our previous study (Kakarla & Min, 2014b). …”

“…Current was calculated according to Ohm's Law: I = V/R and power was calculated using P = I x V. and Coulombic efficiency was calculated using polarization slope method (Vologni et al, 2013). Headspace oxygen levels (%), algal cell density and light intensity (lumen) were measured as previously described (Kakarla & Min, 2014b).…”

“…Generation of electricity from MFC involves oxidation of substrate in anode producing electrons and protons (Kakarla & Min, 2014b), which combine with oxygen in the cathode chamber to form water (Min et al, 2012). However, the operational, maintenance and material costs of MFC should be considered to improve the feasibility of field scale MFC operation (Oliveira et al, 2013).…”

Using live algae at the anode of a microbial fuel cell to generate electricity

“…As algae in the cathode would undergo photosynthesis to produce an oxygen electron acceptor, the power was likely further improved by increasing the light intensity at the cathode to produce more oxygen. One advantage in using algae in the cathode is that a more stable power generation than the mechanically aerated cathode would be produced (Juang et al 2012) probably by improving oxygen transfer via the physical attachment of algae on the surface of the cathode electrode (Kakarla and Min 2014). Secondly, different from bacteria-driven MFC in which a high-salt medium would harm the bacterial population (Lefebvre et al 2012), algae could survive in a high-salt medium nicely, and so it could be used in MFC to improve the conductivity and power production (Lefebvre et al 2012).…”

“…In the past, plant was used in plant MFC in generating electric power (Timmers et al 2012), but the role of an electron donor mainly relied on the bacteria located on root surfaces of the plant (Timmers et al 2012). Although algae were also used in MFC in various studies, it was either used as dead algal biomass as substrate for the growth of bacteria at the anode (Cui et al 2014;Gouveia et al 2014;Rashid et al 2013;VelasquezOrta et al 2009) or as an electron acceptor placed at the cathode of MFC (Gouveia et al 2014;Kakarla and Min 2014;Powell et al 2011). Using algae biomass as substrate in bacteria-driven MFC, pretreatment of algae biomass was often required, including sonication and thermal pretreatment, in order to improve the digestibility of algae by bacteria (Rashid et al 2013).…”