Activation, Sensing, and Prevention of Formation of EPFRs in Thermal Treatment of Superfund Wastes

项目摘要/摘要：项目4 包括超级基金场址废物和土壤在内的危险废物的热处理导致形成 与排放的颗粒物(PM)相关的环境持久性自由基(EPFR)。许多金属 例如以PM形式存在的铜、铁、锌或镍具有不同的产率和不同程度的EPFR 稳定性和坚持性。这种EPFR实体被证明是导致 观察暴露人群的心肺健康影响。我们对模型系统的研究，包括 具有单一金属形态的粒子和相关的EPFR允许在 了解EPFR的形成机制及其对呼吸和心脏健康的影响 由EPFR暴露所致。项目4的中心假设是EPFR的形成及其 生物活化和它们经历催化循环，产生·OH的倾向由 PM的组成和介质的物理化学性质(介质的pH、离子强度和极性) 加速或阻止EPFR激活。项目4探索的主要科学问题包括1)如何 环境空气中的持久性EPFR在生物系统中转化为非常活跃的氧化还原循环物种，2)可以 利用EPFR的反应性来预防或控制EPFR的形成及其检测？ 项目4采用系统的方法来解决这些问题，首先通过以下方式定义机制 其中EPFR从持久的自由基转变为产生·OH的活性物种(即活化)。一个底部- 研究中使用了UP方法；从实验室制作的简单成分的样品中获得的结果 将与更复杂的燃烧产生的EPFR进行比较和评估，最后，现场- 收集的EPFR。在借鉴前人研究成果的基础上，我们提出了预防EPFR的方法 编队将被详细研究。这种方法是基于金属中心的“就地”失活 热处理(TT)设施，从而有效地阻止EPFR排放。现场传感器的开发是 基于EPFR生成羟基自由基的倾向，以及基于 感官解决方案。这些研究的结果将为技术开发提供基础，以控制 超级基金场址材料TT期间EPFR的排放和开发简单快速的检测装置 以及田间EPFR的测量。

Project Summary/Abstract: Project 4 Thermal treatment of hazardous waste including Superfund Site wastes and soils leads to the formation of environmentally persistent free radicals (EPFRs) associated with emitted particulate matter (PM). Many metals such as copper, iron, zinc or nickel present in PM form EPFRs with varying yields and different degrees of stabilization and persistency. Such EPFR entities were shown to be potentially a primary factor causing the observed cardiopulmonary health effects in exposed populations. Our studies of model systems containing particles with single metal speciation and associated EPFRs has allowed for significant advancement in understanding the formation mechanism of EPFRs as well as the respiratory and cardiac health effects resulting from EPFR exposure. The central hypothesis of Project 4 is that the formation of EPFRs and their biological activation and their propensity to undergo catalytic cycle, producing •OH, is defined by the constituents of PM and physico-chemical properties of the media (media pH, ionic strength, and polarity) accelerate or prevent EPFR activation. Major scientific questions explored by Project 4 include 1) how does the persistent EPFR in ambient air transform to very active, redox cycling species in biological systems and 2) can the reactivity of EPFRs be exploited as a means to prevent or control EPFR formation and their detection? Project 4 takes a systematic approach to address these questions, starting with defining the mechanism by which EPFRs transition from persistent radicals to reactive species generating ·OH (i.e., activation). A bottom- up approach is used in the studies; results obtained from laboratory-made samples with simple composition will be compared and evaluated against more complex combustion-generated EPFRs and, finally, field- collected EPFRs. Capitalizing on the results from previous studies, we propose a method for EPFR prevention formation that will be studied in detail. This method is based on the “in situ” deactivation of the metal centers in thermal treatment (TT) facilities, thus effectively blocking the EPFR emissions. The field sensor development is based on EPFR propensity to generate hydroxyl radicals and is based on the visible light absorption by sensory solution. The results of these studies will provide a basis for technology development to control the emission of EPFRs during TT of Superfund sites materials and to develop devices for simple and fast detection and measurement of EPFRs in field.