Bioelectrochemical hydrogen production with cheese whey as sole substrate

BACKGROUND Microbial electrochemical systems (MXCs) are an emerging technology aiming at recovering energy contained in wastewaters either as electrical energy in microbial fuel cells (MFCs) or as hydrogen in microbial electrolysis cells (MECs). Successful results have been reported with readily biodegradable substrates, but the performance with real complex substrates needs to be evaluated to bridge the gap between lab- and full-scale. This work aims at studying bioelectrochemical hydrogen production using real cheese whey as sole substrate. RESULTS A microbial consortium able to consume cheese whey to produce electricity or H2 was developed. Cheese whey was fermented mainly by lactic acid bacteria (Enterococcus genus) and exoelectrogenic activity was performed by Geobacter sp. The coulombic efficiency was 49 ± 8% in the MFC fed only with cheese whey, which is higher than most previous values reported for MFCs fed with dairy products. Good results for H2 production in MEC (0.8 LH2 L−1REACTOR d−1) were also obtained. CONCLUSION The high potentiality of cheese whey as carbon source for bioelectrochemical systems is demonstrated in this study. The populations involved were determined by advanced microbial tools. The efficient selection of a syntrophic consortium to produce H2 directly from cheese whey in a single-chamber MEC was demonstrated. © 2016 Society of Chemical Industry