Microbial electrolysis cell scale-up for combined wastewater treatment and hydrogen production

► We demonstrate microbial electrolysis cell scale-up from a 50 mL to a 10 L cell. ► MEC operation on domestic wastewater showed an energy consumption of 0.9 Wh/g-COD removed. ► Low wastewater strength led to low volumetric rate of hydrogen production. ► High rate of hydrogen production can be only achieved at high organic loads.