08. İYTE Tezler / IZTECH Theses & Dissertations

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This collection of IZTECH Theses in DSpace contains selected theses and dissertations from all IZTECH departments.

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Ambient Air Persistent Organic Pollutant Monitoring, Backtrajectory Modeling, and Health Risk Assessment
(Izmir Institute of Technology, 2015-07) Güngörmüş, Elif; Sofuoğlu, Aysun; Sofuoğlu, Sait Cemil; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Turkish Government has officially become a party to the Stockholm Convention as of 2010, therefore, determination of POPs in environmental compartments in Turkey is a critical concern. In this study, 22 organochlorine pesticides (OCPs) and 43 polychlorinated biphenyls (PCBs) were measured in gas and particulate phases of ambient air samples collected in Izmir and Istanbul from May to October 2014 on a weekly basis. Gas chromatography–mass spectrometry was used to quantify the targeted pollutants. Potential source regions were assessed by applying back-trajectory and Potential Source Contribution Function (PSCF). Population carcinogenic risk levels associated with inhalation exposure were estimated by using Monte Carlo simulation, for which sensitivity and uncertainty analyses were also conducted. The highest mean concentration compounds were heptachlor (61±126 pg/m3) and p,p’-DDE (54±57 pg/m3) in Izmir and Istanbul, respectively. The mean Ʃ43PCBs concentration was found as 232±224 pg/m3 in Izmir, and 104±48 pg/m3 in Istanbul. Gas phase concentartions of OCPs and PCBs were generally much higher than particle phase. The PSCF results pointed out different potential source regions: Middle East, Eurasia, and Europe. All the estimated carcinogenic risks based on the 95% percentile values for individual OCPs and Ʃ43PCBs were calculated below the acceptable risk levels (10-6), indicating no significant potential health risk via inhalation route.
Assessmanet of Exposure and Risk Associated With Trihalomethanes and Other Volatile Organic Compounds in Drinking Water
(Izmir Institute of Technology, 2005) Kavcar, Pınar; Sofuoğlu, Sait Cemil; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Concentrations of 54 volatile organic compounds (VOCs) were measured in İzmir drinking water, and associated health risks due to ingestion of these compounds were investigated using a semi-probabilistic sampling design. 100 houses were visited in different districts of İzmir and drinking water samples were collected from consumer taps and bottled waters. Using questionnaires, demographics and drinking water consumption rates were determined. Individual and population based exposures and risks were estimated by employing deterministic and probabilistic approaches, respectively.Trihalomethanes (THMs) (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs in İzmir drinking water with concentrations ranging from below detection limit to 35 .g/l. None of the samples exceeded the maximum contaminant levels stated in the Turkish, European, and American drinking water regulations. For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water.Noncarcinogenic risks attributable to ingestion of VOCs in İzmir drinking water were negligible whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the acceptable level of one in a million (10-6). Deterministic approach revealed that 23%, 29%, and 2% of individuals had lifetime cancer risks greater than 10-6 associated with ingestion of bromodichloromethane, dibromochloromethane, and bromoform, respectively. The results of this study show that exposures to drinking water contaminants and associated risks may be higher than the acceptable level even if the concentrations fall below the drinking water standards.
Assessment of concentrations and air-dust partitioning of azaarenes in an urban primary school
(01. Izmir Institute of Technology, 2024) Başar, Aleyna; Sofuoğlu, Aysun; Sofuoğlu, Sait Cemil; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Polisiklik aromatik hidrokarbonlar (PAH'lar), fosil yakıtların eksik yanma ürünleri olup önemli hava kirleticileridir. Özellikle on altı PAH, kanserojen ve toksik özelliklerinden dolayı çevre ve insan sağlığı üzerinde büyük bir etkiye sahiptir. Son çalışmalar, PAH türevlerinin ana bileşiklerinden daha zararlı olabileceğini ve bazılarının kanserojen özellikler taşıdığını göstermektedir. Bu çalışmada, PAH türevi olan Azaarenlerin (Kinolin, İzokinolin, Akridin Benzo[f]kinolin, Karbazol) derişimleri, 2022-2023 eğitim-öğretim yılı boyunca İzmir'in kentsel alanında yer alan bir ilkokulda, hava ve çökelmiş toz fazlarında ölçülmüştür. Örnekleme okulu, otoyol ve sanayi bölgelerine yakınlığı ve sınıfta mekanik havalandırma bulunması nedeniyle seçilmiştir. Aktif örnekleme hem iç ortamda mekanik (MV) ve doğal havalandırmalı (NV) ve dış ortamda gerçekleştirilmiştir. Sonuçlarda güz dönemi ortalama derişimleri, bahar dönemine göre daha yüksek bulunmuş ve dönemler arasında önemli bir fark görülmüştür. Azaarenler için örnekleme boyunca toplam ortalama (ΣAZA5) derişim değerleri gaz fazı için 27.17 ± 25.19 ng/m3, toz fazında 8.97 ±10.01 μg/g bulunmuştur. En sık tespit edilen bileşikler kinolin ve izokinolindi. Kimyasal denge modeli temelli gaz-oktanol dağılım parametresi olan Koa değerleri bulundu. Bazı limitasyonlara rağmen korelasyon düşük olsa da model yaklaşık tahmin için kullanılmıştır.
