A^2/O-BAF组合工艺对生活污水脱氮除磷的影响研究

Influence of Combined Process A^2/O-BAF System on Nitrogen and Phosphorus Removal from Domestic Sewage

以生活污水为研究对象,重点考察了A2/O-BAF组合工艺的脱氮除磷特性。试验结果表明,该工艺可以实现有机物、氮、磷的同步深度去除,出水水质满足《城镇污水处理厂污染物排放标准》(GB18918-2002)一级标准中A标准;COD、NH4+-N和TP的去除率与内循环回流比之间没有明显的相关性;曝气生物滤池对氨氮的硝化效率接近100%;在4种不同的内循环回流比条件下,出水TN分别为20.6、14.5、8.2和7.8 mg.L-1,TN的去除率分别为66.1%、76.0%、86.5%和87.1%,TN的去除率随着内循环回流比的增大呈增大趋势;当内循环回流比为200%、300%和400%时,TN去除率的增大幅度呈递减规律;系统中存在着明显的反硝化除磷现象,且内循环回流比增大有利于反硝化除磷。

Removal behaviors of biological phosphorus and nitrogen from domestic sewage were investigated in a combined process A2/O-BAF system. The results show that the combined process can simultaneously achieve the advanced removal of organic matter, nitrogen and phosphorus. The effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918-2002）. There was no distinct relationship between the internal return ratio and the removal efficiencies of COD, ammonia nitrogen and TP. Almost 100 % ammonium nitrogen removal efficiency was achieved in the BAF reactor. Under different internal return ratios, the concentrations of＇IN could be reduced to 20.6, 14.5, 8.2 and 7.8 mg.L^-1 in the effluent and the removal efficiencies of TN were 66.1%, 76.0 %, 86.5 % and 87.1%. The removal efficiencies of TN increased with the increasing of the internal return ratio. However, the rising rate was descending with the internal return ratio of 200 %, 300 % and 400 %. In addition, there was obvious phenomenon of denitrifying phosphorus removal in the combined process A2/O-BAF system. The capacity of denitrifying phosphorus removal in anoxic zone increased simultaneously with the increasing of the internal return ratio.