The Characteristics of Biological Nutrient Removal in a SBR through Aerobic Granular Sludge

The characteristics of biological nutrient removal was investigated with aerobic granular sludge in an anaerobic/aerobic SBR system. The anaerobic/aerobic SBR system showed a very stable phosphorus, nitrogen and organic carbon removal performance. The average removal rate for NH4+-N, total inorganic nitrogen (TIN), PO43--P and CH3COO--C reached 97.8%, 89.7%, 96.8% and 98.8%, respectively, when dissolved oxygen concentration in the aerobic phase was controlled at 1~2mg/L, with 80~90min anaerobic phase followed by 240min aerobic phase during the SBR cycle. The nitrification, denitrification, aerobic phosphate uptake and anoxic phosphate uptake could occur simultaneously in aerobic granular sludge under aerobic condition. The microorganism population in the granular sludge has a diversification, the formed microecosystem is more stable and the ability to withstand shock loading and the self-regulation ability are stronger.