Hu Zhi-rong, Wentzel M C, Ekama G A
Water Research Group, Department of Civil Engineering, University of Cape Town, Rondebosch Cape Town 7701, South Africa.
Water Res. 2003 Aug;37(14):3430-44. doi: 10.1016/S0043-1354(03)00168-4.
The external nitrification (EN) biological nutrient removal (BNR) activated sludge (ENBNRAS) system shows considerable promise for full-scale implementation. As an aid for this implementation, a mathematical simulation model would be an invaluable tool. To develop such a model, a study was conducted to select the most suitable simulation model to serve as a starting point for further development. For this, the existing available simulation models for BNRAS systems are compared with one another and evaluated against experimental observations in the literature and on ENBNRAS systems. One process immediately apparent to be crucially important is the anoxic growth of phosphorus accumulating organisms (PAOs), with associated PAO denitrification and anoxic P uptake for polyP formation. These linked processes are lacking in the earlier kinetic simulation models for BNRAS systems, which were based on aerobic PAO growth and P uptake only, but have been incorporated into the more recent kinetic models. This provides a substantive body of information on modelling this aspect. Other processes of significance identified to require consideration are anaerobic slowly biodegradable COD (SBCOD) hydrolysis to readily biodegradable COD (RBCOD), and COD loss. Both processes have significant impact on the predicted BEPR performance. Due to the uncertainties associated with the mechanisms and quantification of these two processes, it is concluded that the most extensively validated kinetic simulation model should be selected for development, and that the omissions in this model should be addressed progressively, using the relevant information drawn from the existing models, the literature and observations on ENBNRAS systems.
外置硝化（EN）生物营养物去除（BNR）活性污泥（ENBNRAS）系统在全面实施方面显示出巨大的潜力。作为实施这项工作的辅助手段，数学模拟模型将是一个非常有价值的工具。为了开发这样一个模型，开展了一项研究，以选择最合适的模拟模型作为进一步开发的起点。为此，将现有的BNRAS系统模拟模型相互比较，并对照文献中的实验观察结果以及ENBNRAS系统进行评估。一个立即显现出至关重要的过程是聚磷菌（PAO）的缺氧生长，以及相关的PAO反硝化和缺氧吸磷以形成聚磷。这些相互关联的过程在早期基于好氧PAO生长和吸磷的BNRAS系统动力学模拟模型中并不存在，但已被纳入到更新的动力学模型中。这为模拟这一方面提供了大量信息。确定需要考虑的其他重要过程是厌氧条件下缓慢可生物降解COD（SBCOD）水解为易生物降解COD（RBCOD）以及COD损失。这两个过程对预测的生物除磷脱氮（BEPR）性能都有重大影响。由于这两个过程的机制和量化存在不确定性，得出的结论是应选择经过最广泛验证的动力学模拟模型进行开发，并且应利用从现有模型、文献以及ENBNRAS系统的观察中获取的相关信息，逐步解决该模型中的遗漏问题。
