Li Yuqi, Xiang Tao, Liang Hong, Wang Peng, Gao Dawen
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China.
School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China.
Sci Total Environ. 2022 Feb 1;806(Pt 4):151415. doi: 10.1016/j.scitotenv.2021.151415. Epub 2021 Nov 4.
The start-up of a stable mainstream deammonification requires sufficient anaerobic ammonia-oxidizing bacteria (AnAOB). This study used a plug-flow fixed-bed reactor (PFBR) to verify the feasibility of establishing the mainstream deammonification system by inoculating the sidestream sludge after long-term refrigeration. A rapid resuscitation of the mainstream deammonification system was accomplished by controlling the front-end aeration rate of the PFBR. Results showed that the system was rapidly resuscitated in 44 days eventually with the nitrogen removal rate and nitrogen removal efficiency of 0.1 kg N·(m·d) and 79.1%, respectively. Also, the efficient performance was secured by the proportionate approaching equilibrium of AnAOB and ammonia-oxidizing bacteria (AOB) activity of 2.35 ± 0.40 and 2.60 ± 0.29 mg N·(g VSS·h), respectively. In addition, Pearson correlation analysis revealed that AnAOB abundance (detected Candidatus Kuenenia) negatively correlated with the AOB (mainly Nitrosomonas)/AnAOB abundance ratio, while correlated positively with the residual ammonium concentration of a region. Furthermore, long-term refrigeration probably reduced the cross-feed relationship between AnAOB and other symbiotic organisms (Armatimonadetes and Chloroflexi) to maintain the basic metabolism. Meanwhile, extracellular polymeric substances produced by other genera (order Xanthomonadales and Pseudomonadales) decreased the mass transfer, protecting AnAOB from unfavorable conditions, thereby facilitating high AnAOB abundance during refrigeration. Thus, this study provides a promising perspective towards the practical applications of mainstream process.
稳定的主流厌氧氨氧化工艺启动需要足够的厌氧氨氧化细菌（AnAOB）。本研究采用推流固定床反应器（PFBR），通过接种长期冷藏后的侧流污泥来验证建立主流厌氧氨氧化系统的可行性。通过控制PFBR前端曝气速率，实现了主流厌氧氨氧化系统的快速复苏。结果表明，该系统最终在44天内迅速复苏，脱氮速率和脱氮效率分别为0.1 kg N·(m·d)和79.1%。此外，AnAOB与氨氧化细菌（AOB）活性分别按比例接近平衡，即2.35±0.40和2.60±0.29 mg N·(g VSS·h)，从而确保了高效运行。此外，Pearson相关性分析表明，AnAOB丰度（检测到的Candidatus Kuenenia）与AOB（主要是亚硝化单胞菌）/AnAOB丰度比呈负相关，而与某一区域的残余铵浓度呈正相关。此外，长期冷藏可能减少了AnAOB与其他共生生物（装甲菌门和绿弯菌门）之间的交叉馈送关系，以维持基本代谢。同时，其他属（黄单胞菌目和假单胞菌目）产生的胞外聚合物降低了传质，保护AnAOB免受不利条件影响，从而在冷藏期间促进了高AnAOB丰度。因此，本研究为该主流工艺的实际应用提供了一个有前景的方向。
