| Summary: | 碩士 === 國立成功大學 === 環境工程學系碩博士班 === 90 === Due to the consumption of fossil fuel and production of green house gases (i.e., methane and carbon dioxide), developing clean and new energy will be one of the important researches in the further. Hydrogen, high energy yield (122 KJ/g, about 2.75 times greater than that of hydrocarbon fuels), is considered a promising candidate as an ideal and clean source of energy. Biohydrogen production process not only can solve environmental pollution, but also achieve resource recycling. Hence, hydrogen production via bioprocesses may have a great potential to provide a cheap, clean and sustainable energy in the further and deserves to have further investigations.
This study aimed at thermophilic (55 ℃) anaerobic hydrogen production reaction that digested the multiple substrates (sucrose and peptone). To achieve this purpose, biomembrane reactor, which could control biomass concentration in the reactor, was performed. Under hydraulic retention time (HRT) of 6 hrs and sludge retention time (SRT) of 2 days condition, maximum specific hydrogen production rate, amount of hydrogen production and hydrogen yield were 110.1 mmol H2/g VSS/day, 673 mmol H2/L/day and 16.8 mmol H2/g COD, respectively. As F/M value was low 4 g COD/g VSS/day，specific hydrogen production rate would decrease. The morphology of thermophilic anaerobic hydrogen producing bacteria was rod and endspore-formation. From DGGE fingerprint, the GC content of thermophilic anaerobic hydrogen producing bacteria was higher than mesophilic anaerobic hydrogen producing bacteria.
In thermophilic (55 ℃) anaerobic hydrogen production process, only 10 % COD converted to hydrogen and most carbohydrate converted to acids and ethanol.Factors infuenced the hydrogen production, the lower temperature and lower pH value would make the activity of hydrogen producing bacteria decrease. In the BHP test, the results revealed that the activation enthalpy of hydrogen producing bacteria was 60.6 kJ/mol and inhibition concentration of molecular acetate was 0.036 – 0.085 M. Comparing the addition of sodium and potassium ion for thermophilic hydrogen producing bacteria, the hydrogen producing bacteria were more sensitivity with potassium ion.
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