Hydrogen production in a semi-single-chamber microbial electrolysis cell based on anode encapsulated in a dialysis bag

This study focuses on a semi-single-chamber microbial electrolysis cell (MEC) based on an anode made of carbon cloth (CCp) combined with stainless-steel (SS) and encapsulated in a dialysis bag with different molecular weight cut-offs of 2, 14, and 50 kDa (D2-, D14-, and D50-COMBp, respectively). The encapsulated anode was inoculated with Geobacter sulfurreducens in a small volume directly into the dialysis bag. While the MEC with the non-encapsulated anode was inoculated into the main chamber volume. The hydrogen evolution rates obtained in the MECs based on D2-COMBp, D14-COMBp, and D50-COMBp anodes were 0.134 ± 0.005, 0.144 ± 0.014, and 0.160 ± 0.009 m³m⁻²d⁻¹, respectively; while the COMBp led to only 0.122 ± 0.004 m³m⁻²d⁻¹. When the MEC utilizing D50-COMBp was fed with wastewater, the current density was only 12.4 ± 0.21 A m⁻², compared to feeding with acetate (15.7 ± 0.63 A m⁻²). The encapsulated anode in the presence of wastewater included 70% of G. sulfurreducens, while the non-encapsulated included only 58%.