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Item The fate and transport of some commonly used pesticides in the Konya plain(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2022., 2022) Ongar, Yağmur.; Demirel, Burak.; Copty, Nadim.By protecting the agricultural products, pesticides are substances that are widely used worldwide to increase crop yields. Although pesticides can have beneficial effects on crop production, these chemicals have various adverse effects on human health, other living and environmental systems. By virtue of the aforementioned reasons, it is a necessity to understand the fate, transport and interactions of the pesticides in the natural systems. In this study, in order to investigate the fate and transport of two pesticides widely used in the Konya Plain (2,4-dichlorophenoxyacetic acid and fenoxaprop-p ethyl), a series of batch sorption and column transport experiments were conducted. Soil samples collected from the Konya Plain were screened for a wide range of pesticides using liquid chromatography coupled with tandem mass spectroscopy (LC-MS/MS). Extraction of the pesticides from the soil samples was performed using “quick, easy, cheap, effective, rugged, and safe” QuEChERS method. Batch tests were conducted using selected soil samples to investigate the sorption potential of the target pesticides. Sorption kinetics as well as sorption isotherms were developed for the two pesticides. Column tests were conducted to evaluate the mobility potential of the target pesticides. Calibration curves with linear regression coefficients (R2 ) greater than 0.990, were used for the estimation of distribution coefficients (Kd). The 24h Kd value of the Fenox was calculated as 297.4 mL g-1. There was no significant Kd value calculated for 2,4-D. Overall, the experiments demonstrated that the transport potential of 2,4-D is high while Fenox mobility is limited due to its high sorption.Item An state-of-the-art design technique in landfill engineering :|a case study(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2001., 2001.) Aykan, S. Birkan.; Onay, Turgut T.Disposal of solid wastes, the final functional element of the solid waste management system. is a major problem throughout the industrialized world. Sanitary landfilling is today widely recognized as the most common and economic method and viable solution for the disposal of municipal and industrial solid wastes. Despite the implementation of waste reduction recycling and transformation technologies disposal in landfills still remains an important component of integrated solid waste management strategy. The purpose of this study was to present the design steps of sanitary landfills through Sinop (Meşedağı) sanitary landfill project. The study indicates that planning and design of modern landfills involves the application of a variety of scientific. economic and engineering principles. The main criteria in design studies were the Turkish Environmental Regulations. The other main feature of the study was the evaluation of the differeat models and approaches employed in the design of modern landfills. In this manner. it is intended to gather appropriate data by comparing the results. The major topics covered in this study include description of the landfill site, estimation of population and solid waste generation. definition of waste properties, slope and berm stability analysis. design of sub-base liners and Dnal (ap, estimation of leachate generation and design of leachate collection system. design of surface water drainage system, estimation of gas generation and design of gas venting system, design of leachate treatment plant and closure of landfill and longterm monitoring.Item Enhanced anaerobic mono-digestion and co-digestion of crop residues by NaOH alkalı pre-treatment(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2021., 2021.) Mansour, Muhammad.; İnce, Bahar Kasapgil.; Özbayram, Gözde.The main objective of the study was to determine the effect of different dosages of NaOH alkali pre-treatment on the lignocellulosic structures and the methane production of crops’ residues. In this regard, NaOH pre-treatment was implemented with different dosages on three different crops’ residues: wheat, rye, and rice straws. Substrates were soaked into NaOH solutions at different dosages with solid to liquid ratios of 100 and 200 gTS/L to investigate both conditions. Anaerobic digestion process was conducted using AMPTS II under mesophilic conditions. By 8 % NaOH pre-treatment dosage, the reduction of hemicellulose and lignin was 81 % and 62 % for rice straw, 86 % and 69 % for wheat straw, 80 % and 74 % for rye straw, respectively. The concentrations of CODs in the liquid fraction after pre-treatment were regarded as 3 times higher than untreated samples. Pre-treatment with 8 % NaOH dosage increased the methane yield of rice, wheat, and rye straws by 55 %, 40 %, and 46 % respectively. During the co-digestion test, an increase in VFA production was regarded by (rice/wheat) and (rice/wheat/rye) sets by values of 1930 and 1710 mg/L total acetic acid on the 5th day. Samples from digesters that produced the highest methane yield were chosen for further molecular analysis. Proteobacteria was