A novel high-volume Photochemical Emission Aging flow tube Reactor (PEAR)
A novel high-volume Photochemical Emission Aging flow tube Reactor (PEAR)
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DOI：
10.1080/02786826.2018.1559918
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发表时间：
2019-03-04
影响因子：
5.2
通讯作者：
Sippula, Olli
中科院分区：
文献类型：
--
作者：
Ihalainen, Mika;Tiitta, Petri;Sippula, Olli
各种人为和自然来源排放的气溶胶在大气中不断发生物理化学变化，改变其对健康和气候的影响。本文介绍了一种新型光化学辐射老化流管反应器（PEAR）的设计和特点。PEAR旨在提供足够的气溶胶质量和流量，用于同时测量老化气溶胶的理化性质和排放暴露研究（体内和体外）。PEAR的性能进行了评估，通过使用常见的二次气溶胶的前体，以及从木材炉和汽油发动机的燃烧排放。发现PEAR提供接近层流的流动轮廓，对于大于40 nm的粒度可忽略的颗粒损失，和窄的停留时间分布。这些特征使得能够分辨小规模木材燃烧等动态排放源的时间排放模式。二次有机气溶胶（SOA）在PEAR的形成被认为是类似于SOA形成的烟雾室时，甲苯和原木燃烧排放物被用作气溶胶源。当木材燃烧被用作排放源时，从PEAR和烟雾室获得的气溶胶质谱高度相似。总之，PEAR被发现可以模拟高流速有机气溶胶的光化学老化，这是研究老化气溶胶对人类健康影响所需的。该方法还能够研究高时间分辨率的不同排放阶段的老化，并与不同的OH-自由基暴露的条件下，代表远程传输的气溶胶。版权所有（c）2019美国气溶胶研究协会
Aerosols emitted from various anthropogenic and natural sources undergo constant physicochemical transformations in the atmosphere, altering their impacts on health and climate. This article presents the design and characteristics of a novel Photochemical Emission Aging flow tube Reactor (PEAR). The PEAR was designed to provide sufficient aerosol mass and flow for simultaneous measurement of the physicochemical properties of aged aerosols and emission exposure studies (in vivo and in vitro). The performance of the PEAR was evaluated by using common precursors of secondary aerosols as well as combustion emissions from a wood stove and a gasoline engine. The PEAR was found to provide a near laminar flow profile, negligible particle losses for particle sizes above 40 nm, and a narrow residence time distribution. These characteristics enable resolution of temporal emission patterns from dynamic emission sources such as small-scale wood combustion. The formation of secondary organic aerosols (SOA) in the PEAR was found to be similar to SOA formation in a smog chamber when toluene and logwood combustion emissions were used as aerosol sources. The aerosol mass spectra obtained from the PEAR and smog-chamber were highly similar when wood combustion was used as the emission source. In conclusion, the PEAR was found to plausibly simulate the photochemical aging of organic aerosols with high flow rates, needed for studies to investigate the effects of aged aerosols on human health. The method also enables to study the aging of different emission phases in high time resolution, and with different OH-radical exposures up to conditions representing long-range transported aerosols. Copyright (c) 2019 American Association for Aerosol Research