CAREER: Determining the mechanism and significance of microplastic pollution impacts on soil hydrology

职业：确定微塑料污染对土壤水文影响的机制和意义

• 批准号: 2340588
• 负责人: Farhad Jazaei
• 金额: $ 53.76万
• 依托单位: University of Memphis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340588&HistoricalAwards=false
• 关键词: CAREER; Determining; mechanism; significance; microplastic

Microplastics, ranging from 0.001 to 5 mm in size, originate from various sources such as detergents, cosmetics, and the breakdown of larger items like films, fabrics, and vehicle tires. There is extensive evidence that microplastic pollution has been occurring in terrestrial environments for decades. However, agricultural farms are identified as the most microplastic-polluted areas, mainly due to the use of plastic mulching and the application of wastewater biosolids as fertilizer. This project aims to answer fundamental and critically important questions— Can microplastic pollution change the soil-water-plant interactions? If so, in what mechanism, and to what extent? Microplastics are generally not degradable and accumulate in topsoil systems, resulting in exponential pollution growth in the coming decades. Understanding microplastics’ impacts on soil-water-plant interactions will empower policymakers, scientists, and stakeholders to mitigate or prevent negative outcomes. By comprehending the mechanisms of impacts, scientists can develop effective mitigation strategies.The research objectives of this project have been formulated to advance understanding of the extent and mechanism of microplastics’ impact on soil-water retention characteristics and unsaturated hydraulic conductivity (Objective-1), soil pore structure and morphology using micro-computed tomography techniques (Objective-2), and soil desiccation crack development dynamics (Objective-3). This project will also assess the variance between impacts of new (non-degraded) and aged (degraded) microplastic on soil-water-plant interactions, indexing immediate and long-term impacts of microplastics (Objective-4). This project will generate generalizable outcomes through a comprehensive study of various influential factors, including three typical loamy-texture soils found in agricultural farms, two most commonly used plastic types (low and high-density polyethylene), five microplastic shapes (film, fiber, foam, fragment, and powder), four size ranges (50-150, 150-500, 500-2000, and 2000- 5000 µm), two organic matter contents (1% and 3%), two soil hydrophobicity conditions, and five environmentally relevant microplastic concentrations ( 1%), utilizing advanced statistical regressions and variance models, extended evaporation soil tests, and advanced micro-computed tomography techniques. The objectives will be pursued over five years with the support of two graduate and six undergraduate students, emphasizing on underrepresented minorities and students with disabilities. The project will integrate research with education and outreach by 1) implementing a professional development program for K-12 educators and creating a web-based environmental program, 2) introducing underrepresented students to environmental science, technology, engineering, and mathematics (STEM) research and careers; 3) introducing soil-microplastic pollution to local and national public, scientists, and policymakers, and 4) bringing soil pollution topics to the graduate and undergraduate curriculum at the University of Memphis.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.

微塑料的大小从 0.001 毫米到 5 毫米不等，来源于多种来源，例如洗涤剂、化妆品以及薄膜、织物和汽车轮胎等较大物品的分解物。有大量证据表明，陆地环境中一直存在微塑料污染。然而，农业农场被认为是微塑料污染最严重的地区，这主要是由于使用塑料覆盖和使用废水生物固体作为肥料所致。该项目旨在回答根本性且至关重要的问题。问题——微塑料污染会改变土壤-水-植物的相互作用吗？如果是的话，微塑料通常不可降解并在表土系统中积累，导致未来几十年污染呈指数级增长。对土壤-水-植物相互作用的影响将使政策制定者、科学家和利益相关者能够减轻或防止负面后果。通过了解影响机制，科学家可以制定有效的缓解策略。该项目的研究目标是为了加深对这些影响的理解。的程度和机制微塑料对土壤保水特性和不饱和导水率的影响（目标 1）、使用微型计算机断层扫描技术的土壤孔隙结构和形态（目标 2）以及土壤干燥裂缝发展动力学（目标 3）。还将评估新的（未降解的）和老化的（降解的）微塑料对土壤-水-植物差异相互作用的影响，索引微塑料的直接和长期影响（目标4）。通过对各种影响因素的综合研究，包括农业农场中发现的三种典型的壤质土壤、两种最常用的塑料类型（低密度和高密度聚乙烯）、五种微塑料形状（薄膜、纤维、泡沫、碎片），产生可概括的结果和粉末），四种尺寸范围（50-150、150-500、500-2000 和 2000-5000 µm），两种有机物含量（1％和3％），两种土壤疏水性条件，以及五种与环境相关的微塑料浓度（1％），利用先进的统计回归和方差模型、扩展的蒸发土壤测试和先进的微计算机断层扫描技术来实现这些目标。在两名研究生和六名本科生的支持下，该项目将在五年内对代表性不足的少数族裔和残疾学生进行研究，并通过以下方式进行教育和推广：1）为 K-12 教育工作者实施专业发展计划并创建。基于网络的环境计划，2) 向代表性不足的学生介绍环境科学、技术、工程和数学 (STEM) 研究和职业；3) 向当地和国家公众、科学家和政策制定者介绍土壤微塑料污染，以及 4)将土壤污染主题引入孟菲斯大学的研究生和本科生课程。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。