Dissolved oxygen (DO) is a crucial parameter of the completely autotrophic nitrogen removal over nitrite (CANON) process. This study determined the nitrogen removal performance and microbial community of the CANON process in a laboratory-scale submerged aerated biological filter (SABF) over a DO concentration range from 0 to 1.2 mg·L⁻¹. The results showed that the optimum DO (0.2–0.3 mg·L⁻¹) corresponded to an average ammonium nitrogen removal efficiency of 93.4% and a total nitrogen removal efficiency of 81.0%. A 16S rRNA gene high-throughput sequencing technology confirmed that the phyla Proteobacteria and Nitrospirae enriched, whereas the phylum Planctomycetes was inhibited with increasing DO concentration. At the genus level, the increase of DO concentration resulted in the enrichment of genera Dok59 and Nitrospira, but restrained the genus Candidatus Brocadia. This research can be used to improve the nitrogen removal ability of the CANON process in an SABF in the future.

溶解氧（DO）是亚硝酸盐（CANON）工艺中完全自养氮去除的关键参数。这项研究确定了在DO浓度为0至1.2 mg·L ^-1的实验室规模的潜水式曝气生物滤池（SABF）中CANON工艺的脱氮性能和微生物群落。结果表明，最佳溶解氧（0.2–0.3 mg·L ^-1）对应于平均铵态氮去除率93.4％和总氮去除率81.0％。16S rRNA基因高通量测序技术证实门菌中的细菌和硝化螺旋菌丰富，而DO浓度增加时，扁平菌则受到抑制。在属的水平，溶解氧浓度的增加导致属的富集Dok59和硝化，但还是克制属暂定Brocadia。这项研究可用于将来提高SABF中CANON工艺的脱氮能力。