CAREER: An Investigation of Microplastics Fate and Contaminant Transport in Storm Runoff, The Nexus of Environmental Engineering and Material Sciences

在消费品和材料中使用塑料会释放出被称为“微塑料”的小颗粒塑料，这些塑料会污染环境。这些微塑料在环境中具有持久性，通常需要数百年才能完全分解。微塑料可以通过水，空气和食物网在动物和其他生物体摄入和吸收后运输。此外，微塑料还可以吸收有毒污染物，导致它们在环境中传播得更远、更快，包括世界海洋。尽管海洋环境中的大多数微塑料来源于内陆，但人们对城市暴雨径流中释放的微塑料污染物对地表沃茨的相对重要性仍知之甚少。该项目的目标是缩小关于微塑料环境退化的关键知识差距，以及它们如何促进城市雨水中重金属的运输。这项研究的成功完成将极大地促进我们对城市环境中微塑料来源以及它们如何动员重金属的理解。这些知识将大大有助于制定有效的雨水管理战略。通过为K开发教育材料，提高科学素养和改善国家的STEM劳动力，将给社会带来额外的好处。12名教师教育他们的学生对塑料污染，并激励他们追求的职业生涯在环境工程和科学。这个职业生涯项目的目标是利用材料科学和环境工程跨学科的研究，以了解控制命运的过程和城市雨水中微塑料的运输。这将通过具体的研究目标来实现，以阐明内在和外在的材料特性在影响微塑料光降解和颗粒破碎的动力学中发挥的作用，并研究水的物理化学过程如何影响微塑料促进雨水中重金属的运输。本研究中开发的基础知识将为控制微塑料持久性和污染物在城市环境中传输的机制提供更好的概念性理解，这对于评估其对生态系统的负面影响以及制定有效的控制措施和补救策略至关重要。这项研究是对控制雨水中微塑料命运和污染物运输的物理和化学过程进行全面机械理解的首批努力之一。拟议研究的一个关键新奇解决了通常使用原始塑料颗粒和珠粒的实验室实验之间的不匹配问题，这些实验使用了通过较大塑料片段分解产生的与环境相关的降解二次微塑料。这种方法使用微塑料破碎磨料张力下，将促进动态模型的发展，以预测微塑料在各种机械载荷和物理条件下的崩解。综合教育计划将通过每年的研讨会为K-12教育工作者提供专业发展，以增加环境工程中代表性不足的学生的招聘，从而使社会受益。通过传播研究结果，让田纳西州的水资源管理者、从业者、政策制定者和其他利益相关者了解雨水中存在的微塑料，以及解决这一问题的方法，还将带来额外的好处。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The use of plastics in consumer products and materials results in the release of small particles of plastic known as “microplastics” that can pollute the environment. These microplastics are persistent in the environment and will typically take hundreds of years to decompose completely. Microplastics can be transported through water, air, and through the food web following ingestion and uptake by animals and other organisms. In addition, microplastics can also absorb toxic pollutants, causing them to spread further and faster in the environment, including the world’s oceans. Although a majority of microplastics in marine environments originate from inland sources, the relative importance of microplastic pollutants released in urban storm runoff to surface waters is still poorly understood. The goal of this CAREER project is to close the critical knowledge gap on the environmental degradation of microplastics and how they facilitate the transport of heavy metals in urban stormwater. Successful completion of this research will greatly advance our understanding of microplastic sources in urban environments and how they mobilize heavy metals. Such knowledge will greatly aid the development of effective stormwater management strategies. Additional benefits to society will result from advancing scientific literacy and improving the Nation’s STEM workforce through the development of educational materials for K-12 teachers to educate their students on plastic pollution and inspire them to pursue careers in environmental engineering and science.The goal of this CAREER project is to utilize material science and environmental engineering interdisciplinary research to understand processes controlling the fate and transport of microplastics in urban stormwater. This will be achieved through the specific research objectives to elucidate the roles that intrinsic and extrinsic material properties play in influencing the kinetics of microplastic photodegradation and particle fragmentation, and examine how aqueous physiochemical processes impact microplastic facilitated transport of heavy metals present in stormwater. The fundamental knowledge developed in this research will provide a better conceptual understanding of the mechanisms controlling microplastics persistence and contaminant transport within the urban environment, which is crucial to estimating their negative impacts on the ecosystem and developing effective control measures and remediation strategies. This investigation represents one of the first efforts to develop a comprehensive mechanistic understanding of the physical and chemical processes that control microplastic fate and contaminant transport in stormwater. A key novelty of the proposed research addresses the mismatch between laboratory experiments that generally use virgin plastic pellets and beads by using environmentally relevant degraded secondary microplastics generated through the disintegration of larger plastic segments. This approach using microplastic fragmentation under abrasive tension will facilitate the development of dynamic models to predict microplastics disintegration under various mechanical loadings and physical conditions. The integrated educational plan will benefit society by providing professional development for K-12 educators through annual workshops to increase the recruitment of underrepresented students into environmental engineering. Additional benefits will result from dissemination of results to inform water managers, practitioners, policymakers, and other stakeholders in Tennessee on the presence of microplastics in stormwater, and ways to combat the problem.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.