จิราวรรณ สุรโชติ. Source and Optimum Condition of Hydrogen Producing Bacteria in Dark Fermentative Biohydrogen Process. Master's Degree(Environmental Engineering). King Mongkut's University of Technology Thonburi. KMUTT Library.. : King Mongkut's University of Technology Thonburi, 2009.
Source and Optimum Condition of Hydrogen Producing Bacteria in Dark Fermentative Biohydrogen Process
Abstract:
This research aimed to evaluate the source of hydrogen producing microbes and the
optimum glucose concentration in dark fermentative hydrogen process. Prior to the
experiment, all inoculums were treated with heat shock in order to eliminate undesired
anaerobes. Acidic pH at 5.5 could stimulate the growth of hydrogen producing microbes.
Firstly, the preliminary test was performed in amber serum bottles to determine the
source of inoculums which could effectively produce hydrogen. It was found that the
sludge from biodiesel wastewater treatment plant was the best source of hydrogen
producing microbes. This is because this microbial sludge was familiar with acidic pH
and anaerobic condition and thus contained relatively high amount of hydrogen
producing microbes. Secondly, the confirmative test was carried out in a 250 mL
bioreactor. Even though the reactor was scaled up, the seed from biodiesel sludge still
performed the best. Finally, the optimum glucose dose was determined using a 250 mL
bioreactor with various glucose concentrations. The results indicated that the microbes
had the highest hydrogen production potential at the glucose concentration of 6.5 g
CODIL. Several volatile fatty acids, mainly acetic and butyric acids, were detected in
the system. The hydrogen yield, maximum hydrogen production rate, and maximum
specific hydrogen production rate were 0.36 mol Hz/mol glucose, 1.120 mL/h, and
0.560 mUg VSS-h, respectively.