Yazarlar
- Duran, Celal(38)
- Ozdes, Duygu(33)
- Kankal, Murat(13)
- Şan, Murat(12)
- Gundogdu, Ali(11)
- Nacar, Sinan(10)
- Ozeken, Sengul Tugba(7)
- Soylak, Mustafa(7)
- Alemdag, Selcuk(6)
- Bulut, Volkan Numan(6)
- Kıranşan, Murat(6)
- Serencam, Huseyin(6)
- Akar, Bülent(5)
- Baltaci, Cemalettin(5)
- Gücer, Mehmet Ali(5)
- Tufekci, Mehmet(5)
- Akaryali, Enver(4)
- Bozbeyoglu, Pinar(4)
- Camoglu, Aslihan Yilmaz(4)
- Elvan, Hamide(4)
- Imamoglu, Mustafa(4)
- Seker, Serdal(4)
- Akpinar, A.(3)
- Akçay, Fatma(3)
- Alemdağ, Selçuk(3)
- Başoğlu, Aysel(3)
- Günen, Mehmet Akif(3)
- Kaygusuz, K.(3)
- Okkan, Umut(3)
- Senturk, Hasan Basri(3)
- Turfan, Fatma Asya(3)
- Vural, Alaaddin(3)
- Yagmur, Nur(3)
- Yıldız, Mehmet Berkant(3)
- Şibil, Rahim(3)
- Aras, Egemen(2)
- Ayas, Mustafa Sinasi(2)
- Ayas, Selen(2)
- Bahadir, Zekeriyya(2)
- Barinova, Sophia(2)
Yayınlar
- MakaleAçık Erişim2025Türkiye’de Yeşil Liman Olabilecek Limanların ANP-BOCR Yöntemi ile Değerlendirilmesi
Kisa, Ayse Cansu Gok; Peker, İskender; Gergin, Ramazan Eyüp; Keske, Büşra
Yeşil limanlar, kentsel ekonominin gelişmesine ve sürdürülebilir çevresel stratejilerin uygulanmasına imkân sağlayan önemli unsurlardandır. Bu araştırmada, Türkiye’de faaliyet gerçekleştiren limanların yeşil liman sertifikasına sahip olma potansiyellerinin değerlendirilmesi amaçlanmıştır. Bu amaç doğrultusunda sektör raporlarında yer alan veriler çerçevesinde bölgesel anlamda konteyner elleçleme miktarı (TEU) en fazla olup yeşil liman sertifikasyonu olmayan limanlar çalışmanın alternatiflerini oluşturmuştur. Çalışmanın kriterleri ise kapsamlı bir literatür araştırması ve uzmanların görüş önerileri çerçevesinde belirlenmiştir. Problemin çözümünde ise bir Çok Kriterli Karar Verme (ÇKKV) tekniği olan Analitik Ağ Süreci (ANP)- Fayda, Fırsat, Maliyet, Risk (BOCR) yaklaşımından faydalanılmıştır. Buna göre yeşil liman sertifikasyonu sahipliğinde en fazla etkiye sahip olan kriter hava kirliliğini azaltmak (0,049) olmuş iken, en az etkiye sahip kriterler ise soğuk ütüleme ve gemi hızı düşürme teknolojisi kullanılması (0,015) ile liman ücretlerinde ceza fiyatlandırması yapılmaması (0,015) olarak tespit edilmiştir. Mersin International Port (0,055) ise yeşil liman sertifikasına sahip olma potansiyeli en yüksek alternatif olarak belirlenmiştir.
