CAREER: Towards a Better Understanding of Ambient Semi-volatile Organic Aerosol: Investigation of Thermodynamic Properties of Multi-component Organic Aerosols

职业：更好地了解环境半挥发性有机气溶胶：多组分有机气溶胶的热力学性质研究

• 批准号: 0955845
• 负责人: Andrey Khlystov
• 金额: $ 45.35万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-15 至 2013-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0955845&HistoricalAwards=false
• 关键词: CAREER; Towards; Better; Understanding; Ambient

The goal of this project is to obtain empirical parameterizations of thermodynamic properties of multi-component organic aerosol to be used in chemical transport models. The main hypothesis is that volatility of an organic compound in a mixture is a function of the carbon number and the polarity of this compound, as well as those of the mixture; and that volatility of the total mixture can be predicted using a simplified matrix containing binned data on the carbon number and polarity of each of the compounds in the mixture. Prediction of ambient semi-volatile organic aerosol remains highly problematic and air quality models often do not agree with observations. The lack of understanding of the partitioning of semi-volatile compounds between the gas and the complex aerosol matrix is one of the main reasons for this discrepancy.In this study the equilibrium thermodynamic properties of multi-component aerosols will be investigated under controlled laboratory conditions as well as in the field. In the laboratory experiments model mixtures of organic compounds as well as modified ambient aerosols will be tested. The ambient aerosols will be modified in a controlled way by adding known amounts of different organic substances of known thermodynamic properties and variable molecular weight and polarity. The equilibrium gas/aerosol partitioning in a temperature range relevant to ambient conditions will be investigated using the Integrated Volume Method (IVM), developed in the principal investigator's (PI) laboratory. The results will be used to derive equilibrium vapor pressures and activity coefficients of test compounds as a function of their carbon number and polarity and to determine the minimum number of bins along these dimensions that will adequately represent ambient aerosol volatility.This project will improve the understanding, predictions and control of the major fraction of ambient aerosol, which is relevant for public health and global climate change. The educational and outreach component will be directed at a wide audience in order to help educate the public about the current environmental problems related to air pollution and help attract students to environmental science and engineering. Special attention will be given to attracting and retaining under-represented groups, such as women and minorities. The project will include an educational outreach component with hands-on experience for middle school students; summer research projects will be offered to students from the North Carolina School of Science and Math, for graduate and undergraduate students at Duke University and North Carolina Central University (NCCU), an Historically Black University. The research results will be disseminated via conferences and peer-reviewed publications. To reach a wider audience the PI plans to utilize the power of social media tools, such as Facebook groups, to share the research results and engage the community directly.

该项目的目标是获得用于化学传输模型的多组分有机气溶胶热力学性质的经验参数化。 主要假设是混合物中有机化合物的挥发性是该化合物以及混合物的碳数和极性的函数；并且可以使用包含混合物中每种化合物的碳数和极性的分级数据的简化矩阵来预测总混合物的挥发性。 对环境半挥发性有机气溶胶的预测仍然存在很大问题，空气质量模型通常与观测结果不一致。 对气体和复杂气溶胶基质之间半挥发性化合物的分配缺乏了解是造成这种差异的主要原因之一。在本研究中，将在受控实验室条件以及现场研究多组分气溶胶的平衡热力学性质。 在实验室实验中，将测试有机化合物的模型混合物以及改良的环境气溶胶。 通过添加已知量的具有已知热力学性质和可变分子量和极性的不同有机物质，将以受控方式改变环境气溶胶。 将使用主要研究者 (PI) 实验室开发的积分体积法 (IVM) 研究与环境条件相关的温度范围内的平衡气体/气溶胶分配。结果将用于推导测试化合物的平衡蒸气压和活度系数作为其碳数和极性的函数，并确定沿这些维度充分代表环境气溶胶挥发性的最小箱数。该项目将提高对环境气溶胶主要部分的理解、预测和控制，这与公共卫生和全球气候变化相关。 教育和推广部分将面向广泛的受众，以帮助教育公众了解当前与空气污染相关的环境问题，并帮助吸引学生学习环境科学与工程。将特别关注吸引和留住代表性不足的群体，例如妇女和少数群体。 该项目将包括教育外展部分，为中学生提供实践经验；夏季研究项目将为北卡罗来纳州科学与数学学院的学生、杜克大学和北卡罗来纳中央大学（NCCU）（一所历史上的黑人大学）的研究生和本科生提供。 研究结果将通过会议和同行评审出版物传播。 为了吸引更广泛的受众，PI 计划利用 Facebook 群组等社交媒体工具的力量来分享研究成果并直接与社区互动。