Department of Environmental and Energy Engineering, Yonsei University, Wonju, 26493, Republic of Korea.
Department of Environmental Research, Korea Institute of Civil Engineering and Building Technology, 10223, Goyang, Republic of Korea.
Environ Sci Pollut Res Int. 2023 Sep;30(44):99875-99884. doi: 10.1007/s11356-023-29409-5. Epub 2023 Aug 24.
Following the alarming reports of microplastic pollution in the marine environment, increased attention has been given to microplastics in other environmental media. Despite the attention, there is limited research available on the depth-distribution of microplastics in freshwater. Specifically, in the case of water sources used for drinking or tap, the height of intake facilities varies, and it is highly likely that there is a correlation between the vertical distribution of microplastics and these water intake structures. Further, because the size of microplastics varies widely in the environment, the commonly used sampling devices are not suitable for selectively extracting microplastics without causing cross-contamination. Thus, we developed a suitable device for microplastics of size 5-20 µm and studied microplastic distribution in freshwater at various depths by considering various types of microplastics and aqueous systems. Lake and river, two major water sources, were selected for the study of microplastics distribution in water system. The microplastic distribution characteristics in both water systems showed that polypropylene and polyethylene were the most abundant across all depths because of their production volume. Plastic types with higher density were found only at the lower layers, and polystyrene was found in the upper layers because of the environmental effects on its buoyancy caused pore diameter and surface area. The lake and river had higher microplastic distribution in the lower layer and upper layer, respectively. This was because the flow rate in river was higher than that of lake. The higher flow rate reduced the settling velocity in river. Thus, hydrodynamic stability influences the vertical distribution and concentrations of microplastics in the water systems. These results are expected to be used for understanding the behavioral characteristics of microplastics in water systems and to manage water sources.
在海洋环境中微塑料污染的惊人报告之后，人们对其他环境介质中的微塑料给予了更多关注。尽管已经引起了关注，但关于淡水中微塑料的深度分布的研究仍然有限。具体来说，在用于饮用水或自来水的水源的情况下，进水设施的高度不同，微塑料的垂直分布与这些进水结构之间很可能存在相关性。此外，由于环境中微塑料的尺寸差异很大，常用的采样设备不适合在不引起交叉污染的情况下选择性地提取微塑料。因此，我们开发了一种适用于 5-20 µm 大小微塑料的设备，并考虑了各种类型的微塑料和水系统，研究了不同深度的淡水中的微塑料分布。湖泊和河流是两种主要的水源，被选为水系统中微塑料分布的研究对象。两种水系统中的微塑料分布特征表明，由于其产量，聚丙烯和聚乙烯在所有深度都是最丰富的。密度较高的塑料类型仅在较低层发现，而聚苯乙烯在上层发现，这是由于其环境对浮力的影响，导致孔径和表面积的影响。湖泊和河流在较低层和较高层的微塑料分布较高，这是因为河流的流速高于湖泊。较高的流速降低了河流中的沉降速度。因此，水动力稳定性会影响水系统中微塑料的垂直分布和浓度。这些结果有望用于了解水系统中微塑料的行为特征，并管理水源。
