Microstructural Pathway of EPFR Formation and their Decay Mechanisms

项目概要/摘要：项目5 有强有力的证据表明，环境持久性自由基（EPFRs）与部分- 在申报和潜在的超级基金场地内/周围发现的颗粒物（PM）和土壤对环境造成不利影响。 健康影响。减轻相关的环境风险需要详细了解 EPFR污染的空气和土壤系统。具体而言，项目5与SRP Man- 日期4，这是阐明化学和物理方法，以减少这些数量和毒性 有害物质。项目5将研究EPFR的微观或原子性质，用于- 信息，包括它们在环境中的显著稳定性，并将模拟由此产生的影响 在广泛的金属氧化物（MO）平台上进行化学衰变。使用一个工具箱， 最先进的实验和分子从头计算方法跨越不同的材料平台， 形式（表面，纳米团簇/粉末，粘土，EPA粉煤灰，土壤），我们继续关注的是阐明 有机物的个别细节和相应的局部效应（电子/化学/原子结构） 分子金属氧化物/中心化学吸附，随后的电荷转移（氧化还原），以及随后的化学反应， 与含有EPFR的系统（如PM、粉末、粘土和真实世界）相关的校准降解 （场EPFR）材料。我们的目标是在原子层次上回答三个简单的问题：1） EPFR是如何化学形成的？2)EPFR衰减的原因是什么？3）为什么EPFR的性质相似- 在不同平台上更大？虽然我们以前的努力已经阐明了EPFR形成的趋势， EPFR衰变机制、寿命和对MO的依赖性之间的联系- 不稳定/补救（SRP任务4）-尚未解决，是我们的主要目标 项目虽然主要集中在揭示基础环境科学，我们的项目将 与中心合作通过从我们的其他SRP项目中识别重要因素， 将不同材料平台的结果相关联，我们将获得协同/拮抗趋势 EPFR不稳定/补救的参数，这些参数转化为其他项目，并反过来启动 并阐明缓解和补救战略。通过采用实验过程， 模型和概括真实的世界的曝光，项目5将提供一个微观系统的图片， 产生EPFR和相关吸附物系统的项目，但更重要的是，将询问效率， 促进/阻碍降解的因素以及影响和增强 整个中心的活动（项目1-4和所有核心）。与之紧密结合， 项目4，这将使我们的中心协同阐明的原子机制的EPFR 以可扩展和可预测的方式研究化学，有助于了解生物化学健康 影响，缓解和补救这些颗粒结合的污染物在超级基金网站。

Project Summary/Abstract: Project 5 There is strong evidence that environmentally persistent free radicals (EPFRs) associated with partic- ulate matter (PM) and soils found in/around declared and potential Superfund sites pose adverse health effects. Mitigation of the associated environmental risks requires a detailed understanding of EPFR-contaminated air and soil systems. Specifically, Project 5 is in direct alignment with SRP Man- date 4, which is elucidating chemical and physical methods to reduce the amount and toxicity of these hazardous substances. Project 5 will study the microscopic, or atomistic, properties of EPFR for- mation, including their remarkable stability in the environment, and will model the resulting influences of chemical decay on a broad base of metal oxide (MO) platforms. Employing a toolbox of state-of- the-art experimental and molecular ab initio computational methods across differing material plat- forms (surfaces, nanoclusters/powders, clays, EPA fly ash, soil), our continued focus is on elucidating individual details of and corresponding local effects (electronic/chemical/atomic structure) on organic molecular-metal oxide/center chemisorption, ensuing charge transfer (redox), and consequent chemi- cal degradation pertinent to EPFR-containing systems such as PM, powders, clays, and real-world (field EPFR) materials. Our Aims focus on answering three simple questions at an atomistic level: 1) How do EPFRs chemically form? 2) What causes EPFR decay? and 3) Why are EPFR properties simi- lar across differing platforms? While our previous efforts have elucidated trends in EPFR formation, the connection between EPFR decay mechanisms, lifetimes, and dependence on MO—the path to destabilization/remediation (SRP Mandate 4)—has not yet been addressed and is a main goal of our project. Although focused primarily on revealing fundamental environmental science, our Project will work symbiotically with the Center. By identifying material factors from our other SRP Projects and correlating results across differing material platforms, we will obtain synergistic/antagonistic tendency parameters for EPFR destabilization/remediation that translate to other Projects, and in turn, initiate and clarify mitigation and remediation strategies. By employing experimental processes that both model and recapitulate real world exposures, Project 5 will provide a picture of the microscopic sys- tems generating the EPFRs and related adsorbate systems, but more importantly, will interrogate ef- fects that promote/hinder degradation and the corresponding products that influence and enhance activities across the Center (Projects 1–4 and all the Cores). Integrating closely with and expanded by Project 4, this will allow our Center to synergistically elucidate the atomic mechanisms of the EPFR chemistry in a scalable and predictive manner that contributes to understanding biochemical health effects, mitigation, and remediation of these particle-bound pollutants at Superfund sites.