Shrivastava Manish K, Lipsky Eric M, Stanier Charles O, Robinson Allen L
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Environ Sci Technol. 2006 Apr 15;40(8):2671-7. doi: 10.1021/es0522231.
Experimental measurements of gas-particle partitioning and organic aerosol mass in diluted diesel and wood combustion exhaust are interpreted using a two-component absorptive-partitioning model. The model parameters are determined by fitting the experimental data. The changes in partitioning with dilution of both wood smoke and diesel exhaust can be described by two lumped compounds in roughly equal abundance with effective saturation concentrations of approximately 1600 microg m(-3) and approximately 20 microg m(-3). The model is used to investigate gas-particle partitioning of emissions across a wide range of atmospheric conditions. Under the highly dilute conditions found in the atmosphere, the partitioning of the emissions is strongly influenced by the ambient temperature and the background organic aerosol concentration. The model predicts large changes in primary organic aerosol mass with varying atmospheric conditions, indicating that it is not possible to specify a single value for the organic aerosol emissions. Since atmospheric conditions vary in both space and time, air quality models need to treat primary organic aerosol emissions as semivolatile. Dilution samplers provide useful information about organic aerosol emissions; however, the measurements can be biased relative to atmospheric conditions and constraining predictions of absorptive-partitioning models requires emissions data across the entire range of atmospherically relevant concentrations.
采用双组分吸收分配模型对稀释柴油和木材燃烧废气中气体-颗粒分配及有机气溶胶质量的实验测量结果进行了解释。通过拟合实验数据确定了模型参数。木材烟雾和柴油废气稀释时分配的变化可用两种丰度大致相等的集总化合物来描述，其有效饱和浓度分别约为1600微克/立方米和约20微克/立方米。该模型用于研究广泛大气条件下排放物的气体-颗粒分配。在大气中发现的高度稀释条件下，排放物的分配受环境温度和背景有机气溶胶浓度的强烈影响。该模型预测，随着大气条件的变化，一次有机气溶胶质量会有很大变化，这表明不可能为有机气溶胶排放指定一个单一值。由于大气条件在空间和时间上都有所不同，空气质量模型需要将一次有机气溶胶排放视为半挥发性的。稀释采样器提供了有关有机气溶胶排放的有用信息；然而，测量结果可能相对于大气条件存在偏差，并且约束吸收分配模型的预测需要整个大气相关浓度范围内的排放数据。