Assessment of Land Use Change Impacts on Hydrological Parameters in Porsuk River Basin - Turkey
(01. Izmir Institute of Technology, 2023-07) Zulal, Khalilullah; Gündüz, Orhan; Alp, Emre; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Land Use Land Cover (LULC) change is considered to play an essential role in river basin hydrology. Climate change, and increase in urbanization have disrupted the hydrological parameters pattern in Porsuk River Basin (PRB). The current study is aimed to investigate the LULC change impacts on surface runoff, groundwater, evapotranspiration, and lateral flow parameters in the five sub-basins of the PRB under different LULC development scenarios (1990 & 2006) and one climate period (1989- 2010) through hydrological modeling. In this study, the Soil and Water Assessment Tool (SWAT) model was utilized to analyze the hydrology of the river basin at watershed scale. The hydrological pattern characterization is based on five discharge gauges monitored by State Hydraulic Works (DSI) in the basin. The Kiranharmani, Parsibey, and Porsuk Ciftligi subbasins, the yearly increase in surface runoff reached 25%, 18%, and 12.91%, respectively, are more affected by landuse changes. The Scenario 2, contrary to Scenario 1, showed a noticeable reduction of groundwater infiltration in all subbasins with exception of Parsibey, due to rapid increased area of residential regions. In comparison to the 1990 LULC, changes in the 2006 LULC have a greater overall impact on hydrological processes in all sub-basins of the PRB. Therefore, it is believed that changes in specific LULC classifications can be linked to the reaction to changes in hydrological processes in a subbasin. Overall, this research is believed to be among the first to be done in the PRB, and the findings are thought to be helpful for water management.
Bioremediation of Marine Sediments Contaminated by a Mixture of Persistent Organic Pollutants
(01. Izmir Institute of Technology, 2025) Kurtoğlu, Miray; Demirtepe, Hale; Ökten, Hatice Eser; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Poliklorlu bifeniller (PCBs) ve polibromlu difenil eterler (PBDEs) gibi kalıcı organik kirleticiler, çevrede karışım halinde bulunarak ekosistem ve insan sağlığı için önemli riskler oluşturur. Bu küresel sorunun çözümü bu kirleticilerin çevresel ortamlardan uzaklaştırılması, yani iyileştirilmesidir. Bu çalışma, endüstriyel faaliyetlerin yoğun olduğu Aliağa, İzmir, Türkiye'deki gemi söküm sahalarından alınan kirlenmiş sedimanlar kullanılarak, biyoogmentasyon (BO) ve biyostimulasyon (BS) gibi biyoiyileştirme stratejilerinin etkinliğini sediman mikrokozmları ile incelemiştir. Mikrobiyal analizler, sedimanlarda Chloroflexi filumu ile ilişkili mikroorganizmaların çokluğunu (%37,6) ortaya koymuştur ve bu mikroorganizmalar zenginleştirilerek BO uygulaması için kullanılmıştır, BS uygulamasında ise doğal mikrobiyal aktiviteyi teşvik etmek amacıyla ortama mikrobesinler sağlanmıştır. BO ve BS, toplam PCB'ler için sırasıyla %14 ve %19, PBDE'ler için ise %33 ve %24 olarak giderim verimlilikleri sağlamış; bu değerler, doğal giderim (PCB'ler için %12 ve PBDE'ler için %8) setine kıyasla daha iyi performans gösterdiği için harici katkıların önemini kanıtlamıştır. PCB'ler için bozunma hızları BO'da (0,00124 klor/bifenil/gün-Cl/bp/gün) BS'den (0,00085 Cl/bp/gün) daha yüksek iken, PBDE'lerin bozunma hızı BS'de (0,00945 brom/difenil eter/gün-Br/dp/gün) BO'ya (0,00741 Br/dp/gün) kıyasla daha hızlı olmuştur. BO ve BS stratejileri toplam PCB ve PBDE konsantrasyonlarını azaltmış olsa da, zamanla daha düşük halojenli bileşiklerin oluşumu ekotoksikolojik riski işaret etmiştir. PCB-52 sürekli olarak yüksek risk sergilerken, BDE-28 BS'de yüksek risk kategorisine çıkmış ve BDE-153 tüm uygulamalarda yüksek ve orta risk seviyeleri arasında değişiklik göstermiştir. Bu bulgular, in situ biyoiyileştirme uygulamalarından önce laboratuvar ölçekli çalışmaların yapılmasının, giderim verimliliği ve potansiyel riskleri değerlendirme açısından önemini ve gerekliliğini vurgulamaktadır.
