Suppression of air pollution via aerosol mediated removal of peroxy radicals

通过气溶胶介导去除过氧自由基抑制空气污染

• 批准号: NE/Y000226/1
• 负责人: Dwayne Heard
• 金额: $ 109.88万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FY000226%2F1
• 关键词: Suppression; air; pollution; via; aerosol

Air quality is a pressing societal concern with around 7 million people dying per year from the combined effect of outdoor and indoor air pollution. Two of the key pollutants are gaseous ozone (which can also influence crop yields and damage ecosystems) and particular matter (PM), both of which also influence the climate system through the absorption and scattering of solar radiation. Policies to reduce the concentrations of these compounds are often implemented independently of each other and focus on reducing the emissions of different compounds with different sources. Ozone is a secondary pollutant, and so is not directly emitted into the atmosphere but produced by chemical chain reactions where volatile organic compounds (VOCs) are oxidized in the presence of oxides of nitrogen (NOx).For ozone, the scientific basis for emission reduction policy depends on the photochemical regime of a given region. Two well established regimes for ozone production are the so-called "VOC limited" regime where reductions in the VOC emissions are required in order to reduce ozone, and the "NOx limited" regime where reduction in NOx emissions is required. Which regime operates depends on which chemical reactions limit ozone production. This separation between NOx or VOC limited policies has underpinned ozone control strategies over the last three decades where policymakers have either reduced NOx or VOC emissions to reduce ozone. Controls of PM pollution, on the other hand, have focussed on the reduction of a different set of compounds (sulfur, black carbon, dust etc.). Thus, for decades ozone and PM pollution have been considered as effectively separate problems with unrelated policies for controlling PM and ozone.This proposal builds on the discovery by one of the investigators of a new third "aerosol inhibited" regime where the dominant process limiting ozone production is the reactive removal of peroxy radicals onto aerosol surfaces. In these locations there is a strong interaction between policies to reduce particulate matter and ozone. Efforts to reduce aerosol pollution would lead to the unintended consequence of increasing ozone concentration.Given the uncertainties on the rate of uptake of HO2 onto aerosols, a better understanding of this regime is necessary if policy is to be updated. This proposal will address a number of uncertainties that remain in these calculations. We will develop a new instrument for the direct field measurement of the rate of removal of peroxy radicals onto aerosols, and will measure for the first time in the laboratory how quickly organic peroxy radicals react on the surface of aerosols. The new field capability will be deployed in the UK and the measurements (together with those from a Japanese collaborator) and the results from the laboratory will be used to formulate new parameterizations which will allow heterogeneous removal to be more accurately represented in atmospheric models. We will use simple zero-dimensional box models and more complex three dimensional chemical transport models to quantify the impact on surface and global ozone concentrations, and atmospheric oxidation rates in the past, present and future. In this way we will explore the importance of the new ozone regime for air quality and climate.This proposal brings together leading complementary expertise from groups in Leeds, York and Manchester who have considerable experience in field measurements, laboratory measurements of gas-phase and heterogeneous aerosol processes, and numerical modelling on a range of spatial scales.

空气质量是一个紧迫的社会问题，每年大约有700万人因室外和室内空气污染的综合影响而死亡。两个关键污染物是气态臭氧（也可能影响作物产量和损害生态系统）和特定物质（PM），这两者也通过太阳辐射的吸收和散射来影响气候系统。降低这些化合物浓度的政策通常是独立于彼此独立实施的，并着重于减少具有不同来源的不同化合物的排放。臭氧是一种次要污染物，因此不是直接排放到大气中，而是由化学链反应产生的，在这些反应中，在氮（NOX）存在下，挥发性有机化合物（VOC）被氧化。对于臭氧的氧化物（NOX），对于给定区域的光学化学制度而言，臭氧的科学基础取决于臭氧的科学基础。所谓的“ VOC有限”制度是两个建立的臭氧产生制度，其中需要减少VOC排放以减少臭氧，而需要减少NOX排放的“ NOX有限”制度。哪种政权取决于哪种化学反应限制了臭氧的产生。在过去的三十年中，NOX或VOC有限政策之间的这种分离为臭氧控制策略提供了支持，在该策略中，决策者减少了NOX或VOC排放以减少臭氧。另一方面，对PM污染的控制重点是减少不同化合物（硫，黑碳，灰尘等）。因此，数十年来，臭氧和PM污染被认为是控制PM和臭氧无关的政策有效分开的问题。该提案是建立在新的第三个“ Aerosol抑制”状态的研究人员的基础上，其中限制臭氧产生的主要过程是对Aeroxy Radicals oferoxy Aerososol Surofforefore的反应性。在这些位置，减少颗粒物和臭氧的策略之间存在很强的相互作用。减少气溶胶污染的努力将导致臭氧浓度增加的意外后果。赋予HO2对气溶胶摄取率的不确定性，如果要更新政策，则需要更好地了解该政权。该提案将解决这些计算中仍然存在的许多不确定性。我们将开发一种新的仪器，用于直接现场测量过氧自由基在气溶胶上的去除速率，并将在实验室中首次测量有机过氧自由基在气溶胶表面上反应的速度。新的现场能力将在英国部署，并且测量值（以及日本合作者的测量值）将用于制定新的参数化，这将使异质删除在大气模型中更准确地表示。我们将使用简单的零维盒模型和更复杂的三维化学传输模型来量化过去，现在和未来对表面和全球臭氧浓度的影响以及大气氧化速率。通过这种方式，我们将探讨新的臭氧制度对空气质量和气候的重要性。该提案将利兹，约克和曼彻斯特群体的领先互补专业知识汇集在一起​​，他们在现场测量，气相测量，气相测量和异质气溶胶过程的实验室测量方面具有丰富的经验，以及在Spatial spatial spatial spatial级别上进行数字模型。