Environmental Engineering / Çevre Mühendisliği
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Article Citation - WoS: 11Citation - Scopus: 11An Appraisal of the Local-Scale Spatio-Temporal Variations of Drought Based on the Integrated Grace/Grace-fo Observations and Fine-Resolution Fldas Model(Wiley, 2023) Khorrami, Behnam; Ali, Shoaib; Gündüz, Orhan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe gravity recovery and climate experiment (GRACE) observations have so far been utilized to detect and trace the variations of hydrological extremes worldwide. However, applying the coarse resolution GRACE estimates for local-scale analysis remains a big challenge. In this study, a new version of the fine resolution (1 km) Famine early warning systems network Land Data Assimilation System (FLDAS) model data was integrated into a machine learning model along with the GRACE data to evaluate the subbasin-scale variations of water storage, and drought. With a correlation of 0.99 and a root mean square error (RMSE) of 3.93mm of its results, the downscaling model turned out to be very successful in modelling the finer resolution variations of TWSA. The water storage deficit (WSD) and Water Storage Deficit Index (WSDI) were used to determine the episodes and severity of drought events. Accordingly, two severe droughts (January 2008 to March 2009 and September 2019 to December 2020) were discerned in the Kizilirmak Basin (KB) located in Central Turkiye. The characterization of droughts was evaluated based on WSDI, scPDSI, and model-based drought indices of the soil moisture storage percentile (SMSP) and groundwater storage percentile (GWSP). The results indicated discrepancies in the drought classes based on different indices. However, the WSDI turned out to be more correlated with GWSP, suggesting its high ability to monitor groundwater droughts as well.Article Citation - WoS: 5Citation - Scopus: 6Bleach-Containing Automatic Toilet-Bowl Cleaners as Sources of Vocs, Associated Indoor Air Concentrations and Carcinogenic Risk(Turkish National Committee for Air Pollution Research (TUNCAP), 2020) Ayrı, İlknur; Genişoğlu, Mesut; Gaygısız, Handan; 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 TechnologyHousehold cleaning products are sources of volatile organic compounds (VOCs). Bleach containing products are a special case because reactions occur between chloride and their organic content such as surfactants, perfumes, etc., generating VOCs. This study aimed to determine concentration of 13 VOCs in bleach-containing automatic toilet cleaners, to estimate their indoor air concentrations and associated exposure and health risk levels. Experiments with products purchased from supermarkets were conducted in 20-mL headspace vials by placing 1 g of sample with and without water. Solid-phase micro extraction with a DVB/CAR/PDMS fiber assembly was used for adsorption of VOCs from the headspace, and analyzed using a GC-MS. The median carbon tetrachloride and chloroform concentrations of the studied products ranged from 5.03 × 10?3 to 2.37 × 10?2 ?g/g and 2.53 × 10?2 to 2.37 ?g/g, respectively. The modeled 95th percentile indoor air concentrations in a 1.6 m3 bathroom with no ventilation were estimated to be 1 and 20 ?g/m3 for carbon tetrachloride and chloroform, respectively. The 95th percentile carcinogenic risk associated even with the use of the highest content product, 3.72 × 10?7 and 8.62 × 10?7 for carbon tetrachloride and chloroform respectively, were below the acceptable risk. In conclusion, automatic toilet-bowl cleaners were found to be sources of VOCs, but their emission potentials are not high to cause considerable indoor air concentrations over their suggested product lifetime. In turn, carcinogenic risks associated with inhalation exposure are below the de Minimis risk level of 10?6. © 2020Article Citation - WoS: 11Citation - Scopus: 12Countrywide Spatial Variation of Potentially Toxic Element Contamination in Soils of Turkey and Assessment of Population Health Risks for Nondietary Ingestion(American Chemical Society, 2022-10) Gören, Ayşegül Yağmur; Genişoğlu, Mesut; Kazancı, Yiğithan; Sofuoğlu, Sait Cemil; 03.07. Department of Environmental Engineering; 01. Izmir Institute of Technology; 03. Faculty of EngineeringCountrywide surface soil concentrations of potentially toxic elements (PTEs) in Turkey were reviewed in the Web of Science database. A total of 93 papers were investigated to compose a PTE dataset for determining spatial variations and estimating exposure and health risks. Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were selected as PTEs in surface soil. A compiled PTE concentration dataset was used to estimate chronic toxic risks (CTRs) and carcinogenic risks (CRs) according to the deterministic and probabilistic approaches. While the CTR and CR levels of age and sex groups were estimated using a deterministic approach, population risks were estimated using a probabilistic approach. CTR and CR levels in lower age groups and female sex groups were estimated to be higher than those in higher age groups and associated male sex groups. The average CTR levels of the nondietary ingestion of As-containing soil in <11 year age groups were near/just above the threshold level, while As-associated average CR levels of adults and other age groups were estimated to be in the acceptable risk range (10-6 < CR < 10-5) and low priority risk range (10-5 < CR < 10-4), respectively. As-, Cr(VI)-, and Pb-associated upper-bound CR levels of the Turkish population were simulated to be 5.14 × 10-4, 6.23 × 10-5, and 2.34 × 10-6, respectively. Health risk models show the significance of As in both chronic toxic and carcinogenic effects.Article Citation - WoS: 13Citation - Scopus: 14Desalination and Detoxification of Textile Wastewater by Novel Photocatalytic Electrolysis Membrane Reactor for Ecosafe Hydroponic Farming(MDPI, 2022-01) Aydın, Muhammed Iberia; Özaktaç, Damla; Yüzer, Burak; Doğu, Mustafa; İnan, Hatice; Ökten, Hatice Eser; Coşkun, Serdar; Selçuk, Hüseyin; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn this study, a novel photoelectrocatalytic membrane (PECM) reactor was tested as an option for the desalination, disinfection, and detoxification of biologically treated textile wastewater (BTTWW), with the aim to reuse it in hydroponic farming. The anionic ion exchange (IEX) process was used before PECM treatment to remove toxic residual dyes. The toxicity evaluation for every effluent was carried out using the Vibrio fischeri, Microtox® test protocol. The disinfection effect of the PECM reactor was studied against E. coli. After PECM treatment, the 78.7% toxicity level of the BTTWW was reduced to 14.6%. However, photocatalytic desalination during treatment was found to be slow (2.5 mg L-1 min-1 at 1 V potential). The reactor demonstrated approximately 52% COD and 63% TOC removal efficiency. The effects of wastewater reuse on hydroponic production were comparatively investigated by following the growth of the lettuce plant. A detrimental effect was observed on the lettuce plant by the reuse of BTTWW, while no negative impact was reported using the PECM treated textile wastewater. In addition, all macro/micronutrient elements in the PECM treated textile wastewater were recovered by hydroponic farming, and the PECM treatment may be an eco-safe wastewater reuse method for crop irrigation.Article Citation - WoS: 26Citation - Scopus: 30Detection and Analysis of Drought Over Turkey With Remote Sensing and Model-Based Drought Indices(Taylor & Francis, 2022) Khorrami, Behnam; Gündüz, Orhan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyUnder the severe impacts of climate change, drought has become one of the most undesirable and complex natural phenomena with critical consequences for the environment, economy and society. The orthodox drought monitoring approaches use observations of meteorological stations, which are typically restricted in time and space. Remote sensing, conversely, provides continuous global coverage of a variety of hydro-meteorological variables that are influential in drought, and data extracted from remote sensing and modeling missions are now considered more practical and alluring for researchers. In this study, we applied a combination of field data, remotely sensed data and modeled data to detect and quantitatively analyze drought phenomena. To achieve this objective, we utilized Terrestrial Water Storage Anomalies (TWSA) estimations from GRACE mission, Normalized Difference Vegetation Index (NDVI) from MODIS mission, Surface Runoff (R) and Evapotranspiration from ERA5 reanalysis datasets and Soil Moisture (SM) from GLDAS data model to evaluate their feasibility in detecting recent droughts over Turkey. We