Characterizing Chemical Production and Loss of Nitrous Acid (HONO) Via Stable Isotopes

通过稳定同位素表征亚硝酸 (HONO) 的化学生产和损失

• 批准号: 1904570
• 负责人: Meredith Hastings
• 金额: $ 49.98万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-11-01 至 2023-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904570&HistoricalAwards=false
• 关键词: Characterizing; Chemical; Production; Loss; Nitrous

This award from the Environmental Chemical Sciences Program supports Professor Meredith Hastings at Brown University to study nitrous acid. Nitrous acid is a key species in atmospheric chemistry, with important implications for air quality both indoors and outdoors. This project focuses on addressing the difficult-to-resolve sources and sinks of atmospheric nitrous acid. Nitrous acid is typically produced on an environmental surface by reactions of nitrogen dioxide, nitric acid or particulate nitrate. The project uses stable isotopic analysis of these species to determine potential pathways of gaseous nitrous acid production. It builds on measurements of isotopic signatures from previous work and leads to improved understanding of the relative contributions from each source and pathway to the atmospheric nitrous acid budget. This has strong implications for understanding air quality, climate change, and their impact on human and ecosystem health. It also provides a potential tool for better prediction and decision making related to emissions that lead to nitrous acid production. This award also advances the career development of a postdoctoral scientist and a graduate student. Results are being integrated into a newly developed course on air quality at Brown University. A new method has been developed and verified in Professor Hasting's lab to efficiently capture nitrous acid in the air for stable isotopic characterization of nitrogen and oxygen isotopes. This technique has been used to distinguish the isotopic signature of nitrous acid from major sources including vehicle, soil and biomass burning emissions. In this project, a flow reactor is being designed and built to couple with the collection technique to isotopically characterize the nitrous acid heterogeneously produced on environmentally representative surfaces that are both prepared in the lab and collected in the actual environment. The results from this project will constrain atmospheric nitrous acid budget and trace reactive nitrogen species cycling from regional to global scales.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

环境化学科学计划的这一奖项支持布朗大学梅雷迪思·黑斯廷斯教授研究亚硝酸。亚硝酸是大气化学中的关键物质，对室内和室外的空气质量具有重要影响。该项目重点解决难以解决的大气亚硝酸源汇问题。亚硝酸通常是通过二氧化氮、硝酸或颗粒硝酸盐的反应在环境表面产生的。该项目利用这些物种的稳定同位素分析来确定气态亚硝酸生产的潜在途径。它建立在以前工作的同位素特征测量的基础上，有助于更好地了解每个来源和大气亚硝酸预算途径的相对贡献。这对于了解空气质量、气候变化及其对人类和生态系统健康的影响具有重要意义。它还为更好地预测和决策有关导致亚硝酸生产的排放提供了潜在的工具。该奖项还促进了博士后科学家和研究生的职业发展。结果正在被纳入布朗大学新开发的空气质量课程中。黑斯廷教授的实验室开发并验证了一种新方法，可以有效捕获空气中的亚硝酸，从而对氮和氧同位素进行稳定同位素表征。该技术已用于区分亚硝酸与主要来源（包括车辆、土壤和生物质燃烧排放物）的同位素特征。在该项目中，正在设计和建造一个流动反应器，以与收集技术相结合，以同位素表征在环境代表性表面上异质产生的亚硝酸，这些表面在实验室中制备并在实际环境中收集。该项目的结果将限制大气亚硝酸预算，并追踪从区域到全球范围内的活性氮物种循环。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。