Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 27Citation - Scopus: 28Fast Formation of Nitro-Pahs in the Marine Atmosphere Constrained in a Regional-Scale Lagrangian Field Experiment(American Chemical Society, 2019) Mulder, Marie D.; Dumanoğlu, Yetkin; Sofuoğlu, Sait Cemil; Kukucka, Petr; Matejovicova, Jana; Sofuoğlu, Aysun; Pribylova, Petra; Prokes, Roman; Sofuoğlu, Aysun; Sofuoğlu, Sait Cemil; Wilson, Jake; Zetzsch, Cornelius; Wotawa, Gerhard; Lammel, Gerhard; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPolycyclic aromatic hydrocarbons (PAHs) and some of their nitrated derivatives, NPAHs, are seemingly ubiquitous in the atmospheric environment. Atmospheric lifetimes may nevertheless vary within a wide range, and be as short as a few hours. The sources and sinks of NPAH in the atmosphere are not well understood. With a Lagrangian field experiment and modeling, we studied the conversion of the semivolatile PAHs fluoranthene and pyrene into the 2-nitro derivatives 2-nitrofluoranthene and 2-nitropyrene in a cloud-free marine atmosphere on the time scale of hours to 1 day between a coastal and an island site. Chemistry and transport during several episodes was simulated by a Lagrangian box model i.e., a box model coupled to a Lagrangian particle dispersion model, FLEXPART-WRF. It is found that the chemical kinetic data do capture photochemical degradation of the 4-ring PAHs under ambient conditions on the time scale of hours to 1 day, while the production of the corresponding NPAH, which sustained 2-nitrofluoranthene/fluoranthene and 2-nitropyrene/pyrene yields of (3.7 ± 0.2) and (1.5 ± 0.1)%, respectively, is by far underestimated. Predicted levels of NPAH come close to observed ones, when kinetic data describing the reactivity of the OH-adduct were explored by means of theoretically based estimates. Predictions are also underestimated by 1-2 orders of magnitude, when NPAH/PAH yields reported from laboratory experiments conducted under high NOx conditions are adopted for the simulations. It is concluded that NPAH sources effective under low NOx conditions, are largely underestimated.Article Citation - WoS: 18Citation - Scopus: 21Polybrominated Diphenyl Ethers (pbdes) in Background Air Around the Aegean: Implications for Phase Partitioning and Size Distribution(Springer Verlag, 2017) Besis, Athanasios; Lammel, Gerhard; Sofuoğlu, Sait Cemil; Sofuoğlu, Aysun; Sofuoğlu, Aysun; Dumanoğlu, Yetkin; Eleftheriadis, Kostas; Kouvarakis, Giorgos; Sofuoğlu, Sait Cemil; Vassilatou, Vassiliki; Voutsa, Dimitra; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe occurrence and atmospheric behavior of tri- to deca-polybrominated diphenyl ethers (PBDEs) were investigated during a 2-week campaign concurrently conducted in July 2012 at four background sites around the Aegean Sea. The study focused on the gas/particle (G/P) partitioning at three sites (Ag. Paraskevi/central Greece/suburban, Finokalia/southern Greece/remote coastal, and Urla/Turkey/rural coastal) and on the size distribution at two sites (Neochorouda/northern Greece/rural inland and Finokalia/southern Greece/remote coastal). The lowest mean total (G + P) concentrations of ∑7PBDE (BDE-28, BDE-47, BDE-66, BDE-99, BDE-100, BDE-153, BDE-154) and BDE-209 (0.81 and 0.95 pg m−3, respectively) were found at the remote site Finokalia. Partitioning coefficients, KP, were calculated, and their linear relationships with ambient temperature and the physicochemical properties of the analyzed PBDE congeners, i.e., the subcooled liquid pressure (PL°) and the octanol-air partition coefficient (KOA), were investigated. The equilibrium adsorption (PL°-based) and absorption (KOA-based) models, as well as a steady-state absorption model including an equilibrium and a non-equilibrium term, both being functions of log KOA, were used to predict the fraction Φ of PBDEs associated with the particle phase. The steady-state model proved to be superior to predict G/P partitioning of BDE-209. The distribution of particle-bound PBDEs across size fractions < 0.95, 0.95–1.5, 1.5–3.0, 3.0–7.2, and > 7.2 μm indicated a positive correlation between the mass median aerodynamic diameter and log PL° for the less brominated congeners, whereas a negative correlation was observed for the high brominated congeners. The potential source regions of PBDEs were acknowledged as a combination of long-range transport with short-distance sources.