Abstract:

In this study, the anaerobic/aerobic/anoxic/aerobic simultaneous nitrification, endogenous denitrification, and phosphorus removal (AOAO-SNEDPR) system was constructed to investigate the nitrogen and phosphorus removal performance under varying influent phosphorus concentrations. By combining measurements of sludge denitrifying phosphorus removal activity and microbial community structure analysis, the mechanisms of enhanced nitrogen and phosphorus removal via denitrifying phosphorus removal were elucidated. The experimental results demonstrated that under a 6 h operational cycle with influent COD and \mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+}-N concentrations of 312.05 mg/L and 52.37 mg/L, respectively, the system maintained stable treatment efficiency as the influent \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P concentration was incrementally increased from 3 to 14.94 mg/L. The average effluent concentrations of COD, TN, and \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P were 33.47, 7.14 and 0.31 mg/L, respectively. Nitrogen removal was primarily achieved through exogenous denitrification in the anaerobic phase, endogenous denitrification in the aerobic phase, and denitrifying phosphorus removal in the anoxic phase, while phosphorus removal was accomplished via aerobic phosphorus uptake and denitrifying phosphorus uptake. As the influent \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P concentration increased, the proportions of TN and \mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P removal in the anoxic phase relative to the total removal across all phases rose to 17.39% and 7.85%, respectively. Under high phosphorus conditions, the average carbon storage rate in the anaerobic phase reached 93.84%, with polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) contributing approximately 67.14% and 32.86% to the internal carbon storage, respectively. The abundances of the denitrifying phosphate-accumulating organisms (DPAOs) Dechloromonas and Candidatus_Accumulibacter reached 2.69% and 2.49%, respectively, while the abundance of the denitrifying glycogen-accumulating organism (DGAOs) Candidatus_Competibacter reached 3.34%.

Key words: SNEDPR, endogenous denitrification, denitrifying phosphorus removal, DGAOs, DPAOs

摘要：

构建了厌氧/好氧/缺氧/好氧同步硝化内源反硝化除磷（AOAO-SNEDPR）系统，考察了不同进水磷浓度条件下脱氮除磷效果。在运行周期为6 h，进水COD、\mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+}-N浓度分别为312.05 mg/L和52.37 mg/L时，梯度提高进水\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P由3 mg/L至14.94 mg/L，系统出水稳定，COD、TN和\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P平均浓度分别为30.47、7.14和0.31 mg/L。系统脱氮主要是基于好氧段内源反硝化以及缺氧段反硝化除磷而实现的，除磷基于好氧吸磷和反硝化吸磷。随着进水\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P浓度提高，缺氧段TN和\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{3}-}-P去除量占整个反应阶段去除量的比例分别提高至17.39%和7.85%。在高磷条件下，厌氧段内碳源储存率达到93.84%，聚磷菌（PAOs）和聚糖菌（GAOs）对内碳源储存的贡献约为67.14%和32.86%；反硝化聚磷菌（DPAOs）Dechloromonas和Candidatus_Accumulibacter的丰度分别达到2.69%和2.49%，反硝化聚糖菌（DGAOs）Candidatus_Competibacter菌群丰度达到3.34%。

关键词: SNEDPR, 内源反硝化, 反硝化除磷, 反硝化聚糖菌, 反硝化聚磷菌