Arslan Saral

Assessment of odorous VOCs released from a main MSW landfill site in Istanbul-Turkey via a modelling approach.

An air pollution modeling study was conducted to investigate the odorous effects of volatile organic compounds (VOCs) emissions from a sanitary landfill area on ambient air quality. The atmospheric dispersion of hydrogen sulfide (H(2)S) and 22 VOCs was modeled. Industrial Source Complex v3 Short Term (ISCST3) model was used to estimate hourly concentrations of odorous VOCs over the nearest residential area. Odor thresholds of VOCs of interest were also found in the literature. Results showed that short-term averages of three odorous VOCs, namely ethyl mercaptan, methyl mercaptan and hydrogen sulfide, exceeded their odor thresholds, which are reported to be 0.022, 0.138 and 11.1 microg/m(3), respectively, at several points within the domain. Their highest concentrations within Gokturk County were estimated to be 0.09387 microg/m(3) for ethyl mercaptan, 0.07934 microg/m(3) for methyl mercaptan and 6.315 microg/m(3) for hydrogen sulfide. Short-term model results revealed the occasional odor problems being reported for Gokturk County. Hourly concentrations were used to obtain frequencies of odor episodes in Gokturk County via a probability analysis. The results showed that ethyl mercaptan concentrations did not exceed its odor threshold during more than 8.84% of the time. Similarly, the maximum odor episode frequencies for methyl mercaptan and hydrogen sulfide were 0.98% and 0.34% of the time, respectively.

Prediction of Ground Level SO2 Concentration using Artificial Neural Networks

Future (24 h later) daily ground level SO2 concentration in Istanbul was modeled and predicted using a new and powerful technique, Artificial Neural Networks (ANN) in the case of meteorological parameters as input variables. Results show that the trend of SO2 from higher values in winter to lower values in spring and summer, and again to higher values towards winter can be correctly represented by the neural networks. The model better predicted the lower SO2 values in spring and summer seasons when compared to higher values in winter season because of the pattern distribution in training data sets. Beside the amount of the database, the more the variation of the values of the parameters in their own ranges, the more the network learns the database. As a result of this study, considerably successful results were obtained when considering the complex and nonlineer structure of the atmosphere, which is the source of the database.

Effect of diurnal changes in VOC source strengths on performances of receptor models

IntroductionThe effect of diurnal changes in strengths of volatile organic compound (VOC) sources on the performances of positive matrix factorization (PMF) and principal component analysis (PCA) was investigated using ambient measurement results that were taken during daytime and nighttime hours between March 24 and May 14, 2011, within Davutpasa Campus of Yildiz Technical University (Istanbul, Turkey).MethodsForty-five VOC species, ranging from C5 to C11 in volatility, were measured in the samples, 40 of which are included in the analyses. Ambient samples were grouped as daytime, nighttime, and all day datasets, and both PMF and PCA were applied to each dataset. A total of six source groups were extracted from each dataset: solvent use, general industrial paint use, gasoline and diesel vehicle exhausts, and biogenic as well as evaporative emissions. Estimated source contributions showed great diurnal variations.ResultsThe results suggested that extraction of possible sources by PCA depends greatly on the number of samples and the strength of the sources, while PMF produced stable results regardless of number of samples and source strengths.ConclusionAlthough PMF was unable to resolve gasoline vehicle and evaporative emissions, it was found to be successful in explaining diurnal fluctuations in source strengths, while the performance of PCA depends on the strength of emission source.

Gas/particle partitioning of PCDD/F compounds in the atmosphere of Istanbul

Gas/particle partitioning of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) compounds in the ambient atmosphere were investigated at three different sites (urban-industrial, urban and sub-urban) in İstanbul. Average gas and particle phase concentrations were measured as 133fgm(-3) and 1605fgm(-3), respectively. Gas phase concentrations of polychlorinated dibenzo-p-dioxin/furan (PCDD/F) compounds were determined to be 128fgm(-3), 50fgm(-3), 153fgm(-3) during summer season and 204fgm(-3), 164fgm(-3), 154fgm(-3) during winter season for the respective three sampling sites. Particle phase concentrations were determined to be 287fgm(-3), 176fgm(-3), 160fgm(-3) during summer and 6586fgm(-3), 2570fgm(-3) and 1861fgm(-3) during winter season for those three sampling sites. Chlorination level and molecular weight of congeners affected gas/particle partitioning of PCDD/F compounds. Gas phase percentages of 2,3,7,8-TCDD and OCDD concentrations were determined to be 47% and 1% respectively. A relatively high correlation was found between total particle matter (TPM) and particle phase PCDD/F concentration during winter season.

Study of the Decrease of Air Pollution Concentration Levels with the Meteorological Factors in Istanbul

The aim of this study is twofold: First, to gain perspective for the assessment of the spatial distribution of one of the air pollutants, sulfur dioxide, in the region by the use of a statistical modelling scheme, kriging; and second, to show the decrease of sulfur dioxide concentrations over Istanbul by elaborating on the reasons of this decrease in terms of the meteorological factors.

