碳源对低温A^2O工艺反硝化除磷的影响

Influence of carbon source on the denitrifying phosphorus removal in A^2O process at low temperature

为丰富低温污水脱氮除磷途径并了解碳源对A2O工艺反硝化除磷的影响程度,采用单独的乙酸钠、丙酸钠及其混合物对A2O工艺处理低温污水时厌氧释磷与缺氧反硝化吸磷过程进行研究.结果表明,在水温为10～12℃、HRT为8 h、污泥回流比为50%和硝化液回流比为150%～250%的条件下,不同碳源时厌氧释磷与缺氧吸磷速率差异较大.乙酸钠每克MLSS释磷与反硝化吸磷速率分别为6.3和2.8 mg.h-1,而丙酸钠以及混合基质时每克MLSS释磷速率分别为3.44和5.56 mg.h-1,每克MLSS反硝化吸磷速率分别为2.05和3.81 mg.h-1.另外,不同碳源时厌氧阶段聚磷菌合成PHA的组成差别较大,丙酸钠能够促进PH2MV比例,从而提高反硝化聚磷菌对硝态氮电子受体的利用效率.脱氮除磷效率和硝态氮利用率的综合比较可以看出,乙酸钠、丙酸钠混合基质更适宜于低温污水的反硝化除磷作用.

To enrich the nutrients removal pathway and investigate the influence of carbon source on denitrifying phosphorus removal at low temperature（10-12 ℃）,a lab-scale A2O reactor was employed to study the process of phosphorus release and denitrifying phosphorus removal with sodium acetate,sodium propionate and their compounds as carbon source.At hydraulic retention time of 8 h,sludge recirculation ratio and inner recirculation ratio of 50% and 150%-250%,the differences of specific phosphorus release rate and the subsequent phosphorus uptake efficiency with different carbon source were obviously.The specific phosphorus release rate and the phosphorus uptake rate was 6.3 and 2.8 mg·h-1 with sodium acetate as substrate.However,the specific phosphorus release rate of sodium propionate and the compounds was 3.44 and 5.56 mg·h-1.The phosphorus uptake rate was 2.05 and 3.81 mg·h-1,respectively.On the other hand,the intracellular polymers synthesized by phosphorus accumulating organisms were varied with different carbon source.The content of PH2MV was improved by the sodium propionate which consequently increased the utilization efficiency of nitrate nitrogen by denitrification PAOs.The compounds of sodium acetate and sodium propionate were considered as the more suitable carbon source for denitrifying phosphorus removal of low temperature wastewater.