Potential sources and measured concentrations of VOCs in Balikesir ambient atmosphere

The assessment of volatile organic compounds (VOCs) has become an important field of interest in atmospheric pollution. This study quantifies and characterizes the ambient levels and spatial distribution of VOCs in urban and rural areas of Balikesir city, Turkey. For these assessments, passive sampling of VOCs performed at approximately 50 locations in and around the city of Balikesir. Twenty-five VOCs were regularly monitored and analyzed with the GC-FID system. The sampling periods were carried out for seven-day periods during March and August 2010. In the study, mean Sigma VOC concentrations were found to be as high 67 and 51 mu g m(-3) for the winter and summer seasons, respectively. Median concentrations of benzene, toluene, ethylbenzene, m,p-xylene and o-xylene were 2.6, 11, 1.30, 1.80 and 0.73 mu g m(-3), respectively. Although there were some changes between concentrations of VOC groups between the summer and winter campaigns, differences were not dramatic. Winter-to-summer ratios of the target compounds ranged from 0.2 (1,2,4-trimethylbenzene) to 9 (hexane). Most of the target compounds have higher concentrations in winter. Only few VOCs, including n-propylbenzene, 1,2,4- trimethylbenzene, 1-undecene and 1,2,4- trichlorobenzene have higher concentrations in summer. Spatial distribution of VOCs demonstrated that the roads are hot spots for measured VOC concentrations. The drinking water treatment plant, industrial solvent emissions from pesticide and insecticide applications in agriculture, and emissions from traffic were the sources that contribute to total VOC load in the Balikesir atmosphere.Turkish Scientific and Technological Research Council (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108Y166]This study was supported by Turkish Scientific and Technological Research Council (TUBITAK) with project number 108Y166

Does Twinning Vehicular Networks Enhance Their Performance in Dense Areas?

This paper investigates the potential of Digital Twins (DTs) to enhance network performance in densely populated urban areas, specifically focusing on vehicular networks. The study comprises two phases. In Phase I, we utilize traffic data and AI clustering to identify critical locations, particularly in crowded urban areas with high accident rates. In Phase II, we evaluate the advantages of twinning vehicular networks through three deployment scenarios: edge-based twin, cloud-based twin, and hybrid-based twin. Our analysis demonstrates that twinning significantly reduces network delays, with virtual twins outperforming physical networks. Virtual twins maintain low delays even with increased vehicle density, such as 15.05 seconds for 300 vehicles. Moreover, they exhibit faster computational speeds, with cloud-based twins being 1.7 times faster than edge twins in certain scenarios. These findings provide insights for efficient vehicular communication and underscore the potential of virtual twins in enhancing vehicular networks in crowded areas while emphasizing the importance of considering real-world factors when making deployment decisions.Comment: 6 pages, 8 figures, 2tables, conference pape

Dilovası Endüstri Bölgesi ve Çevresinde Hava Kirliliğine Neden olan Organik ve İnorganik Kirleticilerin Düzeylerinin ve Kaynaklarının Belirlenmesi

