Acidification of Waste Activated Sludge during Mesophilic Phase in Two Phases Anaerobic Digestion System

摘要

Waste activated sludge is always used to product methane by two phases anaerobic digestion, but fermenting to accumulate VFAs has seldom reported. This paper deals with the effects of pH value, adding ratio and hydraulic retention time (HRT) on WAS acidification during mesophilic phase in two phases anaerobic digestion (TPAD) system through batch experiments. In order to gain the most amount of VFAs for providing more carbon source, the optimal conditions for WAS mesophilic anaerobic digestion observed in this study are pH=7, adding ratio=12.5%, HRT=4d and TC/TNb value=l .7～2.0. Finally, we analyzed acid production kinetic under the optimal conditions. It can be inferred that the performance of WAS acidification is sensitive to operating conditions.