Exploring optimal environmental factors for fermentative hydrogen production from starch using mixed anaerobic microflora
- 作者：Kuo-Shing Lee ; Yao-Feng Hsu ; Yung-Chung Lo ; Ping-Jei Lin ; Chiu-Yue Lin ; Jo-Shu Chang
- 关键词：Fermentative hydrogen production ; Starch ; Environmental factors ; pH ; Kinetics
- 刊名：International Journal of Hydrogen Energy
- 出版年：2008
- 期刊代码：42_03603199
- 类别：ch
- 出版时间：March 2008
- 卷：33
- 期：5
- 页码：1565-1572
- 文件大小：267 K
摘要
Our previous work demonstrated that an acclimated mixed bacterial consortium was able to produce H2 from sugar substrates. To reduce the medium cost for more commercially viable H2 production, cassava starch was used as the feedstock to produce H2 via dark fermentation. Three factors, namely, temperature, pH and starch concentration (Cstarch), were intensively examined for their effects on H2 production activity. The H2 production kinetics was determined using a Monod-type kinetic model. The results show that mesophilic temperature 
is preferable for baee48972dc6e" title="Click to view the MathML source" alt="Click to view the MathML source">H2 production with the H2-producing sludge used. The daedab60" title="Click to view the MathML source" alt="Click to view the MathML source">H2 production efficiency and the composition of soluble metabolites were found to be highly sensitive to the change in pH, as pH 6.0 seemed to give the best overall H2 production performance. In a non-pH-controlled culture (initial pH=8.5), ethanol and butyrate were the major soluble metabolites, whereas the predominant metabolites switched to butyrate alone (accounting for 70–80%of total soluble microbial products) when the culture pH was controlled at a fixed level ranging from 5.5 to 7.0. Meanwhile, the maximum H2 production rate occurred when the initial starch concentration was 24 g COD/l. The dependence of H2 production rate on starch concentration could be described by using Monod-type model and the predicted kinetic constants, namely, maximum H2 production rate (vmax,H2) and Monod constant (Ks), were 1741 ml/h/l and 16.28 g COD/l, respectively. Under the optimal conditions (
, pH 6.0, 
), the H2 production rate increased to 1119 ml/h/l, while a high H2 yield of 9.47 mmol H2/g starch was obtained. This performance appeared to be superior to that obtained from other starch-to-bioH2 systems reported in the literature.