Effect of Intracellular Carbon Resource on Competition between PAOs and GAOs for Enhanced Biological Phosphorus Removal

Abstract

Batch tests were conducted to study the effect of internal carbon resource on the competition between phosphorus accumulating organisms (PAOs) and glycogen accumulating organism (GAOs) for simultaneous N and P removal. The result showed that the average P removal rate of PAOs was above 98.5%. Both PAOs and GAOs enriched sludge released P effectively on the anaerobic phase, and about 20 mg/L P was released. In the anoxic-P uptake process, 2.24 mmol/g-MLVSS and 2.44 mmol/g-MLVSS of polyhydroxyalkanoates (PHA) were consumed by PAOs enriched sludge and GAOs enriched sludge, respectively. Simultaneously, the glycogen concentration of GAOs enriched sludge was higher than that of PAOs enriched sludge during the anoxic process, on the contrast, more glycogen was synthesized in PAOs enriched sludge than GAOs enriched sludge, and 0.95 mmol/g-MLVSS glycogen was synthesized in PAOs enriched sludge.