Anaerobic sludge was capable of producing anaerobic ammonium oxidation (anammox) cultures. However, the low activity of anammox bacteria in the seed sludge often led to a long time for stable anammox to initiate. The objective of this study was to investigate the influence of an extended reaction-phase time in the sequencing batch reactor (SBR) on the rapid startup of anaerobic ammonium oxidation (anammox) using anaerobic heterotrophic bacteria as the seed sludge. After the startup, suspended and attached bacteria in anammox were separately analyzed for comparison. The variations of nitrogen concentrations and shifts of the microbial community structures were studied. The results showed that anammox occurred after a long reaction-phase time in the SBR with the efficient removals of NH₄⁺ (96.4%) and NO₂⁻ (99.8%). The effective NO₂⁻ treatment before anammox startup was attributable to inevitable denitrification or dissimilatory nitrate reduction (e.g., Denitratisoma). The occurrence of anammox was supported by the anammox stoichiometry, bacteria diversity variation, and principal component analysis. The overall nitrogen removal rate (NRR) and nitrogen removal efficiency (NRE) was 0.07 kg/m³-d and 92.8%, respectively. The relative molar quantities of NH₄⁺ and NO₂⁻ removed as well as N₂ and NO₃⁻ formed were 1(1):1.29(1.32):1.45(1.02):0.15(0.26), as the numbers in the parentheses represent the theoretical values. Denitratisoma and Desulfatiglans dominated in the seed sludge, whereas Candidatus_Jettenia abundances were significantly higher in anammox attached- (26.0%) and suspended-growth cultures (14.5%). Fifty-three genera were simultaneously identified in all samples, suggesting their importance in the startup of anammox from anaerobic sludge. Candidatus_Jettenia was observed to be more associated with the growth of anammox biofilm (the abundances were 26.0% and 14.5% in attached- and suspended-growth cultures, respectively) and supported the fine nitrogen removal performance in the attached-growth cultures.

厌氧污泥能够产生厌氧氨氧化（厌氧氨氧化）培养物。然而，种子污泥中厌氧氨氧化菌的低活性往往导致稳定厌氧氨氧化的启动时间较长。本研究的目的是研究在序批式反应器 (SBR) 中延长反应阶段时间对使用厌氧异养细菌作为种子污泥的厌氧氨氧化 (anammox) 快速启动的影响。启动后分别对厌氧氨氧化中的悬浮菌和附着菌进行对比分析。研究了氮浓度的变化和微生物群落结构的变化。结果表明，厌氧氨氧化在 SBR 中经过较长的反应相时间后发生，NH ₄ ⁺的有效去除(96.4%) 和 NO ₂ ^- (99.8%)。厌氧氨氧化启动前的有效NO ₂ ^-处理归因于不可避免的反硝化或异化硝酸盐还原（例如，Denitratisoma）。厌氧氨氧化的发生得到了厌氧氨氧化的化学计量、细菌多样性变化和主成分分析的支持。总脱氮率(NRR)和脱氮效率(NRE)分别为0.07 kg/m ³ -d和92.8%。除去的NH ₄ ⁺和NO ₂ ^-以及N ₂和NO ₃ ^-的相对摩尔量形成为 1(1):1.29(1.32):1.45(1.02):0.15(0.26)，因为括号中的数字代表理论值。Denitratisoma和Desulfatiglans在种子污泥中占主导地位，而Candidatus_Jettenia丰度在厌氧氨氧化附着（26.0%）和悬浮生长培养（14.5%）中显着更高。在所有样品中同时鉴定了 53 个属，表明它们在厌氧污泥中启动厌氧氨氧化的重要性。观察到Candidatus_Jettenia与厌氧氨氧化生物膜的生长更相关（在附着生长和悬浮生长培养物中的丰度分别为 26.0% 和 14.5%），并支持附着生长培养物中的精细脱氮性能。