改良UCT分段进水脱氮除磷工艺的性能分析

Performance Analysis of Modified UCT Step-feed Nutrients Removal Process

结合北京某污水处理厂升级改造工程,以实际生活污水为处理对象,研究新型改良UCT分段进水深度脱氮除磷工艺降解有机物、深度脱氮和除磷机理,并在此基础上探讨了工艺特点及设计和操作运行要点。长达2年的中试结果表明,出水总氮平均为8.51 mg/L,总磷为0.44mg/L,COD为44 mg/L,达到国家一级A排放标准;系统深度脱氮途径主要包括传统硝化反硝化和好氧同步硝化反硝化两个过程;缺氧吸磷量占总吸磷量的比例为32.6%～39.5%,强化了系统的除磷性能;55.9%的原水COD为厌氧释磷和反硝化过程提供能源或碳源,系统对碳源的利用率高;该工艺仅在传统A/O、A2/O工艺基础上取消了硝化液内回流设施,调整了进水管路,用于已建污水处理厂的升级改造简单易行,应用前景广阔。

Combined with the upgrading and reconstruction project of a wastewater treatment plant in Beijing, the mechanisms for organic degradation, enhanced nitrogen and phosphorus removal in a novel modified UCT step-feed nutrients removal process treating real municipal wastewater were studied, and the process characteristics and the main points in design and operation were discussed. The results of the pilot-scale test for about two years show that the average TN, TP and COD in the effluent are 8.51 mg/L, 0.44 mg/L and 44 mg/L respectively, meeting the requirement of the first-A discharge standard in China. Both the conventional nitrification and denitrification process and aerobic simultaneous nitrification and denitrifieation process contribute to the advanced nitrogen removal, and the anoxic phosphorus uptake, which accounts for approximately 32.6% to 39.5% of the total phosphorus uptake, is benefit for the phosphorus removal. Moreover, the system has high utilization efficiency of the influent organics since 55.9% of the influent organics are efficiently utilized in the anaerobic phosphorus release and denitrification process. Compared to A/O and A2/O processes, the modified UCT step-feed nutrients removal process just needs to cancel the internal recycle system and adjust the influent pipelines, and therefore the process is easy to be used in upgrading and reconstruction of existing wastewater treatment plants with a promising application market.