found the most abundant bacterial phylum in the inoculum used, while Methanothermobacter and Methanoculleus were the major archaeal communities found. Compared to untreated digesters, 16S rRNA gene amplicon sequencing revealed more diverse microbial communities in NaOH digesters.Item In situ immobilization of the selected heavy metals by sulfide compounds in landfills under methanogenetic conditons(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2001., 2001.) Erses, Aliye Suna.; Onay, Turgut T.Co-disposal is a technique for the controlled disposal of hazardous wastes together with municipal solid waste. Co-disposal of industrial wastes including heavy metals and disposal of household hazardous substances such as batteries, paints, dyes and inks -in paper result in release of heavy metals into a landfill environment. Zinc, iron, nickel, copper and cadmium are the most common heavy metals disposed to landfills. These metals are controlled by several attenuation mechanisms including adsorption, acid-base, oxidation-reduction and precipitation-complexation reactions. This research aimed to better understand the extent of heavy metal attenuation in landfills by means of precipitation by sulfide compounds. The effect of selected heavy metals (Zn, Cu, Cd, Fe, Ni) on solid waste stabilization together with the effect of leachate recirculation on the attenuation mechanisms was also investigated. For this purpose, two landfill simulating reactors were used in the laboratory. These reactors were constructed and filled with shredded and compacted municipal solid waste having typical solid waste composition determined for istanbul region. Two reactors, one with leachate recirculation, the other without were operated in the constant temperature room of 32°C to enhance the growth of anaerobic microorganisms. Moreover, moisture addition was done into the reactors in order to simulate the annual rainfall. After the onset of the methanogenetic conditions in both reactors, the selected heavy metals including iron, copper, nickel, cadmium and zinc were added into the simulated landfill reactors. The metals (Fe, Cu, Ni, Cd, Zn ) were prepared by dissolving the metal salts in one liter deionized water and introduced into the bioreactors according to the amounts suggested for co-disposal under the directives of the Turkish Hazardous Waste Control Regulations to prevent inhibition of the microbially mediated processes during waste stabilization This research indicated that when sulfide concentration was very low or insufficient, the removal of the metals was controlled by other anions such as C03 = and P04- 3 until the reduction of sulfate coming from loaded metal salts into the reactors Moreover, leachate recirculation offers opportunities for more rapid waste stabilization including attenuation of co-disposed heavy metals.Item Numerical modeling of the coupled mechanisms underlying salt accumulation in agricultural soils(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2022., 2022.) Arıcan, Mehmet Tuna.; Copty, Nadim.Sodicity is a widespread significant threat to agricultural soils with adverse impact on soil properties and crop yields. The main processes underlying this environmental hazard is the excessive accumulation of sodium ions within the soil due to the use of saline groundwater for irrigation along with high rates of evaporation. This situation naturally puts agricultural soils in arid and semi-arid regions into that risk and therefore understanding the mechanisms behind it gains importance. Although, there have been numerous studies to understand and model the problem, a detailed modeling of the coupled processes can provide further insight into the different mechanisms and their interactions. The main processes included in the model include liquid and vapor water flow, solute transport and sorption, heat transport, and evapotranspiration assess, and according to that, a numerical 1D model code is developed using an explicit finite difference method. The model is applied to a series of different cases with crop and meteorological data adopted from the Konya Closed Basin a significant agricultural region of Turkey and under the risk of sodicity with increasing drought in recent years. The factors tested in assessing soil sodicity are irrigation water quality, crop type and climate change. The importance of including heat and vapor transport during such calculations are presented and discussed.Item Aggregation on natural colloidal particles under solar irradiation(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2021., 2021.) Sağlık, Didem.; Bekbölet, Miray.Aggregation/agglomeration of nanoparticles affects their fate and transport in natural waters. Although nanoparticles behave as colloidal matter expressing aggregation/agglomeration properties under natural water conditions, the role of aggregation/agglomeration during photocatalysis has not been demonstrated clearly so far. The main objective of this study could be described as assessment of the colloidal behavior of the binary system i.e., NOM representative organics and nanoparticles representative of photocatalyst specimens described by following basic experimental procedures prior to, during and under post