Effect of Excessive Aeration on Biological Phosphorus Removal

This paper adopts two parallel SBRs(the dissolved oxygen is respectively 2~4 mg/L and 6~8 mg/L) running with anaerobic/anoxic/aerobic behaviors to research the effect of excessive aeration on biological phosphorus removal.Results show that,in the early excessive aeration,the phosphorus concentration in effluents is lower than that in the control group,and one week later the phosphorus removal decreases by 18%;in the condition of excessive aeration,the amount of phosphorus release is 1.45 times of that in the control group while the release rate is the same,and the amount of anoxic phosphorus uptake increases while the ratio of DPB decreases;the amount of aerobic phosphorus uptake is only 75% of that in the control group,and the uptake rate also decreases to 68% of that in the control group;the main reason for the deterioration of the phosphorus removal is the invalid increased phosphorus release and the decrease of aerobic phosphorus uptake capacity caused by endogenous losses;SVI increases,particle diameter is smaller,effluent SS is slightly better than that in the control group,and sludge phosphorus content decreases;however,long-term excessive aeration will lead to the deterioration of biological phosphorus removal.