- MakaleAçık Erişim2025Removal of anionic and cationic dyes from aqueous solutions using drinking water treatment plant sludge (DWTS): Equilibrium and kinetic evaluation
Duran, Celal; Ozdes, Duygu; Turfan, Fatma Asya; Kılıç, Neslihan; Yaltirik, Fatma
The present research investigates the removal of Brilliant Green (BG) and Remazol Brilliant Blue R (RBBR) dyes by an adsorption system utilizing drinking water treatment sludge (DWTS) as an adsorbent. It aims to contribute to sustainable treatment methods by evaluating waste sludge as a low-cost and environmentally friendly adsorbent. In the study, the significant parameters affecting the adsorption process were systematically investigated. During the experiments, the effects of factors such as initial pH of the solution, equilibrium time, adsorbent amount and initial dye concentration on the adsorption efficiency were evaluated. The obtained data were tested with Langmuir and Freundlich isotherm models and it was determined that adsorption occurred on both homogeneous and heterogeneous surfaces. The maximum adsorption capacity of DWTS was calculated as 100.0 mg g-1 and 38.9 mg g-1 for BG and RBBR, respectively. Kinetic analyses were performed to understand the dynamics of the adsorption process. Pseudo-first order and Pseudo-second order kinetic models were evaluated and it was noticed that the pseudo-second order model explained the adsorption data better. As a result, DWTS has been proven to be an effective adsorbent in the removal of BG and RBBR. The findings indicated that DWTS has significant potential for evaluation in advanced treatment processes in terms of environmental sustainability.
- MakaleAçık Erişim2025Green synthesis of fluorescent carbon quantum dots from field horsetail Equisetum Arvense L and fluorimetric detection of Pd2+ ions
Başoğlu, Aysel
The study presents a comprehensive phytochemical analysis of A. caucasicus, examining both the leaf and flower parts of this plant. The Fluorescent carbon quantum dots (CQDs) were synthesized via a hydrothermal method using field horsetail (Equisetum arvense L.) as a green carbon source at 180 °C. The resulting CQDs were characterized by various techniques, including UV–Vis absorption spectroscopy, fluorescence spectroscopy, fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). Under UV illumination at 365 nm, the CQDs displayed intense blue fluorescence. The effects of 32 different metal ions, including Li⁺, Na⁺, K⁺, Ag⁺, NH₄⁺, Tl⁺, Ba²⁺, Be²⁺, Ca²⁺, Cd²⁺, Co²⁺, Cu²⁺, Pb²⁺, Mg²⁺, Mn²⁺, Ni²⁺, Zn²⁺, Sr²⁺, Cr³⁺, Au³⁺, Y³⁺, Al³⁺, V³⁺, Bi³⁺, B³⁺, Sc³⁺, Sb³⁺, Ti⁴⁺, Se⁴⁺, Mo⁶⁺, W⁶⁺, and Pd²⁺, on the fluorescence properties of the CQDs were systematically investigated using fluorescence spectrophotometry. Among them, Pd²⁺ ions caused significant fluorescence quenching. Based on this response, a sensitive and straightforward fluorometric sensing strategy was developed for detecting Pd²⁺ in tap water. The method showed a good linearity over the concentration range of 0.5 to 15.0 μM, with a detection limit of 50.2 nM and a quantification limit of 150.6 nM. The applicability of the method was further validated through spiking experiments, yielding satisfactory recoveries at various concentrations. The approach also demonstrated excellent reproducibility, with a relative standard deviation (RSD) consistently below 2.3%.
- MakaleAçık Erişim2025Uydu Görüntüleri Yardımıyla Burdur Gölü'nün Su Seviyesi Değişiminin Farklı Su İndeksleriyle Analizi ve Gelecek Yıllardaki Değişiminin Tahmini
Demir, Vahdettin; Tona, Aziz Ugur; Öztaş, Ayşe; Eren, Mehmet
Çalışmanın amacı, Burdur Gölü'nün su yüzey alanı üzerindeki mekânsal değişimleri analiz etmek ve Burdur Gölü Havzası'ndaki uzun yıllık iklim kayıtlarındaki eğilimleri inceleyerek göl yüzey alanının gelecekteki durumu hakkında tahminler yapmaktır. Bu doğrultuda, çalışma alanı için Landsat 4-5 ve Landsat 8 uydu görüntüleri kullanılarak analizler gerçekleştirilmiştir. Bu görüntülerin sınıflandırılması, Modifiye Normalleştirilmiş Fark Su İndeksi (mNDWI), Normalleştirilmiş Fark Su İndeksi (NDWI) ve Su İndeksi 2015 (WI2015) su indisleri kullanılarak yapılmıştır ve 1985-2021 yılları arasında her yıl için göl yüzey alanı verileri toplanmıştır. Çalışmanın sonuçlarına göre, Burdur Gölü'nün su alanı 1985 yılı ile 2021 yılı arasında büyük oranda (81.7-92.3 km²) azalmıştır. Yapılan doğrusal regresyon analizlerine dayanarak, gölün 2070-2080 arasında kuruyacağı tahmin edilmektedir. WI2015 yöntemi, OMH (7.0554) ve GOMH (4.1711) gibi düşük hata değerleri ile 0.9923'lük yüksek korelasyon katsayısı ile en başarılı yöntem olarak değerlendirilebilir.
