Continuous photosynthetic biohydrogen production from acetate-rich wastewater: Influence of light intensity

摘要

Photo-biohydrogen by microalgae is attractive sustainable energy caused by the utilization of solar energy and water. However, due to oxygen (O2) sensitive hydrogenase (HydA) activity, effective control of O2 and light intensity is critical for achieving sustainable photosynthetic hydrogen (H2) production. Here we demonstrate continuous algal H2 production using acetate-enriched fermenter effluent, achieving the complete O2 cessation without sulfur depletion. Average H2 production of 108 +/- 4 mmol L-1 for Chlamydomonas reinhardtii and 88 +/- 7 mmol L-1 for Chlorella sorokiniana at 100 mmol m-2 s-1 were observed for 15 days, respectively. The highest light energy to H2 energy conversion efficiency (LHCE) of 1.61% for C. reinhardtii and 1.06% for C. Sorokiniana was obtained under low light intensity (50 mmol m-2 s-1) but the LHCE decreased with the increase of light intensity followed by photoinhibition, which led to a decrease of HydA activity and H2 production. Low H2 production was observed at 50 mmol m-2 s-1 under the highest LHCE, in which microalgae exhibited photoinhibition biomass growth kinetics to produce chlorophyll a (Chl a) for electron generation. These results demonstrate that light is a feasible strategy for producing electron for H2 production under anoxygenic photosynthesis. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.commentSuperscript/Subscript Available/comment