Evaluation of a Conceptual Model for Gas-Particle Partitioning of Polycyclic Aromatic Hydrocarbons Using Polyparameter Linear Free Energy Relationships

Abstract

ABSTRACT:A model for gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs) was evaluated using polyparameter linear free energy relationships (ppLFERs) following a multiphase aerosol scenario. The model differentiates between various organic (i.e., liquid water-soluble (WS)/organic soluble (OS) organic matter (OM), and solid/semisolid organic polymers) and inorganic phases of the particulate matter (PM). Dimethyl sulfoxide and polyurethane were assigned as surrogates to simulate absorption into the abovementioned organic phases, respectively, whereas soot, ammonium sulfate, and ammonium chloride simulated adsorption processes onto PM. The model was tested for gas and PM samples collected from urban and nonurban sites in Europe and the Mediterranean, and the output was compared with those calculated using single-parameter linear free energy relationship (spLFER) models, namely JungePankow, Finizio, and Dachs-Eisenreich. The ppLFER model on average predicted 96 ± 3% of the observed partitioning constants for semivolatile PAHs, fluoranthene, and pyrene, within 1 order of magnitude accuracy with root-mean-square errors (RMSE) of 0.35−0.59 across the sites. This was a substantial improvement compared to Finizio and Dachs-Eisenreich models (37 ± 17 and 46 ± 18% and RMSE of 1.03−1.40 and 0.94−1.36, respectively). The JungePankow model performed better among spLFERs but at the same time showed an overall tendency for overestimating the partitioning constants. The ppLFER model demonstrated the best overall performance without indicating a substantial intersite variability. The ppLFER analysis with the parametrization applied in this study suggests that the absorption into WSOSOM could dominate the overall partitioning process, while adsorption onto salts could be neglected.

Global long-range transport and lung cancer risk from polycyclic aromatic hydrocarbons shielded by coatings of organic aerosol

“…Gas−particle partitioning of PAHs is described by various theoretical/empirical models based on single-parameter or polyparameter linear free energy relationships (sp-or pp-LFER) (46). The sp-LFER models, which relate the partitioning constant for PAH to OA or BC to just one thermodynamic property (e.g., subcooled liquid vapor pressure of PAHs), have often been used in regional and global atmospheric chemistry models to predict gas−particle partitioning of PAHs (11,22).…”

“…The sp-LFER models, which relate the partitioning constant for PAH to OA or BC to just one thermodynamic property (e.g., subcooled liquid vapor pressure of PAHs), have often been used in regional and global atmospheric chemistry models to predict gas−particle partitioning of PAHs (11,22). In comparison, the pp-LFER models relate partitioning constant to more than one property, and thus account for all significant interactions between solute and sorbent (46). In this study, we implement the pp-LFER model to calculate partitioning of PAHs by adsorption to BC and absorption into OA, similar to Shahpoury et al (46).…”

“…In comparison, the pp-LFER models relate partitioning constant to more than one property, and thus account for all significant interactions between solute and sorbent (46). In this study, we implement the pp-LFER model to calculate partitioning of PAHs by adsorption to BC and absorption into OA, similar to Shahpoury et al (46).…”

Snow scavenging and phase partitioning of nitrated and oxygenated aromatic hydrocarbons in polluted and remote environments in central Europe and the European Arctic

“…KDMSO (m Table S2 and ppLFER models listed in Table S3 (Abraham et al, 2010;Kamprad and Goss, 2007;Roth et al, 2005;Goss et al, 2003). See Shahpoury et al, (2016) …”

Global simulation of semivolatile organic compounds – development and evaluation of the MESSy submodel SVOC (v1.0)

“…Nevertheless, the focus of this submodel development is the global distribution of four PAH species of largely varying properties. PAHs enter the atmospheric environment as by-products of all technological combustion processes (Shen et al, 2013) and of open fires (Gullett et al, 2008). They are ubiquitous pollutants of particular environmental and health concern (WHO, 2003;Laender et al, 2011;Lammel, 2015) and due to their continuous global emissions.…”