Chen Zhikun, Elektorowicz Maria, An Chunjiang, Tian Xuelin
Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec H3G 1M8, Canada.
Environ Sci Technol. 2023 Feb 28;57(8):3176-3186. doi: 10.1021/acs.est.2c09340. Epub 2023 Feb 13.
Sea ice can serve as a temporary sink for microplastics (MPs), and thus, it too can function as a secondary source of and transport medium for MPs. This study aimed to explore the effect of various MP properties and environmental characteristics on the entrainment and enrichment of MPs in ice under varying turbulence conditions. It was found that high rotation speed in freshwater distinctively enhanced the entrainment of hydrophobic MPs in ice, this being attributable to the combined effects of frazil ice and air bubbles. The hydrophobic nature of these MPs caused them to be attracted to the water/air or water/ice interface. However, in saline water, high turbulence inhibited the entrainment of all of the MP types under study. The ice crystals formed a loose structure in saline water instead of congealing, and this allowed the exchange of MPs between ice and water, leading to the rapid expulsion of MPs from the ice. The enrichment factors of all the MPs under study increased in calm saline water compared to in calm freshwater. The results revealed that the entrainment and enrichment of MPs in ice can be critical pathways affecting their fate in cold regions.
海冰可以作为微塑料（MPs）的临时汇，因此，它也可以作为微塑料的二次来源和运输介质。本研究旨在探讨在不同湍流条件下，各种微塑料特性和环境特征对微塑料在冰中的夹带和富集的影响。研究发现，淡水中的高转速显著增强了疏水性微塑料在冰中的夹带，这归因于冰晶和气泡的共同作用。这些微塑料的疏水性导致它们被吸引到水/空气或水/冰界面。然而，在盐水中，高湍流抑制了所有研究的微塑料类型的夹带。冰晶在盐水中形成了松散的结构而不是凝结，这使得微塑料在冰和水之间得以交换，导致微塑料迅速从冰中排出。与平静的淡水相比，所有研究的微塑料在平静的盐水中的富集因子都有所增加。结果表明，微塑料在冰中的夹带和富集可能是影响其在寒冷地区归宿的关键途径。
