Atmospheric chemistry of reactive trace species through direct real-time measurements

通过直接实时测量反应性痕量物质的大气化学

• 批准号: 2743355
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2743355
• 关键词: Atmospheric; chemistry; reactive; trace; species

"Poor air quality represents the greatest environmental risk to public health in the UK, and has been reported to affect every organ in the body, with links to illnesses including cardiovascular and respiratory diseases, vascular dementia, and Alzheimer's disease causing over 4.2 million premature deaths worldwide and costing the UK economy ~£15 billion each year. The properties and impacts of our air are governed by atmospheric composition, the understanding of which is vital to the development of policies aimed at improving air quality and requires knowledge of the emission rates, concentrations and chemistry of reactive trace species in the atmosphere. This project will investigate the chemistry and atmospheric impacts of reactive species using time-resolved ultraviolet and infrared absorption spectroscopy to make direct measurements of reactive atmospheric species in real-time during the course of their reactions. Laboratory experiments will focus on the chemistry of Criegee intermediates (CIs), a family of reactive species generated in the atmosphere through the reactions of ozone (O3) with unsaturated volatile organic compounds (VOCs). A particular challenge since the proposal of their existence in 1949 has been the direct measurement of CIs. The advent of photolytic sources for CIs, reported in 2012, has facilitated laboratory studies of CIs and has enabled greater understanding of the chemistry and properties of CIs, but there are still significant uncertainties regarding the kinetics and mechanisms of Criegee intermediate reactions under atmospherically relevant conditions.Recent NERC-funded work in this group has used photolytic CI sources to develop novel techniques to monitor the kinetics and products of Criegee intermediate reactions under atmospherically relevant conditions. This project will investigate the kinetics of CI + water reactions, which are atmospherically important but have yet to be explored in detail. The combination of UV and IR absorption techniques will enable the investigation of the kinetics, mechanisms, and product yields of these reactions, and provide insight to the potential role of CI-water complexes in the atmosphere.There will also be opportunities to develop the UV absorption experiment to make field measurements of OH reactivity, a measure of the total loading of reactive pollutants in an air mass that oxidise to secondary pollutants, and to make measurements of CIs in an atmospheric simulation chamber to explore Criegee intermediates directly, and quantitatively, in ozonolysis reactions. This project links to the NERC objectives related to atmospheric pollution and human health, clean air, and climate. "

“空气质量差是英国公共健康面临的最大环境风险，据报道，它会影响身体的每个器官，与心血管和呼吸系统疾病、血管性痴呆和阿尔茨海默病等疾病有关，导致超过 420 万人过早死亡。每年给英国经济造成约 150 亿英镑的损失 我们空气的特性和影响受大气成分的影响，了解大气成分对于制定旨在改善空气质量的政策至关重要，并且需要了解排放率，反应性痕量物质的浓度和化学性质该项目将利用时间分辨紫外和红外吸收光谱研究活性物质的化学和大气影响，以在反应过程中实时直接测量活性物质。实验室实验将重点关注化学。 Criegee 中间体 (CI) 是通过臭氧 (O3) 与不饱和挥发性有机化合物 (VOC) 反应在大气中产生的一族活性物质，自 1949 年提出其存在以来一直是一个特殊的挑战。 2012 年报道的 CI 光解源的出现促进了 CI 的实验室研究，并使人们能够更好地了解 CI 的化学和性质，但 Criegee 的动力学和机制仍然存在很大的不确定性。该小组最近由 NERC 资助的工作利用光解 CI 源开发了新技术，以监测大气相关条件下 Criegee 中间反应的动力学和产物。该项目将研究 CI + 水反应的动力学，该反应在大气中很重要，但尚未详细探索。紫外线和红外吸收技术的结合将能够研究这些反应的动力学、机制和产物产率。并深入了解 CI-水复合物在大气中的潜在作用。还将有机会开发紫外线吸收实验，对 OH 反应性进行现场测量，这是氧化空气中反应性污染物总负荷的一种测量到中学该项目与 NERC 与大气污染和人类健康、清洁空气和气候相关的目标相关。