Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
Browse
2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 220Citation - Scopus: 234Determination of Octanol-Air Partition Coefficients and Supercooled Liquid Vapor Pressures of Pahs as a Function of Temperature: Application To Gas-Particle Partitioning in an Urban Atmosphere(Elsevier Ltd., 2006) Odabaşı, Mustafa; Çetin, Eylem; Sofuoğlu, AysunOctanol-air partition coefficients (KOA) for 14 polycyclic aromatic hydrocarbons (PAHs) were determined as a function of temperature using the gas chromatographic retention time method. log KOA values at 25° ranged over six orders of magnitude, between 6.34 (acenaphthylene) and 12.59 (dibenz[a,h]anthracene). The determined KOA values were within factor of 0.7 (dibenz[a,h]anthracene) to 15.1 (benz[a]anthracene) of values calculated as the ratio of octanol-water partition coefficient to dimensionless Henry's law constant. Supercooled liquid vapor pressures (PL) of 13 PAHs were also determined using the gas chromatographic retention time technique. Activity coefficients in octanol calculated using KOA and PL ranged between 3.2 and 6.2 indicating near-ideal solution behavior. Atmospheric concentrations measured in this study in Izmir, Turkey were used to investigate the partitioning of PAHs between particle and gas-phases. Experimental gas-particle partition coefficients (Kp) were compared to the predictions of KOA absorption and KSA (soot-air partition coefficient) models. Octanol-based absorptive partitioning model predicted lower partition coefficients especially for relatively volatile PAHs. Ratios of measured/modeled partition coefficients ranged between 1.1 and 15.5 (4.5±6.0, average±SD) for KOA model. KSA model predictions were relatively better and measured to modeled ratios ranged between 0.6 and 5.6 (2.3±2.7, average±SD).Article Citation - WoS: 24Citation - Scopus: 25Mass Transfer Coefficients for Polycyclic Aromatic Hydrocarbons (pahs) To the Water Surface Sampler: Comparison To Modeled Results(Elsevier Ltd., 2001) Odabaşı, Mustafa; Sofuoğlu, Aysun; Holsen, Thomas M.A sampling program was conducted between June and October 1995 in Chicago, IL using a modified water surface sampler (WSS) and dry deposition plates to measure the particulate dry deposition and gas exchange of PAHs. Oxygen transfer experiments were also conducted to evaluate the collection properties of the WSS for gas-phase compounds. Gas-phase fluxes were determined by subtracting the dry deposition plate fluxes (particulate) from WSS fluxes (particulate+gas). These fluxes were divided by concurrently measured ambient concentrations to obtain overall gas phase mass transfer coefficients. Two different two-film models, one developed based on experiments performed with the WSS and, one previously published, were compared to these results. Experimentally determined average gas phase overall mass transfer coefficient (Kg) for seven PAHs was 0.74±0.52cms-1. Experimental Kg values agreed well with those predicted by the model developed for WSS. The values predicted by previously proposed models were within a factor of 3 of the experimental ones.