Effects of phosphorus release amount and temperature on denitrifying phosphorus removal in a two-sludge system

To improve the efficiency of denitrifying phosphorus removal in the two-sludge process,the effects of phosphorus release amount and temperature on denitrifying phosphorus removal were investigated in parallel batch experiments.The results indicated that as phosphorus release amount increased from 8.64 mg·L-1 to 28.93 mg·L-1,phosphorus uptake amount,net phosphorus uptake amount and nitrate removal efficiency increased,but the ratio of uptake amount and release amount remained almost unchanged.At the temperatures of 8℃,16℃,28℃,denitrifying phosphorus removal all ended after approximately 260 min reaction.Nitrate and phosphorus removal efficiency decreased at lower temperatures.A good linear relationship between nitrate consumption and phosphorus uptake amount was observed in the experiments with the correlation coefficient ranging from 1.002 to 1.044.This relationship between nitrate consumption and phosphorus uptake amount indicated the sludge intrinsic characteristics.