TÜBİTAK ÇAYDAG15.11.2016Dilovası Türkiye?nin en büyük endüstriyel bölgelerinden biridir. Ilçede endüstriyel bölgeler veyerlesim yerleri iç içe bulunmakta, aynı zamanda ilçe yogun bir trafigin etkisi altındadır. Bununsonucu olarak bölgede kanser yüksek yogunlukla ölüm nedenlerinin basında gelmektedir. Buçalısma ile havadaki organik ve inorganik kirleticilerin seviyeleri, kaynakları ve muhtemelsaglık etkileri incelenmistir. Arazi çalısması Subat 2015 tarihinde baslamıs ve Subat 2016?desonlandırılmıs ve PAHlar ve PCBler zamansal ve mekânsal olarak incelenmistir. AyrıcaDilovası Belediyesi?nin bahçesinde kurulan sabit bir istasyonda sıralı PM2,5 örnekleyicikullanılarak EC/OC, 14C, metaller, çesitli anyon ve katyon derisimleri ve aynı istasyonda O3ve NOx miktarlarının zamansal degisimleri incelenmistir. Arazi çalısması 23 noktada PUF diskpasif örnekleyiciler kullanılarak yapılmıstır. Toplam PAH konsantrasyonu 4,2 ile 3842 ng m-3aralıgında degismektedir (ORT±SS; 285 ± 431 ng m-3). Fenantren en fazla elde edilen PAHtürü olurken, bunu floranten ve piren izlemektedir. Toplam PCB konsantrasyonu 177 ile 41781pg m-3 aralıgında degismektedir (ORT±SS; 4152 ± 6072 pg m-3). PCB-28, -18, -31 ve -33 enfazla elde edilen PCBlerdir. PMF sonuçlarına gör PAHlar için 5, PCBler içinse 4 farklı kaynakbelirlenmistir. Bunlar PAHlar için dizel ve benzinli araç emisyonları, biyokütle ve kömüryanması, demir-çelik endüstrisi gibi endüstriyel faaliyetlerden kaynaklı emisyonlar veyanmamıs petrol/petrol ürünleri emisyonları olarak belirlenmistir. PCBler içinse kaynaklardemir-çelik üretimi, kömür ve biyokütle yanması, teknik PCB karısımları ve endüstri olarakbelirlenmistir. Sabit istasyondan elde edilen PM2,5 kütlesini etkileyen faktörler yine PMFkullanılarak incelenmistir. Buna göre 6 faktör bulunmus, bunlar yol tozu (%23), tasıtemisyonları (%20), petrol yanması (%19), kömür yanması (%14), toz (%14), ikincil inorganikaerosol (%10) olarak belirlenmistir. Aynı sonuçlar kullanılarak bölgeyi etkileyen uzun mesafelikaynaklar potansiyel kaynak katkı fonksiyonu (PKKF) kullanılarak incelenmis ve Cezayir, BatıSahra, Rusya, Iran ve Lübnan örnekleme bölgesini etkileyen ülkeler olarak bulunmustur. Aynınoktalarda kuru çökelme örneklemesi de yapılmıs ve PAHlar için hesaplanan kuru çökelmeakısı degerlerinin 829 ile 7424 ng m?2 gün?1 aralıgında (2950 ± 1349 ng m?2 gün?1)degistigi gözlenmistir. PCBler içinse bu degerler 47,9 ile 535 ng m?2 gün?1 aralıgındadegismektedir (191 ± 102 ng m?2 gün?1). Sabit istasyonda ortalama EC, OC ve TCkonsantrasyonları sırasıyla 15,8±17,7, 2,8±2,3 ve 19,2±18,9 μg m-3 olarak bulunmustur.EC/OC konsantrasyonları özellikle kasım ayının ortasından baslayarak önemli derecede artısgöstermektedir. Bu sonuç sıcaklıgın düsmesine baglı olarak evsel ısınma faaliyetlerinin vebuna baglı olarak da karbon emisyonlarının artmasıyla, ayrıca karısım yüksekliginin düsmesive emisyonların atmosferde dagılamaması ile açıklanabilir. PAHlar, PCBler ve metaller içinsaglık riski degerlendirmesi yapılmıstır. En yüksek maruziyet-risk seviyeleri konsantrasyondegerleriyle paralel olarak PAHlar ve PCBler için sırasıyla kıs ve yaz döneminde tespitedilmistir. Tahmini kitlesel maruziyet-risk seviyelerinin hepsi ve ortalama maruziyet-riskseviyelerinin çogu kabul edilebilir kanserojen risk degerinin (10-6) üzerinde bulunmustur.Hedeflenen kanserojen metallere bakıldıgında ise Ni ve Pb için risk söz konusu degildir. Asiçin hesaplanan tahmini risk degerleri, bütün mevsimlerde kabul edilebilir risk degerininüzerinde bulunurken, Cd ve Co için hesaplanan tahmini risk degerlerinin bazıları kabuledilebilir degerin üzerinde bulunmustur. Bulunan risk degerleri kabul