Hydrogen yields of three typical acidogenesis fermentation communities in an anaerobic activated sludge process

摘要

A continuous stirred-tank reactor (CSTR) was introduced and the hydrogen productivity of the three type fermentation communities, i.e. propionic acid, butyric acid and ethanol type fermentation, was researched under the same organic ioading rate and temperature ,in this paper. The reactor was fed continuously with diluted molasses with a COD concentration of 5000 mg/L, a HRT of 8 h under (35±1) °C. The results indicated that the specific hydrogen production rate of ethanol type fermentation community reached 2.96 mol/kgMLVSS/d [mol per kilogram mixed liquid volatile suspended solid (MLVSS) per day], while butyric acid and propionic acid type fermentation communities were 0.57 mol/kgMLVSS/d and 0.022 mol/kgMLVSS/d respectively. The specific hydrogen production rate of ethanol type fermentation was 4.11 times as much as butyric acid type fermentation and 148 times as much as propionic acid type fermentation. The results obtained in the course of this investigation clearly demonstrated that ethanol type fermentation was optimum for bio-hydrogen production by organic wastewater fermentation.