Bioremediation of Sediments Contaminated by Persistent Organic Pollutants: an In-Silico Approach
(01. Izmir Institute of Technology, 2024) Yıldırım, Batuhan; Demirtepe, Hale; Ökten, Hatice Eser; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Bromlu alev geciktiriciler arasında en yaygın kullanılanlardan biri olan polibromlu difenil eterler (PBDE), çevre ve insan sağlığı üzerinde ciddi riskler oluşturan kalıcı organik kirleticiler olarak bilinmektedir. Bu nedenle, bozunma süreçleri ile çevresel ortamlardan giderilmeleri gerekmektedir. Fakat, karmaşık çevresel ortamlarda bozunmanın ilerleyişini takip etmek zordur. Bu sebeple, PBDE'lerin bozunma süreçlerini anlamak ve etkili iyileştirme yöntemleri geliştirmek için modelleme çalışmaları gereklidir. Bu çalışma, PBDE'lerin sedimanlardaki anaerobik dehalojenasyonunu modellemek ve iyileştirme senaryoları altında bozunma yollarını ve bozunma hızlarını analiz etmeyi amaçlamaktadır. Bu amaçla, doğal giderim, biyostimulasyon ve biyoogmentasyon senaryolarını taklit eden bir mikrokozm çalışmasının deneysel verileri kullanılmıştır. Daha önce geliştirilmiş olan anaerobik dehalojenasyon modeli (ADM), geliştirilip entegre edilerek 'ADM-IE' adı verilen yeni bir model oluşturulmuştur. ADM-IE, PBDE bozunması için tüm olası dehalojenasyon yollarını listeleme, bu yolların reaksiyon miktarlarını belirleme, ölçülen bileşikler için bozunma hız sabitlerini hesaplama ve ölçülmeyen bileşikler için makine öğrenimi algoritmalarıyla hız sabitlerini tahmin etme yeteneklerine sahiptir. Sonuç olarak, modelin yüksek konsantrasyonlu bileşikler için daha başarılı tahminler yaptığını, ancak düşük konsantrasyonlu bileşikler için tahmin doğruluğunun daha düşük olduğunu gösterilmiştir. Brom atomlarının pozisyonlarının dehalojenasyon yollarında kritik bir rol oynadığı belirlenmiştir. İyileştirme senaryoları arasında, biyoogmentasyon genellikle en yüksek bozunma hızlarını sağlarken, bazı durumlarda biyostimulasyon daha yüksek hızlar göstermiştir. Bununla birlikte, belirli reaksiyonlar toksik ürünlerin oluşumunu desteklemiştir, bu da biyostimulasyon uygulamasında dikkatli olunması gerektiğini vurgulamıştır. Model, iyileştirme stratejilerinin optimize edilmesi ve daha az zararlı ürünlerin elde edilmesi için bir analiz çerçevesi sunmaktadır.
Co-Production of Chitin Nanofibers, Proteins, and Lipids in Marine Diatoms Belonging To the Thalassiosira Genus
(Izmir Institute of Technology, 2022) Sezgin, Tuğçe; Özkan, Altan; Özkan, Altan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Chitin is a biopolymer used in various industries, including biomedical, pharmaceutical, medical, and food. Today, the vast majority of chitin is obtained from waste shellfish. Shellfish chitin has an inherent impurity problem because chitin in these organisms is embedded in other organics and inorganics. Thus, new sources have been investigated. Diatoms, particularly Thalassiosira and Cyclotella species, have the potential to be the providers for applications requiring high quality through their unique ability to biosynthesize and extrude chitin nanofibers. The primary aim of this study is to study this potential. This investigation entailed the cultivation of three Thalassiosira strains according to a standard cultivation protocol under photobioreactor conditions. The secondary aim was to assess the possibility of commercially valuable co-product generation. For this, biomass protein, lipid, and fatty acids contents were analyzed. Chitin productivity varied significantly between the strains. The peak productivities and final concentrations ranged from 4 to 25 mg/L-day and from 60 to 250 mg/L, respectively. Average fiber diameters ranged from 68.5 to 95.0 nm. Silicon limited growth increased the chitin biosynthesis in T.weissflogii 1336 and T.pseudonana 2135. Biomass lipid contents of over 45% were obtained with T.pseudonana 2135 under silicon depletion. The fatty acid profiles indicated the suitability for application as live aquaculture feed for T.weissflogii 1336, and biodiesel feedstock material for T.pseudonana 2135. The highest biomass protein contents were about 30%, which were obtained under silicon availability. This study, for the first time, assessed the chitin productivity of Thalassiosira strains and demonstrated unique multiproduct generation scenarios.
