基于好氧反硝化及反硝化聚磷菌强化的低温低碳氮比生活污水生物处理中试研究

Pilot-scale biological treatment process of domestic wastewater under low temperature and low C/N ratio enhanced by aerobic denitrification and denitrifying phosphorus accumulation bacteria

摘要:

【背景】低碳氮比生活污水很难达标处理，多级A/O工艺、生物强化技术及生物膜技术的有机结合可有效解决这一问题。【目的】开发出一种泥膜共生多级A/O工艺并进行中试研究，驯化出高效脱氮除磷菌剂并对系统进行生物强化。【方法】通过测定中试设备出水及污水处理厂出水化学需氧量(chemical oxygen demand，COD)、氨氮(NH4+-N)、硝氮(NO3?-N)、总氮(total nitrogen，TN)、总磷(total phosphorus，TP)对比分析两种工艺的污染物去除效能，利用高通量测序技术对比生物强化技术对系统微生物群落结构的影响。【结果】中试设备对COD、NH4+-N、NO3?-N、TN、TP的去除效果均优于污水处理厂的处理工艺；驯化的低温好氧反硝化菌TN去除率最大值可达84.21%，驯化的低温反硝化聚磷菌群对磷的去除率最高可达85.75%；利用驯化菌群对中试设备进行生物强化后较好地改善了系统NH4+-N、NO3?-N、TN、TP的去除效果；经生物强化后，具有好氧反硝化和反硝化聚磷功能的Pseudomonas菌群明显增多。【结论】泥膜共生多级A/O工艺对于低碳氮比生活污水的处理具有很好的效果，利用生物强化技术可有效提高低温条件下系统污染物去除效能。

Abstract:

[Background] The treatment of low C/N domestic wastewater is difficult to meet the discharge standard. The integration of multistage A/O, bioaugmentation and biofilm can effectively solve this problem. [Objective] This study aimed to develop a pilot-scale multistage A/O with biofilm process, and domesticate efficient microbial agent for nitrogen and phosphorus removal to perform bioaugmentation in the system. [Methods] Chemical oxygen demand (COD), NH4+-N, NO3?-N, total nitrogen (TN) and total phosphorus (TP) in effluent of the pilot-scale plant and the full-scale wastewater treatment plant were measured and compared to analyze the removal efficiencies. Meanwhile, high through-put sequencing was used to examine the impact of bioaugmentation on microbial community structure. [Results] The removal efficiencies of COD, NH4+-N, NO3?-N, TN and TP in the pilot-scale plant were better than those in the full-scale wastewater treatment plant. The maximum removal rate of TN by the acclimated low-temperature aerobic denitrifying bacteria was 84.21%, when the phosphorus removal rate by the acclimated low-temperature denitrifying phosphorus accumulation bacteria was 85.75%. After bioaugmentation, the removal performance of COD, NH4+-N, NO3?-N, TN and TP was improved, when Pseudomonas for aerobic denitrification and denitrifying phosphorus accumulation obviously increased. [Conclusions] Multistage A/O with biofilm process showed an ideal performance on the treatment of low C/N domestic wastewater. Bioaugmentation can effectively improve the pollutant removal efficiencies of the system under low temperature.