Enhanced biohydrogen production in a membraneless single-chamber microbial electrolysis cell during high-strength wastewater treatment: Effect of electrode materials and configurations

The selection of better electrode material and studies of the electrocatalytic activities of the electrodes are crucial to increasing biohydrogen production in a microbial electrolysis cells (MEC). In the present work, we studied biohydrogen production and electrocatalytic activities using a membraneless single-chamber MEC fed with high-strength wastewater, using different electrode materials (metal and carbon electrode), configurations and electrode distance. The electro-fermentation (EF) process showed a significantly higher biohydrogen production and COD removal, compared to conventional dark fermentation reactor (DF). The maximum hydrogen production rate (HPR) obtained was 314 m3 H2/m3R.d with an overall biohydrogen recovery (rH2) of 340% using the electrode configuration stainless steel 304 pleated mesh 60 as anode and stainless steel 304 flat mesh 60 as cathode at 4 cm of electrode distance. The onset potential for the hydrogen evolution reaction (HER) with metal electrode was significantly lower than carbon electrode.