- MakaleYalnız künye2025Evaluation of effectiveness of municipalities in black sea region with data envelopment analysis
Bolayır, Banu; Yegin, Şahin Murat
This study aims to measure to what extent 18 municipalities in the Black Sea Region are effective compared to each other. The Data Envelopment Analysis (DEA) method was employed to measure the effectiveness of municipalities in comparison to each other. To calculate effectiveness values, the input-oriented CCR and BCC models from DEA models, as well as the input-oriented dual CCR models for ineffective municipalities were established based on the CCR model results. In the present study, input variables were determined as goods and services procurement expenses, personnel expenses, and capital expenses, while output variables were determined as enterprise and property revenues, tax revenues, and other revenues. The LINDO 6.1 software program was used in the solution of the models. According to the solutions of CCR and BCC models, the municipalities of Bartın, Bayburt, Bolu, Çorum, Düzce, Karabük, Kastamonu, Ordu, Rize, Samsun, Sinop, Tokat, and Trabzon are fully effective, while Amasya, Artvin, Giresun, Gümüshane, and Zonguldak are not. According to the solutions of dual CCR models, the municipalities of Bartın, Bolu, Çorum, Düzce, Karabük, Ordu, Samsun, Sinop, Tokat, and Trabzon are fully effective, while Amasya, Artvin, Bayburt, Giresun, Gümüşhane, Kastamonu, Rize, and Zonguldak are not. Moreover, the dual CCR model results suggested new input values for the ineffective municipalities to achieve effectiveness.
- MakaleYayıncıda açık erişim2025The Effect of Heavy Metals in Mining Emissions on Worker’s Blood Lead Levels: A Case Study of The Gumushane Zn-Pb Mine, Turkey
Bozbeyoğlu, Pınar; Doğan, Onur; Budak, Burhan
The wastewater from mining facilities contains toxic elements such as arsenic (As), cadmium (Cd), chromium (Cr), manganese (Mn), zinc (Zn), and lead (Pb). If not disposed of correctly, it can lead to environmental pollution in case of accidents or overflow. Lead-zinc mining activities pose a significant risk of high blood lead levels (BLLs) among workers. Therefore, monitoring the blood lead levels of workers exposed to these heavy metals, especially lead, is crucial. This study aims to determine the levels of potentially harmful elements in the wastewater dam of the largest Zn-Pb mine in the Black Sea Region. It also seeks to assess the environmental and human health risks comprehensively. Additionally, the study aims to establish a relationship between the levels of lead in the mining wastewater in Gumushane and the lead levels accumulated in the blood of workers exposed to this metal. The study analyzed heavy metals such as As, Zn, Cu, Sb, and Pb in mining wastewater using Inductively Coupled Plasma – Mass Spectrometer (ICP-MS). The results indicated high levels of Pb in the studied wastewater. Furthermore, the blood lead levels of workers in the mining area (n=30; mean: 7.42 μg/dL) exceeded background levels (>40 μg/dL). These results suggest a significant relationship between the presence of lead in wastewater and high lead levels in the blood of individuals with high exposure to concentrated lead.
