Department of Environmental Engineering, China Jiliang University, Hangzhou 310018, China.
Department of Environmental Engineering, China Jiliang University, Hangzhou 310018, China.
Sci Total Environ. 2022 Feb 20;808:152154. doi: 10.1016/j.scitotenv.2021.152154. Epub 2021 Dec 4.
Microplastic (MP) pollution has become a global concern given its wide occurrence and potential ecological risks. The retention/transport features of MPs in porous media govern the fate and risks of MPs in subsurface environments. Polystyrene (PS) microspheres are employed as representative MPs to explore the migration behaviors in water-saturated quartz sand columns. The hydrodynamic size mainly determines the deposition and size exclusion straining of MPs in porous media, and further the attachment efficiency. PS50 (PS with 50 nm diameter) shows a total migration rate greater than 85% in each of the studied conditions. In contrast, PS500 commonly exhibits slower migration velocities and higher attachment efficiencies than those of PS50 and PS100. The ionic strength, pH, and dissolved organic matter content of the solution show obvious effects on the retention/transport of PS MPs. The influences of solution chemical properties are consistent with the prediction of Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The results in this study clarify the size-dependent migration characteristics of MPs in porous media and provide a basis for risk assessment of MPs in terrestrial environments.
微塑料（MP）污染因其广泛存在和潜在的生态风险而成为全球关注的焦点。MP 在多孔介质中的保留/传输特征决定了 MP 在地下环境中的归宿和风险。聚苯乙烯（PS）微球被用作代表性的 MPs，以探索在水饱和石英砂柱中的迁移行为。水动力粒径主要决定了 MPs 在多孔介质中的沉积和尺寸排阻过滤作用，进而影响 MPs 的附着效率。在研究的所有条件下，PS50（粒径为 50nm 的 PS）的总迁移率均大于 85%。相比之下，PS500 的迁移速度通常比 PS50 和 PS100 慢，附着效率也比它们高。溶液的离子强度、pH 值和溶解有机物含量对 PS MPs 的保留/传输有明显影响。溶液化学性质的影响与德加古林-朗道-维尔韦尔-奥弗贝克（DLVO）理论的预测一致。本研究结果阐明了 MPs 在多孔介质中迁移的尺寸依赖性特征，为评估 MPs 在陆地环境中的风险提供了依据。
