Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 64Citation - Scopus: 65Dry Deposition Fluxes and Velocities of Polychlorinated Biphenyls (pcbs) Associated With Particles(Elsevier Ltd., 2004) Taşdemir, Yücel; Odabaşı, Mustafa; Vardar, Nedim; Sofuoğlu, Aysun; Murphy, Thomas J.; Holsen, Thomas M.The interest in atmospheric deposition by the scientific community has increased a great deal over the past several years because of its significant contribution to the pollution budget of many natural waters. Dry deposition is an effective removal mechanism for polychlorinated biphenyls (PCBs) from the atmosphere. This study focuses on the understanding of the particulate dry deposition of PCBs in urban areas. In this paper, 43 chromatographic PCB congener peaks which represent 50 individual or coeluting congeners were evaluated. The PCB dry deposition fluxes were measured using a smooth, greased, knife-edge surrogate surface holding greased Mylar strips in Chicago, IL. The average PCB dry deposition flux measured (190±80ngm-2day -1) was similar to those measured in other urban areas. Ambient air samples were also collected simultaneously with flux samples. The average apparent dry deposition velocity, calculated by dividing the fluxes to the particle phase concentrations was 5.2±2.9cms-1. This value is in good agreement with the values calculated using similar techniques.Article Citation - WoS: 65Overall Elemental Dry Deposition Velocities Measured Around Lake Michigan(Elsevier Ltd., 2001) Yi, Seung-Muk; Shahin, Usama; Sivadechathep, Jakkris; Sofuoğlu, Sait Cemil; Holsen, Thomas M.Overall dry deposition velocities of several elements were determined by dividing measured fluxes by measured airborne concentrations in different particle size ranges. The dry deposition measurements were made with a smooth surrogate surface on an automated dry deposition sampler (Eagle II) and the ambient particle concentrations were measured with a dichotomous sampler. These long-term measurements were made in Chicago, IL, South Haven, MI, and Sleeping Bear Dunes, MI, from December 1993 through October 1995 as part of the Lake Michigan Mass Balance Study. In general, the dry deposition fluxes of elements were highly correlated with coarse particle concentrations, slightly less well correlated with total particle concentrations, and least well correlated with fine particle concentrations. The calculated overall dry deposition velocities obtained using coarse particle concentrations varied from approximately 12 cm s−1 for Mg in Chicago to 0.2 cm s−1 for some primarily anthropogenic metals at the more remote sites. The velocities calculated using total particle concentrations were slightly lower. The crustal elements (Mg, Al, and Mn) had higher deposition velocities than anthropogenic elements (V, Cr, Cu, Zn, Mo, Ba and Pb). For crustal elements, overall dry deposition velocities were higher in Chicago than at the other sites.