- MakaleAçık Erişim2025One-Step Green Hydrothermal-Assisted Synthesis of Carbon Quantum Dots From Robinia hispida L. Flowers, and Flourimetric Detection of Au3+ Ions in Aqueous Media
Başoğlu, Aysel
Water-soluble fluorescent carbon quantum dots (CQDs) were synthesized via a single-step, eco-friendly hydrothermal process using Robinia hispida L. flowers as a novel carbon source. Advanced characterization techniques (HRTEM, XRD, XPS, FTIR, UV–vis, and fluorescence spectroscopy) revealed spherical CQDs with an average size of 3.96 ± 0.83 nm and a quantum yield of 5.13%. Under 365 nm UV light, the CQDs emitted blue fluorescence. Fluorescence quenching studies with various metal ions showed a significant 93.5% reduction in FL intensity with 500 μM Au3+ ions. At pH 7.0, a linear detection range of 0.5–3.5 μM was achieved, with limits of detection (LOD) and quantification (LOQ) of 0.4 and 1.2 μM, respectively. The non-functionalized CQDs effectively detected Au3+ ions in tap, drinking, and river water, acidic mine drainage (sludge), and a standard reference material (CRMSA-C Sandy Soil C), achieving spike recoveries of 96.06%–101.71% with variability below 4.13%.
- MakaleYayıncıda açık erişim2025Efficient extraction and determination of Au(iii) ions from acid mine drainage and water samples using silica gel immobilized with Brevibacillus borstelensis
Camoglu, Aslihan Yilmaz; Duran, Celal; Ozdes, Duygu; Nalcaoglu, Aleyna; Bektas, Kadriye Inan; Belduz, Ali Osman
The analysis of gold, which is a precious metal with limited resources, in environmental samples is crucial for the sustainable utilization of natural resources. Therefore, in the present research we have aimed to develop a novel and environmentally friendly bioadsorbent, Brevibacillus borstelensis loaded on silica gel (BB@Si), with outstanding adsorptive properties that can be implemented for quantitative recovery of Au(iii) ions via the solid phase extraction (SPE) technique. After characterizing the developed adsorbent using FTIR and SEM techniques, we conducted a detailed investigation of the critical parameters that influence the extraction performance of Au(iii) ions. Optimum parameters were observed as follows: pH 3.0, adsorption contact time 30 min, eluent type 0.1% (w/v) thiourea in 0.5 M HNO3, elution time 60 min, BB@Si amount 1.0 g L−1, and sample volume 400 mL. Some of the well-known isotherm and kinetic models were applied to the results observed from the adsorption studies. Equilibrium adsorption capacity of BB@Si was estimated to be 66.2 mg g−1 utilizing the Langmuir isotherm model while the limit of detection (LOD) and relative standard deviation (RSD%) were established as 0.99 μg L−1 and 3.7%, respectively. The developed method was utilized smoothly for the quantification of Au(iii) ions in mining wastewater, acid mine drainage (AMD), streams and seawater.
- MakaleYalnız künye2025Spatial and temporal patterns of drought under different scenarios for Türkiye in the 21st century
Yıldız, Mehmet Berkant; Nacar, Sinan; Şan, Murat; Kankal, Murat
This study investigates the impact of climate change on drought conditions in Türkiye for two distinct future periods: the near future (2021–2050) and the far future (2071–2100), under two emission scenarios (RCP4.5 and RCP8.5). High-resolution regional climate projections from 19 GCM-RCM combinations within the EURO-CORDEX framework were evaluated. Based on performance analysis against ERA5-Land data, the four best-performing models were selected for multi-model ensemble averaging (MMEA). Drought conditions were assessed using the Standardized Precipitation Index (SPI) at 3-, 6-, and 12-month time scales. Three trend analysis methods, Innovative Trend Analysis (ITA), Modified Mann-Kendall (MMK), and Sen's Slope, were applied to examine spatiotemporal drought patterns. SPI-based analyses show a significant increase in short- and medium-term variability (SPI-3 and SPI-6) and long-term droughts (SPI-12), especially in the Central Anatolia, Southeastern and Eastern regions. The applied trend detection methods consistently point to a widespread drying tendency, with more pronounced changes projected in the latter half of the century. Under the RCP4.5 scenario, although the drought signals are less severe, the persistence of negative trends highlights that Türkiye will still be at risk, even with moderate efforts to mitigate climate change. These findings underscore the urgent need for integrating climate-driven drought projections into national and regional planning efforts.
