改进型A~2/O工艺处理城市生活污水的脱氮除磷效能研究

在分析传统A2/O工艺缺陷的基础上,提出了一种改进型A2/O工艺。为了防止回流污泥中的硝酸盐进入厌氧区,在传统A2/O工艺的厌氧区后面增加一个体积较小的缺氧选择池,回流污泥进入缺氧选择池,并进行反硝化消耗回流污泥中的硝酸盐;同时,在缺氧区通过反硝化除磷实现"一碳两用"。结果表明,改进型A2/O工艺有较好的脱氮除磷效果,在COD为298mg/L、TN为55mg/L左右、TP为7mg/L左右时,系统对COD、TN、TP的平均去除率分别为88.44%、77%、95%。

Research on phosphorus and nitrogen removal efficiency of modified A2/O process in municipal sewage treatment

A modified A2/O process was designed base on analyzing the defects of traditional A2/O process.In order to prevent the nitrate in the returned sludge flows into the anaerobic zone,a small selector zone was added behind the anaerobic zone of traditional A2/O process to accept the returned sludge.The nitrate in the returned sludge was consumed in selector zone through denitrification so as to decrease the nitrate quantity in anaerobic zone.In the anoxic zone,the organic carbon substrate can be used simultaneously for both nitrogen and phosphorus removal through the denitrifying dephosphatation.The experimental result showed that the modified A2/O process presented favorable effect on simultaneous nitrogen and phosphorus removal.Under the condition of influent COD 298 mg/L,TN 55 mg/L and TP 7 mg/L,the removal rates of COD,TN and TP were 88.44%,77% and 95%,respectively.