Hydrogen gas production from cheese whey powder (CWP) solution by thermophilic dark fermentation

摘要

Hydrogen gas production from cheese whey powder (CWP) solution by thermophilic dark fermentation was investigated at 55℃. Experiments were performed at different initial total sugar concentrations varying between 5.2 and 28.5 g L~(-1) with a constant initial bacteria concentration of 1 gL~(-1). The highest cumulative hydrogen evolution (257 mL) was obtained with 20 g L~(-1) total sugar (substrate) concentration within 360 h while the highest H_2 formation rate (2.55 mL h~(-1)) and yield (1.03 mol H_2 mol~(-1) glucose) were obtained at 5.2 and 9.5 g L~(-1) substrate concentrations, respectively. The specific H_2 production rate (SHPR = 4.5 mL h~(-1) g~(-1)cells) reached the highest level at 20 g L~(-1) total sugar concentration. Total volatile fatty acid (TVFA) concentration increased with increasing initial total sugar content and reached the highest level (14.15 g L~(-1)) at 28.5 g L~(-1) initial substrate concentration. The experimental data was correlated with the Gompertz equation and the constants were determined. The optimum initial total sugar concentration was 20 g L~(-1) above which substrate and product (VFA) inhibitions were observed.