Prediction of Toxic Semi-Volatile Organic Gas-Particle Partitioning in the Atmosphere with the Use of Activity Coefficients

本研究的主要目的是显著提高我们计算分布在气相和气溶胶相之间的半挥发性有机有毒化合物平衡分配的能力。这将特别用于具有有机液体层的颗粒，例如来自柴油燃料，木材燃烧和二次有机气溶胶的颗粒。将调查含有环境排放或产生的有机酸、羰基、氯化有机物、烷烃、多核芳香烃和循环硅氧烷的化合物类别的划分。在给定的液体颗粒混合物中，有机物的活度系数将使用基团贡献法计算。然后，这些活度系数将与蒸汽压力和其他气溶胶特性一起用于计算平衡分配常数。室外室测量将进行，以提供气体-颗粒划分数据。由于气溶胶化学成分和大气湿度对活度系数的预测有很大影响，因此将在恒定湿度下使用已知的气溶胶成分进行初步实验。以后的实验将研究更复杂的粒子系统。

9708533 Kamens The main objective of this research is to dramatically improve our ability to calculate the equilibrium partitioning of semi-volatile organic toxic compounds, which distribute between gas and aerosol phases. This will be done specifically for particles which have organic liquid layers, such as particles from diesel fuel, wood combustion, and secondary organic aerosols. The partitioning of compound classes which contain environmentally emitted or created organic acids, carbonyls, chlorinated organics, alkanes, polynuclear aromatic hydrocarbons, and cyclical siloxanes, will be investigated. The activity coefficients of the organics in given liquid particle mixtures will be calculated using the group contribution method. These activity coefficients will then be used along with vapor pressures and other aerosol properties to calculate equilibrium partitioning constants. Outdoor chamber measurements will be performed to provide gas-particle partitioning data. Since aerosol chemical composition and atmospheric humidity strongly influence activity coefficient predictions, initial experiments will be carried out with known aerosol compositions at constant humidities. Later experiments will investigate more complex particle systems.