摘要

微塑料（MP）污染陆地，水生和大气环境。尽管关于MP浓度的河流取样研究的数量正在增加，但是对水道中MP的主要运输过程的理解仍然非常有限。为了获得更好的工艺理解，进行了大约500次物理实验，以更多地了解颗粒形状，尺寸和密度对MP的上升和沉降速度的影响。对于聚酰胺纤维（沉降），确定的速度在0.39cm / s之间，对于发泡聚苯乙烯粒料（上升），确定的速度在31.4cm / s之间。随后，将确定的速度与来自沉积物运输的公式进行比较，并且由于在理论上和实验上确定的速度之间存在很大差异，因此开发了自己的公式来描述具有各种形状，尺寸和密度的MP颗粒的沉降和上升速度。这项研究表明，MP的行为与沉积物显着不同，应谨慎对待普通沉积物运输公式的转移。此外，现在可以在数值模拟中使用已建立的公式来更精确地描述MP的稳定和上升。

Microplastic (MP) contaminates terrestrial, aquatic, and atmospheric environments. Although the number of river sampling studies with regard to MP concentrations is increasing, comprehension of the predominant transport processes of MP in the watercourse is still very limited. In order to gain a better process understanding, around 500 physical experiments were conducted to shed more light on the effects of particle shape, size and density on the rise and settling velocities of MP. The determined velocities ranged between 0.39 cm/s for polyamide fibers (settling) and 31.4 cm/s for expanded polystyrene pellets (rise). Subsequently, the determined velocities were compared with formulas from sediment transport and, as there were large differences between theoretically and experimentally determined velocities, own formulas were developed to describe settling and rise velocities of MP particles with a large variety of shapes, sizes and densities. This study shows that MP differs significantly from sediment in its behavior and that a transfer of common sediment transport formulas should be treated with caution. Furthermore, the established formulas can now be used in numerical simulations to describe the settling and rising of MP more precisely.

https://www.ncbi.nlm.nih.gov/pubmed/30688437