High-rate hydrogen production from galactose and rapid granule formation were achieved in a mesophilic (37 °C) upflow anaerobic sludge blank reactor (UASBr). Hybrid immobilized cells were seeded to a CSTR fed with galactose (15 g L-1) at a hydraulic retention time (HRT) of 12 h for 12 days, after which the mixed liquor from the CSTR was transferred to the UASBr. Rapid granule formation was observed after 5 days of initial UASBr operation at 6 h HRT and further enhanced at 3 h HRT. The peak hydrogen production rate (HPR) and hydrogen yield (HY) of 32.7 L L-1 d-1 and 1.95 mol mol-1 galactose were attained at the HRT of 3 h with an organic loading rate (OLR) of 120 g L-1 d-1. Microbial community analysis characterized by pyrosequencing of 16S rRNA genes showed that the proportion of Clostridium increased during the HRT at 3 h, whereas Bacilli proportions dominated at 6 h HRT.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2014R1A2A2A04005475)
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)