validated the accuracy of several remote sensing-based indices (GRACE Drought Severity Index, Water Storage Deficit Index [WSDI], Soil Moisture Index, Standardized Runoff Index and NDVI) with the traditional indices (SPI and SPEI) calculated from in situ observations of precipitation. The results revealed that the GRACE-based WSDI gave the best performance with high correlations with the SPI index both temporally and spatially over Turkey. We also found that monthly and annual time series of WSDI agreed well with the SPI index with correlations of 0.69 and 0.73, respectively. The results of drought analysis also indicated that WSDI could be used as a proxy to standard meteorological drought indices over Turkey as it performed well to detect and characterize the recent droughts of Turkey based on its comparisons to SPI results.Article Citation - WoS: 19Citation - Scopus: 21Determination of Caco 3 and Sio 2 Content in the Binders of Historic Lime Mortars(Springer Verlag, 2012-06) Uğurlu Sağın, Elif; Böke, Hasan; Aras, Nadir; Yalçın, Şerife; 02.01. Department of Conservation and Restoration of Cultural Heritage; 03.07. Department of Environmental Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureThe binders of historic mortars composed of small grain sized silica (SiO 2) and carbonated lime (CaCO 3) are considered as the main part that give hydraulic character and high strength to the mortar. In this study, FTIR, SEM-EDS, LIBS and XRD spectroscopy were used to find out the weight ratios of CaCO 3 to SiO 2 in the binders of historic lime mortars. For this purpose, a series of pure calcium carbonate and silica mixture were prepared in ten combinations in varying ratios from 0.5 to 5. Calibration curve was prepared for each analysis by plotting the peak area or intensity ratios of CaCO 3 to SiO 2 versus the weight ratios of CaCO 3 to SiO 2. A good linear correlation coefficient was obtained for each analysis respectively. The analyses were then tested on the binder of the Roman mortar samples. The results indicated that FTIR, SEM-EDS and LIBS spectroscopy are convenient tools to determine the weight ratios of CaCO 3 to SiO 2 in the binders of mortars. But XRD spectroscopy is not convenient for quantitative analysis of binders due to the presence of varied amounts of amorphous or poor crystalline silica in their compositions.Article Citation - WoS: 3Citation - Scopus: 6Effect of High Salinity and Temperature on Water-Volcanic Rock Interaction(Springer, 2021) Gören, Ayşegül Yağmur; Topçu, Gökhan; Demir, Mustafa M.; Baba, Alper; 03.07. Department of Environmental Engineering; 03.03. Department of Civil Engineering; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn order to understand the processes occurring in natural hydrothermal systems, it was carried out a series of water-volcanic rock interaction studies in the laboratory and an intermediate volcanic rock samples from geothermal production wells in Tuzla geothermal field (TGF) in western Turkey. A high-pressure autoclave was used to conduct water-rock interaction experiments under similar conditions of the field. Rainwater and seawater were treated with volcanic rocks at 140 degrees C (reservoir temperature) and 4.5 bar pressure. The change in the ionic content of the resulting fluids was examined in terms of the type of volcanic rocks and mineral saturation index. The results indicate that talc and diopside minerals in geothermal systems may cause scaling at high temperatures depending on the geothermal fluid and pH.Article Citation - WoS: 26Citation - Scopus: 32Electrochemical Degradation of Methylene Blue by a Flexible Graphite Electrode: Techno-Economic Evaluation(American Chemical Society, 2022-09) Gören, Ayşegül Yağmur; Recepoğlu, Yaşar Kemal; Edebali, Özge; Şahin, Çağrı; Genişoğlu, Mesut; Ökten, Hatice Eser; 03.07. Department of Environmental Engineering; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn this study, electrochemical removal of methylene blue (MB) from water using commercially available and low-cost flexible graphite was investigated. The operating conditions such as initial dye concentration, initial solution pH, electrolyte dose, electrical potential, and operating time were investigated. The Box-Behnken experimental design (BBD) was used to optimize the system's performance with the minimum number of tests possible, as well as to examine