İzmir bölgesinde atmosferik polisiklik aromatik hidrokarbonların (PAHlar) belirlenmesi

İzmir bölgesinde 14 adet polisiklik aromatik hidrokarbon bileşiği (PAHlar) (fluorene, phenanthrene, anthracene, carbazole, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]-pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene) dış havada, toprakta ve su örneklerinde incelenmiştir. Dış hava çalışmaları üç örnekleme noktasında (yarıkentsel ve 2 kentsel) gerçekleştirilmiş ve PAH'ların mevsimsel ve yerel değişimleri incelenmiştir. Tüm ölçüm noktalarında ve örneklerde en çok bulunan bileşiğin phenanthrene olduğu ve düşük moleküler ağırlıklı PAH bileşiklerinin baskın olduğu gözlenmiştir. Absorpiyon ile absorpsiyon ve adsorpsiyon tabanlı modeller kullanılarak PAH'ların gaz-partikül dağılımları incelenmiştir. Kuru çökelme akıları yarıkentsel ve kentsel örnekleme bölgelerinde dış hava örnekleriyle eş zamanlı olarak ölçülmüş ve bu veriler kullanılarak partikül kuru çökelme hızları hesaplanmıştır. Toprak örnekleri yarı kentsel örnekleme noktasından alınmıştır. Dış hava örneklerinde olduğu gibi toprak örneklerinde de düşük moleküler ağırlıklı bileşiklerin baskın olduğu gözlenmiştir. Dış hava-toprak arakesitindeki net akı hesaplanmıştır. Fluorene, phenanthrene, anthracene ve carbazole kışın havadan toprağa çökelme eğilimi gösterirken, bu bileşiklerin yazın topraktan buharlaşma eğiliminde oldukları gözlenmiştir. Diğer bileşiklerin (flouranthene- benzo[g,h,i]perylene) ise her iki mevsimde de havadan toprağa çökelme eğilimi gösterdiği bulunmuştur. Dış hava ve su konsantrasyonları İzmir körfezi kıyısındaki bir noktada eş zamanlı olarak ölçülmüştür. Hava-su arakesitindeki net akı hesaplanmış ve örnekleme süresince havadan suya çökelme eğiliminde olduğu bulunmuştur. Anahtar Sözcükler: Polisiklik aromatik hidrokarbonlar (PAHlar), dış hava, gaz-partikül dağılımı, kuru çökelme, çökelme hızı, hava/su arakesitinde taşınım, hava/toprak arakesitinde taşınım. Fourteen PAH compounds including fluorene, phenanthrene, anthracene, carbazole, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]-anthracene, benzo[g,h,i]perylene were investigated in ambient air, soil and water samples in Izmir. Ambient air studies were carried out at three sampling sites a suburban and two urban sites and their spatial and seasonal variations were investigated. Phenanthrene was the most abundant compound at all sites, and all samples were dominated by low molecular weight PAHs. Gas-particle partitioning of PAHs were examined using octanol-based and soot-based partitioning models. Dry deposition samples were collected in suburban and urban sampling sites concurrently with ambient air samples. Particle dry deposition velocities were calculated using particle concentrations and fluxes. Soil samples were collected at suburban sampling site. Like the air samples the PAH profile in soil was dominated by lower molecular weight compounds. The net air-soil exchange of PAH fluxes were examined. Fluorene, phenanthrene, anthracene and carbazole were deposited to soil in winter while they were volatilized in summer seasons. Other compounds (flouranthene- benzo[g,h,i]perylene) were deposited to soil in both periods. Concurrent ambient air and water concentrations were measured at a coastal site of Izmir Bay. The net air-water exchange PAH fluxes were also examined. Net PAH fluxes were mainly deposition from air to water during the sampling periods. Keywords: Polycyclic aromatic hydrocarbons (PAHs), ambient air, gas/particle partitioning, dry deposition, deposition velocity, air/water exchange, air/soil exchange

Particle-phase dry deposition and air–soil gas exchange of polycyclic aromatic hydrocarbons (PAHs) in Izmir, Turkey

