CFD analysis of liquid flow pattern and floc particulates in a new multi-environment wastewater treatment system

生物反应器流体动力学的研究是生物反应器合理设计和规模化的前提，是工业生物反应器规模化运行的必要条件。这些研究提供了关于生物反应器中液体滞留时间和流动模式、气含率、氧传递系数和每液体体积的功率输入的信息。水动力学评价传统上是在实验室或中试规模的设施中进行的，需要在较长时间内进行详细的实验和严格的方法。由于与传统技术相比，多环境生物反应器具有许多技术和经济优势，因此在工业操作中鼓励使用混合设计且需要较低资本和运营成本的多环境生物反应器。然而，这些生物反应器由于其非常规的设计和操作策略，需要进行彻底的流体动力学评估，以确保其适当的设计和规模。鉴于此，工业界经常用计算机建模和仿真分析来补充水动力特性研究，以便在较短的时间内以通常费用的一小部分扩大参数的检查范围。本项目的目标是利用计算流体动力学（CFD）分析来评估新型多环境生物反应器的流体动力学特性，促进对其运行原理的理解，同时促进其在大规模运行时的优化设计。将特别关注生物反应器几何形状和操作条件的影响，包括进水液体和空气流速对液体流动模式和循环的影响，生物反应器各区域的停留时间分布，以及颗粒轨迹和絮体沉淀率。拟议的研究项目将在康考迪亚大学和SNC-Lavalin的研究人员的联合监督下进行。该项目将为研究生提供优秀的培训，并为水和废水处理行业提供特别有吸引力的专业技能。

The investigation of bioreactor hydrodynamics is a prerequisite for its proper design and scale up which are required for full-scale operation of industrial bioreactors. These studies provide information about liquid retention time and flow patterns, gas hold up, oxygen transfer coefficient and power input per liquid volume in the bioreactor. Hydrodynamic evaluations have been traditionally carried out at laboratory- or pilot-scale setups, requiring elaborate experiments and rigorous methodologies conducted at an extended period of time. The use of multi-environment bioreactors that use hybrid designs and require lower capital and operational costs are encouraged in industrial operations due to the numerous technical and economical advantages that they offer compared to the conventional technologies. However, these bioreactors, due to their unconventional design and operation strategies, require a thorough hydrodynamic evaluation in order to ensure their adequate design and scale up. In view of this, industries often complement hydrodynamic characterization studies with computer modeling and simulation analysis in order to expand the examined range of parameters in a shorter time and at a fraction of usual expenses. It is the objective of the proposed project to employ computational fluid dynamics (CFD) analysis to evaluate the hydrodynamic characteristics of new multi-environment bioreactors, advancing the understanding of their operation principles while facilitating their optimized design at large-scale operations. Special focus will be on the impact of bioreactor geometry and operating conditions including influent liquid and air flow rates on liquid flow pattern and circulation, residence time distribution in various zones of bioreactors, as well as particulate trajectories and floc precipitation rate. The proposed research project will be carried out under the joint supervision of researchers at Concordia University and SNC-Lavalin. This project will provide excellent training for graduate students, and specialized skills particularly attractive to the water and wastewater treatment industry.