Used A/O-SBR(anaerobic/aerobic alternating enhanced biological phosphorus removal system) to study carbon source and phosphate accumulating organisms (PAO) intracellular energy storage substance transformation, also studied PAO’s phosphorus removal capacity. PAO could uptake quick degradation organic matters and synthesis polyhydroxyalkanoates(PHA). PHA was a kind of intracellular energy storage substance, its content could affect PAO’s phosphorus removal capacity. When carbon source was plentiful, PAO could synthesis a lot of PHA, phosphorus removal capacity could reach 38.16 mgp/gvss. Sludge retention time could affect PAO synthesis PHA of quantity and structure. Along with the sludge retention time growth, intracellular PHA content was increased, and phosphorus uptake of desired aerobic time continues to decrease, so increasing the phosphorus removal efficiency. When the municipal sewage as carbon source, PHA was mainly composed of PHB(poly-ß-hydroxyvalerate) and PHV(poly-ß-hydroxyvalerate). Along with the sludge retention time prolongation, PAO could synthesis more PHV, PHB content was remain unchanged, PHA composition structure was changed.
