Elucidating the atmospheric chemistry of organic nitrates and reactive halogens in laboratory experiments and in ambient air

阐明实验室实验和环境空气中有机硝酸盐和活性卤素的大气化学

• 批准号: 355607-2011
• 负责人: Osthoff, Hans
• 金额: $ 1.82万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=572621
• 关键词: Elucidating; atmospheric; chemistry; organic; nitrates

There is growing public awareness that the composition of the atmosphere can be altered by man-made emissions with often unintended consequences. One example is the impact of persistent greenhouse gases on climate; another is the impact of pollutants such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) on regional air quality. NOx is a byproduct of high-temperature combustion and found, for example, in automobile exhaust. VOCs are emitted naturally by vegetation but also by a multitude of human activities. Accurate knowledge of the impact of NOx and VOCs and their decomposition products on the abundances of ozone and fine particulate matter is needed for policy makers to make informed decisions on pollution control. This research program will address some of the key uncertainties in the chemical transformations of NOx and VOCs as well as naturally occurring halogenated compounds (e.g., iodine containing species) in the atmosphere. The initial focus is on development of novel instrumentation to accurately measure some key intermediates (for example, organic nitrates) in ambient abundance. Students at both the graduate and undergraduate level will be involved in this research. Through their training, the public will gain a pool of qualified candidates to staff regional environmental agencies and industrial workplaces alike. The specific techniques to be developed and deployed are cavity ring-down and cavity enhanced-absorption spectroscopy, mass spectrometry, and electrophoresis. The second focus of this research program is on studying relevant transformations taking place in controlled laboratory experiments. For example, we will measure uptake rates of semi-volatile organic nitrates on fine particulate matter to better constrain ambient air quality models. Finally, we will take some of our instruments to the field and make ambient air measurements in and around Calgary, throughout the province of Alberta, and funding permitting, in regions heavily influenced by pollution (such as the Lower Fraser Valley, or Southern Ontario). Our measurements will help refine regional air quality models and ultimately allow more accurate predictions of the impacts of pollutants on air quality.

公众越来越意识到，人为排放可能会改变大气的成分，并常常带来意想不到的后果。一个例子是持久性温室气体对气候的影响；另一个是氮氧化物（NOx）和挥发性有机化合物（VOC）等污染物对区域空气质量的影响。氮氧化物是高温燃烧的副产品，例如存在于汽车尾气中。挥发性有机化合物不仅由植被自然排放，也由多种人类活动排放。政策制定者需要准确了解氮氧化物和挥发性有机化合物及其分解产物对臭氧和细颗粒物丰度的影响，才能就污染控制做出明智的决策。 该研究计划将解决大气中氮氧化物和挥发性有机化合物以及天然存在的卤代化合物（例如含碘物质）化学转化的一些关键不确定性。最初的重点是开发新型仪器，以准确测量环境丰度中的一些关键中间体（例如有机硝酸盐）。研究生和本科生都将参与这项研究。通过培训，公众将获得一批合格的候选人，为地区环境机构和工业工作场所等工作。待开发和部署的具体技术是腔衰荡和腔增强吸收光谱、质谱和电泳。该研究计划的第二个重点是研究受控实验室实验中发生的相关转变。例如，我们将测量细颗粒物对半挥发性有机硝酸盐的吸收率，以更好地约束环境空气质量模型。最后，我们将把一些仪器带到现场，在卡尔加里及其周边地区、整个阿尔伯塔省以及资金允许的情况下，在受污染严重影响的地区（例如弗雷泽河谷下游或安大略省南部）进行环境空气测量。我们的测量将有助于完善区域空气质量模型，并最终能够更准确地预测污染物对空气质量的影响。