Treatment of landfill leachate was conducted in a lab-scale sequencing batch reactor (SBR). The SBR was started through inoculating activated sludge with controlling dissolved oxygen of 0.5-1.0 mg/L. Anammox reaction took place within around three months. The SBR established robust nitrogen removal with incremental NLRs of 0.25-2.17 kg N/m³/d. At the final phase, it achieved elevated nitrogen removals of 1.68-1.91 kg N/m³/d. 16S rRNA gene amplicon sequencing analysis revealed Nitrosomonas, unclassified Anammox bacterium, and diverse denitrifying populations coexisted and accounted for 4.02%, 20.05% and 34.69%, respectively. Phylogenic analysis and average nucleotide identity comparison jointly suggested the unclassified Anammox bacterium potentially pertained to a novel Anammox lineage. The functional profiles’ prediction suggested sulfate reduction, arsenate reduction and eliminations of antibiotics and drugs likely occurred in the SBR. The finding from this study suggests contribution of unclassified Anammox bacteria in influencing nitrogen budget in natural and engineering systems is currently being underestimated.

垃圾渗滤液的处理是在实验室规模的分批反应器（SBR）中进行的。通过接种活性污泥并控制溶解氧为0.5-1.0 mg / L来开始SBR。厌氧氨氧化反应在大约三个月内发生。SBR建立了强大的除氮功能，NLR的增量为0.25-2.17 kg N / m ³ / d。在最后阶段，它的脱氮量提高了1.68-1.91 kg N / m ³ / d。16S rRNA基因扩增子序列分析揭示亚硝基胞菌，未分类的厌氧细菌和不同的反硝化细菌种群共存，分别占4.02％，20.05％和34.69％。系统发生分析和平均核苷酸同一性比较共同表明，未分类的Anammox细菌可能与新型Anammox谱系有关。功能概况的预测表明，SBR中可能发生硫酸盐还原，砷酸盐还原以及消除抗生素和药物。这项研究的发现表明，目前尚未低估未分类的厌氧氨氧化细菌在影响自然和工程系统中氮预算中的作用。