Cultivate of granular sludge based on denitrifying phosphate accumulating bacteria

Aerobic granules based on denitrifying phosphate accumulating bacteria were developed in sequencing batch reactors(SBRs) with flocs sludge as seed to improve nitrogen and phosphorus removal rate. The results showed that the denitrifying phosphate accumulating bacteria was successfully cultivated after 45days. During the synthetic domestic wastewater treatment, the phosphate removal rate of this system was around 90%, and the both removal rates of COD and ammonia nitrogen were around 95%. Meanwhile, the unit amount of nitrate denitrifying phosphate uptake reached 0.876mg/mg, and the ratio of denitrifying phosphate accumulating bacteria was 74.36% in phosphorus-accumulating bacterias(PAOs). The highest volume percentage of the granules was in the range of 1.0~2.0mm, and the settling velocity of mature granules in reactor was 44~72m/h. It can be concluded that aerobic granules based on denitrifying phosphate accumulating bacteria can be cultivated by adjusting the dissolved oxygen of SBR.