edilebilir degerin oldukçaüstündedir. Bu sonuçlar ile Dilovası havasının mevcut kirleticiler açısından insan saglıgı içinyüksek risk içerdigini söylemek mümkündür.Dilovasi is one of the most industrialized area in Turkey. In district, industrial sites are withinthe residential areas and the distinct is under the influence of heavy traffic. Consequently,the cancer became the main cause of death in Dilovasi. In present study, the levels oforganic and inorganic pollutants in the atmosphere, their sources and possible health riskswere investigated. The field campaign was started in February 2015 and completed inFebruary 2016, and spatial and temporal variations of PAHs and PCBs were investigated.EC/OC, 14C, anions and cations concentrations in samples collected using sequential PM2.5sampler, and NOx and O3 by active sampling were also investigated in sampling stationlocated in Dilovasi Municipality. Field studies were conducted using PUF disk sampler at 23sampling points. At all sites, total PAH concentrations ranged from 4.2 to 3842 ng m -3 with amean value of 285 ng m -3. They were dominated by phenanthrene, fluoranthene andpyrene. Total PCB concentrations were found to be between 177 and 41781 pg m -3 with amean value of 4152 pg m -3. They were dominated by low molecular weight (LMW)congeners such as PCB-28, PCB-18, PCB-31 and PCB-33. PMF was used to apportion thesources of PAHs and PCBs. Five sources were identified for PAHs including diesel andgasoline exhaust emissions, coal and biomass combustion, industrial activities such as ironsteelplants and unburned crude oil/petroleum products. For PCBs, the identified sources areiron-steel production, coal and biomass combustion processes, technical PCB mixtures andindustry. PMF was also used to find out the factors that affect the PM2.5 concentrations and 6factors were specified; road dust (23% contribution), vehicle emissions (20%), petroleumcombustion (19%), coal combustion (14%), dust (14%) and secondary inorganic aerosols(10%). Potancial Source Contribution Function (PSCF) was also applied to determine thelong-distance sources that affect the sampling region using these PMF results obtained forPM2.5. Algeria, West Sahara, Russia, Iran and Lebanon were found to be the possiblesources. Dry deposition studies were also conducted in same sampling points with passivesampling. The dry deposition fluxes obtained for PAHs were between 829 and 7424ng m−2 day−1 (2950 ± 1349 ng m−2 day−1) and for PCBs they were found between 47.9 and535 ng m−2 day−1 (191 ± 102 ng m−2 day−1). The average concentration of OC, EC and TCwere found as 15.8±17.7, 2.8±2.3 and 19.2±18.9 μg m-3, respectively. Especially afterNovember, the EC/OC concentrations found to be increased gradually. This can beattributed to domestic heating with decreasing temperature and lower mixing height inwinter. Risk assessment studies were also conducted for exposure to PAHs, PCBs andmetals. The highest exposure-risk levels were found in winter and summer for PAHs andPCBs, respectively. All of the estimated population risk and most of the average risk werefound to be the higher than general acceptable level (10-6). Among metals, no risk wasobserved for Ni and Pb. All of the estimated risks calculated for As for all seasons and someof risks for Cd and Co were higher than acceptable level. Estimated risks were substantiallyhigher than general acceptable levels. These results indicated that the atmosphere ofDilovasi has significant potential health risks for human beings in terms of these pollutants.Keywords: Dilovasi, PAHs, PCBs, Passive Sampling, EC/OC, Metals, Ions, Ozone, NOx,Positive Matrix Factorizatio

