进水配比对三级 AO 工艺处理城市污水的影响

Adjustable influent flow distribution is one of the advantages of the multi-feed influent three-stage anoxic aerobic (AO) process. This work constructed a lab-scale three-stage AO process to explore the superior distribution for improved efficiency of pollutant removal. The removal efficiency of pollutants was researched under different distinct distributions. Furthermore, a mass balance model was used to assess the amount of pollutant removal in different functional units. The results indicated that the best influent flow distribution of 5:3:2 for the three-stage AO process. The average effluent concentrations of COD, NH₄⁺-N, TN, and TP were 25.2, 0.48, 14.7, and 0.48 mg/L respectively under the above distribution. These effluent concentrations of pollutants met the first-class A effluent discharge standard, and the pollutant removal rates were kept relatively stable. The mass balance calculation showed that the multi-feed influent process contributed to sharing the load of pollutant removal, and improved heterotrophic nitrification and denitrifying phosphorus removal for the removal of nitrogen and phosphorus. Thus, this work could provide a theoretical basis for the selection of influent flow distribution for sewage-treatment plants.