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

Abstract

This study demonstrates microbial electrolysis cell (MEC) scale-up from a 50. mL to a 10. L cell. Initially, a 50. mL membraneless MEC with a gas diffusion cathode was operated on synthetic wastewater at different organic loads. It was concluded that process scale-up might be best accomplished using a " reactor-in-series" concept. Consequently, 855. mL and 10. L MECs were built and operated. By optimizing the hydraulic retention time (HRT) of the 855. mL MEC and individually controlling the applied voltages of three anodic compartments with a real-time optimization algorithm, a COD removal of 5.7. g LR-1d-1 and a hydrogen production of 1.0-2.6. L LR-1d-1 was achieved. Furthermore, a two MECs in series 10. L setup was constructed and operated on municipal wastewater. This test showed a COD removal rate of 0.5. g LR-1d-1, a removal efficiency of 60-76%, and an energy consumption of 0.9. Wh. per. g of COD removed. © 2012.