photo-treatment conditions. To fulfill this aim, dynamic light scattering, sedimentation and turbidity experiments were performed. Aggregation and/or agglomeration of TiO2 nanoparticles were assessed by using the above indicated physico-chemical parameters in relation to water matrix effects as well as photocatalytic removal efficiencies. Aggregation and/or agglomeration behavior of both matrix components provided information on expected reactivity under irradiation during photocatalysis. Overall evaluation of the systems provided information both during photocatalysis as well as light induced reactions under environmental conditions. Therefore, a broader insight was deduced on the fate of nanoparticles through photocatalysis.Item Life cycle assessment of the biogas plant producing energy for Marmara Region(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2021., 2021.) Kozal, Duyguhan.; Cılız, Nilgün.Industrialization and overpopulation have been accelerating global energy consumption, and this situation increases the need for renewable energy sources more and more. In addition to the increasing energy demand, population growth leads to an increase in food consumption. Expired food products have been evaluated with various practices to meet the increased energy demand and to adopt sustainable waste management. For this purpose, many technologies have been developed and some facilities that carry out waste processing and recovery operations have been established. In this study, the transportation of various wastes, mostly expired food waste, into the specified biogas plant in the Marmara Region of Turkey, the energy production from these waste compositions and the utilization options of the produced energy were evaluated by Life Cycle Assessment Methodology. In this sense, the conversion of the produced biogas formed as a result of the anaerobic digestion process into electricity and heat was analyzed, and the utilization options of the produced energy were environmentally evaluated. The environmental performances of the specified biogas plant were determined through two different energy utilization options: on-site energy utilization and energy utilization from the electricity grid and natural gas. Within the scope of energy utilization from the electricity grid and natural gas, the revenues from the sale of electricity and profit margin were considered The results demonstrated that the decrease in the environmental impact categories was observed in the on-site energy utilization option. Furthermore, the entire energy requirements of the specified biogas plant were met by using some of the produced energy within the plant. In this sense, thanks to the on-site energy utilization option, fossil fuel consumption was eliminated, and thus the decrease in greenhouse gas emission was achieved.Item Impact of irrigation and soil compaction on agricultural lands with shallow ground water table(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2021., 2021.) Nick, Sina Maghami.; Copty, Nadim.; Demirel, Burak.Salt accumulation in agricultural soils is a long-lived problem for farmers in many regions of the world, leading to a decrease in crop yields and threatening food security. The salinity challenge amplifies in absence of proper soil water drainage in areas with shallow groundwater table. Hence, this study was carried out by examining the impact of irrigation pattern and soil compaction on the salt dynamics within a soil profile with a shallow aquifer. A series of laboratory-scale column experiments were conducted to examine the impact of different irrigation patterns, water quality and soil compaction conditions on salt dynamics. Two water qualities were applied: fresh (DI water) and saline (~3.4 mS/cm). The soil columns (60 cm height and 16 cm diameter) were packed with agricultural soil from a 10-year non-tilled profile of an apple farm located in the Konya plain, Turkey. A saline shallow water table was maintained at the bottom of the columns. The experiments were numerically modelled with the HYDRUS-1D computer program which can simulate water and solute movement in unsaturated soils. Results showed that without having proper drainage the salinity within the profile would only accumulate in the presence of a shallow saline aquifer. Furthermore, the numerical simulations showed that short-term solutions such as the application of freshwater during the critical plant growth period can limit the accumulation of salts in agricultural soils. The type of soil, the kind of plant and the availability of freshwater all play a role in the practicability of such short-term solution.Item Recovery and purification of natural antioxidants from olive mill wastewater concentrates by a sustainable process(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2021., 2021.) Doğan, Sena.; Balcıoğlu, Işıl.Olive mill wastewater (OMWW) resulting from olive oil production is characterized with high organic load and phytotoxicity due to the presence of phenolic compounds (PCs). Antioxidant properties of PCs make this waste a potential resource for some industries. Hence, instead of spending effort to treat the toxic components, the recovery of value-added compounds from OMWW can be