CAS: Understanding Glyphosate's Reactions at Mineral and Organic-Coated Mineral Surfaces: Sorption-Desorption Dynamics

CAS：了解草甘膦在矿物和有机涂层矿物表面的反应：吸附-解吸动力学

• 批准号: 2003505
• 负责人: Carmen Martinez
• 金额: $ 42.5万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003505&HistoricalAwards=false
• 关键词: CAS; Understanding; Glyphosate; Reactions; Mineral

The Environmental Chemical Sciences Program of the NSF Division of Chemistry funds Professor Carmen Enid Martínez at Cornell University to study the dynamics of glyphosate reaction with mineral and organic-coated mineral surfaces present in soils. Glyphosate is the world’s most heavily applied herbicide used to kill broadleaf plants and grasses. As a result, environmental contamination with glyphosate occurs frequently and widely in U.S. soils, sediments, surface and groundwater. Glyphosate’s interaction with soil greatly influences glyphosate’s environmental behavior including toxicity, mobility, and bioavailability. The goal of this project is to learn how and how fast glyphosate is retained and released upon interaction with soil components. Given the widespread use of glyphosate, it is essential to understand the conditions for its accumulation. Of interest is also whether its reactions with soil components create a reservoir with slow-release capability, which is a route to surface and groundwater contamination. This project provides research opportunities and training for graduate students. The project integrates an outreach component with the Sciencenter (Ithaca, NY), and outreach activities with NYS 4-H and Cornell Cooperative Extension. Graduate students participate in all outreach activities which supports their development and professional training.This project provides comprehensive information on molecular-scale processes of glyphosate at mineral and organic-coated mineral surfaces. The overarching question is: Does glyphosate accumulate in soils, and is its accumulation a reversible process? Research activities are designed to test the hypothesis that mineral and organic-coated mineral surfaces differ in their ability to retain (sorb) and release (desorb) glyphosate, and that glyphosate sorption at mineral surfaces outcompetes sorption of dissolved organic matter. Mechanisms of interaction and kinetics of glyphosate sorption-desorption are investigated using minerals that represent a variety of surface structures, and organic-coated minerals where the organic-coating differ in structural characteristics, functionality and aromaticity. Molecular-scale sorption-desorption behavior and kinetics of these processes are probed utilizing surface sensitive approaches coupled to simultaneous analyses of outflow solutions from these experiments. Process-based parameters are obtained that help explain glyphosate sorption-desorption behavior (binding constants, sorption maximum) and their rate constants. The simultaneous monitoring of surface reactions and solution chemistry facilitates a more comprehensive understanding of molecular-scale processes.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.

NSF化学部的环境化学科学计划资助康奈尔大学的Carmen Enid Martínez教授研究草甘膦与土壤中矿物和有机涂层矿物表面反应的动力学。草甘膦是世界上使用最多的用于杀死阔叶植物和草的除草剂。因此，草甘膦的环境污染在美国土壤、沉积物、地表和地下水中频繁而广泛地发生。草甘膦与土壤的相互作用极大地影响了草甘膦的环境行为，包括毒性，流动性和生物利用度。该项目的目标是了解草甘膦在与土壤成分相互作用时如何以及多快地被保留和释放。鉴于草甘膦的广泛使用，了解其积累的条件至关重要。还有一个问题值得关注，即它与土壤成分的反应是否会形成一个具有缓释能力的水库，这是一个导致地表水和地下水污染的途径。该项目为研究生提供了研究机会和培训。该项目整合了与科学中心（纽约州伊萨卡）的外联部分，以及与纽约州4-H和康奈尔合作推广的外联活动。研究生参加所有支持他们发展和专业培训的外展活动。该项目提供了关于草甘膦在矿物和有机涂层矿物表面的分子尺度过程的全面信息。首要的问题是：草甘膦是否在土壤中积累，其积累是一个可逆的过程？研究活动的目的是测试的假设，矿物和有机涂层矿物表面不同的能力，以保留（吸附）和释放（解吸）草甘膦，草甘膦在矿物表面的吸附胜过溶解的有机物质的吸附。草甘膦吸附-解吸的相互作用和动力学的机制进行了研究，使用代表各种表面结构的矿物，和有机涂层的矿物，其中有机涂层的结构特征，功能和芳香性不同。分子尺度的吸附-解吸行为和动力学的这些过程中，利用表面敏感的方法，结合从这些实验流出的解决方案的同时分析探测。基于过程的参数，获得有助于解释草甘膦的吸附-解吸行为（结合常数，吸附最大值）和它们的速率常数。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。