To explore the reasons for the excellent denitrification performance of the Micro-pressure double-cycle reactor (MPDR), the nitrogen removal mechanism of the reactor in the treatment of municipal wastewater was studied. Through analysis of flow simulation and dissolved oxygen (DO) distribution, it was determined that the reactor had a macroscopic biochemical reaction environment for simultaneous nitrification and denitrification (SND) because of the special structure of reactor. The result of sewage treatment showed that the average removal rates of COD, NH₄⁺-N, TN, TP were 92.29%, 96.64%, 73.6% and 91.66% respectively, and the SND rate was 60.9%. Dechloromonas, Thermomonas, Micropruina, Tetrasphaera, etc. for nitrogen and phosphorus removal existed in the reactor at the same time to explain the excellent performance of the system. PICRUSt2 showed that the metabolic pathways related to nutrient degradation in the reactor were highly active and the abundance of denitrification functional genes was higher in the central zone and lower in the peripheral zone. The research results not only perfected the basic theory of the reactor, but more importantly, provided theoretical and technical support for the further application of the reactor.

为探究微压双循环反应器（MPDR）脱氮性能优异的原因，研究了该反应器在城市污水处理中的脱氮机理。通过流动模拟和溶解氧（DO）分布分析，确定由于反应器的特殊结构，反应器具有同时硝化反硝化（SND）的宏观生化反应环境。污水处理结果表明，COD、NH ₄ ⁺ -N、TN、TP的平均去除率分别为92.29%、96.64%、73.6%和91.66%，SND率为60.9%。脱氯，Thermomonas，Micropruina，Tetrasphaera等同时存在于反应器中的脱氮除磷，说明了该系统的优异性能。PICRUSt2表明，反应器内与养分降解相关的代谢途径高度活跃，反硝化功能基因丰度在中心区较高，在外围区较低。研究成果不仅完善了反应堆的基础理论，更重要的是为反应堆的进一步应用提供了理论和技术支持。