the independent variables' impact on the removal efficiency, energy consumption, operating cost, and effluent MB concentration. The electrical potential and electrolyte dosage both improved the MB removal efficiency, since increased electrical potential facilitated production of oxidizing agents and increase in electrolyte dosage translated into an increase in electrical current transfer. As expected, MB removal efficiency increased with longer operational periods. The combined effects of operating time-electrical potential and electrical potential-electrolyte concentration improved the MB removal efficiency. The maximum removal efficiency (99.9%) and lowest operating cost (0.012 $/m3) were obtained for initial pH 4, initial MB concentration 26.5 mg/L, electrolyte concentration 0.6 g/L, electrical potential 3 V, and operating time 30 min. The reaction kinetics was maximum for pH 5, and as the pH increased the reaction rates decreased. Consequent techno-economic assessment showed that electrochemical removal of MB using low-cost and versatile flexible graphite had a competitive advantage.Article Citation - WoS: 2Citation - Scopus: 4Enhancing Biogas Production From Chicken Manure Through Vacuum Stripping of Digestate(Springer Heidelberg, 2023) Sengur, Ozlem; Akgul, Deniz; Bayrakdar, Alper; Calli, Baris; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe vacuum stripping's combined ammonia removal and disintegration effect on chicken manure digestate was evaluated for the first time at different pH values (8.5, 9.5, and 10.5) and temperatures (30, 50, and 70 degrees C). In this way, the potential increase in biogas production by recirculating the vacuum-stripped digestate to the anaerobic digester was determined. Experimental results showed that increasing pH and temperature significantly increase TAN removal, but pH is more effective. A significant portion of the ammonia was removed in the first 30 min. Therefore, a second set of stripping tests was performed for 30 min and at 70 degrees C and pH 10.5. After 30-min tests, a biomethane potential (BMP) assay was performed using the vacuum-stripped digestate to determine how vacuum stripping affects biomethane production. Despite having the lowest disintegration efficiency, the highest biomethane potential (56.2 +/- 29.7 mL CH4/gVS) was obtained with the digestate, which was subjected to vacuum stripping at 70 celcius without pH adjustment, and 48.7% more methane was produced than the control set. The lower residual biomethane potential in vacuum-stripped digestate at pH 9.5 and 10.5 was attributed to Na+ inhibition resulting from high NaOH consumption for pH adjustment.Article Citation - WoS: 1Citation - Scopus: 1Exposure To Fumes of a Vegetable Margarine for Frying: Respiratory Effects in an Experimental Model(American Chemical Society, 2023) Cimrin, Arif H.; Alpaydin, Aylin Ozgen; Ozbal, Seda; Toprak, Melis; Yılmaz, Osman; Uluorman, Funda; Ergur, Bekir Uğur; Gürel, Duygu; Sofuoğlu, Sait Cemil; 01. Izmir Institute of Technology; 03.07. Department of Environmental Engineering; 03. Faculty of EngineeringDeep frying is one of the strongest emission sources into indoor air. A vegetable margarine has recently been used in commercial kitchens. This study investigated the respiratory effects of exposure to its fumes in an experimental model. A setup with glass chambers was constructed. A chamber housed a fryer. The fumes were transported to the other chamber where 24 Wistar albino rats were placed in four randomized groups: acute, subacute, chronic, and control for the exposure durations. PM10 concentration in the exposure chamber was monitored to ensure occupational levels were obtained. Sacrification was performed 24 h after exposure. Lung, trachea, and nasal concha specimens were evaluated by two blinded histologists under a light microscope with hematoxylin–eosin. Mild mononuclear cell infiltration, alveolar capillary membrane thickening, alveolar edema, and diffuse alveolar damage, along with diffuse hemorrhage, edema, and vascular congestion in the interstitium were observed in the acute and subacute groups, and were overexpressed in the chronic group, whereas normal lung histology was observed in the control group. The results indicate that exposure to fumes of vegetable margarine for frying in commercial kitchens may cause pulmonary inflammation that becomes severe as the