Scalable tubular membrane cathodes for microbial fuel cell applications

One of the greatest challenges for using microbial fuel cells (MFCs) for wastewater treatment is creating a scalable architecture that provides large surface areas for oxygen reduction at the cathode and for bacterial growth on the anode. We demonstrate here a scalable cathode concept by showing that two tubular hydrophilic or hydrophobic filtration membranes with conductive graphite coatings and a non-precious metal catalyst (CoTMPP) can be used to produce power in an MFC. Using a high surface area graphite brush anode with two hydrophilic ultrafiltration tubular membrane cathodes placed inside the reactor (Acat,s= 93 m2/m3), the MFC produced 18 W/m3 with a high Coulombic Efficiency (CE) of 70-74 %. Further increases in power output will require the development of membrane cathodes with lower internal resistances.