Overall performance of waste activated sludge alternate anaerobic/anoxic fermentation system

Sludge alternate anaerobic/anoxic fermentation system(SAF) was established by adding nitrate to the waste activated sludge(WAS) anaerobic fermentation system, therefore it created an alternate anaerobic/anoxic process for the sludge simultaneous fermentation and denitrification. In this research, the overall performance was analysisd both in SAF and typical anaerobic fermentation(TAF), in order to study the characteristics of fermentation and denitrification. Both of the performance in two systems stabilised till the 60^th day, SAF achieved higher sludge reduction, while owned less productivity of fermentation product compared to TAF. SAF showed its excellent denitrifying ability in the overall process, which proved the feasibility of simultaneous fermentation and denitrification in it. Besides, the trend of pH, ORP could be the indicators of denitrification in SAF.