[Nitrogen Removal Characteristics and Diversity of Microbial Community in ANAMMOX Reactor]

The volume loading of upflow blanket filter increased from 0.52 kg·(m³·d)^-1to 2.75 kg·(m³·d)^-1 by improving the influent NH₄⁺-N and NO₂^--N concentrations. The removal efficiency of NH₄⁺-N, NO₂^--N and TN increased from 76.18%, 53.47%, 55.66% to 94.04%, 86.97%, 82.96% respectively. Meanwhile, the microbial community of UBF ANAMMOX reactor was analyzed by Illumina high-throughput sequencing during the initial and later operational process. The results indicated that the denitrifying bacteria coexisted in the reactor. The percentages of Planctomycetes, Proteobacteria and Nitrospirae in the sludge were 27.9%-39.9%, 1.1%-26.4% and 0.035%-0.188%, respectively. The proportions of Planctomycetes and Proteobacteria increased from 1.1%, 27.9% in the enrichment stage to 26.4%, 39.9% in the stable operation stage respectively. In addition, Planctomycetes increased significantly. The proportion of Brocadiacea reached 24.57%. Therefore, Brocadiacea became the dominant bacteria in the phylum Planctomycete, which contained Candidatus brocadia. The alpha diversity index and relative abundance of clustering figure indicated that the diversity of microbial community decreased gradually and the structure of microbial community changed obviously.