Wind tunnel simulation of microplastics transport in atmospheric boundary-layer flows

塑料是现代日常生活中不可分割的组成部分，存在于我们的衣服纤维和我们使用的设备中。它们可以被模塑、挤压或吹制成几乎任何形状或大小的物体，生产成本低廉，耐腐蚀或生物降解，绝缘体良好，重量轻但相对较强。所有的塑料都是在陆地上制造的，在那里可能会添加稳定剂或着色剂等潜在的有害化合物。无论是在5毫米以下产生的，还是在环境中风化而缩小到5毫米的，微塑料颗粒都可以通过风和自来水在地球大气和地表水中长距离运输，积聚在深海甚至偏远的极地地区。80多年来，地球科学家利用风洞和数值方案相结合来了解粒子在风中的传输物理，并预测传输开始和沉积发生的大气条件。然而，人造塑料颗粒的性能远比沉积颗粒复杂。来自加拿大和英国的研究人员最近在特伦特大学（TEWT）的一个环境风洞中进行了实验，结果表明，与石英颗粒相比，微塑料纤维更容易被传输，比预期的传播频率更高，传播距离更远。在持续的合作中，我们将使用高速摄影和材料科学技术来评估在拉夫堡的磨损室和特伦特的风洞进行的三相流实验中的微塑料磨损和运动。总体目标是完善和量化我们对大气运输过程中微塑料行为的理解，并改进模型预测。来自英国的工人最近获得了自然环境研究委员会的资助来支持这个项目。该提案寻求NSERC的联盟资助，这将允许TEWT研究人员和受训者充分参与这一多学科国际合作，并扩大工作范围，以改善实验方法之间的整合。

Plastics are an inseparable component of modern daily life, present in the fibers of our clothing and the devices we use. Capable of being molded, extruded or blown to form objects of almost any shape or size, they are inexpensive to produce, largely resistant to corrosion or biodegradation, good insulators, and lightweight yet relatively strong. All plastics are manufactured on land, where potentially hazardous compounds like stabilizers or colourants may be added. Whether produced in lengths under 5 mm or reduced to this size via weathering within the environment, microplastic particles can be transported by wind and running water over very long distances within Earth's atmosphere and surface waters to accumulate in deep oceans and even in remote polar regions. For over 80 years, Earth scientists have used wind tunnels in combination with numerical schemes to understand the physics of particle transport by wind and to predict the atmospheric conditions under which transport is initiated and deposition occurs. However, the properties of manmade plastic particles are far more complex than sedimentary particles. Researchers from Canada and the UK recently carried out experiments in an environmental wind tunnel at Trent University (TEWT) which suggest that microplastic fibers are preferentially transported as compared to quartz particles, travelling with higher frequency and over greater distances than expected. In continued collaboration, we will use high-speed photography and materials science techniques to assess microplastic abrasion and motion in three-phase flow experiments carried out in abrasion chambers at Loughborough and the wind tunnel at Trent. The overarching goal is to refine and quantify our understanding of microplastic behaviour during atmospheric transport and to improve model prediction. Workers from the UK have recently received a Natural Environment Research Council grant to support this project. This proposal seeks Alliance funding from NSERC that will allow TEWT researchers and trainees to fully participate in this multidisciplinary international collaboration and to expand the scope of the work to improve integration between the experimental approaches.