Han Naipeng, Zhao Qichao, Wu Chenxi
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100039, China.
Bureau of Hydrology, Changjiang Water Resources Commission, Ministry of Water Resources of People's Republic of China, Wuhan 430010, China.
Water Res. 2023 Aug 15;242:120253. doi: 10.1016/j.watres.2023.120253. Epub 2023 Jun 18.
Surface runoff is a major pathway for the transport of plastics. However, most previous studies focus on the transport of microplastics in aquatic environment, whereas the migration of plastics from terrestrial environment to aquatic ecosystems receives limited attention. In this work, we investigated the migration of plastic on different surfaces via surface runoff. Results indicate that the threshold migration condition increases with the size and density of plastics, while decreases as the surface inclination increases. Plastics show a higher degree of mobility on smooth surfaces, but plastic films exhibit lower mobility due to the frictional forces induced by the downward pressure exerted by the water flow. Conversely, rough surfaces such as concrete and macadam can trap small fragments and rigid film plastics, and plastics can be embedded within the soil matrix under the water flow. In summary, smaller size, steeper incline, and greater water flow rate facilitate the movement of plastics on surfaces. Results from this work improve the understanding of the process of plastic migration from land to water, and are of great significance for the prevention and control of plastic pollution.
地表径流是塑料运输的主要途径。然而，以前的大多数研究都集中在微塑料在水生环境中的运输，而塑料从陆地环境向水生生态系统的迁移受到的关注有限。在这项工作中，我们通过地表径流研究了塑料在不同表面上的迁移。结果表明，塑料迁移的临界条件随塑料的尺寸和密度增加而增加，随表面倾斜度增加而降低。塑料在光滑表面上表现出较高的迁移率，但塑料薄膜由于水流施加的向下压力引起的摩擦力而表现出较低的迁移率。相反，混凝土和碎石等粗糙表面可以捕获小碎片和刚性薄膜塑料，并且在水流作用下塑料可以嵌入土壤基质中。总之，较小的尺寸、较陡的坡度和较大的水流速度有利于塑料在表面上的移动。这项工作的结果增进了对塑料从陆地向水体迁移过程的理解，对塑料污染的防治具有重要意义。
