Conversion of volatile fatty acids by hydrogen-producing and aceogenic microflora from bio-hydrogen producing reactor

Conversion and hydrogen production of ethanol, acetate, propionic acid, butyric acid, valeric acid and lactic acid by hydrogen-producing and aceogenic microflora were investigated with batch culture. In glucose fermentation of activated sludge, accumulative biogas yield was 356 mL and hydrogen yield was 209 mL, hydrogen content in biogas was 58.7%. Concentration of ethanol, acetic acid, propionic acid, butyric acid, valeric acid were 427.1 mg/L, 716.5 mg/L, 172.5 mg/L, 689.4 mg/L, 123.6 mg/L, respectively. Hydrogen-producing and aceogenic microflora in anaerobic activated sludge would convert ethanol and lactic acid into acetate and hydrogen. Concentration of acetate converted form ethanol was about 270 mg/L and accumulative hydrogen yield was 15 mL. While, concentration of acetate converted from lactic acid was about 190 mg/L and accumulative hydrogen yield was 7 mL. Activated sludge couldn't convert acetate, propionic acid, butyric acid, valeric acid to acetate and couldn't produce any hydrogen during batch culture, therefore conversion of ethanol and volatile fatty acids by hydrogen-producing and aceogenic microflora was not the main hydrogen production pathway for bio-hydrogen producing reactor.