典型城市污水生物处理工艺的冬季运行稳定性分析

Operation Stability of Typical Urban Sewage Biological Nutrients Removal Process in Winter

对3个典型的城市污水生物营养物去除(BNR)工艺进行了冬季低温运行期的连续监测,通过分析碳(C)、氮(N)、磷(P)等目标污染物浓度在不同工艺单元中的连续变化趋势,构建包括过程质量分析、简单化学计量和生物动力学计算在内的标准生物工艺过程快速分析方法,确定了典型生物处理工艺冬季低温期出水水质稳定达到GB 18918—2002一级A标准的主要影响因子。结果显示,在实际BNR工艺的冬季运行过程中,尽管温度对生物硝化反应速率影响显著,但非曝气区域COD的高去除比例(>77%)是工艺稳定去除整体目标污染物的关键因素。3个工艺的活性污泥镜检结果显示,在以缺氧/好氧(A/O)为主的BNR工艺中,冬季低温期易诱发以Type0092和Type0041等骨架丝状菌为优势菌的污泥膨胀现象,但对出水水质影响较小。

Three typical biological nutrients removal(BNR)processes for urban sewage treatment were monitored continuously during the low temperature period in winter.By analyzing the continuous variable trend of carbon(C),nitrogen(N),phosphorus(P)and other target pollutant concentrations in different units,a quick method of process analysis was established,including process quality analysis,simple stoichiometry calculation and biokinetic calculation,to find the main factors affecting the stability of effluent quality meeting the first level A of GB 18918-2002 of typical biological treatment process during the low temperature period in winter.The results showed that,during the operation of the BNR process in winter,although temperature had a significant effect on the biological nitrification rate,however,the high COD removal ratio(>77%)in the non-aerated area was the key factor for the stable removal of the overall target pollutants.The microscopy identification results showed that,the sludge bulking phenomenon was easily induced by the filamentous bacteria such as Type0092 and Type0041 in the anoxic/aerobic(A/O)BNR process during low temperature periods in winter,but had little influence on the effluent quality.