Institute of Hydraulic Engineering and Water Resources Management E222/2, TU Wien, Vienna, Austria.
Interuniversity Cooperation Centre (ICC) Water and Health, Vienna, Austria.
J Environ Qual. 2024 Sep-Oct;53(5):727-742. doi: 10.1002/jeq2.20618. Epub 2024 Aug 20.
Microplastics in urban runoff undergo rapid fragmentation and accumulate in the soil, potentially endangering shallow groundwater. To improve the understanding of microplastic transport in groundwater, column experiments were performed to compare the transport behavior of fragmented microplastics (FMPs ∼1-µm diameter) and spherical microplastics (SMPs ∼1-, 10-, and 20-µm diameter) in natural gravel (medium and fine) and quartz sand (coarse and medium). Polystyrene microspheres were physically abraded with glass beads to mimic the rapid fragmentation process. The experiments were conducted at a constant flow rate of 1.50 m day by injecting two pore volumes of SMPs and FMPs. Key findings indicate that SMPs showed higher breakthrough, compared to FMPs in natural gravel, possibly due to size exclusion of the larger SMPs. Interestingly, FMPs exhibited higher breakthrough in quartz sand, likely due to tumbling and their tendency to align with flow paths, while both sizes (larger and smaller relative to FMPs) of SMPs exhibited higher removal in quartz sand. Therefore, an effect due to shape and size was observed.
城市径流中的微塑料会迅速破碎，并在土壤中积累，从而可能危及浅层地下水。为了更好地了解微塑料在地下水中的迁移，进行了柱实验，比较了破碎微塑料（FMPs，直径约 1μm）和球形微塑料（SMPs，直径约 1μm、10μm 和 20μm）在天然砾石（中细）和石英砂（粗中）中的迁移行为。通过用玻璃珠对聚苯乙烯微球进行物理磨损，来模拟快速破碎过程。实验以恒定的流速 1.50 m·d进行，注入两孔隙体积的 SMPs 和 FMPs。主要发现表明，与天然砾石中的 FMPs 相比，SMPs 的穿透率更高，这可能是由于较大的 SMPs 存在尺寸排除。有趣的是，FMPs 在石英砂中表现出更高的穿透率，这可能是由于翻滚和它们与流动路径对齐的趋势，而 SMPs 的两种尺寸（相对于 FMPs 较大和较小）在石英砂中表现出更高的去除率。因此，观察到了由于形状和尺寸而产生的效果。