A Comparative Study of Thin-Film Coated Silicon Wafer Surfaces for Laser-Induced Breakdown Spectroscopic Analysis of Liquids
(01. Izmir Institute of Technology, 2021-07) Aras, Nadir; Yalçın, Şerife Hanım; 03.07. Department of Environmental Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Laser-Induced Breakdown Spectroscopy, LIBS, is a relatively new atomic emission spectroscopic technique that shows rapid growth due to its many special peculiarities, like its ability to provide spectral signatures of all chemical species at the same time, in all environments of solid, liquid, or gas. Liquid sample analysis by LIBS is more troublesome compared to analysis of solids. Therefore, liquid analysis by LIBS requires some pretreatment steps to be applied before direct analysis of the samples. In the literature, a variety of approaches has been successfully applied and there is still plenty of room to improve methodologies used in the liquid-LIBS analysis. The main purpose of this thesis study was to perform studies for the development of a LIBS-TARGET for sampling liquids on it, after drying, by repetitive laser pulses. With this purpose, silicon wafer-based substrates with differing surface compositions; uncoated (crystalline silicon, c-Si), oxide-coated silicon, SiO2, and nitride coated silicon, Si3N4, were tested for several experimental parameters. Within the content of this study, a fast and accurate methodology for direct analysis of aqueous samples by LIBS is proposed. This methodology has two important attributes: one is the use of the non-metal substrate, silicon wafer, for the first time for direct analysis of aqueous samples dried on, and two is the use of high energy laser pulses focused outside the minimum focal point of a plano-convex lens at which relatively large laser beam spot covers the entire droplet area for plasma formation. Si-wafer-based substrates were used for both qualitative and quantitative analysis of Cd, Cr, Cu, Mn, and Pb elements, and analytical figures of merit were determined. The analytical performance of each substrate was evaluated from the experiments performed with aqueous standards and real water samples. Silicon nitride-coated substrate has shown superior properties in terms of enhancing the LIBS signal and as low as 11 pg detection limits for Pb were obtained.
Development of a Hybrid Sorbent Composed of Natural Materials for the Removal of Arsenic From Waters
(Izmir Institute of Technology, 2014) Yılmaz, Dilek; Sofuoğlu, Sait Cemil; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
A novel sorbent has been developed by immobilizing chitosan onto pumice for As(V) sorption from waters. In order to ensure its functionality, sorption performance was determined by measuring As concentrations in water using hydride generation atomic absorption spectrometry. The success of the immobilization was checked with characterization techniques as scanning electron microscopy, thermal gravimetric analysis, and elemental analysis. Points of zero charges were determined with potentiometric mass titration. Batch type equilibration studies showed that the sorbent can be employed at a wide pH range resulting in quantitative sorption (>90%) at pH 3.0-7.0, and greater than 70% sorption at pH>8.0. These results demonstrate the advantage of immobilizing chitosan onto pumice, because, under the same conditions, pumice displays <20% sorption towards As(V) whereas chitosan gives approximately 90% sorption but only at pH 3.0. The validity of the method was verified through the analysis of ultra-pure, bottled drinking, and tap water samples spiked with arsenate; the respective sorption percentages of 93.2 (±0.7), 89.0 (±1.0), and 80.9 (±1.3) were obtained by batch type equilibration. The sorbent was applied in a column for the spiked samples of ultra-pure and tap water. Similar sorption percentages (60% at the 18th fraction) were obtained for ultra-pure water whereas the methodology gave more efficient results for tap water (90% at the 20th fraction) demonstrating the potential of the sorbent for an efficient water treatment system. Arsenic sorption was also examined in the presence of common interfering ions resulting in competing effects of PO43- and NO3- on As(V) adsorption.
Drought Assessment in Afghanistan Using Remotely Sensed Data
(2023) Anwari, Ezatullah; Gündüz, Orhan; Tayfur, Gökmen; 03.07. Department of Environmental Engineering; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Afghanistan's climate ranges from arid to semi-arid because it is a landlocked country in central and southern Asia. The vast majority of people work in agriculture, and agriculture accounts for a significant portion of the nation's GDP. Climate change-related droughts that have occurred repeatedly have made it increasingly difficult to implement practical water resources management techniques. Another noteworthy concern involves transboundary water flowing downstream to neighboring countries without any established sharing arrangements. Consequently, this study aims to examine drought assessment in Afghanistan over the period from 1992 to 2021. This assessment will be based on various indices, including the Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Reconnaissance Drought Index (RDI), and Surface Runoff Index (SRI). Data used in this study are remotely sensed precipitation, temperature and surface runoff data. In order to make compression between short term period and long-term period each of the indices are calculated in three different time scales (3_month, 6_month and 12_month). At the end Afghanistan's yearly drought maps of each four indices for each of the three-time scales are drawn by Geographic Information System (GIS) and the results obtained are discussed. Accordingly, the results revealed that most of the country, notably the west of Afghanistan, has endured several, significant droughts over the last 20 years at least, and also due to regional climate variations (arid and semi-arid), these four indexes behave differently in specific situations.