- MakaleAçık Erişim2025Combined innovative trend analysis methods for seasonal trend testing
Şan, Murat
While holistic trend identification is essential, it does not consider the periodic, e.g., monthly, trend characteristics needed to identify seasonal trend behavior. Furthermore, identifying seasonal trends can help manage or regulate water resources systems and irrigation and agricultural operations. In this study, the innovative trend significance test (ITST), the revised ITST, and the Wilcoxon signed-rank test, which are non-parametric methods, are proposed as alternative seasonal trend tests by combining them with the innovative polygon trend analysis (IPTA), which provides visual and linguistic examinations of seasonal behaviors. Groundwater level data from the Chilgrove House (United Kingdom), flow data from the Danube River Basin (Romania), precipitation and temperature data from Türkiye were used to compare the proposed methods with the seasonal Mann-Kendall (SMK) method. For temperature and groundwater level data, all methods showed an increasing trend at different confidence intervals, but for other data, trends emerged according to the characteristics of the methods. So, some of the proposed methods are more rigid than the SMK in trend detection, while others are more sensitive. In addition to the advantage of its applications to seasonal trend behaviors, the proposed significance tests are combined with the IPTA method and comparable alternative methods to the SMK. So, seasons with a clear increase or decrease can be seen visually in the proposed combined methods contrary to the SMK method. Thus, both seasonal trend behaviors and inter-seasonal transitions can be examined graphically, and seasonal significance testing can be applied. According to the characteristics of these combined methods, they can be used not only for seasonal trend tests, just like the SMK method, but also for regional trend tests using stations data instead of seasons.
- MakaleYalnız künye2025Kinetics and Isotherm Evaluation for Adsorptive Removal of Anionic and Cationic Dyes from Aqueous Media by Sulfuric Acid-Modified Beech Sawdust
Ozdes, Duygu; Ozeken, Sengul Tugba; Top, Yener; Kalkisim, Ozgun; Duran, Celal
A novel and efficient adsorbent was prepared by modifying Fagus orientalis L. (beech) sawdust with H2SO4. The adsorption behavior of H2SO4-modified beech sawdust (SMBS) was investigated by batch experiments to offer a straightforward, inexpensive, and effective method for the retention of anionic and cationic model dyes, indigo carmine (IC) and methylene blue (MB), from wastewater. The experimental conditions were optimized by investigating the effects of the initial pH, initial concentrations of IC and MB dyes, dosage of SMBS, period of the contact, and the presence of salts in the aqueous media on the adsorptive performance of SMBS. The initial pH values of the aqueous solutions, from which IC and MB dyes will be removed, were optimized as 2.0 and 6.5 (natural), respectively. The optimum contact time for the adsorption of both dyes onto SMBS was determined to be 240 min. The mechanisms in the adsorption of IC and MB onto SMBS were investigated by evaluating the experimental data through different isotherm and kinetic models. The Langmuir isotherm model and pseudo-second order kinetic model performed well in explaining the mechanism of adsorption. Langmuir monolayer adsorption capacity of SMBS adsorbent was 38.85 mg g−1 for IC and 58.82 mg g−1 for MB. As a result, CMCP exhibited excellent performance in adsorbing organic pollutants, providing a low-cost and easily prepared alternative to other adsorbents found in the literature.
- MakaleYalnız künye2025Application of SnO2@CTAB-modified zeolitic clay nanocatalyst for the efficient sonocatalytic degradation of methylene blue in wastewater: Structural characterization, catalytic activity, and mechanistic insights
Önen, Hakan; Kıranşan, Murat
This study investigates the sonocatalytic degradation of dyes in wastewater using SnO2 nanoparticles and a hybrid SnO2@CTAB-modified zeolitic clay (SnO2@M-ZLT) nanocatalyst. The catalysts were synthesized in solution medium and characterized by XRF, XRD, FT-IR, SEM, TEM, and nitrogen adsorption-desorption analyses, confirming their successful formation and suitable surface properties. The effects of critical parameters including initial dye concentration, catalyst dosage, pH, water matrix, and radical scavengers on the removal of methylene blue (MB) were systematically evaluated. Under optimal conditions (10 g L−1 catalyst, 10 mg L−1 MB, Ultrasonic power: 300 W/L, pH for MB: Natural pH), the SnO2@M-ZLT nanocatalyst achieved 97.40 % ± 1.12 % degradation within 120 min, while 95.05 % ± 1.25 % efficiency was observed at 5 g L−1 catalyst and 5 mg L−1 MB. The sonocatalytic degradation of MB over SnO₂@M-ZLT followed pseudo-first-order kinetics, with kapp values ranging from 0.004 to 0.082 mg L−1 min−1 depending on catalyst dosage, 0.012–0.083 mg L−1 min−1 with varying MB concentration, and 0.030–0.055 mg L−1 min−1 across different water matrices. The optimal degradation efficiency was obtained at a catalyst dosage of 2–2.5 g L−1, an initial MB concentration of 5–10 mg L−1, and in distilled water, confirming the strong dependence of the reaction rate on both operational and environmental factors. Reusability tests showed that SnO2@M-ZLT retained high catalytic activity after five cycles. These results highlight the strong potential of SnO2@M-ZLT as an efficient and stable nanocatalyst for sustainable wastewater treatment.
