112 research outputs found
Field Measurements of the Atmospheric Dry Deposition Fluxes and Velocities of Polycyclic Aromatic Hydrocarbons to the Global Oceans
Anthropogenic platinum group element (Pt, Pd, Rh) concentrations in PM10 and PM2.5 from Kolkata, India
Aliağa ağır sanayi bölgesinde yarı-uçucu toksik organik hava kirleticileri üzerine bir çalışma
Dış hava, kuru çökelme ve toprak örnekleri, yaz ve kış örnekleme dönemleri boyunca Aliağa endüstri bölgesine yakın bir noktadan toplanmışÃ¦ ayrıca Aliaga genelinde 48 farklı noktadan toprak örnekleri alınmıştır. Yarı uçucu toksik organik hava kirleticileri (SOC'lar: PAH'lar, PCB'ler ve OCP'ler) tüm örneklerde incelenmiştir. Dış havada ölçülen PAH seviyelerinin, evsel ısınmaya bağlı olarak kış mevsiminde arttığı görülmektedir. Yaz mevsiminde artan PCB ve OCP seviyeleri, önceden kirletilmiş olan yüzeylerden bu bileşiklerin sıcaklıkla orantılı olarak artan buharlaşma oranlarına ve kullanımda olan pestisitlerin bu mevsimde artan tarımsal uygulamalarına bağlı olabilir. Her iki mevsimde alınan dış hava örneklerinde düşük molekül ağırlıklı PAH'lar (phenanthrene, fluorene, fluoranthene) ve PCB'ler (tri-, tetra-, penta-CBs) baskındır. Yaz periyodu için dış havada ölçülen en yüksek seviyeler sırasıyla endosulfan-I, endosulfan-II ve chlorpyrifos'a, kış periyodunda ise chlorpyrifos, ?-HCH ve endosulfan-I'e aittir. PCB'lerin tersine, partikül fazındaki PAH'lar ve OCP'ler yaz mevsiminde daha yüksek kuru çökelme akılarına sahiptirler. SOC'lar icin hesaplanan partikül çökelme hızları literatürdeki değerlerle tutarlıdır. Dış hava-toprak arakesitindeki net gaz akısı hesaplanmışÃ¦ önceden kirletilmiş olan toprak yüzeyinin, düşük molekül ağırlıklı PAH'lar ve PCB'ler için atmosfere ikincil bir kaynak gibi davrandığı, daha ağır bileşikler içinse deponi vazifesi gördüğü gözlenmiştir. Chlordane grubundaki OCP'ler ve p,p'-DDT yaz mevsimindeæ ?-CHL, ?-CHL, t-nonachlor, endosulfan sulfate ve p,p'-DDT ise kış mevsiminde toprak yüzeyinden buharlaşma eğilimindedir. Çalışılan SOC'ların hava ile toprak arasındaki geçişleri tüm olası mekanizmalar için önemli ise de, toprakta absorpsiyonun daha baskın olduğu görülmüştür. Bunu, kuru ve yaş çökelme izlemektedir. Ambient air, dry deposition, and soil samples were collected during the summer and winter periods at a sampling site close to the Aliaga industrial region in Izmir, Turkey. Soil samples were also taken from additional 48 different sites around the study area. All samples were investigated for SOCs (PAHs, PCBs, and OCPs). Atmospheric PAH concentrations were higher in winter than in summer, indicating that wintertime concentrations were affected by residential heating emissions. On the contrary, increased atmospheric PCBs and OCP levels were observed in summer, probably due to increased volatilization at higher temperatures and seasonal agricultural applications of in-use pesticides. Low molecular weight PAHs (phenanthrene, fluorene, fluoranthene) and PCBs (tri-, tetra-, penta-CBs) were the most abundant compounds in air for both seasons. For OCPs, they were endosulfan-I, endosulfan-II and chlorpyrifos in summer, and chlorpyrifos, ?-HCH, and endosulfan-I in winter, respectively. In contrast to PCBs, particulate fluxes of PAHs and OCPs were generally higher in summer than in winter. Overall average deposition velocities calculated for SOCs agree well with the literature values. Calculated net gas fluxes at the soil-air interface indicated that the contaminated soil is a secondary source to the atmosphere for lighter PAHs and PCBs and as a sink for heavier ones. OCPs tending to volatilize were chlordane related compounds and p,p'-DDT in summer, and in winter, they were ?-CHL, ?-CHL, t-nonachlor, endosulfan sulfate, and p,p'-DDT. All mechanisms were comparable for the studied compounds, but their input was generally dominated by gas absorption, followed by dry and wet deposition
Processes affecting the movement of organochlorine pesticides (OCPs) between soil and air in an industrial site in Turkey
Soil and atmospheric concentrations, dry deposition and soil-air gas exchange of organochlorine pesticides (OCPs) were investigated at an industrial site in Aliaga, Izmir, Turkey. Current-use pesticides, endo-sulfan and chlorpyrifos, had the highest atmospheric levels in summer and winter. Summertime total (gas + particle) OCP concentrations in air were higher, probably due to increased volatilization at higher temperatures and seasonal local/regional applications of current-use pesticides. Particle deposition fluxes were generally higher in summer than in winter. Overall average dry particle deposition velocity for all the OCPs was 4.9 +/- 4.1 cm, s(-1) (average +/- SD). Sigma DDXs (sum of p,p'-DDT, p,p'-DDD, and p,p'-DDE) were the most abundant OCPs in Aliaga soils (n = 48), probably due to their heavy historical use and persistence. Calculated fugacity ratios and average net gas fluxes across the soil-air interface indicated volatilization for alpha-CHL. gamma-CHL. heptachlorepoxide, cis-nonachlor, trans-nonachlor, and p,p'-DDT in summer, and for alpha-CHL, gamma-CHL trans-nonachlor, endosulfan sulfate, and p,p'-DDT in winter. For the remaining OCPs, soil acted as a sink during both seasons. Comparison of the determined fluxes showed that dry particle, gas-phase, and wet deposition are significant OCP input mechanisms to the soil in the study area. (C) 2009 Elsevier Ltd. All rights reserved
