一种改良型A^2/O工艺脱氮除磷的影响因素研究

RESEARCH ON INFLUENCE FACTORS OF NITROGEN AND PHOSPHORUS REMOVAL IN BI-BIO-SELECTIVE SIMULTANEOUS PHOSPHORUS AND NITROGEN( BBSPN) PROCESS

在传统A^2/O工艺基础上,提出了一种改良型A^2/O工艺(两级生物选择同步脱氮除磷工艺)。为了防止回流污泥中的硝酸盐进入厌氧区,在传统A^2/O工艺的厌氧区后耦合一小型缺氧选择池,进行反硝化和污泥回流;同时,在缺氧区通过反硝化除磷实现"一碳两用"。研究了C/N比、硝化液回流比、混合液回流比和污泥回流比对系统脱氮除磷的影响,结果表明:系统获得最佳脱氮除磷效果的工艺参数如下:进水为C/N=6、混合液回流比为150%、污泥回流比为100%、硝化液回流比为200%。

A modified A^2/O process was developed based on analyzing the drawbacks of the traditional A^2/O process（ bi-bioselective simultaneous phosphorus and nitrogen（ BBSPN） process）. A small selective zone was added behind the anaerobic zone of traditional A^2/O process for accepting the returned sludge,in order to prevent the nitrate getting into the returned sludge flows in the anaerobic zone. Therefore,the nitrate in the returned sludge was consumed in selective zone through denitrification so as to decrease the nitrate quantity. In the anoxic zone,the organic carbon substrate could be used simultaneously for the removal of both nitrogen and phosphorus through the denitrifying dephosphatation. Effect of C/N ratio,recirculation ratio of the nitrification liquid,the mixed liquid and the sludge on removal efficiencies of nitrogen and phosphorus of the modified process were investigated in this study. At the best condition of C/N ratio of 6,recirculation ratio of the nitrification liquid of 200%,recirculation ratio of the mixed liquid of 150% and recirculation ratio of the sludge of 100%,the system could achieve the best removal effect of nitrogen and phosphorus in the modified A^2/O process.