上升流速对CANON工艺稳定性及微生物群落的影响

采用膨胀颗粒污泥床（EGSB）反应器作为全程自养脱氮（CANON）工艺启动运行的装置，考察了不同上升流速对CANON工艺脱氮性能的影响，并对固定生物膜-活性污泥（IFAS）系统内颗粒污泥粒径的变化和生物膜上的生物量进行定量分析，同时对颗粒污泥和生物膜上的微生物进行高通量分析，探究在不同聚集体上微生物群落结构的特点.结果表明，在连续运行过程中，上升流速由2m/h增加至6m/h的过程中，总氮去除负荷由0.20kg/（m³·d）逐渐增加至0.66kg/（m³·d），而ΔNO₃^--N/ΔNH₄⁺-N的比值稳定在0.11，成功实现了CANON的高效稳定运行.当上升流速增加至8m/h时，CANON工艺脱氮性能失稳，总氮去除负荷（NRR）降低至0.42kg/（m³·d），污泥平均粒径由1.3mm减小到0.9mm.上升流速恢复至6m/h后，CANON脱氮工艺脱氮性能逐渐恢复，最终NRR稳定在0.60kg/（m³·d）以上，污泥平均粒径恢复至1.2mm，生物膜生物量的比生长速率为0.0024d^-1.高通量测序显示，颗粒污泥中主要以氨氧化细菌（AerAOB）功能菌Nitrosomonas（2.45%），和厌氧氨氧化细菌（AnAOB）功能菌Candidatus Kuenenia（2.38%）为主要菌属；而生物膜中主要是AnAOB功能菌Candidatus Kuenenia（9.78%）、Candidatus Brocadia（4.23%），同时还检测出少量AerAOB功能菌Nitrosomonas（0.40%）.结果表明两种微生物在不同聚集体上存在一定的差异性.

The Effect of upflow velocity on CANON process stability and microbial community

Expanded Granular Sludge Bed (EGSB) reactor was used as the start-up device of the CANON process in this experiment, in the effects of different upflow velocity on the nitrogen removal performance of the Completely Autotrophic Nitrogen removal Over Nitrite (CANON) process was investigated. The change of particle size of granular sludge in Integrated Fixed-film and Activated Sludge (IFAS) system and the biomass of biofilm were quantitatively analyzed. In addition, high-throughput sequencing analysis was carried out for microorganisms on granular sludge and biofilm to explore the characteristics of microbial community structure on different aggregates. The results showed that the total nitrogen removal rate (NRR) increased from 0.20kg/(m³·d) to 0.66kg/(m³·d) in the continuous operation process when the upflow velocity increased from 2m/h to 6m/h. The ratio of ΔNO₃^--N/ΔNH₄⁺-N was steadily kept at 0.11, a realization of the efficient and stable operation of CANON. When the upflow velocity increased to 8m/h, the nitrogen removal performance of CANON process was unstable, the NRR decreased to 0.42kg/(m³·d), and the average particle size of sludge decreased from 1.3mm to 0.9mm. When the upflow velocity restored back to 6m/h, the nitrogen removal performance of CANON process gradually recovered. Ultimately, the NRR was stabilized at 0.60kg/(m³·d), the average particle size of sludge was restored to 1.2mm, and the specific growth rate of biofilm biomass was 0.0024d^-1. High throughput sequencing showed that Aerobic Ammonia Oxidation Bacteria (AerAOB) functional bacteria Nitrosomonas (2.45%) and Anaerobic Ammonia Oxidation Bacteria (AnAOB) functional bacteria Candidatus kuenenia (2.38%) were the main genera in the granular sludge. The main bacteria in the biofilm were AnAOB functional bacteria Candidatus kuenenia (9.78%) and Candidatus brocadia (4.23%), while a small amount of AerAOB functional bacteria Nitrosomonas (0.40%) were also detected. The results suggested that there were some differences in two microorganisms in different aggregates.