基于ASM 2d的数学模型在六箱一体化工艺分析中的应用

以六箱一体化工艺为例,建立了基于ASM 2d(activated sludge process 2d,活性污泥工艺2d)的数学模型,并研究其在脱氮除磷中的应用. 在HRT(水力停留时间)为16 h的工况下,利用灵敏度分析挑选了含有7个参数的待优化参数集,通过使用遗传算法优化校正函数的方式进行校正计算,获得了校正后的六箱一体化工艺模型,并在HRT为20和24 h下对该模型做了进一步验证. 结果表明,校正后的模型对出水水质的预测性较好,在HRT为16 h下,出水ρ(COD_Cr)、ρ(TN)、ρ(TP)和ρ(NH₄+-N)的模型计算值与实测值间的绝对差值较小,分别为1.96、0.83、0.06和0.24 mg/L. 在校正后模型的基础上,详细分析了HRT为20 h时各池中ρ(NH₄+-N)、ρ(NO₃--N)和ρ(PO₄3--P)在1个周期内的动态变化,指出了影响该工艺处理效果的主要原因(如碳源不足的问题),并与通过试验分析得到的结果基本一致. 

Application of Mathematical Model for Analysis of Six-Tank Integrative Activated Sludge Process

A novel six-tank integrative activated sludge process (STIASP), similar to Unitank but with another three tanks, is available in China for treating domestic wastewater. Because the process is alternative and periodical, it is necessary to apply a mathematical model to simulate the operation. In the present study, ASM 2d was selected as a model base. Sensitivity analysis was applied to assess the importance of the parameters in the model, and seven kinetic constants were selected. The parameters were calibrated through minimizing a cost function by the genetic algorithm under HRT 16 h. The calibrated model was further validated under HRT 20 h and 24 h, indicating that the absolute differences of effluent ρ(COD_Cr), ρ(TN), ρ(TP) and ρ(NH₄+-N) between the simulated and the experimental data were very small, being 1.96,0.83,0.06 and 0.24 mg/L, respectively. Based on the validated model, the dynamic variations of ρ(NH₄+-N), ρ(NO₃--N) and ρ(PO₄3--P) in each tank during one running cycle under HRT 20 h were analyzed. Several factors limiting the performance of the STIASP process were pointed out, such as shortage of carbon source; these results were basically the same as the results from the experimental data.