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 l/day with OLR. The maximum Hydrogen yield and production rate were 111.1 mL-H 2 /g-VS added and 10.7 l-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 CH 4 -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. [ABSTRACT FROM AUTHOR]