低碳源城市污水厂碳源优化利用运行模式研究

采用中试规模试验,利用物质平衡分析方法,追踪碳源在各个季节不同工艺条件下的分配和利用情况,以求掌握控制碳源分配的关键性参数,从而建立基于碳源利用的污水厂优化运行模式.在原水年均COD,NH4+-N,TN和TP浓度分别为129,25.6,31.5和3.38mg/L,C/N值和C/P值分别为4.3和39.5的条件下,冬季宜采用倒置A2/O工艺,春季宜选用改良型A2/O工艺,夏季宜选用预缺氧+倒置A2/O工艺,秋季宜选用低氧/常氧交替的预缺氧+倒置A2/O工艺,此时出水带走的COD占系统输入总量的26.1%～29.4%,同化COD比例为27.5%～36.2%,直接好氧氧化的COD比例为4%～22.2%,用于反硝化脱氮的COD比例为14.8%～33.6%,用于聚磷菌超量储磷的COD比例为3.05%～6.9%,出水除总磷指标外,可以达到GB 18918-2002一级B标准.碳源分配的优劣可以作为污水厂工艺筛选和参数调整的重要依据.

Research on the Optimum Operation Strategy for Deficient Carbon Source Urban Sewage Treatment Plants

Analytical methods based on mass balance were adopted in the experiment to trace the carbon source distributed and utilized in a pilot scale system.The key parameters of carbon source distribution were investigated and the optimum operation strategy for urban sewage treatment plants was built.In the conditons that the influent concentration of the COD,NH+4-N,TN and TP were 129 mg/L,25.6 mg/L,31.5 mg/L and 3.38 mg/L,respectively,and the C/N and C/P value were 4.3 and 39.5,inverted A2/O process was recommended in winter period,enhanced A2/O process was recommended in spring period,pre-anoxic inverted A2/O process was recommended in summer period and alternating oxygen concentration inverted A2/O process was appropriate in autumn period.In this case,the ratio of effluent COD to influnent COD was 26.1%~29.4%,the ratio of assimilating COD was 27.5%~36.2%,the ratio of directly oxidating COD was 4%~22.2%,the ratio of denitrificating COD was 14.8%~33.6%,and the ratio of COD utilizing for removal was 3.05%~6.9%.The effluent of the pilot scale reactor could reach the standard of grade B,classⅠin Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002) apart from the concentration of phosphorus.The rationalization of carbon source utilization should be an important rule for the design and adjustment of wastewater treatment plants.