Mathematical simulating the process of aerobic granular sludge treating high carbon and nitrogen concentration wastewater

The Activated Sludge Model No. 3 (ASM3) was modified by considering the simultaneous storage and growth, heterotrophic nitrification and aerobic denitrification processes. The model was used to simulate the biological process of aerobic granular sludge (AGS) treating high COD and nitrogen piggery wastewater without any pretreatment. In the model, the AGS utilizes readily biodegradable substrates for simultaneous storage, growth and metabolism during the feast phase. It further utilizes storage products for secondary growth and metabolism during the famine phase. Finally, it produces inert organic carbon through the decay. For nitrogen removal, nitrification process is mainly heterotrophic nitrification. Denitrification is completed by a combined process of anoxic and aerobic denitrification. The comparison between simulation results and experimental data shows that the modified model satisfactorily simulated the organic substrates degradation, nitrification and denitrification processes of treatment of high-concentration piggery wastewater by AGS.