Rahaman M S, Mavinic D S, Ellis N
Environmental Engineering Group, Department of Civil Engineering, University of British Columbia, 2010-6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada.
Water Sci Technol. 2008;58(6):1321-7. doi: 10.2166/wst.2008.721.
This paper is an attempt to model the UBC (University of British Columbia) MAP (Magnesium Ammonium Phosphate) fluidized bed crystallizer. A mathematical model is developed based on the assumption of perfect size classification of struvitre crystals in the reactor and considering the movement of liquid phase as a plug flow pattern. The model predicts variation of species concentration of struvite along the crystal bed height. The species concentrations at two extreme ends (inlet and outlet) are then used to evaluate the reactor performance. The model predictions provide a reasonable good fit with the experimental results for both PO4-P and NH4-N removals. Another important aspect of this model is its capability of predicting the crystals size and the bed voidage at different height of the reactor. Those predictions also match fairly well with the experimental observations. Therefore, this model can be used as a tool for performance evaluation of the reactor and can also be extended to optimize the struvite crystallization process in the UBC MAP reactor.
本文旨在对英属哥伦比亚大学的磷酸铵镁流化床结晶器进行建模。基于反应器中鸟粪石晶体尺寸完全分级的假设，并将液相运动视为活塞流模式，建立了一个数学模型。该模型预测了沿晶体床高度鸟粪石物种浓度的变化。然后利用两端（入口和出口）的物种浓度来评估反应器性能。对于PO4-P和NH4-N的去除，模型预测与实验结果相当吻合。该模型的另一个重要方面是其能够预测反应器不同高度处的晶体尺寸和床层空隙率。这些预测也与实验观察结果相当匹配。因此，该模型可作为评估反应器性能的工具，也可扩展用于优化英属哥伦比亚大学磷酸铵镁反应器中的鸟粪石结晶过程。
