Fermentative hydrogen production from anaerobic bacteria using a membrane bioreactor

Continuous H2 production from glucose was studied at short hydraulic retention times (HRT) of 4.69 - 0.79 h using a membrane bioreactor (MBR) with a hollow-fiber filtration unit and mixed cells as inoculum. The reactor was inoculated with sewage sludge, which were heat-treated at 90 C for harvesting spore-forming, H2-producing bacteria, and fed with synthetic wastewater containing 1% (w/v) glucose. With decreasing HRT, volumetric H2 production rate increased but the H2 production yield to glucose decreased gradually. The H2 content in biogas was maintained at 50 - 70% (v/v) and no appreciable CH4 was detected during the operation. The maximal volumetric H2 production rate and H2 yield to glucose were 1714 mmol H2/L.d and 1.1 mol H2/mol glucose, respectively. These results indicate that the MBR should be considered as one of the most promising systems for fermentative H2 production. (authors)