sustainable waste management solution providing economic benefits. This study was aimed to find out a recovery process for antioxidant PCs mainly hydroxytyrosol (HTyr). The concentrated OMWW samples by Mechanical Vapor Recompression (MVR) evaporator at two different rates, OMWC1 and OMWC2 were subjected to solid phase extraction (SPE) by using different synthetic polymeric resins stands alone (Process I) and as integrated to aqueous two-phase extraction (ATPE) (Process II). Process I and II with non-ionic PAD 950 yielded higher total PCs recovery from both OMWCs while the performance of Amberlyst A26 resin in Process II was better for HTyr recovery. The recoveries of HTyr were 21.77 and 34.31 mg/g from more concentrated OMWC2 by Process II whereas 4.88 and 3.86 mg/g HTyr were recovered from OMWC1 by the application of Process I with PAD 950 and Amberlyst A26 resins, respectively. The first extraction stage of Process II with ATPE system minimized the coextraction of non-target compounds and in overall Process II provided the eliminations of 85-90% carbohydrates and almost complete proteins from the extract of OMWC2. The antioxidant activities of the extracts achieved from more productive Process II exhibited variation depending the applied activity assays.Item Predictive analysis of flight traffic at New York JFK Airport on air pollution using machine learning(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2020., 2020.) Türkoğlu, Batuhan Burç.; Copty, Nadim.Anthropogenic activities like transportation result in the emission of numerous pollutants like NO2, CO, SO2, PM2.5-10, O3, and Pb, which are identified as major air pollutants by environmental and health agencies. Emissions of those major pollutants result in negative health impacts like cardiovascular and respiratory diseases. Even though emissions from on-road traffic have decreased in recent years due to stricter regulations and technological advancements, less strict regulations on aircraft have resulted in an increase in emissions with the increasing air traffic. This study aims to estimate NO2 emissions from commercial flights at John F. Kennedy Airport (JFK) in New York and their impacts on air quality. The study combines numerical modeling using the AERMOD air dispersion model along with a machine learning model to predict NO2 concentration distributions as a function of space and time. To achieve this goal, departure and arrival flight data of John F. Kennedy Airport (JFK) in New York for the year 2018 is used. After the data is cleaned and prepared for the analysis, AERMOD is used to simulate atmospheric pollutant dispersion. The results of this study indicate that aircraft emissions can lead to significant NO2 concentrations in the vicinity of the airport. The simulated concentrations are then used in the training of a machine learning model. Decision tree-based extreme gradient boosting (XGBoost) is used as a machine learning model. It is shown that training in the emission prediction model has resulted in a well-generalized and well-performing model. Overall, this study demonstrates that machine learning modeling can be an effective tool for estimating pollutant dispersion.Item Groundwater appropriation game :|a dynamic simulation approach(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2020., 2020.) Bal, Elif.; Saysel, Ali Kerem.This research explores the common pool resource (CPR) characteristics of groundwater resources by dynamic simulation modeling and computer gaming. As the largest source of freshwater in the world, groundwater is deemed one of the most valuable resources. Due to the difficulty of excluding potential users and high subtractability of the benefits consumed by one user from those available to others, groundwater resource is conceptualized as a CPR. As a CPR, groundwater is prone to both provision and appropriation problems including but not limited to drying up of wells, increased pumping costs and deterioration of water quality due to the intrusion of salt water. In this research, allocation of flow (the extracted groundwater) from the resource stock (extractable water at the aquifer bed) during a single irrigation season is investigated. When groundwater users act independently to increase their water extraction, the resulting drawdown of the water table may lead to an increase in energy costs and reduce overall, as well as individual benefits. This represents a CPR dilemma among the irrigators, where the actors have to cooperate for the quantity and coordinate for the timing of their irrigation activity to increase overall benefits. To facilitate learning in and about the dynamic complexity of this dilemma, a network based dynamic simulation game is developed. The game is grounded on a dynamic simulation model. The model represents the groundwater dynamics (i.e. groundwater flows within the aquifer and recharge mechanism) and dynamic relationship between water extraction and crop yield. The model also calculates biweekly and end of-the-season statistics for the individual farms on finances and water use efficiencies. Namely the Groundwater Irrigation Game is a multiplayer, dynamic game in which participants seek to maximize their farm profits while they are faced