Dry Deposition of Gas-Phase Polycyclic Aromatic Hydrocarbons to Greased Surrogate Surfaces

Abstract

Recently, greased surrogate surfaces have been successfully used to directly measure the dry deposition of semivolatile organic chemicals (SVOCs). However, it has been difficult to interpret these measurements because the extent to which the grease used to collect the deposited particles absorbs the gas phase SVOCs is not clear. In this study, the partitioning between polycyclic aromatic hydrocarbons (PAHs) in the vapor phase and grease used on surrogate surfaces was investigated. This interaction was parameterized by defining a partition factor as the ratio between the individual PAH air phase equilibrium concentration and the PAH grease phase equilibrium concentration multiplied by the square root of the PAH diffusion coefficient in the grease. This factor was used to estimate the vapor phase PAH deposition to greased surrogate surfaces deployed in the field for periods between 1 and 5 days. For these samples, naphthalene had the largest gas phase deposition to the grease while fluorene had the lowest. ...