A Pilot-Scale Experimental Research on Biological Phosphorus Removal in a Modified SBR Treating Urban Wastewater
A pilot-scale modified SBR process was used to treat urban wastewater. The average NH4+-N efficiency removal was 98 %. The average TN removal efficiency was 52 %. The average TP removal efficiency was 85 %. The average COD removal efficiency was 85 %. The average effluent NH4+-N was 0.34 mg/L. The average effluent TN was 12 mg/L. The average effluent phosphorus was 0.75 mg/L. The average effluent COD was 35 mg/L. The result shows that the increase of 100 mg/L MLSS concentrations by proliferation or decrease of 100 mg/L MLSS concentrations by discharging residual sludge can remove 1 mg/L total phosphorus from wastewater. The faster the MLSS increases, the higher efficiency the phosphorus removal is achieved. When MLSS is fluctuating or decreasing, the phosphorus removal would be worse than MLSS increase. When MLSS increases 500 mg/L everyday, phosphorus removal efficiency would be very high; the average phosphorus removal efficiency would be higher than 90 % in the most urban wastewater treatment plant.