ABSTRACT
The interests in the aerobic granular sludge (AGS) technology were initially focused on the excellent settleability of the granular sludge because it can largely improve the liquid-solid separation efficiency of the biological wastewater treatment. This technology has recently received increased attention due to its capacity to achieve simultaneous nitrification, denitrification, and phosphorus removal (SNDNPR). This chapter introduces the concept of the SNDNPR, the formation mechanisms of AGS, the performance and cycle behavior of SNDNPR in AGS reactors, and the role of denitrifying phosphate accumulating organisms in the SNDNPR. Enhanced biological phosphorus removal involves uptake of phosphorus from wastewater by phosphorus accumulating organisms and subsequent removal of phosphorus via sludge wasting. The SNDNPR AGS can exhibit a strong phosphate release behavior during the anaerobic period and show the simultaneous nitrogen and phosphate removal during the aerobic period. For the SBR operation, a settling period prior to the decantation is necessary to separate the sludge from the treated wastewater.