Effects of Frying on Indoor Air Quality
(Izmir Institute of Technology, 2013) Toprak, Melis; Sofuoğlu, Sait Cemil; 01. Izmir Institute of Technology; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering
Frying is an important indoor air pollution source. It may cause chronic health effects on cooks. This study measured indoor air concentratinos of volatile organic compounds (VOCs), aldehydes, particulate matter, CO and CO2 in a small scale restaurant kitchen before, during, and after frying with a margarine produced specifically for frying. Both sampling and monitoring strategies were employed. Individual VOCs, aldehydes, and PM2.5 concentrations were determined by sampling. Total VOCs, PM10, CO, and CO2 concentrations were determined using a monitoring device. Temperature and relative humidity were also monitored as comfort variables in addition to CO2. Two campaigns were conducted. In Campaign-1 real working conditions were studied. In Campaign-2 only potatoes were fried with varying amounts. N-heptane, ethyl acetate, nonanal, and n-octane were the realtively higher concentration compounds in both campaigns. The increase in PM10 concentrations, however, was much more pronounced: about five times higher when the lowest concentration observed in the very beginning and the peak concentration during frying are compared, and two times higher when the average concentrations are compared. CO and CO2 concentrations were relatively low, and temperature and relative humidity levels were generally in the comfort zone. The observed PM10 concentrations during frying and the average PM2.5 concentrations (80-250 Î¼g/m3) of 4-hr period that covers the all three periods (before, during, and after) in Campaign-1 indicate that chronic health effects are probable for cooks who frequently cook by frying with the frying margarine.
Effects of Oxygenation in Stratified Reservoirs on Concetrations of Manganese and Iron in Bottom Sediments
(Izmir Institute of Technology, 2019-12) Vural Aydın, Buse; Elçi, Şebnem; Ökten, Hatice Eser; 03.07. Department of Environmental Engineering; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Iron and manganese accumulation in drinking water reservoirs is a challenging issue and should be controlled in order to prevent their adverse effects on human health. Accumulation of these elements not only clogs pipeline systems but also causes stains on fixtures and laundry. In addition, high concentrations of iron and manganese may lead to various health problems when ingested. This study focuses on the release mechanism of iron and manganese from sediments to water column and investigates methods to prevent this release. Effects of lack of hypolimnetic aeration, acid-base condition and thermal stratification on iron and manganese concentrations at water column were investigated through laboratory experiments. Experiments showed that total iron (Fe) and ferrous iron (Fe2+) concentrations in the water column decreased gradually following aeration in hypoxia conditions. A similar behavior was also observed for manganese concentrations. However, the concentration of dissolved manganese (Mn) in alkaline water condition is observed to be less than the aerated water case. This is an indication that iron and manganese react differently under different acidity of water in consideration.
The effects of photobioreactor average shear rate on chitin nanofiber production characteristics of the diatom cyclotella cryptica
(01. Izmir Institute of Technology, 2024) Ağaoğlu, Cemre; Özkan, Altan; Yılmaz, Benay Uzer; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Kitin biyomedikal uygulamalar açsıından çok yüksek potansiyelli doğal bir biyopolimerdir. Halihazırda, ticari kitin üretiminin çoğunluğu deniz ürünleri endüstrisi tarafından işlenen kabuklu deniz canlılarının atıkları kullanılarak yapılmaktadır. Diatom cinslerinden Cyclotella ve Thalassiosira kitin nanofiberlerini direkt olarak hücre duvarları üzerinde bulunan fultoportula adı verilen açıklıklardan dış ortama sentezleyebildikleri için kitin hasatı için sert ektraksiyon koşulları uygulanması gerekliliğini ortadan kaldırmaktadır. Bu çalışmada, Cyclotella cryptica CCMP 333 hücrelerinin kitin üretkenliğinin kabarcık kolon fotobiyoreaktörün havalandırma hızındaki farklılıktan kaynaklı maruz kaldıkları hidrolik kesme kuvvetinden nasıl etkilendiği iki aşamalı bir kültivasyon protokolü (birinci aşamada 0,020 mM silikon takviyesini müteakiben ikinci aşamada 1,80 mM silikon takviyesi) uygulanarak araştırılmıştır. Hücrelerin silikon starvasyonuna maruz bırakıldığı birinci aşamada havalandırma hızı 0,5 vvm olarak sabit tutulmuştur, 1,80 mM silikon takviyesinin ardından havalandırma hızlarının 0,25 vvm, 1 vvm ve 1,5 vvm olarak değiştirildiği 3 ayrı fotobiyoreaktör düzeneği kurulmuştur. Bu çalışma kapsamında ulaşılan maksimum kitin üretkenliği 852 mg/L olmuştur ve bu konsantrasyona silikon starvasyon aşamasında 0,5 vvm ile havalandırılan ve ardından 1,8 mM silikon takviyesi ile eş zamanlı olarak havalandırma hızının 1 vvm olarak değiştirildiği deney grubunda saptanmıştır. Cyclotella cryptica CCMP 333 hücre süspansiyonlarında serbest olarak ve hücreye bağlı olarak buluna kitin konsantrasyonları durağan faz sürecinde toplanan numuneler kullanılarak belirlenmiştir. Hücreye bağlı kitin nanofiberlerin konsantrasyonu ile havalandırma akış hızları arasında ters orantı olduğuna dair elde edilen sonuçlar büyük ölçekli diatom üretim tesislerinde hasatlanacak kitin nanofiberi miktarının maksimizasyonu için geliştirilecek stratejilere katkı sağlayacaktır.
