초록
Dark fermentation experiments were performed for bio-hydrogen production from ground wheat starch solution (10 +/- 1 g l<SUP>-1</SUP>) using periodic feeding and effluent removal. A mixed culture of Clostridium butyricum-NRRL 1024 and Clostridium pasteurianum-NRRL B-598 were used with an initial biomass ratio of 1/1.Effects of wheat starch loading rate on the rate and yield of bio-hydrogen formation were investigated. Substrate loading rate was varied between 0.54 and 5.52 g d<SUP>-1</SUP> (HRT = 6-60 h). The highest hydrogen formation rate (280 ml d<SUP>-1</SUP>), volumetric hydrogen formation rate (1857 ml H<SUB>2</SUB> l<SUP>-1</SUP> d<SUP>-1</SUP>) and volatile fatty acids (VFAs) concentration were obtained with a substrate loading rate of 5.52 g d<SUP>-1</SUP> (HRT = 6 h). The highest hydrogen yield (109 ml H<SUB>2</SUB> g TS <SUP>-1</SUP>) was obtained with a substrate loading rate of 1.38 g d<SUP>-1</SUP>1.