Study on Commutative Multi-influent Activated Sludge Process with Five Tanks for Nitrogen and Phosphorus Removal

In order to achieve the higher removal efficiency of nitrogen and phosphorus,a new municipal wastewater nitrogen and phosphorus removal process i.e.commutative multi-influent activated sludge process with five tanks was developed on the basis of UNITANK wastewater treatment process.The pilot-scale experiment for one year in a municipal wastewater treatment plant in Nanjing was conducted.The operation results show that when the influent concentrations of COD,BOD5,TP,NH3-N,TN are 110 to 430 mg/L,52 to 130 mg/L,2.2 to 6.1 mg/L,15 to 41 mg/L and 17 to 50 mg/L respectively,the effluent quality can reach the class I-A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002).The removal efficiencies of TP and TN reach more than 90% and 70% respectively.