Environmental Impact and Capacity Analysis of Renewable Energy Resources: Case Study of Wind Energy in Turkey
(Izmir Institute of Technology, 2016) Değirmenci, Sinem; Bingöl, Ferhat; Sofuoğlu, Sait Cemil; Bingöl, Ferhat; Sofuoğlu, Sait Cemil; 03.07. Department of Environmental Engineering; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The majority of electricity in Turkey is generated from coal and natural gas; however, renewable energy, especially wind power, is a promising energy source for Turkey. Development of new wind energy project requires complex planning process involving many social, technical, economic, environmental, political concerns and different agents such as investors, utilities, governmental agencies or social groups. To address the proper site selection, a Geographic Information System (GIS) based Multi- Criteria Decision-Making (MCDM) method has been used in previous studies. The aim of this study is to develop a GIS-based multi-criteria decision making application which can be updated by the changing regulations to identify potential sites for wind power plants in Turkey. A variety of constraints and factors were identified based on a literature review, regulations and gathered from variety of agencies. After excluding of infeasible sites, pairwise comparisons was carried out using analytic hierarchy process (AHP) as MCDM method by the study group to estimate relative importance of the criteria. The suitability map obtained from MCDM analysis was divided into four classes from the low suitable to extremely suitable area. As a final stage, decision making was carried out with the objectives by environmental impact approach. The output of this study can be used by energy planners to estimate the extent that wind energy can be developed based on public perception, administrative and environmental aspects.
Enzymatic Degradation of Phthalic Acid Esters
(Izmir Institute of Technology, 2013) Baytak, Derya; Sofuoğlu, Sait Cemil; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Endocrine disrupting compounds (EDCs) are environmental pollutants which interfere with the hormone system even at low concentrations resulting in adverse health effects on both human and wildlife. In this study, we aimed to investigate enzymatic degradation of diethylhexyl phthalate (DEHP) and diethyl phthalate (DEP) using both commercial porcine pancreas lipase and lipase from recombinant E.Coli strains that contain lipase genes from thermophilic Bacillus sp. isolated from Balçova Geotermal region in İzmir. Incubation of 20 mg/L DEHP with 20,000 U/L PPL enzyme for 7 days resulted in formation of monoethyl phthalate (MEHP), phthalic acid (PA), and dimethyl phthalate (DMP) which are the possible metabolites of DEHP. The percent decrease in DEHP (20 mg/L) was found to be 92% compared to positive control samples. In the case of DEP, about 53% decrease was obtained after incubation with 20.000 U/L for 7 days. Hydrolysis constants for DEHP ranged between 0.13 and 0.22 d-1, whereas those for DEP ranged 0.43 and 0.54 d-1. As a result of enzymatic hydrolysis of DEHP (1-20 mg/L) with 4000 U PPL enzyme, DEP was produced as hydrolysis product of DEHP after 44 h. In the case of DEP (1-20 mg/L) incubated with 4000 U crude lipase solution for 140 h, DMP was obtained as a possible product of transesterification reaction. The maximum rate (Vmax) of enzymatic hydrolysis reaction for DEHP and DEP was calculated as 0.79 mg/L.h and 1.83 mg/L.h, respectively. The Michealis-Menten constants (Km) for enzymatic hydrolysis of DEHP and DEP were calculated as 2.45 and 2.12 mg/L, respectively.