Ambient air and dry deposition samples were collected at suburban and urban sites in Izmir, Turkey. Atmospheric total (particle + gas) 14PAHs concentrations were 36±39 and 144±163 ngm−3 for suburban and urban sites, respectively. Phenanthrene was the most abundant compound at all sites, and all samples were dominated by low molecular weight PAHs. Average particulate 14PAH dry deposition fluxes were 8160±5024 and 4286±2782 ngm−2 day−1 and overall average particulate dry deposition velocities were 1.5±2.4 and 1.0±2.3cms−1 for suburban and urban sites, respectively. Soil samples were collected at suburban site. Average soil concentration for 14PAH was 55.9±14.4 ng g−1 dry weight. Calculated gas-phase air–soil exchange fluxes indicated that fluorene, phenanthrene, anthracene, and carbazole were deposited to soil in winter while they were volatilized in summer. Other compounds (fluoranthene-benzo[g,h,i]perylene) were deposited to soil in both periods. Annual average fluxes of PAHs representing soil to air (i.e., gas volatilization) and air to soil transfer (i.e., gas absorption, dry deposition, and wet deposition) processes were also compared. All processes were comparable for 14PAHs however their input was dominated by gas absorption. Gas absorption dominated for lower molecular weight PAHs, however dry deposition dominated for higher molecular weight PAHs. The results have suggested that for fluorene, soil and air may be approaching a steady state condition. For the remaining compounds, there was a net accumulation into the soil.The Research grant (ICTAGC033) from the Scientific and Technical Research Council of Turkey (TUBITAK)

Atmospheric concentrations and phase partitioning of polycyclic aromatic hydrocarbons in Izmir, Turkey

Ambient air polycyclic aromatic hydrocarbon (PAH) samples were collected at a suburban (n=63) and at an urban site (n=14) in Izmir, Turkey. Average gas-phase total PAH (∑ 14PAH) concentrations were 23.5ngm -3 for suburban and 109.7ngm -3 for urban sites while average particle-phase total PAH concentrations were 12.3 and 34.5ngm -3 for suburban and urban sites, respectively. Higher ambient PAH concentrations were measured in the gas-phase and ∑ 14PAH concentrations were dominated by lower molecular weight PAHs. Multiple linear regression analysis indicated that the meteorological parameters were effective on ambient PAH concentrations. Emission sources of particle-phase PAHs were investigated using a diagnostic plot of fluorene (FLN)/(fluorine+pyrene; PY) versus indeno[1,2,3-cd]PY/(indeno[1,2,3-cd]PY+benzo[g,h,i]perylene) and several diagnostic ratios. These approaches have indicated that traffic emissions (petroleum combustion) were the dominant PAH sources at both sites for summer and winter seasons. Experimental gas-particle partition coefficients (K P) were compared to the predictions of octanol-air (K OA) and soot-air (K SA) partition coefficient models. The correlations between experimental and modeled K P values were significant (r 2=0.79 and 0.94 for suburban and urban sites, respectively, p<0.01). Octanol-based absorptive partitioning model predicted lower partition coefficients especially for relatively volatile PAHs. However, overall there was a relatively good agreement between the measured K P and soot-based model predictions. Ambient air polycyclic aromatic hydrocarbon (PAH) samples were collected at a suburban and at an urban site in Izmir, Turkey. The multiple linear regression analysis indicated that the meteorological parameters were effective on the measured ambient PAH concentrations. The results indicated that traffic emissions were the dominant PAH sources at both sites for summer and winter seasons

Air-water exchange of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) at a coastal site in Izmir Bay, Turkey

The air-water exchange of polychlorinated biphenyl (PCB) and organochlorine pesticides (OCPs) were investigated using paired air-water samples (n = 16) collected in July and February-March, 2005 from Guzelyali Port in Izmir Bay, Turkey. Atmospheric PCBs and OCPs were mainly in gas-phase in both periods. However, their dissolved and particle-phase water concentrations were comparable. For PCBs, 3 and 4-Cl congeners were dominant while chlorpyrifos, endosulfans and HCHs were the most abundant OCPs for all samples. Especially in summer, calculated net gas-exchange PCB fluxes were mainly volatilization from the water ranging from - 0.2 (volatilization, PCB-101) to - 30.0 (volatilization, PCB-31) ng m- 2 day- 1. For OCPs, net flux ranged from - 0.03 (volatilization, cis-nonachlor) to 1568 (deposition, endosulfan I) ng m- 2 day- 1 and they have seasonal variations with generally deposition in winter and volatilization in summer. However, endosulfan I, II, endosulfan sulfate, α- and γ-HCH deposited in both periods. The calculated residence times of PCBs and OCPs in the water column indicated that the gas-exchange in the Bay is at least as or a more important mechanism than advection. Annual gaseous absorption and volatilization fluxes were calculated and were used along with the estimated dry deposition fluxes and wet deposition fluxes measured recently at a suburban site in Izmir to determine the relative contributions of different atmospheric mechanisms to the pollutant inventory of the Bay water column. Results suggested that the relative contributions of all studied mechanisms to the water column PCB and OCP inventories were significant.Dokuz Eylul University (Project No:03.KB.FEN.101); TÜBİTAK (Project no. ICTAG-C033), and İzmir Institute of Technology (Project no. IYTE-20