The necessity for sustainable farming practices, wastewater valorisation and circular economy applications have prompted increased interest in duckweed cultivation. As floating plants, duckweed species show rapid growth and can be cultured agri-food industry wastewater. Further, the resulting plant biomass is a valuable high-protein livestock feed and a biofuel feedstock. The development of multitiered (i.e., vertically stacked) indoor bioreactors enable reliable, high-capacity growth irrespective of seasons. Here, a Computational Fluid Dynamic (CFD) approach was applied to a pilot-scale duckweed cultivation system to provide insight into wastewater hydrodynamics to support further development and optimisation. CFD modelling and validation indicated that the pilot-scale system behaved non-ideally, with 60.1 % of the volume considered stagnant, and with surface channelling also identified. Analysis of the aspect ratio and inlet/outlet port positions of the cultivation tray enabled a 24.3 % decrease in stagnation, as well as a significant reduction in channelling, when the number of tray inlet/outlet ports was increased from two to three. Thus, the current study highlights the value of in-depth evaluation of the fluid flow using CFD, as a strategy to improve design of duckweed cultivation systems. This strategy can be further expanded to incorporate local and temporal nutrient depletion and predict duckweed growth rates.

可持续农业实践、废水增值和循环经济应用的必要性促使人们对浮萍种植的兴趣日益浓厚。作为漂浮植物，浮萍种类生长迅速，可在农业食品工业废水中培养。此外，所得植物生物质是有价值的高蛋白牲畜饲料和生物燃料原料。多层（即垂直堆叠）室内生物反应器的开发可以实现可靠、高容量的生长，无论季节如何。在这里，计算流体动力学（CFD）方法被应用于中试规模的浮萍栽培系统，以提供对废水流体动力学的深入了解，以支持进一步的开发和优化。CFD 建模和验证表明，中试规模的系统表现并不理想，60.1% 的体积被认为是停滞的，并且还发现了表面沟道。当托盘入口/出口端口的数量从两个增加到三个时，对培养托盘的长宽比和入口/出口端口位置的分析使停滞减少了 24.3%，并且通道效应显着减少。因此，当前的研究强调了使用 CFD 深入评估流体流动的价值，作为改进浮萍栽培系统设计的策略。该策略可以进一步扩展，以纳入局部和暂时的养分消耗并预测浮萍的生长速度。