【摘要】 针对城镇污水中碳源不足、C/N比低导致脱氮性能不佳的问题,建立了A2/O中试装置,通过调整系统缺氧/好氧分区比例及好氧区溶解氧水平,探究亚硝氮积累率及氮类污染物去除情况.结果表明,在DO为2. 0～2. 5 mg·L^-1条件下,改变缺氧/好氧分区比例对系统的影响较小,难以实现短程硝化;当控制DO为0. 5～0. 8 mg·L^-1、V_缺∶V_好=1∶1时为系统最优工况,此时系统好氧区末端亚硝氮积累率稳定在62%以上,出水总氮降至9. 0 mg·L^-1,能够实现深度脱氮的目标.分析硝化菌表观活性可知,最优工况下SAOR与SNOR分别（以N/VSS计）为0. 14 g·（g·d）^-1和0. 04 g·（g·d）^-1,二者差值较试验其他阶段更为明显,即NOB活性受到更高程度抑制是提高亚硝氮积累率的直接原因. Illumina MiSeq测序结果表明,该阶段NOB数量显著低于其他阶段.通过间歇OUR法分析缺氧区进出口碳源组成情况,结果表明最优工况下系统通过短程硝化节约碳源27. 3%,可生化性COD在缺氧区消耗63. 6%,远高于其他阶段,是低C/N比城市污水实现深度脱氮的碳源有力保障.更多还原

【Abstract】 Poor nitrogen removal from municipal sewage is mainly due to insufficient carbon source and low C/N ratio. The A2/O pilot plant was established to investigate the accumulation rate of nitrous nitrogen and the removal of nitrogen pollutants by adjusting the ratio of anoxic/aerobic zoning and dissolved oxygen levels in the aerobic zone. The results showed that when DO is 2. 0-2. 5 mg·L^-1,changing the ratio of anoxic to aerobic zoning had little effect on the reaction system,and it was difficult to realize partial nitrification.When DO is 0. 5-0. 8 mg·L^-1,V_Anoxic∶ V_Aerobic= 1∶ 1,this is the best working condition of the system. The accumulation rate of nitrous nitrogen at the end of aerobic zone is stable at more than 62%,and the total nitrogen of effluent is reduced to 9. 0 mg·L^-1,which can achieve the goal of deep denitrification. Analyzing the apparent activity of nitrifying bacteria,it was found that the SAOR and SNOR（ according to N/VSS calculation） were 0. 14 g·（ g·d）^-1 and 0. 04 g·（ g·d）^-1,respectively,under the optimum conditions. The difference between them was more obvious than that in other stages of the experiment,that is,the higher inhibition of NOB activity was the direct reason for the increase of nitrite accumulation rate. Illumina MiSeq sequencing showed that the number of NOB in this stage was significantly lower than that in other stages. Intermittent OUR method was used to analyze the composition of carbon sources at the inlet and outlet of the anoxic zone. The results showed that short-cut nitrification and denitrification could save 27. 3% of the carbon sources under the optimal operating conditions. The biodegradable COD consumption in the anoxic zone was 63. 6%,which was much higher than that in other stages.更多还原