改良型A^(2)/O污水处理厂的工艺优化调控方案及其对同步脱氮除磷效率的提升

Process optimization regulation scheme of a full-scale modified A^(2)/O wastewater treatment plant and its improvement of simultaneous nitrogen and phosphorus removal efficiency

以一座处理规模为10×10^(4) m^(3)·d^(-1)的市政污水处理厂为研究对象,分析了优化调控参数对系统污水处理效果的影响,并探讨了各构筑物对脱氮除磷的贡献。结果表明:在改变曝气及回流方式后,出水TN和TP同步下降;厌氧池为氮磷去除的主要场所,TN、TP在厌氧池中的削减量分别占其总削减量的70.8%和89.5%;在生物除磷实验中,厌氧段平均释磷速率(以每克VSS计)为3.35 mg·h^(-1);好氧吸磷和缺氧吸磷实验证实,反硝化除磷菌(DPAO)占生物聚磷菌(PAO)的90%以上,且DPAO可在好氧段吸磷。在对工艺进行优化调控后,系统出水水质均可达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准,同时还可实现节能降耗、降低污水处理成本。本研究结果可为同类市政污水处理厂的性能提升提供参考。

The influence of optimal control parameters on processing effect and the contribution of main structures to nitrogen and phosphorus removal were analyzed by taking a municipal wastewater treatment plan(WWTP)with a treatment capacity of 10×10^(4) m^(3)·d^(-1) as the research object.The results showed that the tota nitrogen(TN)and total phosphorus(TP)in the effluent decreased simultaneously after changing the aeration and reflux modes.Anaerobic tank was the main place for nitrogen and phosphorus removal since the reduction of TN and TP in anaerobic tank accounted for 70.8%and 89.5%respectively.The biological phosphorus remova experiments showed that the anaerobic phosphorus release rate(measured by VSS)was 3.35 mg·h^(-1) on average.Aerobic and anoxic phosphorus uptake experiments confirmed that denitrifying phosphate accumulating organisms(DPAO)accounted for over 90%of phosphate accumulating organisms(PAO),and DPAO could also absorb phosphorus in the aerobic stage.After optimizing and regulating the process,the effluent quality of treatment system could meet the class 1A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918–2002),and at the same time,energy saving and consumption reduction can be realized to reduce the cost of wastewater treatment.The result of this study can provide a reference for the performance improvement of similar municipal WWTPs.