The partitioning model of PAHs betweeen gaseous and particulate phases based on PM 10μ in urban atmosphere

Abstract

A new partitioning model of the PAHs between gaseous and paniculate phases for PM10μ, Log { (A/F) PM10μ } = m /T + b, was investigated in this study. Where A and F stand for PAHs amount in gas and particulate phases respectively. PM10μ is the mass of PM10μ, T represnets the ambient temperature, and m and b are constants. A basic assumption of current model is the proportionality between the particle surface area available for adsorption of PAHs and the particle mass . But, this is not true most of time. Thus, the partitioning model is further modified by using surface area of particle. Both models were evaluated by real measurements of PAHs content in gaseous and paniculate phases. A series of ambient sampling of PAHs for gaseous and particulate phases by using the PM10μ sampler, cascade impactor, and volatile vapor sampler (PS‐1 sampler) were performed during 1990 and 1991 in downtown of Taipei city. In particular, it is the first time the real measurement of PM10μ surface area in urban atmosphere has ever been taken by Automated Adsorption System. Also, partice shape of PMlOu, separated by the cascade impactor were examined by SEM. The performance of partitioning models of both PM10μ mass and surface area were evaluated by the regression analysis between the term on the left hand side of the model and the inverse of temperature for Fluoranthene, Pyrene and Chrysene +Benzo(a)anthracene. It is indicated that partitioning model using surface area does provide higher coefficient of determination(r²), particularly for Chr+BaA.

Key words:

• Partitioning Models
• PAHs
• PM10μ
• Surface Area