The Role of Peroxy Radicals: Linking Gas-Phase Oxidation Chemistry to Secondary Organic Aerosol Formation

过氧自由基的作用：将气相氧化化学与二次有机气溶胶形成联系起来

• 批准号: 1455588
• 负责人: Nga Lee Ng
• 金额: $ 23.88万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-15 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1455588&HistoricalAwards=false
• 关键词: Role; Peroxy; Radicals; Linking; Gas

This work focuses on improving the fundamental understanding of processes that contribute to the formation of secondary organic aerosol (SOA - very small particles formed from gas-phase compounds) in the atmosphere. A series of laboratory chamber experiments is being conducted to evaluate the atmospheric conditions and concentrations of various chemical species that lead to SOA formation. The results of this research will lead to improved models for predicting SOA formation.The objectives of this research are: (1) To experimentally map out the effects of the different reaction channels of peroxy radicals on SOA yields, gas- and aerosol-phase composition from photochemical oxidations of biogenic and anthropogenic hydrocarbons, and (2) To determine the effects of different peroxy radical reaction pathways on aerosol volatility. The proposed work focuses on oxidation by OH radicals under dry conditions (relative humidity 1%). Ammonium sulfate is being used as seeds for aerosol growth and hydrogen peroxide (H2O2), nitrous acid (HONO), or methyl nitrite (CH3ONO) is being used as the OH source. This research will also help improve understanding of how nitrogen oxides influence the SOA formation process.The project includes outreach plans at the Columbia Middle School (a Title 1 school) to work with an Earth Science teacher and middle school students to increase their knowledge and experience in science, technology, engineering, and math (STEM) disciplines.

这项工作的重点是增进对大气中二次有机气溶胶(SOA--由气相化合物形成的极小颗粒)形成过程的基本了解。目前正在进行一系列实验室室内实验，以评估导致SOA形成的大气条件和各种化学物质的浓度。本研究的目的是：(1)实验研究不同过氧基反应通道对SOA产率、生物和人为碳氢化合物光化学氧化气相和气溶胶相组成的影响；(2)确定不同过氧基反应途径对气溶胶挥发性的影响。建议的工作重点是在干燥条件下(相对湿度为1%)由羟基自由基氧化。硫酸铵被用作气溶胶生长的种子，过氧化氢(H_2O_2)、亚硝酸(HONO)或亚硝酸甲酯(CH_3ONO)被用作氢氧化源。这项研究还将有助于加深对氮氧化物如何影响SOA形成过程的理解。该项目包括哥伦比亚中学(标题1学校)的外展计划，与地球科学教师和中学生合作，增加他们在科学、技术、工程和数学(STEM)学科的知识和经验。