Ambient concentrations and dry deposition fluxes of trace elements in Izmir, Turkey
Dry deposition samples were collected using a smooth surrogate surface at the Kaynaklar Campus of the Dokuz Eylul University in Izmir, Turkey. Concurrently ambient aerosol samples were collected. All samples were analyzed for anthropogenic and crustal trace elements. The average trace element concentrations and fluxes measured in this study were generally higher than those reported previously for urban and rural areas. The contribution of local terrestrial and anthropogenic sources were also investigated using enrichment factors (EFs) calculated relative to the local soil. Relatively lower EFs for ambient samples and high ambient concentrations indicated that the local soil was polluted and contributed significantly to ambient trace element concentrations. Deposition samples had higher EFs than the air samples. The EF sequences of trace elements were also different for deposition and ambient samples, probably due to the fact they have different mass median diameters and deposition velocities. The overall dry deposition velocities for trace elements calculated by dividing the particulate fluxes measured with the. surrogate surfaces by ambient concentrations ranged from 0.6 (Al) to 6.2 cm s(-1) (Fe). The agreement 'between the experimental dry deposition velocities determined in this study and the previously reported ones using similar techniques for trace elements was good. (C) 2002 Elsevier Science Ltd. All rights reserved
Dry deposition and soil-air gas exchange of polychlorinated biphenyls (PCBs) in an industrial area
Ambient air and dry deposition, and soil samples were collected at the Aliaga industrial site in Izmir, Turkey. Atmospheric total (particle + gas) Sigma(41)-PCB concentrations were higher in summer (3370 1617 pg m(-3). average + SD) than in winter (1164 +/- 618 pg m(-3)), probably due to increased volatilization with temperature. Average particulate Sigma(41)-PCBs dry deposition fluxes were 349 +/- 183 and 469 +/- 328 ng m(-2) day(-1) in summer and winter, respectively. Overall average particulate deposition velocity was 5.5 +/- 3.5 cm s(-1). The spatial distribution of Sigma(41)-PCB soil concentrations (n = 48) showed that the iron-steel plants, ship dismantling facilities, refinery and petrochemicals complex are the major sources in the area. Calculated air-soil exchange fluxes indicated that the contaminated soil is a secondary source to the atmosphere for lighter PCBs and as a sink for heavier ones. Comparable magnitude of gas exchange and dry particle deposition fluxes indicated that both mechanisms are equally important for PCB movement between air and soil in Aliaga. (C) 2008 Elsevier Ltd. All rights reserved
Atmospheric concentrations, dry deposition and air-soil exchange of polycyclic aromatic hydrocarbons (PAHs) in an industrial region in Turkey
Concurrent ambient air and dry deposition samples were collected during two sampling periods at the Aliaga industrial region in Izmir, Turkey. Sigma(15)-PAH (particulate + gas) concentrations ranged between 7.3 and 44.8 ng m-3 (average +/- S.D., 25.2 +/- 8.8 ng m(-3)) and 10.2-71.9 ng m(-3) (44.1 +/- 16.6 ng m(-3)) in summer and winter, respectively. Winter/summer individual ambient PAH concentration ratios ranged between 0.8 (acenaphthene) and 6.6 (benz[a]anthracene) indicating that wintertime concentrations were affected by residential heating emissions. In contrast to the ambient concentrations, Sigma(15)-PAH particle dry deposition fluxes were higher in summer (5792 +/- 3516 ng m(-2) day(-1), average +/- S.D.) than in winter (2650 +/- 1829 ng m(-2) day(-1)), probably due to large particles from enhanced re-suspension of polluted soil particles and road dust. Average overall dry deposition velocity of PAHs calculated using the dry deposition fluxes and particle-phase concentrations was 2.9 +/- 3.5 cm s(-1). Sigma(15)-PAH concentrations in soils taken from 50 points in the area ranged between 11 and 4628 mu g kg(-1) in dry weight. The spatial distribution of these concentrations indicated that the urban Aliaga, steel plants, the petroleum refinery, and the petrochemical plant are the major Sigma(15)-PAH sources in the area. Fugacity calculations in air and soil showed that the soil acts as a secondary source to the atmosphere for low molecular weight PAHs in summer and as a sink for the higher molecular weight ones in summer and winter. (C) 2007 Elsevier B.V. All rights reserved
Investigation of seasonal variations and sources of atmospheric polychlorinated naphthalenes (PCNs) in an urban area
- …