with the renewable resource limits. This game allows participants to explore consequences of different strategies and gain insights about the complex dynamics of the commons. Accordingly, the initial observations obtained from the pilot gaming indicate that the game instructions are sufficient for participants to develop a strategy and achieve their goals.Item Assessment of health-cost externalities of air pollution caused by transit ship traffic in Istanbul(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2020., 2020.) Sarıgül, Oğuz.; Copty, Nadim.Air pollution has become a leading environmental concern as a result of rapid urbanization in recent decades. The pollutants of most concern relating to the burning of fossil fuels include sulphur dioxide (SO2), nitrogen oxides (NO2) carbon monoxide (CO) and particulate matter (PM). The purpose of this study is to evaluate the contribution of transit marine traffic through the Bosphorus (Istanbul Strait) on the air quality of Istanbul. Atmospheric emissions originating from ships passing through the Bosphorus were computed and the EPA-approved CALPUFF atmospheric dispersion modelling computer program was used to estimate the air pollutant concentration distributions resulting from maritime traffic. The corresponding health impacts and related health costs due to emissions from maritime traffic are estimated using the EVA (Economic Valuation of Air pollution) methodology. The results show that, ship emissions have major effect on the overall air quality. Along the Bosphorus strait, the yearly average impact due to ship emissions is upto 60 % of the SO2 Turkish air quality standard, nearly 35 % of the NO2 Turkish air quality standard and approximately 2.5 % of the PM10 Turkish air quality standard. The corresponding health impacts expressed in morbidity and premature mortality estimates as significant. It is estimated the transit maritime traffic through the Bosphorus is causing about 2,540,000 adverse health incidents, the vast majority are asthma. More severe morbidity impacts include 47 cases of lung cancer and 116 cases of congestive heart failure. The model also estimates 69 cases of acute death and 2255 of YOLL (years of life lost). The total associated health-related costs are estimated to be 83.3 million euros. Given the proximity of large populations to the Bosphorus strait and the large volume of maritime traffic that passes thorugh it, there is a need to impose stricter standards on ship stack emissions.Item Techno-economic assessment of an integrated algal biorefinery(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2021., 2021.) Erdinçler, Begüm.; Haznedaroğlu, Berat Z.There is an urgent global need to access sustainable energy sources as the supply-demand imbalance of non-renewable energy resources is one of the most critical issues of humankind. All alternate solutions offered to replace fossil-based non-renewables must be both economically viable and environmentally sustainable. In this respect, techno-economic assessments play crucial roles in achieving economic viability while covering the whole production pipeline of the offered product. Algae-based biofuels are strong candidates compared to other biofuels concerning their higher biomass yield, shorter growth cycle and the capability of year-round cultivation in marine and brackish water. Despite these advantages, high energy requirements and costly equipment increase both capital and operational expenses, weakening the viability of commercialization of algae-based biofuels. To address this issue, integrated algal biorefineries have become prominent; implementing production of multi-valorized, value-added products, while optimizing the usage of resources from different feedstocks. To assess the viability, this study conducts a techno-economic assessment of a full-scale carbon-negative integrated algal biorefinery for bio-jet fuel, astaxanthin, beta-carotene and Spirulina powder production. Viable prices for bio-jet fuel commercialization were calculated to be 3.227-9.011$/ton for 50 % blend (with commercial Jet A-1 fuel), 866-1.444$/ton for 5 % blend, 656- 771$/ton for 1 % blend without carbon credit. With the addition of carbon credit, the prices were found to decrease to 3.199-8.807$/ton for 50 % blend, 838-1.240$/ton for 5 % blend and 567- 628$/ton for 1 % blend. Minimum viable prices for astaxanthin, beta-carotene and Spirulina powder were calculated as 850$/kg, 43,50$/kg, and 307$/kg, respectively.Item Investigation of temporal variations in particle number concentrations of ambient air in Ankara and the relationship between particle number and mass concentrations(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2020., 2020.) Yosuncığır, Caner.; Erdinçler, Ayşen.In this study, temporal variations in the number and mass distribution of atmospheric particles are investigated. Particle number distribution of particles was measured using a laser spectrometer at every minute for 12 months. In addition to particle number measurements, PM2.5 and PM10 samples were collected at the same time and at the same location. Particle mass concentrations were measured in the collected samples. Statistical tests are used to determine factors affecting