Project 1: Formation and Reactions of Environmentally Persistent Free Radicals in

项目1：环境持久性自由基的形成和反应

• 批准号: 9303528
• 负责人: Barry Dellinger
• 金额: $ 21.25万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9303528
• 关键词: Affect; Binding; Biochemistry; Biological; Breathing; Caliber; Cardiac; Chemistry; Chlorobenzene; Chlorophenols; Collaborations; Complex; Copper; Data; Defect; Devices; Electron Spin Resonance Spectroscopy; Electron Transport; Environment; Free Radical Formation; Free Radicals; Fright; Functional disorder; Gases; Genetic Recombination; Hazardous Substances; Hazardous Waste; Hydroxyl Radical; Kinetics; Knowledge; Laboratories; Lead; Literature; Lung; Measurement; Measures; Mediating; Metals; Modeling; Modification; Molecular; Oxidation-Reduction; Oxidative Stress; Oxides; Oxygen; Particle Size; Particulate Matter; Pathway interactions; Pentachlorophenol; Phase; Reaction; Reporting; Research; Roentgen Rays; Role; Sampling; Silicon Dioxide; Soil; Soot; Source; Spectroscopy, Fourier Transform Infrared; Structure; Superfund; Surface; System; Techniques; Toxic effect; Transition Elements; Wood material; base; chemical property; density; dibenzo(1,4)dioxin; dibenzofuran; fly ash; innovation; iron oxide; metal complex; metal oxide; particle; phenoxy radical; pollutant; reaction rate; remediation; semiquinone radicals; superfund site; theories

Environmentally persistent free radicals (EPFRs) are formed on the surfaces of transition metal-containing particles by chemisorption of a molecular precursor and electron transfer from the organic to the metal, resulting in reduction of the metal and formation of the EPFR. Association of some radicals with the metal increases their stability and reduces their rate of reaction with oxygen such that they can persist for several days in the environment. EPFRs have been found associated with soot and fly-ash produced from the combustion of hazardous wastes and Superfund soils from a former wood-treatment facility contaminated with pentachlorophenol. EPFRs are formed in high concentrations in the thermal and cool-zones of incinerators and other thermal treatment devices for remediation of Superfund sites where they can also react, primarily by radical-radical recombination, to form polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This project explores the origin and fate of EPFRs in thermal treatment devices through four Specific Aims: 1) Identify the mechanisms of EPFR formation and stabilization on transition metal surfaces; 2) Determine the role of iron oxide-containing, combustion-generated particles in the formation of PCDD/F from chlorobenzenes and chlorophenols; 3) Assess the effect of particle size on EPFR and PCDD/F formation for Fe2O3 - containing particles; and 4) Develop Reaction Kinetic Models of Surface-Mediated Formation of EPFRs and PCDD/Fs. This project provides the basic chemistry needed for the other projects in the Center. Collaboration with Project 6 will lead to understanding how the structure and chemical properties of particles affect EPFR formation and reactivity. It provides the background for study of formation and stabilization of EPFRs in contaminated Superfund soils in Project 3. It also provides the basic biological chemistry necessary to understand the cardiac and pulmonary dysfunction induced by inhalation of EPFRs demonstrated in Biomedical Projects 2, 4, and 5. Collaboration with the Oxidative Stress Core, Materials Core, and Computational Core has already shown EPFR-particle systems participate in long chain cycles in biological media producing hydroxyl radical that initiates oxidative stress in the exposed host.

环境持久性自由基(EPFR)是通过分子前体的化学吸附和电子从有机物向金属的转移而在过渡金属颗粒表面形成的，从而导致金属的还原和EPFR的形成。一些自由基与金属的缔合增加了它们的稳定性，降低了它们与氧气的反应速度，使它们可以在环境中持续几天。EPFR已被发现与危险废物燃烧产生的烟尘和飞灰以及受污染的前木材处理设施产生的超级基金土壤有关 含有五氯苯酚。EPFR在焚烧炉和用于修复超级基金场所的其他热处理设备的热区和冷区中浓度很高，在那里它们也可以反应，主要是通过自由基-自由基复合，形成多氯二苯并-对-二恶英和二苯并呋喃(PCDD/FS)。本项目通过四个具体目标探索热处理设备中EPFR的起源和去向：1)确定EPFR的形成和稳定机制 这些研究包括：2)确定含铁氧化物燃烧生成的颗粒在氯苯和氯苯酚生成多氯二苯并二恶英/氟的过程中的作用；3)评估颗粒尺寸对含Fe2O3颗粒的EPFR和多氯二苯并二恶英形成的影响；以及4)建立表面介导的EPFR和多氯二苯并二恶英形成的反应动力学模型。这个项目提供了该中心其他项目所需的基础化学。与Project 6的合作将导致了解粒子的结构和化学性质如何影响EPFR的形成和反应性。这为研究提供了背景 项目3中受污染的超级基金土壤中EPFR的形成和稳定。它还提供了必要的基本生物化学，以了解吸入EPFR引起的心和肺功能障碍，在生物医学项目2、4和5中展示了这一点。与氧化应激核心、材料核心和计算核心的合作已经表明，EPFR-颗粒系统参与生物介质中产生羟基自由基的长链周期，从而在暴露的宿主中启动氧化应激。