Continuous Biohydrogen Production with CSTR Reactor under High Organic Loading Rate Condition
A continuous stirred-tank reactor (CSTR) was used to produce biohydrogen gas from organic wastewater. The hydrogen producing reactor was operated under high organic loading rate of 21 kgCOD/m3·d, and molasses wastewater was used as substrate. Hydrogen production rate, pH value, sugar utilizing rate and fermentative products in effluent were investigated in continuous fermentation. When Organic Loading Rate was controlled at 21 kgCOD/m3·d, the average concentrations of acetic acid, ethanol, propionic acid, butyric acid and valeric acid in liquid fermentative products were 833, 748, 482, 484 and 256mg/L respectively. There is not any fermentation product playing dominant role absolutely in hydrogen production fermentation. The pH value in effluent was about 4.7~4.9, the average utilizing rate of sugar reached 92.1%, most of the sugar in molasses wastewater was utilized. The biogas production rate in hydrogen producing fermentation was from 21.2 to 27.1L/d, and the average biogas production rate was about 25.1L/d. The hydrogen content was about 37%.