Estimation of Exposure To Persistent Organic Pollutants and Associated Health Risks
(01. Izmir Institute of Technology, 2024) Genişoğlu, Mesut; Genişoğlu, Mesut; Sofuoğlu, Aysun; Sofuoğlu, Sait Cemil; Sofuoğlu, Sait Cemil; Sofuoğlu, Aysun; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Kalıcı Organik Kirleticiler (POPs), çevresel bozunmaya karşı dirençli, uzun mesafeler boyunca taşınabilen ve organik maddelere olan yüksek afiniteleri nedeniyle çevresel ortamlarda ve gıda zincirinde biriken, küresel olarak yaygın maddeler oldukları için insan sağlığı açısından önemli riskler oluşturur. Pertikül ve hava, toprak ve hava, sedimen ve su arasında dağıldıkları için tarım ürünlerinde, etlerde ve deniz ve tatlı su ürünlerinde bulunurlar. Bu da yutma, soluma ve deri teması yoluyla maruziyete ve sağlık risklerine yol açar. Sonuç olarak, mümkün olduğunca çok sayıda POP grubunu araştırmak için kapsamlı bir tarama çalışması tasarlanmıştır. İzmir'de rastgele seçilen ev ve okullardan, iç ve dış mekan havasıyla beraber çökelmiş toz ve yemek örnekleri toplanmıştır. Ayrıca, kafe/bar/restoranlardan iç mekan çökelmiş toz örnekleri toplanmıştır. Örnekler hazırlık, ekstraksiyon ve temizleme işleminden geçirildikten sonra, PAH'lar, PCB'ler, PBDE'ler, NBFR'ler ve OPFR'lerin hedef bileşikleri GC/MS cihazıyla analiz edilmiştir. Ölçülen konsantrasyonlar ve toplanan maruziyetle ilgili anket bilgileri, USEPA maruziyet-risk modellerine girdi değişkenleri olarak kullanılarak yutma ve soluma maruziyetlerini (kronik günlük alım) Monte Carlo yöntemi kullanılarak ilgili sağlık riskleri simüle edilmiştir. Örnekleme yerleri, kentleşmenin etkisini araştırmak için kırsal, banliyö, kentsel alanlar ve bir sanayi bölgesinin rüzgaraltı yerleri arasında mekansal olarak dağıtılmıştır. Bu tez çalışması kapsamında, küresel literatüre girmiş çalışmalar arasında çevresel ve gıda örneklerinde analiz edilen bu kadar yüksek sayıda hedef POP bileşiği düzeyleri konusunda bilgi veren en kapsamlı veriseti oluşturulmuştur.
Estimation of Total Carcinogenic Risk Due To Multipathway Exposure To Trihalomethanes in Izmir Drinking Water
(Izmir Institute of Technology, 2012) Ergi, Ceyda; Sofuoğlu, Sait Cemil; Tokatlı, Figen; Sofuoğlu, Sait Cemil; Tokatlı, Figen; 03.07. Department of Environmental Engineering; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The goal of this study was to investigate the cumulative and total carcinogenic risk levels of trihalomethanes (THMs) in İzmir drinking water by considering multi exposure routes and pathways. Drinking water THM concentrations measured and questionnaire data collected by Kavcar (Assessment of Exposure and Risk Associated with Trihalomethanes and Other Volatile Organic Compounds in Drinking Water, MSc Thesis, İYTE, 2005) were used for the exposure â€“ risk assessment. Ingestion of drinking water, inhalation and dermal absorption during showering, bathing, hand washing, and dish washing were the considered exposure pathways. THM concentrations in air were estimated by using chemical specific transfer efficiencies. Chemical specific skin permeability coefficients and body surface areas were used . The contributions of exposure routes to the total risk, in the order of low to high, were dermal absorption, ingestion, and inhalation. Cumulative and total cancer risks were estimated using two different methods: commonly employed simple addition method and recently proposed Cumulative Relative Potency Factors (CRPF) approach. The total carcinogenic risks estimated by the both methods were acceptable (<1Ã—10-6) in the minimum and lower bound exposure scenarios, generally acceptable (1Ã—10-6 - 1Ã—10-4) in the central tendency exposure scenario, and not acceptable (>1Ã—10-4) in the upper bound and maximum exposure scenarios while simple addition produced an order magnitude higher risk levels compared to the CRPF method. The results of this study show that carcinogenic risks may be overestimated by using simple addition method. Nevertheless, risk mitigation measures are needed by the local water authorities.