duration of the exposure increases.Article Citation - WoS: 9Citation - Scopus: 13An Exposure–risk Assessment for Potentially Toxic Elements in Rice and Bulgur(Springer Verlag, 2017-04-10) 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 TechnologyRice and wheat are rich sources of essential elements. However, they may also accumulate potentially toxic elements (PTE). Bulgur, the popular alternative to rice in the eastern Mediterranean, is produced by processing wheat, during which PTE content may change. This study determined PTE concentrations in rice and bulgur collected from 50 participant households in the City of Izmir, Turkey, estimated ingestion exposure, and associated chronic-toxic and carcinogenic human health risks. Comparison of the determined concentrations to the available standard levels and the levels reported in the literature revealed that Cd, Co, and Pb in rice might be of concern. The estimated health risks of individual participants supported this result with exceedance of respective threshold or acceptable risk levels at the 95th percentile. Population risk estimates indicated that the proportion with higher than the threshold or acceptable risk is about 10%, 24%, and 12% for Cd, Co, and Pb in rice, respectively. Results of this study showed that health risks associated with PTE exposure through bulgur consumption are lower than those of rice, and below the threshold or acceptable risk levels.Article Citation - WoS: 1Citation - Scopus: 1Groundwater Recharge Estiaton in the Alaşehir Sub-Basin Using Hydro-Geochemical Data; Alaşehir Case Study(Springer, 2021) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin; Demirkesen, Ali Can; 03.06. Department of Energy Systems Engineering; 02.03. Department of City and Regional Planning; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureThe issue of groundwater recharge has gained importance in countries where there is not enough water supply to the aquifer. However, groundwater recharge is a difficult parameter to determine. This difficulty stems from factors such as the location of the area to be studied, time, cost, and hydrological data. Numerical, isotope, and chemical approaches are used in groundwater recharge investigations. Numerical and chemical approaches are more costly and time-consuming than chemical approaches. This study aims to ascertain alluvial aquifer recharge in Alaehir (Manisa) sub-basin using chemical approaches (Chloride Mass Balance Method) and its applicability. For this purpose, research wells were drilled at 25 different points in the alluvial aquifer, water sampling was done in wet and dry periods, and rainwater water samples were collected. Groundwater recharge was calculated by using chemical approaches from the chloride concentrations of the water samples collected. An annual average of 74.84 mm of recharge was found in the Alaehir sub-basin. This value corresponds to 16.38% of annual rainfall. At the same time, it was examined the groundwater and geothermal mixing mechanism to demonstrate the applicability of the Chloride Mass Balance Method. It was concluded that geothermal fluid in Alaehir sub-basin mixed with groundwater at a rate of 17%.Article Citation - WoS: 2Citation - Scopus: 5Halogenated By-Products in Chlorinated Indoor Swimming Pools: a Long-Term Monitoring and Empirical Modeling Study(Amer Chemical Soc, 2023) Genişoğlu, Mesut; Minaz, Mert; Tanacan, Ertaç; Sofuoğlu, Sait Cemil; Kaplan-Bekaroğlu, Şehnaz Şule; Kanan, Amer; Ateş, Nuray; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyMonitoring the disinfection process and swimming pool water quality is essential for the prevention of microbial infections and associated diseases. However, carcinogenic and chronic-toxic disinfection by-products (DBPs) are formed with reactions between disinfectants and organic/inorganic matters. DBP precursors in swimming pools originate from anthropogenic sources (body secretions, personal care products, pharmaceuticals, etc.) or chemicals used in pools. Temporal (48 weeks) water quality trends of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and halonitromethanes (HNMs) in two swimming pools (SP-A and SP-B) and precursor-DBP relationships were investigated in this study. Weekly samples were taken from swimming pools, and several physical/chemical water quality parameters, absorbable organic halides (AOX), and DBPs