- MakaleYalnız künye2025Analysis of drought in upper Moulouya Basin (Morocco): a combination of drought indices, classic and innovative trend tests
Qadem, Zohair; Hadria, Rachid; Ettaqy, Abderrahim; Kankal, Murat; Şan, Murat; Nacar, Sinan
This study aimed to examine the temporal and spatial variation of drought in the upper Moulouya Basin, Morocco’s arid and semi-arid region. For this purpose, the Standardized Precipitation Index (SPI) was calculated at various time scales (3, 6, 12, and 24 months) using precipitation data collected from eight stations between 1977 and 2019. The data trends were analysed by classical modified Mann-Kendall (MMK) and Innovative Trend Analysis (ITA). Severe drought events were identified in the 1980s, and 1998–2000, while exceptionally wet years were recorded in periods 1996–1997 and 2008–2012. SPI trend analyses revealed a holistic increase on almost all timescales and at all stations. The increase was found to be higher in more extended time scales. Except for a few stations, SPI values in dry, normal, and wet classes of ITA method increased in the second half (1998–2019) compared to the first half (1978–1997). The ITA method detected different trends for different classes at two stations compared to the MMK method. This situation revealed the importance of analysing the trends of different methods in drought studies. These results are essential for water resources management and adaptation to climate change in arid and semi-arid zones.
- MakaleAçık Erişim2025Insight into the adsorptive removal of Cr(VI) ions and 4-chlorophenol from aqueous media on cationic surfactant-modified cucumber peels
Ozeken, Sengul Tugba; Ozdes, Duygu; Duran, Celal
A new and cost-effective adsorbent material was developed by chemical modification of cucumber peels (CP) with a cationic surfactant, cetyltrimethylammonium bromide (CTAB). The adsorptive behavior of CTAB-modified cucumber peels (CMCP) was investigated in the retention of an organic pollutant (4-chlorophenol) and an inorganic pollutant (Cr(VI)) through batch experiments. The adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscopy (SEM) technique. Influences of initial concentrations of both pollutants, dosage of CMCP, initial solution pH, contact time, and foreign ions were parameters used to specify the optimized conditions. Results of the experiments were evaluated by three kinetic models, namely pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, to find out the dominant mechanisms in the retention of 4-chlorophenol and Cr(VI). Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were applied to the adsorption data to estimate the adsorption capacity of CMCP and to describe the interactions between the species. Langmuir isotherm model fitted the data well, and the maximum Cr(VI) and 4-chlorophenol adsorption capacities of CMCP were 84.03 mg g−1 and 107.5 mg g−1, respectively. Consequently, CMCP demonstrated outstanding performance in the adsorption of both inorganic and organic pollutants, offering a low-cost, easily prepared alternative to other adsorbents reported in the literature.
