The effects of aeration and stirring systems on the physical properties of sludge were analyzed using a computational fluid dynamics (CFD) model. The aims of this study were to (1) compare the effects of aeration and stirring on sludge properties using the same turbulent mixing intensity, and (2) to reveal the relationship between sludge properties and hydrodynamic indicators to determine how hydrodynamic conditions influence sludge flocculation. Mixing experiments with stirring and aeration were carried out in 2-L beakers with the average velocity gradient (G) set to 90, 190, or 280 s⁻¹. The sludge flocculation performance, zeta potential, and Gibbs free energy (ΔG) were analyzed and the flow rate, turbulence energy, turbulence dissipation rate, and Kolmogorov microscale were calculated as hydrodynamic parameters. The average flow rate and the turbulence dissipation rate were obviously higher in the stirring system than in the aeration system at the same G. However, the turbulence energy and Kolmogorov microscale in the aeration system were much higher than those in the stirring system. Both the zeta potential and ΔG were lower in the aeration system than the stirring system. The zeta potential and ΔG results for the two systems suggest that aeration is more beneficial for sludge flocculation than stirring even though the sludge flocculation performance F/F₀ in the stirring and aeration systems showed no obvious differences. Significant relationships between hydrodynamic parameters calculated based on the CFD model and average values of sludge properties in the stable phase showed that the Kolmogorov microscale, average flow rate, and turbulence energy were appropriate hydrodynamic parameters for evaluating the flocculation performance F/F₀, zeta potential, and ΔG, respectively.

使用计算流体动力学（CFD）模型分析了曝气和搅拌系统对污泥物理性质的影响。这项研究的目的是（1）在相同的湍流混合强度下比较曝气和搅拌对污泥特性的影响，以及（2）揭示污泥特性与流体动力指标之间的关系，以确定流体动力条件如何影响污泥絮凝。在2-L烧杯中进行搅拌和充气的混合实验，将平均速度梯度（G）设置为90、190或280 s ^-1。污泥的絮凝性能，ζ电势和吉布斯自由能（ΔG进行了分析，并计算了流量，湍流能量，湍流耗散率和Kolmogorov微米级作为流体力学参数。在相同的G下，搅拌系统的平均流量和湍流耗散率明显高于曝气系统。但是，曝气系统中的湍流能和Kolmogorov微观尺度远高于搅拌系统。曝气系统中的ζ电位和ΔG均低于搅拌系统。这两个系统的zeta电位和ΔG结果表明，曝气对污泥絮凝比搅拌更有利，即使污泥絮凝性能为F / F ₀在搅拌和曝气系统中无明显差异。基于CFD模型计算的流体力学参数与稳定相中污泥特性平均值之间的显着关系表明，Kolmogorov微观尺度，平均流速和湍流能是评估絮凝性能F / F ₀，ζ电位的合适流体力学参数。，和ΔG。