Distribution and sources of polychlorinated biphenyls in air, dust and sediment from India

Persistent organic pollutants, such as polychlorinated biphenyls (PCBs), pose a serious risk for human health and the environment. In this study, PCBs contamination and sources of ambient air, road dust, and sediments in the most polluted city in India, Raipur, has been measured over the period 2008–2015. The seasonal variations of particulate matter (PM), elemental carbon (EC), organic carbon (OC), and carbonate carbon (CC) were studied, and maximum concentrations were detected in the December–January period each year. Total PCBs concentrations in the ambient air (associated with PM), road dust, and sediments samples during 2008 were in the 186–645 pg m−3, 102–537, and 241–538 ng g−1 range, respectively. 2-chlorobiphenyl (PCB-1) and 4-chlorobiphenyl (PCB-3) were the dominant chemical compounds identified. A substantial vertical migration of the PCBs in the sediments was observed. Concentration variations (spatial and temporal), correlations, and sources of PCB are discussed. In particular, an average increment rate of 6.2%, 4.9%, and 5.4% of PCBs concentration in the particulate matter (PM10), road dust, and sediments, respectively, was observed over the 2008–2015 period. The reported data points to India's low degree of accomplishment of the Stockholm Convention's requirement to phase out the use of PCBs in equipment by 2025 and ensure elimination of PCBs by 2028

Bursa atmosferindeki uçucu organik bileşik konsantrasyonlarının zamansal değişimi.

Volatile organic compounds (VOC’s) attracted attention as air pollutants due to their health effects, particularly with their potential to induce cancer. The levels and sources of VOCs in Bursa atmosphere, which is one of the most heavily industrialize cities in Turkey, were investigated by measuring C2 – C12 VOCs in two campaigns. Concentrations of 148 VOCs were measured with 60 minute intervals using an on-line gas chromatograph. Data generated in this study is the first extensive and high-resolution data set generated in Turkey. VOC concentrations measured in this study are generally low compared to similar concentrations reported for cities with similar population with Bursa. VOCs showed well defined short- and long-term temporal variations. The most pronounced short-term variation was diurnal pattern with a morning and afternoon maxima. In addition to diurnal variations, concentrations of VOCs also showed consistent weekend-weekday differences and differences between the two sampling campaigns. One of the important outcomes of this study is the asphalt profile developed from the data generated. Volatile organic compounds, including 1-octene, 1-nonene, 1-undecene, n-nonane, n-decane, 1,2,3-trimethylbenzene, undecane and dodecane were shown to be good tracers for asphalting operations. Emissions from asphalt do not significantly affect concentrations of light hydrocarbons (< C5). Positive Matrix Factorization (PMF) applied to data yielded eight sources for both campaigns, including Light Duty-Vehicle (LDV), Vehicles operating with LPG, paint, gasoline evaporation, asphalting operations, industrial processes, solvent evaporation form small scale commercial activities and industrial solvent evaporation contributing to total VOC concentrations.Ph.D. - Doctoral Progra

Atık odun örneklerinde emisyonların ve yanma kinetiklerinin termal ve spektral yöntemlerle incelenmesi.

The mechanisms and kinetics of combustion of waste wood as well as the phases during combustion processes are important to eliminate these wastes without any possible damage to environment. In the present study, combustion mechanisms, activation energy and pre-exponential constants, and phases of combustion were investigated for untreated natural pine and treated Medium Density Fiberboard (MDF), plywood and particleboard samples that involve some chemicals and additives. Waste wood samples were heated in air at 10, 20 and 30oC/min heating rates in a Thermo Gravimetric Analyzer (TGA) from room temperature to 900oC. Thermogravimetry (TG) and Derivative Thermogravimetry (DTG) curves for all samples were obtained. The gases formed during combustion reactions were directly fed to a Fourier Transform Infrared Spectroscopy (FTIR) instrument coupled to TGA. Emission characteristics of the samples were determined in-situ by using the FTIR spectrums. As a result of TG analysis, thermal decomposition of treated samples was observed at lower temperatures as compared to the untreated pine sample because of the catalyzing effects of the chemicals in the treated samples. Therefore, there were less flammable products, lower weight losses in the main oxidation region, decrease in the max. weight loss temperatures and formation of more char for treated samples as compared to untreated pine sample. In other words, chemicals used during production of these samples lead to decrease in the combustibility of the treated samples. Thermal kinetic constants for the samples were calculated by using Coats Redfern and Broido Methods. In order to find out the mechanisms responsible for the oxidation of the waste wood samples in different regions, six solid state mechanisms of Coats Redfern Method were tested. As a result of FTIR analysis of the emitted gases from TG analysis, several chemical groups were detected from pine and treated samples. Combustion of all samples revealed some gases containing aromatics, C-H groups, CO2 and CO. However, there were some toxic and carcinogenic gases like formaldehyde, isocyanate group, ammonia, phenyl group and benzoylbromide among the emissions of treated samples which need utmost attention when recovering energy from treated waste woods.M.S. - Master of Scienc

