The application of mainstream anammox process is hampered by its overlong start-up and instability under disturbance. A lab-scale mainstream anammox moving bed biofilm reactor (MBBR) was successfully started in 120 days with stepwise decrement in influent nitrogen concentration from sidestream to mainstream condition. The initial colonization by Candidatus Jettenia and filamentous fermenter Anaerolineaceae were potentially mediated by hydrophobic interaction and type IV pilus. Ca. Kuenenia with higher substrate affinity outcompeted Ca. Jettenia, and the predominant fermenters shifted to fermentative Ignavibacteriaceae in the mature biofilm. A novel mainstream anammox biofilm development (MABD) model was constructed to describe biofilm growth, population dynamics, and nitrogen removal performance. The simulation results suggested that higher inocula biomass (460–690 mgVSS·L⁻¹), relative abundance of low-affinity AnAOB in the inocula (e.g., Ca. Jettenia, 1.3–2%), and the early-stage solids retention time (45–68 days) were desired to form thicker biofilm and improve effluent quality during 120-day mainstream anammox MBBR start-up. The mechanistic insights into biofilm formation and predictive power of the newly developed MABD model are of importance to the design and operation of mainstream anammox processes towards more biofilm biomass and higher nitrogen removal efficiency.

主流厌氧氨氧化工艺启动时间过长，扰动不稳定，阻碍了其应用。实验室规模的主流厌氧氨氧化移动床生物膜反应器 (MBBR) 在 120 天内成功启动，进水氮浓度从侧流到主流条件逐步递减。Candidatus Jettenia 和丝状发酵罐Anaerolineaceae的初始定殖可能由疏水相互作用和IV 型菌毛介导。钙。具有较高底物亲和力的 Kuenenia 胜过Ca。Jettenia，主要的发酵罐转移到发酵的Ignavibacteriaceae在成熟的生物膜中。构建了一种新的主​​流厌氧氨氧化生物膜发展 (MABD) 模型来描述生物膜生长、种群动态和脱氮性能。模拟结果表明，较高的接种物生物量（460-690 mgVSS·L ^-1），接种物中低亲和力 AnAOB 的相对丰度（例如，Ca. Jettenia ，1.3-2%），以及早期固体停留时间（45-68 天），以在 120 天的主流厌氧氨氧化 MBBR 启动过程中形成更厚的生物膜并改善出水质量。新开发的 MABD 模型对生物膜形成和预测能力的机理见解对于主流厌氧氨氧化工艺的设计和操作具有重要意义，以实现更多的生物膜生物质和更高的脱氮效率。