Feng Qi, Chen Zhi, Greer Charles W, An Chunjiang, Wang Zheng
Department of Building, Civil and Environmental Engineering, Concordia University, Montreal H3G 1M8, Canada.
Department of Natural Resource Sciences, McGill University, Montreal H9X 3V9, Canada.
Environ Sci Technol. 2022 Jun 21;56(12):8187-8196. doi: 10.1021/acs.est.2c01599. Epub 2022 Jun 3.
Tidal zones providing habitats are particularly vulnerable to microplastic (MP) pollution. In this study, the effects of tidal cycles on the transport of MPs (4-6 μm polyethylene, PE1; 125 μm polyethylene, PE2; and 5-6 μm polytetrafluoroethylene, PFTE) in porous media combined with various environmental and MPs properties were systemically investigated. The results indicated that smaller substrate sizes exhibited higher retention percentages compared to those of larger substrate sizes under different tidal cycles. In terms of the size of MPs, a larger size (same density) was found to result in enhanced retention of MPs in the column. As the number of tidal cycles increased, although the transport of MPs from the substrate to the water phase was enhanced, PE1 was washed out more with the change in water level, compared to PTFE. Additionally, more MPs were retained in the column with the increase of salinity and the decrease of flow velocity under the same tidal cycles. Ultraviolet and seawater aged PE1 showed enhanced transport, while aged PTFE showed enhanced retention under the same tidal cycles. These results can help understand the MP behaviors in the shoreline environment and provide support for future cleanup and sampling in tidal zones.
提供栖息地的潮间带特别容易受到微塑料（MP）污染。在本研究中，系统地研究了潮汐周期对多孔介质中微塑料（4 - 6μm聚乙烯，PE1；125μm聚乙烯，PE2；以及5 - 6μm聚四氟乙烯，PFTE）传输的影响，并结合了各种环境和微塑料特性。结果表明，在不同潮汐周期下，与较大粒径的基质相比，较小粒径的基质表现出更高的截留率。就微塑料的尺寸而言，发现较大尺寸（相同密度）会导致微塑料在柱中的截留增强。随着潮汐周期数的增加，尽管微塑料从基质向水相的传输增强，但与聚四氟乙烯相比，PE1随着水位变化被冲刷出的更多。此外，在相同潮汐周期下，随着盐度的增加和流速的降低，更多的微塑料被截留在柱中。在相同潮汐周期下，紫外线和海水老化的PE1表现出增强的传输，而老化的聚四氟乙烯表现出增强的截留。这些结果有助于了解微塑料在海岸线环境中的行为，并为未来潮间带的清理和采样提供支持。
