Jubany Irene, Baeza Juan Antonio, Carrera Julián, Lafuente Javier
Departament d'Enginyeria Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
Water Res. 2005 Nov;39(18):4574-84. doi: 10.1016/j.watres.2005.08.019. Epub 2005 Oct 5.
The modelling of the nitrification process of high-strength ammonium wastewater must be designed to consider it as a two-step reaction with substrate inhibition. Consequently, kinetic and stoichiometric parameters of both steps are required. In this work, the second step in the nitrification process was studied: a biological nitrite oxidation model was formulated, calibrated and validated using only oxygen uptake rate (OUR) measurements. The model included biomass growth and substrate inhibition. First, the biomass yield coefficient for nitrite-oxidising biomass was determined. Then, a respirometric experiment with one nitrite pulse of 500 mg N-NO2- L(-1) was performed to estimate the rest of the model parameters. The practical identifiability study showed that the parameters were strongly correlated. Hence, a new experimental design consisting of two consecutive pulses and a delayed third one was designed to improve the parameter identifiability. Both experimental designs were compared using contour plots of the objective function and optimal experimental design criteria for parameter estimation. It was concluded that the parameter identifiability was improved with the new experimental design. Finally, the estimated parameters were validated and the pH effect on the inhibition coefficient was evaluated.
高强度铵废水硝化过程的建模必须设计为将其视为具有底物抑制作用的两步反应。因此，需要这两个步骤的动力学和化学计量参数。在这项工作中，研究了硝化过程的第二步：仅使用氧摄取率（OUR）测量值建立、校准和验证了生物亚硝酸盐氧化模型。该模型包括生物量增长和底物抑制。首先，确定了亚硝酸盐氧化生物量的生物量产率系数。然后，进行了一次500 mg N-NO2-L(-1)亚硝酸盐脉冲的呼吸测定实验，以估计模型的其余参数。实际可识别性研究表明，这些参数高度相关。因此，设计了一种由两个连续脉冲和一个延迟的第三个脉冲组成的新实验设计，以提高参数的可识别性。使用目标函数的等高线图和用于参数估计的最优实验设计标准对这两种实验设计进行了比较。得出的结论是，新的实验设计提高了参数的可识别性。最后，对估计的参数进行了验证，并评估了pH对抑制系数的影响。
