High-rate biohydrogen production was achieved via hybrid immobilized cells fed with galactose in a continuous reactor system. The hybrid immobilized cells were broken down after 20days and began to form granules by self-aggregation. The peak hydrogen production rate (HPR) and hydrogen yield (HY) of 11.8±0.6LH2/L-d and 2.1±0.1molH2/molgalactoseadded, respectively, were achieved at the hydraulic retention time (HRT) of 8h with an organic loading rate (OLR) of 45g/L-d. This is the highest yet reported for the employment of galactose in a continuous system. Various process disturbances including shock loading, acidification, alkalization and starvation were examined through bacterial community analysis via pyrosequencing of the 16S rRNA genes. The proportion of Clostridia increased during the stable biohydrogen production periods, while that of Bacilli increased when the reactor was disturbed. However, due to the stability of the self-aggregated granules, the process performance was regained within 4-7days.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2014R1A2A2A04005475 ).
© 2015 Elsevier Ltd.
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal