Characterization of Urban Grime Photochemistry as Sink or Source for Air Pollutants(GrimePaSS)

城市污垢光化学作为空气污染物汇或源的表征（GrimePaSS）

• 批准号: 415705351
• 负责人: Professor Dr. Hartmut Herrmann
• 金额: --
• 依托单位: Leibniz-Institut für Troposphärenforschung e.V. (TROPOS)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/415705351?language=en
• 关键词: Characterization; Urban; Grime; Photochemistry; Sink

The improvement of urban air quality in Europe is a major concern that strengthens the interest in understanding the most relevant chemical processes and pathways of air pollutants, like nitrogen oxides (NOx), ozone (O3) and several volatile organic compounds (VOCs). Besides gas phase chemistry, also heterogeneous and multiphase reactions when gases interact with urban surfaces (e.g., windows, building walls, rooftops, sidewalks, roads, etc.) are processes which could affect the fate of air pollutants. When such surfaces are exposed to the atmosphere for a certain time, it is known that a so called “urban grime” film consisting of inorganic and organic components will develop. However, the knowledge about the interaction of this new environmental compartment with air pollutants under illumination is still limited to a handful individual studies.The proposed project, therefore, will combine real urban grime sampling with laboratory and modelling studies to characterize the photoreactive behavior of urban grime at impervious surfaces. Small lab scale photoreactor and aerosol chamber experiments will be performed to investigate whether urban grime is potentially acting as a sink or a source for air pollutants. This experimental approach will provide for the first time comprehensive data on the kinetics (uptake coefficients, deposition velocities, etc.) for different air pollutants (e.g., NOx, O3, toluene) and will give insights into reaction mechanisms and potential secondary product formation. The additional analysis of the urban grime chemical composition by CPP-GC-MS and ion chromatography before and after these photoreactivity experiments will extend the results to a multiphase chemical data set which will further be applied in a modelling module. The modelling will finally provide useful insights into the overall lifetimes and fates of air pollutants associated with urban grime.Overall, the proposed project will give for the first time a comprehensive answer to the question how urban grime as a new environmental compartment in urban areas will impact air quality and associated health effects.

欧洲城市空气质量的改善是一个主要问题，它加强了人们对了解空气污染物（如氮氧化物（NOx），臭氧（O3）和几种挥发性有机化合物（VOC））最相关的化学过程和途径的兴趣。除了气相化学之外，当气体与城市表面相互作用时，也会发生多相和多相反应（例如，窗户、建筑物墙壁、屋顶、人行道、道路等）是可能影响空气污染物命运的过程。当这些表面暴露于大气中一定时间时，已知将形成由无机和有机成分组成的所谓的“城市污垢”膜。然而，关于这种新的环境隔间与空气污染物在光照下的相互作用的知识仍然局限于少数个别的研究。因此，拟议的项目将结合联合收割机真实的城市污垢采样与实验室和模拟研究，以表征城市污垢在不透水表面的光反应行为。将进行小型实验室规模的光反应器和气溶胶室实验，以调查城市污垢是否可能作为空气污染物的汇或源。这一实验方法将首次提供关于动力学的全面数据（吸收系数、沉积速度等）。对于不同的空气污染物（例如，NOx、O3、甲苯），并将深入了解反应机理和潜在的二次产物形成。在这些光反应性实验之前和之后，通过CPP-GC-MS和离子色谱法对城市尘垢化学成分进行额外分析，将结果扩展到多相化学数据集，该数据集将进一步应用于建模模块。该模型最终将为与城市污垢相关的空气污染物的整体寿命和归宿提供有用的见解。总体而言，拟议项目将首次全面回答城市污垢作为城市地区的新环境分区将如何影响空气质量和相关健康影响的问题。