were determined. THMs and HAAs were the most detected DBP groups in pool water. While chloroform was determined to be the dominant THM compound, dichloroacetic acid and trichloroacetic acid were the dominant HAA compounds. The average AOX concentrations were measured to be 304 and 746 mu g/L as Cl- in SP-A and SP-B, respectively. Although the amount of AOX from unknown chlorinated by-products in SP-A did not vary temporally, a significant increase in unknown DBP concentrations in SP-B was observed over time. AOX concentrations of chlorinated pool waters were determined to be an important parameter that can be used to estimate DBP concentrations.Article Citation - WoS: 9Citation - Scopus: 11Identifying Geogenic and Anthropogenic Aluminum Pollution on Different Spatial Distributions and Removal of Natural Waters and Soil in Çanakkale, Turkey(Amer Chemical Soc, 2023) Hızlı, Sezin; Koraoğlu, Aybike Gül; Gören, Ayşegül Yağmur; Kobya, Mehmet; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe Canakkale-Kirazli region (Turkey) is enriched with minerals, especially aluminum (Al), which dangerously get transported into aquatic media due to several mining and geological activities in recent years. In this study, Al and other potentially toxic metals (PTMs) including B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Si, and Zn, in both water and soil samples, were measured for quality determination. Selected metals were also analyzed by the enrichment factor (EF), the geoaccumulation index (I-geo), the contamination factor (CF), and the pollution load index (PLI) to evaluate both water and soil pollution geogenically or anthropogenically. Also, the metals were clustered to support the pollution source with Pearson's correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). Forty-five natural water samples and 12 soil samples were collected spatially. To perform pollution assessment, two fundamental treatment processes to remove Al pollution from the sample including the highest Al concentration (38.38 mg/L) in water were applied: (1) precipitation with pH adjustment and (2) removal with ion exchange. The pH values of water samples were changed in the range of 3-9 to test the dissolution of Al. The results demonstrated that the study area was mostly under the influence of geogenic aluminum pollution.Article Citation - WoS: 29Citation - Scopus: 31Model-Coupled Grace-Based Analysis of Hydrological Dynamics of Drying Lake Urmia and Its Basin(Wiley, 2023-05) Khorrami, Behnam; Ali, Shoaib; Şahin, Onur Güngör; Gündüz, Orhan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyLake Urmia basin (LUB), in northwestern Iran, is under the influence of extreme degradation due to a number of natural and anthropogenic factors. The existence of the Lake is critical for the microclimate of the region as well as the quality of human life and wildlife, which necessitates an up-to-date and holistic analysis of its hydrological dynamics. In this premise, satellite-based terrestrial water storage (TWS) received from the Gravity Recovery and Climate Experiment (GRACE) mission was coupled with hydrometeorological modelling and assessment tools to analyse the hydrological status of the lake and its basin. As a new gap-filling approach, the Seasonal-Trend decomposition using Locally estimated scatterplot smoothing (LOESS) (STL) decomposition technique was proposed in this study to reconstruct the missing TWS data. Integrating satellite precipitation data with the Catchment Land Surface Model (CLSM) and WaterGAP model outputs, the hydrological status of the lake was investigated. The STL-based TWS turned out to concord well with the simulated TWS from the CLSM indicating the acceptable performance of the proposed technique. The findings revealed that the LUB had undergone an alarming hydrological situation from 2003 to 2021 with a total loss of 10 and 7.56km3 from its TWS and groundwater storage (GWS), respectively. The water level time series also indicated that the water level of the lake had diminished with an annual rate of -70 +/- 21cm/year corresponding to a total water level depletion of about 13.35 +/- 3.9m during the 2003-2021 period. The GRACE-derived TWS and GWS also agreed well with the CLSM simulations. Assessment of the extreme events of the LUB suggested that the basin suffered from a severe dry event in 2008 resulting in the depletion