Hydrogen production in microbial reverse-electrodialysis electrolysis cells using a substrate without buffer solution

Abstract The aim of this work was to use substrate without buffer solution in a microbial reverse-electrodialysis electrolysis cell (MREC) for hydrogen production under continuous flow condition (10 cell pairs of RED stacks, HRT = 5, 7.5, and 15 h). Decreasing in the HRT (increasing in the organic matter) made cell current stable and increased. Hydrogen gas was produced at a rate of 0.61 m 3 -H 2 /m 3 -V an /d in H-MREC, with a COD removal efficiency of 81% (1.55 g/L/d) and a Coulombic efficiency of 41%. This MREC system without buffer solution could successfully produce hydrogen gas at a consistent rate.