Estimation of atmospheric PCB releases from industrial facilities in Turkey

Abstract PCB production reduced or stopped in most countries in the late 1970s. According to the Stockholm Convention all the party countries have to list their PCB containing equipment and prepare national inventories. A national implementation plan was prepared in Turkey however, this plan is inadequate. Furthermore, there has not been any information prepared about stationary emission sources, contributing to atmospheric PCB inputs so far. It is aimed in this study to meet this deficit. This study will also help to make stronger comments on identifying sources of atmospheric PCB concentrations. PCB emission factors were utilized to determine the emissions. An average of 920 kg yr –1 of PCB emission is estimated in this study within the borders of Turkey. Highest contribution occurs in Kocaeli located on the North–West of the country by 47% of the overall emissions. Secondary most pollutant site is determined to be Aliaga on the west of the country. Both of this regions are heavily, industrialized and several different industrial processes are present. Iron–steel manufacturing and copper smelting processes comprises the 94% of the PCB releases from stationary sources. A simple box model was applied at two hot spots to determine potential contribution of the estimated emissions to atmospheric concentrations. In Dilovasi, the average contribution from industrial sources was determined as 244 pg m –3 while the average contribution for Aliaga was calculated as 126 pg m –3 within a 50 km x 50 km grid.

Investigation of temporal and spatial variations in atmospheric concentrations of PCDDs and PCDFs in Istanbul.

In this study, temporal and spatial variations of the atmospheric concentrations of polychlorinated-p-dibenzo dioxin (PCDDs) and polychlorinated dibenzofuran (PCDFs) congeners were investigated in Istanbul at three different locations. The highest average concentration (3481 fg/m(3)) was observed at the sampling location which is characterized by mixed source groups during colder months. The lowest average concentration (749 fg/m(3)) was observed at sampling station which is characterized by semi-urban characteristics. ∑PCDD/F concentration showed seasonal variation in this study. The highest average concentration was determined to be 4373 fg/m(3) in winter while the lowest average concentration was determined to be 498 fg/m(3) in summer.

Analysis of Air Pollutants in Istanbul: A Preliminary Study

In last ten years, Istanbul faced severe air pollution problems. The occurrences of high concentrations of air pollution in the city have reached to the levels of danger for the habitants (Erturk, 1986). The main cause of Istanbul ’s air pollution comes from the burning of low quality lignite and fossil fuels containing high percent of sulfur used mainly for heating purposes (Erturk, 1986; Erturk et al., 1995). It is the purpose of this article to gain perspective for the assessment of the spatial distribution of one of the air pollutants, SO2, for the Istanbul municipality region by the usage of a spatial prediction scheme, Kriging (Matheron, 1971).The city ’s population increased exponentially at the beginning of 1980 ’s. l/5th of the population and 70% of the country ’s industry is located in Istanbul. The urbanization of the city is badly organized and unplanned.

Estimation of T90 and bacterial die‐off rate values in the Antalya bay of Turkey

Abstract Antalya is a holiday city at south of Turkey, at the side of Mediterranean Sea, and has a great tourism potential. The Environmental Project, including waste water collection and marine outfall systems are going to be developed for this city. By researchers, as presented hereby in this article, oceanographic measurements and microorganism concentration decrease investigation have been carried out in the seasons of Winter and Summer in 1993 at Antalya Bay. To get T90 values two different test methods were used. These are tracer and plastic bag method. For tracer method, 2 m3 of waste water was mixed with 3 kg of Rhodamine‐B and dumped from the boat into the sea at the planed outfall discharged area. Several samples collected in the center of the plume. Then coliform bacteria were tested by using membrane filter technique. Test results of coliform concentration were plotted versus time on a semi‐logarithmic paper. T90 values were taken from slope of the line on the graphs and die‐off rate constant ...

Polycyclic Aromatic Hydrocarbons PAHs on size segregated particle phase in urban atmosphere Istanbul

Polycyclic aromatic hydrocarbons (PAHs) are semi-volatile organic compounds and present widely in ambient atmosphere. Due to the fact that PAHs are widely distributed in the environment and some species of them are carcinogenic, they are very important for human health and environment. High volume cascade impactor was used to collect the particulate matters according to particle size fractions between February 2013 and June 2014, in Istanbul. Particulate matters were collected according to size ranges >7.2 μm, 7.2 3 μm, 3 1.5 μm, 1.5 0.95 μm, 0.95 0.49 μm, <0.49 μm. 15 PAH species were analyzed in samples. Average of total PAH concentrations were found as 31.62 ng/m. Total PAH size distribution was found between 0.95-1.5 μm. All investigated ring PAH species showed single modal distribution in size range of 0.95-1.5 μm. 4, 5 and 6-ring PAH species have high concentration in almost each size range. According to the obtained results, 4, 5, 6-ring PAHs are abundant on the particles below 3 μm when compared to 3-ring PAHs. Despite being abundant of 4, 5, 6-ring PAH types in each size range, 4 and 6-ring PAHs have less TEF values than 5-ring PAH types. Respirable carcinogenic PAH species were found in İstanbul urban area. Keywords—PAHs, particle size distribution, PM2.5, TEF.