of its water storage and water level. It was also found that from 2003 onward, a critical hydrological setting had dominated the LUB with a negative hydrological balance of -0.96km3.Article Citation - WoS: 8Citation - Scopus: 10Novel Hybrid Adsorption-Electrodialysis (aded) System for Removal of Boron From Geothermal Brine(American Chemical Society, 2022-12) Altınbaş, Bekir Fırat; Orak, Ceren; Ökten, Hatice Eser; Yüksel, Aslı; 03.07. Department of Environmental Engineering; 01. Izmir Institute of Technology; 03.02. Department of Chemical Engineering; 03. Faculty of EngineeringA novel hybrid adsorption-electrodialysis (AdED) system to remove environmentally harmful boron from geothermal brine was designed and effective operating parameters such as pH, voltage, and flow rate were studied. A cellulose-based adsorbent was synthesized from glycidyl methacrylate (GMA) grafted cellulose and modified with a boron selective n-methyl-d-glucamine (NMDG) group and characterized with SEM-EDX, FT-IR, and TGA analyses. Batch adsorption studies revealed that cellulose-based adsorbent showed a remarkable boron removal capacity (19.29 mg/g), a wide stable operating pH range (2-10), and an adsorption process that followed the Freundlich isotherm (R2= 0.95) and pseudo-second-order kinetics (R2= 0.99). In the hybrid AdED system, the optimum operating parameters for boron removal were found to be a pH of 10, a voltage of 10 V, a flow rate of 100 mL/min, and an adsorbent dosage of 4 g/L. The presence of the adsorbent in the hybrid system increased boron removal from real geothermal brine (containing 199 ppm boron) from 7.2% to 73.3%. The results indicate that the designed AdED system performs better than bare electrodialysis for boron removal from ion-rich real geothermal brine while utilizing environmentally friendly cellulose-based adsorbent.Article Citation - WoS: 4Citation - Scopus: 4Radiological Modeling of the Impacts of the Chernobyl Nuclear Power Plant Accident on Turkey and Southwest Asia(Elsevier, 2022-02) Bilgiç, Efem; Gündüz, Orhan; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyMany studies investigated the impacts of the Chernobyl Nuclear Power Plant accident on Europe. However, majority of these have spatially excluded the highly populated southeast region of Chernobyl, including countries such as Turkey, Armenia, Georgia and Iran. In this study, a comprehensive environmental and radiological analysis were conducted particularly for this region. For this purpose, atmospheric dispersion and ground deposition of radionuclides were estimated using a Lagrangian particle dispersion model, FLEXPART. Totally, six simulations were conducted and model results were validated with measurements from Europe and Turkey. Furthermore, total effective dose equivalent (TEDE) values were estimated for adults and infants using the most current dose conversion factors of ICRP. Highest deposition of 137Cs were found in around Eastern Black Sea areas (10–40 kBq/m2). Similar values were found in some locations of Armenia and Azerbaijan under some scenarios, but country averages of 137Cs deposition were lower than 10 kBq/m2 for both countries. No significant depositions were found in southwest Iran, but relatively higher depositions (2–10 kBq/m2) of 137Cs were estimated along the Turkish border. Although there were slightly higher values in northern areas of Syria, Iraq, Lebanon and Cyprus, 137Cs depositions were mostly less than 2 kBq/m2. The 1-year TEDE value was calculated less than 1 mSv throughout the model domain except for some regions of eastern Black Sea. Highest values in lifetime dose values were calculated along the Black Sea coasts of Turkey and Georgia. Overall, infants were affected more from ionizing radiation compared to adults in this region.Article Citation - WoS: 7Citation - Scopus: 8Removal of Arsenic in Groundwater From Western Anatolia, Turkey Using an Electrocoagulation Reactor With Different Types of Iron Anodes(Elsevier, 2022-09) Kobya, Mehmet; Dolaz, Mustafa; Özaydın Şenol, Burcu; Gören, Ayşegül Yağmur; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyElectrocoagulation (EC) is a significantly efficient method for As removal from waters and received considerable attention recently. In this study, the natural groundwater (GW) samples containing As concentrations of GW-1: 538.8 μg L−1, GW-2: 1132.1 μg L−1, and GW-3: 52, 