variations in particle number concentrations. The effect of meteorological variations and the effect of anthropogenic and natural events on particle count and mass concentration data are analyzed. In the study, a mathematical model is developed, based on the collected data, to convert the particle number concentration data to particle mass concentration data and evaluate the direct effect of meteorological data on the particle count concentration data. The model is verified by a detailed comparison of the results obtained from the model with the GRIMM mass concentration results.Item Surfactant sorption & desorption on soil surfaces of varying clay content(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2001., 2001.) Küçükaşık, M. Faruk.; Yenigün, Orhan.; Atay, Zeynep.In this research, sorption and desorption behavior of selected surfactants were investigated on a soil sample that was mixed with different clays at different ratios. The surfactants investigated were a cationic surfactant Benzethonium chloride (Hyamine 1622) and an anionic surfactant Sodium Dodecyl Sulphate (SDS). The clays were Kaolin, Attapulgite, and Calcium-Montmorillonite. The sorption and desorption isotherms of soils were fitted to the Langmuir and Freundlich isotherm equations, and related sorption and desorption constants were calculated from these isotherms. It was found that the sorption capacities for all of the three different types of clay at different mixing ratio for Hyamine were higher compared to those of SDS. On the other hand, desorption capacities for SDS is better than those of Hyamine.Item The impact of flow connectivity on the interpretation of pumping test data(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2020., 2020.) Yetişti, Buse.; Copty, Nadim.The spatial variability of subsurface flow parameters, such as the transmissivity or storativity, is a common feature of all geologic systems. Traditional geostatistical techniques expressed this heterogeneity in terms of two-point correlations. Recent research suggests that such characterization technique may not be adequate to fully represent the complex patterns of flow and transport in heterogeneous subsurface systems. The concept of flow connectivity has been introduced to describe how different regions of the aquifer relate to each other. In this study, the impact of point-to-point flow connectivity on radially convergent flow towards a well is investigated numerically. A Monte Carlo approach is adopted whereby a large number of heterogeneous aquifer systems with different levels of connectivity are synthetically generated and then used to simulate pumping tests. Two pumping test methods, the Cooper-Jacob Method and the Continuous Derivation Method, are used to estimate the flow parameters from the time-drawdown curves, and examine how the estimated parameters relate to the underlying heterogeneous aquifer systems. Results indicate that the estimated transmissivity value approaches to the geometric mean of the full transmissivity field as the time-drawdown derivative dataset is included in the interpretation. On the other hand, the estimated storativity is strongly influenced by the spatial distribution of the transmissivity, the aquifer point-to-point flow connectivity and the relative locations of the observation and pumping wells. The relations between the estimated storage coefficient and a static measure of connectivity are also examined.Item Effects arbuscular mycorrhizal fungi interactions and sewage sludge application on heavy metal phytoremediation in mine tailings(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2019., 2019.) Sayın, Fatma Ece.; Erdinçler, Ayşen.; Khalvati, M. Ali.Phytoremediation can be enhanced by the substantial symbiotic relationship between Arbuscular Mycorrhizal Fungi (AMF) and the hyperaccumulator plants (sunflower). AMF set up intimate hyphal network of fungi with the host plant root and enables nutrient, water and heavy metal uptakes. Additionally, application of sewage (wastewater) sludge as a soil amending material improves the phytoremediation efficiency by supplying nutrients and promoting the growth of plants. This study aims to investigate the effects of AMF interactions and sewage sludge application on heavy metal phytoremediation in mine tailings. The samples of chrome tailings having very high heavy metal (Cr, Al, and Fe) contents were ameliorated by phytoremediation enhanced by inoculation of Glomus mosseae or Glomus intraradices and application of three different doses of sewage sludge and buffer soil. The results showed that AMF inoculation improved the efficiency of phytoremediation by increasing the metal uptake of plants. The sludge application improved the growth of plants. The combined Glomus mosseae and sludge (20 g/kg) amendments resulted with the highest plant heavy metal uptake and phytoremediation efficiency. This study offers confirmation on the role of the plant biomass and phytoextraction efficiency interactions in Cr mine tailings as well as mycorrhizal associations and the contribution of the sewage sludge to the plants growth. The outcome of the study confirms that Glomalin related protein rose with the mycorrhizal associations. Meanwhile, the