Effect of organic loading rate on continuous hydrogen production from food waste in submerged anaerobic membrane bioreactor

The characteristics of hydrogen fermentation in a membrane bioreactor (HF-MBR) fed with food waste were investigated at thermophilic condition. The HF-MBR was operated at three different organic loading rates (OLRs) of 70.2, 89.4 and 125.4 kg-COD/m(3)/day. Biogas production rate increased from 22.4 to 32.8 and 62.5 1/day with OLR. The maximum Hydrogen yield and production rate were 111.1 mL-H-2/g-VS added and 10.7 1-H-2/L/day at an OLR of 125.4 kg-COD/m(3)/day. The total carbohydrate degradation was better than 96% throughout the experimental runs. Continuous H-2 production from food waste with CH4-free biogas was successfully sustained in the HF-MBR for 90 days. The microbial community was dominated by Clostridium sp. strain Z6. The H-2 production was significantly improved by shortening the retention time and increasing the OLRs. The HF-MBR showed an H-2 production capacity at the high OLRs due to its higher cell retention. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.