- MakaleAçık Erişim2025Hydrodynamic optimization of full-scale aeration tanks using field measurements and computational fluid dynamics modeling
Yılmaz Çelik, Damla; Yılmaz, Naz; Şibil, Rahim; Aras, Egemen; Vaheddoost, Babak
Improving energy efficiency and operational performance in wastewater treatment plants largely relies on precise hydrodynamic analysis. In this context, field-based studies are essential for understanding system behavior under real operational conditions. This study was conducted at a full-scale wastewater treatment plant, where flow dynamics in the aeration tank were evaluated through extensive field measurements and computational fluid dynamics modeling. Data were collected from 98 locations across 15 different depth levels using an Acoustic Doppler Current Profiler and a Hach FH950 velocity meter. The numerical model was initially validated with the help of experimental field data, enabling an accurate assessment of flow characteristics at varying depths. Results revealed that the low-velocity zones and non-uniform velocity distributions negatively affect system performance. It is also concluded that the inlet and outlet positions disturb the favorable circulation patterns and flow uniformity. Geometric optimization strategies were implemented to develop solutions, which led to a more uniform velocity distribution and improved hydraulic efficiency. By integrating detailed field measurements with numerical modeling, this study provides a comprehensive understanding of aeration tank hydrodynamics and offers practical design recommendations for improving overall system performance.
- MakaleAçık Erişim2025Sol–Gel Synthesized CuFe2O4-Modified Biochar Derived from Tea Waste for Efficient Ni(II) Removal: Adsorption, Regeneration, and ANN Modeling
Duran, Celal; Ozeken, Sengul Tugba; Seker, Serdal; Ozdes, Duygu
In the present research, a novel magnetic adsorbent was developed via the sol–gel method by coating CuFe2O4 nanoparticles on biochar sourced from brewed tea waste. The synthesized adsorbent was utilized for the removal of Ni(II) ions from aqueous media. The adsorption efficiency of Ni(II) ions was assessed under crucial experimental conditions such as initial solution pH, contact time, adsorbent dosage, and initial Ni(II) concentration. The adsorbent exhibited rapid adsorption kinetics, achieving equilibrium in approximately 15 min, and maintained high efficiency across a wide pH range. Adsorption experiments were conducted for Ni(II) solutions at their natural pH (5.6) to minimize chemical usage and enhance process simplicity. An impressive maximum adsorption capacity of 232.6 mg g−1 was recorded, outperforming many previously reported adsorbents. Furthermore, desorption studies demonstrated nearly 100% recovery of Ni(II) ions using 1.0 M HCl solution, indicating excellent regeneration potential of the adsorbent. Additionally, the prediction performance of an artificial neural network (ANN) model was evaluated to predict Ni(II) removal efficiency based on experimental variables, showing strong agreement with experimental data. Isotherm and kinetic models were also applied to the data to estimate the adsorption mechanisms. These findings demonstrate the promise of CuFe2O4-modified tea waste biochar for sustainable water treatment applications.
- MakaleAçık Erişim2024Orman Ekosisteminin Su Üretim Değerinin Galyan Su Üretim Havzasında Değerlendirilmesi (Atasu Barajı)
Çakir, Günay; Sivrikaya, Fatih; Bozali, Nuri
Orman ekosistem hizmetleri; tedarik, düzenleyici, destekleyici ve kültürel hizmetleri bünyesinde barındırmaktadır. İnsanlar ve canlıların ekosistemden doğrudan veya dolaylı olarak elde ettiği faydalar çok çeşitlidir. Ekosistemin sunduğu düzenleyici hizmetler sürdürülebilir kalkınma ve insan yaşamı açısından önem arz etmektedir. Aynı zamanda ekosistem hizmetleri insan refahı ile yakından ilişkilidir. Yaşamın en temel taşlarından birisi de su kaynaklarıdır. Dünya yüzeyinde kullanılabilir suyun çok az olması ve su kaynaklarının insanlara sunduğu hizmetlerin artması bu önemi daha da artırmıştır. Su döngüsünün faydalı bir biçimde kullanılması için evapotranspirasyon süreçlerinin de belirlenmesine ihtiyaç duyulmuştur. Faydalı suyun depolanmasında barajlar inşa edilmektedir. Baraj havzaları içerisinde mevcut arazi örtüsünün korunması ya da geliştirilmesi gerekmektedir. Bu çalışmada, bazı ülkelerdeki içme suyu havzalarındaki ormancılık çalışmaları ile ekosistem hizmetleri arasındaki ilişkiler ele alınarak Trabzon ilinin içme suyu ihtiyacının yaklaşık %70’ini sağlayan Galyan (Atasu Baraj) havzasındaki orman ekosisteminin sürekliliği açısından değerlendirmelerde bulunulmuştur. Orman ekosistemi ile su üretiminin karşılıklı etkileşimlerine değinilmiştir.