Combustion and Co-Combustion characteristics of torrefied poultry litter with lignite

This study investigated the thermal properties and activation energies of raw and torrefied poultry litter samples in the range of 250-300 degrees C by using thermogravimetric analysis (TGA). Four heating rates, 5 degrees C/min, 10 degrees C/min, 20 degrees C/min, and 30 degrees C/min were applied during the thermogravimetric analysis. Furthermore, co-combustion of raw and torrefied poultry litter samples with low-rank Turkish lignite was studied and the effect of the blending ratio on thermal reactivity of poultry litter was also investigated

Investigation of emissions from thermal oxidation of waste wood samples using spectral methods

The objective of this study was to investigate the effects of chemical treatment and heating rate on the emissions released from various waste wood samples including untreated pine and chemically treated MDF, plywood and particleboard after thermal treatment. Emission characteristics of the samples were determined in situ by using their FTIR spectra. Some toxic and carcinogenic gases such as formaldehyde, isocyanate, ammonia and phenyl group were detected in emissions from low temperature combustion of treated samples. For this reason, urea-formaldehyde or melamine formaldehyde treated waste wood samples should be oxidatively pyrolysed at low heating rates and low temperatures to remove nitrogen-containing toxic compounds such as ammonia and isocyanate

Investigation of combustion kinetics of treated and untreated waste wood samples with thermogravimetric analysis

In the present study, combustion mechanisms, thermal kinetics, and phases of combustion were investigated for waste wood samples (untreated pine and treated MDF, plywood and particleboard). Waste wood samples were combusted in air at 10, 20 and 30 degrees C/min heating rates in TGA. The results of TG analysis have shown that thermal decomposition of treated samples takes place at lower temperatures as compared to the untreated pine sample because of the catalyzing effects of the chemicals in the samples. Therefore, there were less flammable products, lower weight losses in the main oxidation region, and decrease in the maximum weight loss temperatures and formation of more char for treated samples as compared to untreated pine sample. Thermal kinetic constants for the samples were calculated by using Coats Redfern Method. In order to find out the mechanisms responsible for the oxidation of the waste wood samples, six solid-state mechanisms of Coats Redfern Method were tested. The results of the Coats Redfern Method have shown that diffusion mechanism is the effective mechanism for all regions of the pine samples. For the main oxidation region, D4 mechanism (Ginstling-Brounshtein equation) was found to be the main diffusion mechanism for pine samples. For the treated samples such as MDF, plywood and particleboard, first-order reaction (F1) was found as an effective mechanism. Treatment of wood with different additives and glues seemed to alter the thermal oxidation process and change the effective oxidation mechanisms

Investigation of Combustion Kinetics of Five Waste Wood Samples with Thermogravimetric Analysis

In the present study, combustion mechanisms, thermal kinetics, and phases of combustion were investigated for untreated pine and treated MDF, plywood and particleboard samples. Waste wood samples were combusted in air at 10, 20 and 30 degrees C/min heating rates in TGA. As a result of TG analysis, thermal decomposition of treated samples was observed at lower temperatures as compared to the untreated pine sample because of the catalyzing effects of the chemicals in the samples. Therefore, there were less flammable products, lower weight losses in the main oxidation region, decrease in the max. weight loss temperatures and formation of more char for treated samples as compared to untreated pine sample. In other words, chemicals used during production of these samples lead to decrease in the combustibility of the treated samples. Thermal kinetic constants for the samples were calculated by using Coats Redfern and Broido Methods. In order to find out the mechanisms responsible for the oxidation of the waste wood samples, six solid state mechanisms of Coats Redfern Method were tested