000 μg L−1 were obtained from different provinces and treated by EC process using different iron anodes (plate, ball, and scrap). To achieve drinking water As standard (10 μg L−1), the operational time, applied current, and As removal optimization for all anode types were studied. At applied current of 0.025 A, the As removal efficiency, EC time, and operating cost were >99.9%, 180 min and 0.406 $ m−3 for ball anodes, >99.9%, 100 min and 0.0813 $ m−3 for plate anodes, >99.9%, 80 min and 0.0815 $ m−3 for scrap anodes for GW-3, respectively. It was observed that as the As concentration in the GW increased, the EC time and operating cost increased. Overall, it was concluded that Fe scrap anodes are more advantageous than other types of anodes in terms of operating cost in EC reactor for As removal.Review Citation - WoS: 33Citation - Scopus: 38Review on the Parameters of Recycling Ndfeb Magnets Via a Hydrogenation Process(American Chemical Society, 2023) Habibzadeh, Alireza; Küçüker, Mehmet Ali; Gökelma, Mertol; 03.09. Department of Materials Science and Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyRegarding the restrictions recently imposed by China on the export of rare-earth elements (REEs), the world may face a serious challenge in supplying some REEs such as neodymium and dysprosium soon. Recycling secondary sources is strongly recommended to mitigate the supply risk of REEs. Hydrogen processing of magnetic scrap (HPMS) as one of the best approaches for magnet-to-magnet recycling is thoroughly reviewed in this study in terms of parameters and properties. The processes of hydrogen decrepitation (HD) and hydrogenation-disproportio-nation-desorption-recombination (HDDR) are two common methods for HPMS. Employing a hydrogenation process can shorten the production route of new magnets from the discarded magnets compared to other recycling routes such as the hydrometallurgical route. However, determining the optimal pressure and temperature for the process is challenging due to the sensitivity to the initial chemical composition and the interaction of temperature and pressure. Pressure, temperature, initial chemical composition, gas flow rate, particle size distribution, grain size, and oxygen content are the effective parameters for the final magnetic properties. All these influencing parameters are discussed in detail in this review. The recovery rate of magnetic properties has been the concern of most research in this field and can be achieved up to 90% by employing a low hydrogenation temperature and pressure and using additives such as REE hydrides after hydrogenation and before sintering.Article Citation - WoS: 3Citation - Scopus: 4Stabilization of Calcareous Subgrade Soils With Polyelectrolytes: Mechanisms and Mechanical Properties(Taylor & Francis, 2023) Huang, Jianxin; Mohomad, Yosef; Kogbara, Reginald B.; Masad, Eyad; Sukhishvili, Svetlana; Little, Dallas; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyOrganic polyelectrolytes, i.e. anionic poly(sodium 4-styrenesulphonate) (PSS), cationic poly(diallyldimethylammonium chloride) (PDADMAC) and their polyelectrolyte complexes (PECs) were evaluated for stabilisation of calcareous sandy subgrade soil. This paper investigated the effects of polymer type, surface charge type of PEC, concentrations of PEC solutions and dosages of polymer solutions added to the soil on improvement of soil mechanical properties. We found that anionic polymers, for both PECs and individual polyelectrolytes, were superior to their cationic counterparts in improving soil strength. Besides, the constituent polyelectrolytes, PSS and PDADMAC, worked better than their PECs for the specific soil investigated. The strength of polymer-treated soils was also found to increase with the increase in dosages of the polymer solutions as well as curing periods. Furthermore, polymer-treated soil specimens exhibited significant toughness improvement, which was higher than cement-treated samples. Scanning electron microscopy images revealed the abundance of long palygorskite fibres covering the surfaces of larger calcite and dolomite particles and linking surrounding aggregates after adding polymers. This observation suggests the interconnection of palygorskite fibres and their linking networks between and among coarse aggregates as the likely mechanism of polymer stabilisation of the soil studied.