Evaluation of Waste Management System in İzmir-Karaburun Peninsula From Sustainability Perspective
(Izmir Institute of Technology, 2022-07) Hajatnia, Haniyeh; Ökten, Hatice Eser; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Global solid waste generation is constantly rising, hence the need for management strategies that implement environmental improvements. The sustainable municipal solid waste management strategy for municipalities must include collection and transportation. The collection and transportation sector have been neglected while it is one of the most significant polluters. As a result, this study aims to model municipal solid waste transportation using Life Cycle Assessment (LCA) software which we used CCalC2 for this study and CML2001 methodology was used. To demonstrate how different approaches to waste management through transportation can reduce environmental impacts, LCA modeling was done for the three districts of Urla, Çeşme, and Karaburun, all of which are located on the Karaburun Peninsula. Each district was assigned three scenarios, with Scenario 0 representing current municipal practices, Scenario 1 representing a 50% reduction in plastic waste, and Scenario 2 representing a 50% reduction in all renewables. Results showed that only plastic separation might not be enough to achieve significant e reductions in environmental impacts. It has been demonstrated that in the transportation sector of Urla and Çeşme, Scenario 1 had a CO2 reduction of 3.7% and Karaburun had a CO2 reduction of 3.8% while Scenario 2 represented at least a 20% reduction of carbon footprint in all three districts. Findings of this research will support municipalities in the roadmaps they will choose for the Municipal Solid Waste Management applications.
Exposure and Risk Assessment for Arsenic in Simav Plain by Ingestion of Edible Crops
(Izmir Institute of Technology, 2017-07) Terzi, Begüm; Sofuoğlu, Sait Cemil; Gündüz, Orhan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Ingestion is the main route of exposure to arsenic. The pathways of concern are ingestion of drinking water and arsenic-accumulating plants. Simav plain has been shown to have the natural arsenic conamination of waters and soil. However, foodstuff was not made a subject of investigation. In this study, arsenic exposure via ingestion of edible plants cultivated in Simav plain was investigated based on the modeling of the measured soil concentrations and data collected from the literature, which were for bioconcentration factors, plant consumption rates, background arsenic concentrations in plants, plant root depths, and body weights. Eighteen plant species, which are bean, broccoli, cabbage, carrot, cauliflower, corn, cucumber, eggplant, garlic, lettuce, okra, onion, potato, radish, spinach, sunflower seed, tomato, and wheat were studied. Chronic-toxic and carcinogenic risks associated with the consumption contaminated foodstuff were assessed with two approaches: scenario based point estimates (deterministic approach) and population based estimates (probabilistic approach). Monte Carlo simulation was used to determine chronic-toxic and carcinogenic risks via ingestion of edible plants probabilistically. Wheat was found as the plant variety with the highest non-carcinogenic and carcinogenic risks which was followed by potato, tomato, cucumber, corn, cabbage, eggplant, and onion. Non-carcinogenic risk levels for broccoli, cauliflower, garlic, and radish were below the threshold level. However, their carcinogenic risk levels were considerable. The risk levels estimated in this study are exceptionally high, indicating consumption of the plants cultivated in Simav may pose significant chronic-toxic and carcinogenic health risks.
Identification and Detection of Phosphorylated Proteins by Laser Induced Breakdown Spectroscopy
(Izmir Institute of Technology, 2011) Aras, Nadir; Yalçın, Şerife; 03.07. Department of Environmental Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
Laser-Induced Breakdown Spectroscopy (LIBS) is an optical atomic emission spectroscopic technique that uses an energetic laser source to generate a luminous plasma. Spectrochemical analysis of the light emitted from the plasma reveals information about the elemental composition of the sample. Phosphorylation is an important regulatory mechanism that activates or deactivates many proteins and enzymes in a wide range of cellular process. Identification and detection of phosphoproteins have a crucial importance in phosphopeptide mapping. This study is based on the assessment of the capabilities and limitations of LIBS as a quick and simple method for in-gel identification and determination of phosphorylated proteins, specifically casein and ovalbumin before mass spectrometric analysis for the elucidation of phosporylation sites. For this purpose, an optical LIBS set-up was constructed from its commercially available parts and the system was optimized for LIBS analysis of polyacrylamide gels. Nd:YAG laser operating at 532 nm wavelength and at 10 Hz frequency was used to create plasma on dry gel surfaces. Emitted light from a luminous plasma was analyzed and detected by an Echelle type spectrograph containing Intensified CCD, detector. With this study, LIBS detection of phosphorous proteins after electrophoretic separation of phosphorylated proteins has been shown, for the first time. After SDS-PAGE gel separation process, phosphoproteins were recognized from prominent P(I) lines (at 253.5 nm and 255.3 nm) in a plasma formed by the focused laser pulses on the gel, just in the center or in the vicinity of the electrophoretic spot. Spectral emission intensity of P(I) lines from LIBS data has been optimized with respect to laser energy and detector timing parameters by using standard Na2HPO4. It has been shown that phosphorylated proteins (casein and ovalbumin in mixture) can be identified by LIBS after both coomassie brilliant blue and silver staining procedures. Technique shows a great promise in microlocal spotting of phosphorylated proteins in gel before MS analysis for the determination of the phosphorylation sites.

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