sewage sludge also helped the plant to propagate glomalin protein.Item Removal and discharge of microplastics from the wastewater treatment plants in İstanbul(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2020., 2020.) Vardar, Suat.; Onay, Turgut T.Wastewater treatment plants (WWTPs) act as both receivers and sources of microplastics as they both receive microplastics from household and commercial activities and release the particles that could not be retained. This study investigated several units of a tertiary WWTP with a nutrient removal unit. Samples after physical treatment and from the effluent were also taken as 3h composite samples in order to observe fluctuation effect of influent wastewaters. Dried sludge from the WWTP was also investigated for potential hazards with application of the sludge to the soils. Particles isolated from samples were divided into fibers, fragments, nylons, pellets and glitters based on their morphological characters. Fibers were the most dominant shape, followed by fragments. 500-1000 μm and 1000-2000 μm was the most common size ranges for wastewater samples and sludge, respectively. Size distributions were different for shape classes. Particles in different size ranges demonstrated distinct behaviors for some size classes in various units of the WWTP. Fragments <500 μm were removed more efficiently where fibers with sizes 250-500 μm and 1000-2000 μm were removed better within the WWTP. 84.6 and 93.0% removal were observed with grab and composite samples. Despite the high removal rates 5,151x106 particles/d were released to Marmara Sea where, 36 days of discharge was equal to abundance value reported for Marmara Sea and 5,069x106 particles/d were present in the dried sludge. Polymer structures were not confirmed therefore, the rates calculated represent the microlitter release and microplastic release rate should be lower with a characterization step utilized.Item Occupational safety dynamics in onshore LNG receiving terminals :|a systems modeling approach(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2019., 2019.) Akar, Ezgi.; Saysel, Ali Kerem.In onshore LNG receiving terminals (LNGRTs), any unsafe condition and/or act that may cause fire and explosion during LNG processes may lead to major occupational accidents that may endanger people, equipment and the environment. Hence, to prevent accidents, determining factors that result in unsafe condition and/or act is crucial. LNGRTs are complex systems of interacting elements of managerial and employee decisions pertaining to occupational safety. Accordingly, in this study, based on system dynamics approach, a dynamic simulation model is developed to unravel the dynamic feedback structures that operate over time and can reveal unsafe conditions and/or acts, which signal probabilities of major occupational accidents. To gain insight into the system, besides literature review, fieldwork is done in a major onshore LNGRT. The model structure comprises the activities of LNG processing, equipment maintenance and repairing, employee training, where the management’s time allocation decision under specific resource constraints is the fundamental driver. The model simulates for 5 years and is validated first structurally then behaviorally. Subsequently, system behaviors are analyzed by applying several scenarios and policies on the model. Though these analyses, the model behaviors reveal that possibility of major occupational accidents increases by decrease in allocated labor time for maintenance that increases unsafe conditions and by decrease in allocated labor time for training that increases unsafe acts. The model can also be used as an experimental platform to test the influence of several factors on safety, such as; schedule pressure, incident learning, equipment reliability, turnover rate, overwork, and occupational experience of employee.Item Environmental sustainability for selected packaging wastes(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2019., 2019.) Korkmaz, Asude Pelin.; Cılız, Nilgün.Rapid production and consumption have led to increase in the waste generation in the past several decades. According to the Eurostat (2018) 19% of total municipal solid waste is comprised of packaging waste. To alleviate the environmental impacts associated with packaging waste in both production and disposal phases, recycling is a key solution. The aim of this study is to evaluate selected plastic and glass beverage packaging wastes in Turkey according to the national recycling targets using a Life Cycle Assessment (LCA) methodology and provide science-based recommendations for development of roadmap for achieving sustainable consumption and production goals. For this purpose, the current years (2017 and 2018) and the future (2025) national and EU recycling targets were assessed by LCA on an annual basis. The data for both production and recycling processes were obtained from packaging factories and recycling facilities. The energy processes used in the study were calculated according to the primary energy sources of the relevant year. With this study, the contribution of recycling to the environmental impacts of glass and PET packaging during the life cycle was analyzed.