Performance of Denitrifying Phosphorus Removal by Aerobic Granular Sludge at Low Temperature

To deeply understand the performance of denitrifying phosphorus removal by aerobic granular sludge at low temperature, an aerobic granular sludge sequencing batch reactor had been operated at 10±1°C. The results showed that the PHAs components synthesized by phosphorus accumulating organisms (PAOs) in granule sludge were affected by different types of carbon source in anaerobic period, and the release and uptake of phosphate were also influenced. It was indicated that the increased ratio of PHV to PHAs led to the increase of the utilization efficiency of nitrate by denitrification PAOs. When initial COD concentration in anaerobic period was lower than 300mg/L, it can effectively keep organic substrates from flowing into the following anoxic period which influenced the efficiency of denitrifying phosphorus removal. Inhibition of nitrite to denitrifying phosphorus removal was decreased due to biology film growth manner of aerobic granular sludge. The inhibitory concentration of nitrite to denitrifying PAOs was 60 mg/L.