| Summary: | 碩士 === 國立中興大學 === 環境工程學系 === 92 === Hydrogen evolution by cyanobacteria is a potential way of biohydrogen production for the future. Nitrogen-fixing cyanobacteria are photosynthetic organism with simple need, using CO2 and N2 as source of carbon and nitrogen, and sunlight as their source of energy. Cyanobacteria are able to evolve H2 in light catalysed by nitrogenase activity, with water serving as the primary electron donor.
Since the optimal operating conditions for the CO2 uptake and H2 production are different, a two-stage system can be effectively employed to separate these two phases. In this study, Anabaena sp. CH1, CH2, and CH3 has been isolated and purified from paddy soils of middle Taiwan and the physiology of nitrogen metabolism of these two species has been studied, ether. These cyanobacterium were incubated in 4% CO2 and 96% air with 40 Wm2 intensity of light in the 150 mL volume reactors. After cultured a pried of time, cyanobacterium was translated into a 60 mL volume batch reactor proceeded a series of biohdyrogen batch experiments such as different kinds and concentrates of carbon source, log or later growth phase, with or without 660 mg/L ammonium, anaerobic or aerobic, light or dark, and different species of cyanobacterium.
When 2000mg/L carbohydrates, such as fructose, glucose, galactose, rhamnose, lactose, and sucrose, been used as carbon source, it indicated that fructose is one of the most helpful inducer to product hydrogen.
Cumulative H2 production was higher when cyanobacterium growing in later phase then in log phase. And there was no H2 production when incubated in 660 mg/L ammonium, nether in the dark.
Over all, it was found that when added 2000 fructose under argon as gas phase with 5 Wm2 intensity of light and growth in later phase, cyanobacterium CH3 produce a maximum cumulative hydrogen pruduction as 80 mL H2 / 100 mL Head Space without oxygen co production.
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