Generation, Characterization, and Atmospheric Aging of Soot Particles from Diesel Combustion

柴油燃烧产生的烟尘气溶胶是颗粒物污染的主要形式之一，深刻影响着人类的健康、天气和气候。然而，由于在受控的实验室条件下柴油烟尘颗粒的产生和采样困难，很少有实验研究来研究它们的转化和相关的化学和物理性质的变化。在这个项目中，探索了一种利用激波管产生碳烟来模拟柴油发动机燃烧的新方法。实验室实验旨在通过暴露于可凝聚的气相物种(如硫酸和羧酸)以及人为和生物挥发性有机化合物氧化产生的半挥发性有机化合物来模拟柴油烟尘气溶胶的大气老化。使用一套气溶胶分析仪器测量了柴油烟尘气溶胶在内部混合过程中的形态、吸湿性和光学性质的变化。这项研究有望提供有关颗粒质量-尺寸关系、碳烟与大气中重要的无机和有机物种的内部混合以及柴油碳烟在大气老化过程中吸湿性和光学性质变化的重要信息。这项拟议的研究产生的结果可以用于实验研究、模型模拟和环境中含有烟尘的气溶胶的测量。烟尘气溶胶的化学和物理性质的结果可纳入大气模式，以评估其对天气和气候的影响。烟尘气溶胶的形态和化学成分信息也可用于评估对人类健康的影响，包括呼吸系统和心血管疾病。更好地了解烟尘气溶胶的产生和大气转化有助于减少气候预测和人类健康影响评估的不确定性，这对制定控制战略非常重要。因此，这项研究不仅有望增进我们对烟尘产生、转化和化学成分的了解，有助于改进烟尘气溶胶的模型模拟和环境测量，而且还将通过识别潜在的健康问题而有益于公众，并为政策决策者制定有效的颗粒物控制战略提供帮助。该项目的多学科性质结合了燃烧研究人员和大气气溶胶化学家的专业知识。该项目为机械工程和大气科学领域的本科生、研究生和博士后研究人员提供跨学科的研究机会。预计他们将在会议上介绍他们的工作，并在两个科学界建立联系，作为其关于全球环境变化研究的教育和培训的一部分。

0932705Zhang Soot aerosol produced from diesel combustion represents one of the major forms of particulate matter pollution, profoundly impacting human health, weather, and climate. However, few experimental studies have been carried out to investigate their transformation and associated variations in chemical and physical properties, because of difficulties in generation and sampling of diesel soot particles under controlled laboratory conditions. In this project, a novel approach using a shock tube is explored to generate soot to mimic diesel-engine combustion. Laboratory experiments are designed to simulate atmospheric aging of diesel soot aerosols by exposure to condensable gas-phase species (such as sulfuric acid and carboxylic acids) and semi-volatile organic compounds generated from oxidation of anthropogenic and biogenic volatile organic compounds. The changes in morphology, hygroscopicity, and optical properties of diesel soot aerosols during internal mixing are measured using a suite of aerosol analytical instruments. The research is expected to provide important information on the particle mass-size relationship, internal mixing of soot with atmospherically important inorganic and organic species, and variations of hygroscopicity and optical properties of diesel soot during atmospheric aging. Results generated from this proposed research can benefit experimental studies, model simulations, and ambient measurements of soot-containing aerosols. The results on chemical and physical properties of soot aerosols can be incorporated into atmospheric models to evaluate their effects on weather and climate. The information on the morphology and chemical compositions of soot aerosols can also be employed to assess human-health effects including respiratory and cardiovascular diseases.A better understanding of production and atmospheric transformation of soot aerosols helps to reduce uncertainties in climate prediction and assessment of human health effects, which are important for development of control strategies. Hence, this research is expected not only to advance our knowledge of generation, transformation, and chemical compositions and contribute to improved model simulations and ambient measurements of soot aerosols, but also to be beneficial to the public by identification of potential health issues and to policy decision-makers for development of effective particulate-matter control strategies. The multidisciplinary nature of this project combines expertise of combustion researchers and atmospheric aerosol chemists. The project provides interdisciplinary research opportunities for undergraduate students, graduate students, and post-doctoral researchers in the areas of mechanical engineering and atmospheric sciences. They are expected to present their work at conferences and build connections within the two scientific communities as part of their education and training on global environmental change research.