Kinetic modeling of secondary organic aerosol formation: effects of particle- and gas-phase reactions of semivolatile products
Kinetic modeling of secondary organic aerosol formation: effects of particle- and gas-phase reactions of semivolatile products
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DOI：
10.5194/acp-7-4135-2007
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发表时间：
2007-01-01
影响因子：
6.3
通讯作者：
Seinfeld, J. H.
中科院分区：
文献类型：
--
作者：
Chan, A. W. H.;Kroll, J. H.;Seinfeld, J. H.
二次有机气溶胶（SOA）形成的区别机制是半挥发性烃氧化产物在气相和气溶胶相之间的分配。虽然SOA的形成通常仅以划分来描述，但SOA的形成速率和最终产率也可能取决于气相和气溶胶相过程的动力学。我们提出了SOA形成的一般平衡/动力学模型，该模型提供了一个框架，用于评估从实验室数据推断出SOA形成的控制机制的程度。通过这个模型，我们研究了第一代产物气相氧化成挥发性物质较多或较少的物质、颗粒相反应（一级和二级动力学）、母烃氧化速率和母烃反应程度对SOA形成的影响。预先存在的有机气溶胶质量对SOA产量的影响，与实验室数据转化为大气应用直接相关的问题，进行了检查。在确定SOA形成机制时，强调了气相和颗粒相物种的直接化学测量的重要性。
The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.