- MakaleAçık Erişim2024Biogenic Iron Oxide Nanoparticles Based on Algal Biofilm Formed in the Wastewater Treatment Plant and Their Dye Removal Performance
Baltaci, Cemalettin; Akar, Bülent; Karpuz, Omer; Demirel, İlyas Taner; Gülbahar, Esma
In the field of environmental pollution removal, bioremediation plays a crucial role in removing or converting toxic substances from the environment. Bacteria, yeasts, molds, algae, and plants are widely used in bioremediation events. Recently, green-synthesized nanoparticles have also been employed in bioremediation applications. In this study, iron oxide nanoparticles (FeONPs) were synthesized from algal biofilms that are naturally formed in the settling ponds of the Gümüşhane Municipality Wastewater Treatment Plant. These biological nanoparticles were utilized to investigate their adsorption efficiency for water-polluting dyes such as methylene blue (MB), malachite green (MG), and phenol red (PR). The synthesized FeONPs were characterized using Fourier transform infrared spectroscopy (FTIR) scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). To test their efficacy, MB, MG, and PR dye solutions were treated with 5.0, 10.0, and 20 g/L FeONP concentrations. The remaining dye concentrations were quantified with a UV-VIS spectrophotometer after filtration. The results showed that FeONPs obtained from algal biofilms effectively removed MB, MG, and PR, with the highest efficiency observed for PR.
- MakaleYalnız künye2024Innovative Polygonal Trend Analysis (IPTA) in detecting the seasonal trend behavior of statistically downscaled precipitation for the Eastern Black Sea Basin of Turkey
Nacar, Sinan; Şan, Murat; Kankal, Murat; Okkan, Umut
This study compares projected and past seasonal precipitation trends in the Eastern Black Sea Basin, Turkey. Historical data from twelve stations representing the basin during 1981–2010 was used, while statistically downscaled data from two representative concentration pathway scenarios (RCP4.5 and RCP8.5) outputs of the GFDL-ESM2M general circulation model were utilized for 2021–2050. To determine the seasonal trend behaviors of precipitation variables and transitions between consecutive months, the Innovative Polygon Trend Analysis (IPTA) was implemented. Furthermore, the star concept was employed to illustrate the changing sizes between consecutive periods. Both scenarios showed considerable summer and autumn declines at almost all locations, with low seasonal precipitation variability. These scenarios indicated January to be the important month for trend shift, except for Rize, Pazar, and Hopa stations. The formation of several polygons, polygons intersecting, and polygons not forming on the global regression line show that the hydro-climatic cycle might be chaotic.
- MakaleYalnız künye2024Adsorption of Azocarmine G dye on H2SO4-modified acacia sawdust
Duran, Celal; Ozeken, Sengul Tugba; Camoglu, Aslihan Yilmaz; Ozdes, Duygu
Presence of hazardous dyes in water cause considerable risks to the human health and environment due to their potential toxicity and ecological disruptions. Therefore, in the present research, to suggest an alternative method for the retention of toxic Azocarmine G (ACG) dye from aqueous media, natural and H2SO4-modified acacia sawdust were performed for the first time as low-cost and efficient adsorbents. Based on batch experiments, it was determined that the best conditions for the developed dye retention process were an initial pH of 2.0 and an equilibrium time of 240 min. Analysis of the data using both pseudo-first order and pseudo-second order kinetic models showed that the retention of ACG onto the adsorbents predominantly occurred through chemical adsorption. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were employed to provide insights into the interaction between the adsorbate and adsorbent and the mechanism of the adsorption process. Maximum monolayer adsorption capacities of natural and H2SO4-modified acacia sawdust were determined as 28.01 and 64.90 mg g-1, respectively by Langmuir isotherm model. Results of the study clearly indicated that the modification of acacia sawdust with H2SO4 leads to a substantial increase in the adsorption performance of anionic dyes.
