A Novel Controlled Thermal Desorption Technique for Evaluation of Organic Aerosol Component Volatility and Absorptive Partitioning

用于评估有机气溶胶组分挥发性和吸收分配的新型受控热解吸技术

• 批准号: NE/H002561/1
• 负责人: Gordon McFiggans
• 金额: $ 25.21万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH002561%2F1
• 关键词: Novel; Controlled; Thermal; Desorption; Technique

Particulate material in the atmosphere has a major effect on both climate and human health; specifically the finer particulate material (below around one micron in diameter) being responsible for the majority of the radiative and air quality impacts. Whilst inorganic components are readily quantified, organic components comprise a large fraction of the particulate material, normally greater than 50% of the total mass. This fraction is very poorly quantified or described. Some of the organic material is known to be emitted directly into the atmosphere and is therefore known as primary material. This is normally a minority of the total organic aerosol mass, the rest comprising 'secondary' components (aerosol being the sum of the particulate and gaseous components). Secondary components may be defined in a number of ways, but a useful working definition is that they are the components that have entered the particles from the gas phase or have been formed in the particle from components that have entered the particles from the gas phase. The absorptive partitioning model of secondary organic aerosol (SOA) component formation has been widely applied and found to provide a useful framework for explanation of the process of gas to particle conversion. More recently there has been a postulation of significant pathways for condensed phase reaction and potential formation of these secondary components by reactive uptake which would impact on the reversibility of SOA formation and the ability to explain SOA formation by the absorptive partitioning alone. In the Manchester aerosol chamber, we have recently noticed some interesting results on dilution of SOA samples. Because of the predictions of absorptive partitioning, it would be expected that SOA mass would reduce more than the amount by which it has been diluted owing to evaporation of more volatile components. This has not been observed in our experiments in several biogenic precursor systems and has very significant atmospheric implications. If absorptive partitioning is demonstrably incapable of explaining the chamber results, then many models of atmospheric organic aerosol behaviour based on chamber yield data will have problems. Previous experiments have used thermal denuders to probe the SOA volatility and loosely infer reversibility of SOA formation. It is proposed to design and construct a novel thermal denuder system to probe, in combination with controlled dilution, the volatility of secondary organic aerosol components formed in the chamber photo-oxidation of biogenic and anthropogenic organic precursors. The denuder system will be characterised using particles of known composition and properties generated in the laboratory prior to coupling it to the Manchester aerosol chamber to establish the validity of the widely accepted absorptive partitioning model of aerosol formation. The anticipated superior performance of the denuder system will be suitable for quantifying component volatility and, by coupling it to the chamber in dilution experiments, for assessing the reversibility predicted by absorptive partitioning theory.

大气中的微粒物质对气候和人类健康都有重大影响；特别是更细的颗粒物质（直径小于1微米）是造成大部分辐射和空气质量影响的原因。虽然无机成分很容易量化，但有机成分占颗粒物质的很大一部分，通常大于总质量的50%。这部分很难量化或描述。已知有些有机物质直接排放到大气中，因此被称为原生物质。这通常是有机气溶胶总量的一小部分，其余的由“次要”成分组成（气溶胶是颗粒和气体成分的总和）。二次组分可以用许多方法来定义，但是一个有用的工作定义是它们是从气相进入粒子的组分，或者是从气相进入粒子的组分在粒子中形成的组分。二次有机气溶胶（SOA）组分形成的吸收分配模型得到了广泛的应用，并为解释气体到颗粒的转化过程提供了一个有用的框架。最近，有一种假设认为，通过反应性吸收，浓缩相反应和这些次要成分的潜在形成有重要的途径，这将影响SOA形成的可逆性，以及仅通过吸收性分配来解释SOA形成的能力。在曼彻斯特气溶胶室中，我们最近注意到一些关于SOA样品稀释的有趣结果。由于对吸收性划分的预测，预计SOA质量的减少将超过由于挥发性组分的蒸发而被稀释的数量。这在我们的几个生物前体系统的实验中没有观察到，并且具有非常重要的大气意义。如果吸收分配显然不能解释室的结果，那么许多基于室产量数据的大气有机气溶胶行为模型就会有问题。以前的实验使用热剥落器来探测SOA的波动性，并粗略地推断SOA形成的可逆性。本文提出设计和构建一种新型的热剥蚀系统，结合控制稀释，探测生物源和人为有机前体在室内光氧化过程中形成的二次有机气溶胶组分的挥发性。在将其耦合到曼彻斯特气溶胶室之前，将使用实验室中产生的已知成分和特性的颗粒来表征珠光体系统，以建立广泛接受的气溶胶形成吸收分配模型的有效性。denuder系统预期的优越性能将适用于量化组分挥发性，并通过将其与稀释实验中的腔室耦合，用于评估吸收分配理论预测的可变性。

项目成果

The sensitivity of Secondary Organic Aerosol component partitioning to the predictions of component properties - Part 2: Determination of particle hygroscopicity and its dependence on "apparent" volatility

二次有机气溶胶组分分配对组分特性预测的敏感性 - 第 2 部分：颗粒吸湿性的测定及其对

• DOI: 10.5194/acp-11-7767-2011
• 发表时间: 2011
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Topping D

A modeling approach to evaluate the uncertainty in estimating the evaporation behaviour and volatility of organic aerosols

评估有机气溶胶蒸发行为和挥发性估计不确定性的建模方法

• DOI: 10.5194/amt-5-735-2012
• 发表时间: 2012
• 期刊: Atmospheric Measurement Techniques
• 影响因子: 3.8
• 作者: Fuentes E