两级A/O-MBBR耦合厌氧氨氧化工艺强化垃圾渗滤液脱氮性能OA

Landfill leachate,characterized by high ammonium concentrations,heavy organic loads,and complex toxic constituents,has long been a major environmental concern due to its treatment difficulty and low nitrogen removal efficiency.To achieve efficient nitrogen removal,a continuous-flow two-stage anoxic/oxic(anoxic/oxic,A/O)-moving bed biofilm reactor(moving-bed biofilm reactor,MBBR)system was developed and coupled with an anaerobic ammonium oxidation(Anammox)process for the long-term treatment of actual landfill leachate.The system was initiated through biofilm cultivation and multi-stage influent acclimation,during which the influent gradually increased from low concentration(NH4+-N≈200 mg·L−1,COD≈2 500～3 000 mg·L−1)to high concentration(NH4+-N≈1 800 mg·L−1;COD≈8 500 mg·L−1).During stable operation,the average removal efficiencies of NH4+-N and COD reached 97.7%and 66.8%,respectively,while the total nitrogen(TN)removal efficiency increased to 93.9%.Spatial monitoring revealed that the front A/O zone mainly achieved organic matter degradation and ammonia oxidation,whereas the rear zone facilitated nitrite accumulation and promoted synergistic Anammox-driven nitrogen removal.High-throughput sequencing results indicated that Proteobacteria was the dominant phylum(>50%),with denitrifying genera such as Azoarcus and Thauera significantly enriched.Meanwhile,the relative abundance of Planctomycetota increased from 0.6%to 3.7%,and the detection of Candidatus Kuenenia confirmed the successful colonization of Anammox bacteria.These findings demonstrate a highly efficient composite nitrogen removal mechanism achieved through the synergistic operation of the A/O-MBBR system and the Anammox process,providing a theoretical basis and technical pathway for the engineering application of high-ammonia wastewater treatment.