Abstract:The design scale of a wastewater treatment plant (WWTP) project in Jinan is 40 000 m3/d, and the improved Bardenpho process is used for the secondary treatment. At the same time, by setting up the multi-point inflow and the multi-point carbon addition, the pre-anaerobic is constructed at the front end, and the secondary anaerobic/aerobic changeable section is added, which provide the multiple technological operation modes for WWTP. The operation result shows that the pollutant removal rates of CODCr, NH3-N, TN and TP by the modified Bardenoho process are 94.98%, 98.35%, 93.95% and 79.68% respectively, and the effluent CODCr , NH3-N, TN and TP are 11.7, 0.68, 3.03 and 0.77 mg/L respectively. Except for TP, which need to be enhanced by the advanced treatment, and the other indexes are all better than the designed effluent qualities.