进水配比对三级AO工艺处理城市污水的影响

Effect of Influent Flow Distribution on the Efficiency of Three-Stage Anoxic Aerobic(AO)Process Treating MunicipalWastewater Treatment

可调节分段进水是分段进水三级缺氧-好氧(AO)工艺优势之一。为探寻较优的进水配比,提高污染物去除效能,本研究构建三级AO小试实验装置,研究不同进水配比下污染物去除效果变化,采用物料衡算模型评估不同功能单元污染物降解量。结果表明,分段进水三级AO工艺最佳进水配比为5∶3∶2,在该条件下,COD和NH_(4)^(+)-N平均出水质量浓度分别为25.2和0.48 mg/L,TN和TP平均出水质量浓度分别为14.7、0.48 mg/L,满足一级A排放标准,各污染物去除率较为稳定。经物料衡算,分段进水有助于分担污染物处理负荷,使缺氧区进行异养硝化和反硝化除磷,以增强脱氮除磷效果。本研究可为污水处理厂选择进水配比提供理论依据。

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,NH_(4)^(+)-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.