For advancing current knowledge on the transport of microplastics (MPs) in the environment, this study used a real-time pore-scale visualization and quantitative system to examine the motions and mobility of fibrous and fragmental MPs under various surfactant (AEO, CTAC, and AES) and electrolyte conditions. The videos showed that fibrous MPs formed tangles through entanglement, which moved in an axial direction aligned with the flow streamline. Both fibrous and fragmental MPs showed suspended movement as well as surface movement (e.g., sliding, rolling, and saltating) in the porous media. Some deposited fibrous MPs showed flexible deformation due to shear flow. Compared to fragmental MPs, fibrous MPs showed lower mobility due to the tendency to deposit and clog the porous media. The mobility of fragmental MPs was enhanced in the presence of AEO but remained relatively unchanged with AES. In the presence of CTAC, the mobility of fragmental MPs was slightly inhibited under low ionic strength (IS) conditions but remarkably enhanced under high IS conditions. However, the mobility of fibrous MPs was largely unaffected by the surfactants. Both the numerical model and FDLVO calculations effectively described the transport and deposition of MPs in porous media.

中文翻译：

---

在各种表面活性剂条件下，多孔介质中纤维状和碎片状微塑料的孔隙级可视化运输和截留


为了推进当前关于微塑料 （MP） 在环境中运输的知识，本研究使用实时孔隙尺度可视化和定量系统来检查纤维和碎片 MP 在各种表面活性剂（AEO、CTAC 和 AES）和电解质条件下的运动和迁移率。视频显示，纤维 MP 通过缠结形成缠结，缠结沿与流线一致的轴向移动。纤维和碎片 MPs 在多孔介质中均表现出悬浮运动和表面运动（例如，滑动、滚动和盐化）。一些沉积的纤维 MPs 由于剪切流而表现出柔性变形。与碎片 MPs 相比，纤维 MP 由于倾向于沉积和堵塞多孔介质，因此表现出较低的迁移率。在 AEO 存在下，碎片 MP 的流动性增强，但在 AES 存在下保持相对不变。在 CTAC 存在下，片段 MP 的迁移率在低离子强度 （IS） 条件下受到轻微抑制，但在高 IS 条件下显着增强。然而，纤维 MP 的迁移率在很大程度上不受表面活性剂的影响。数值模型和 FDLVO 计算都有效地描述了 MP 在多孔介质中的传输和沉积。