基于碳、氮、磷物料平衡的A^(2)/O工艺碳源投加策略研究

Strategy Study on Carbon Source Addition of A^(2)/O Process Based on Carbon,Nitrogen and Phosphorus Material Balance

为了解A^(2)/O工艺中各污染物的去除走向、质量分布以及微生物竞争生长情况,以瓦池污水处理厂为研究对象,建立碳、氮、磷物料衡算方程,同时基于化学计量关系对碳平衡进行了校核,就碳平衡关系式提出不同C/N下碳源投加策略。结果表明,污水厂在现有工艺下运行良好,碳、氮、磷的物料平衡百分比分别为100.54%、103.03%和97.29%。对比发现聚磷菌与反硝化细菌对碳源存在竞争关系,且聚磷菌处于优势。以进水BCOD/COD取值0.68为前提,当进水TN浓度分别为15 mg/L、20 mg/L、25 mg/L、30 mg/L、35 mg/L、40 mg/L及45 mg/L且进水C/N分别不小于2.92、4.00、4.64、5.08、5.38、5.61及5.79时,该厂无需额外投加碳源;当进水C/N低于这些阈值时,需额外投加碳源。

In order to explore the removal direction,mass distribution of each pollutant and microbial competition growth in A^(2)/O process,taking the process of Wachi Sewage Treatment Plant as the research object,the material balance equations of carbon,nitrogen and phosphorus were established,the carbon balance was checked based on the stoichiometric relationship,and the carbon source addition strategy under different C/N was proposed based on the carbon balance relation.The results show that the sewage treatment plant operates well under the existing process,and the material balance percentages of carbon,nitrogen and phosphorus are 100.54%,103.03%and 97.29%.By comparing the organic matter consumption of PAOs and denitrifying bacteria in the anaerobic tank,it is found that PAOs and denitrifying bacteria competed for carbon sources,and PAOs are dominant.On the premise of influent BCOD/COD of 0.68,when the influent TN concentrations are 15 mg/L,20 mg/L,25 mg/L,30 mg/L,35 mg/L,40 mg/L and 45 mg/L,respectively,the influent water quality C/N is not less than 2.92,4.00,4.64,5.08,5.38,5.61 and 5.79,the plant do not need to add additional carbon sources.When the C/N is lower than these thresholds,additional carbon sources are required.