Yazarlar
- Yildirim, Numan(27)
- Tanyol, Mehtap(21)
- Topal, Murat(19)
- Kutlu, Banu(18)
- Yildirim, Nuran Cikcikoglu(17)
- Ince, Muharrem(16)
- Serdar, Osman(16)
- Erguven, Gokhan Onder(14)
- Öbek, Erdal(14)
- Danabas, Durali(13)
- Acar, Ramazan(11)
- Demir, Veysel(11)
- Arslan Topal, E. Işıl(8)
- Ogedey, Aysenur(8)
- Yonten, Vahap(8)
- Tatar, Sule(7)
- Ince, Olcay Kaplan(6)
- Aksu, Onder(5)
- Alp, Hevidar(5)
- Ates, Mehmet(5)
- Korkmaz, Volkan(5)
- Oguz, Ensar(5)
- Topal, E.Işıl Arslan(5)
- Ural, Mesut(5)
- Arslan, Zikri(4)
- Aslan, Naim(4)
- Can, Erkan(4)
- Demirbilek, Deniz(4)
- Goksu, Ali(4)
- Kocabaş, Mehmet(4)
- Korkmaz, Meral(4)
- Kurnaz Yetim, Nurdan(4)
- Lassabatere, Laurent(4)
- Mutlu, Ekrem(4)
- Yilmaz, Deniz(4)
- Akkurt, Nevzat(3)
- Angulo-Jaramillo, Rafael(3)
- Arslan Topal, E.I.(3)
- Aydın, Ayşe Nur(3)
- Camas, Mustafa(3)
Yayınlar
- MakaleAçık Erişim2025The Relationship between Copper Tolerance and Antibiotic Susceptibility of Vagococcus salmoninarum Isolated from Kılavuzlu Dam Lake
Gokhan, Haci Bayram; Ispır, Ünal; Özcan, Mikail; Şeker, Engin
The contamination of aquatic ecosystems by heavy metals has been identified as a significant environmental hazard for aquatic animal species, including fish. The objective of this study was to investigate the tolerance of Vagococcus salmoninarum bacteria to copper and the impact of copper exposure on antibiotic susceptibility. The bacterial isolates, comprising six strains, were obtained from rainbow trout reared in cage culture at Kılavuzlu Dam Lake. The initial assessment of antibiotic susceptibility was conducted using the Kirby-Bauer disc diffusion method, which was subsequently validated through the determination of minimum inhibitory concentration (MIC). The broth microdilution method was employed, with the bacterial isolates exposed to concentrations of copper sulphate ranging from 0.1 to 1 mM. The resistance to multiple antibiotics was altered to be significantly altered following exposure to copper sulphate. The minimum inhibitory concentration (MIC) value of copper was observed to be 0.4 mM against V. salmoninarum. It was noted that V. salmoninarum, which has been exposed to copper in its natural environment, has developed the capacity to withstand stress and has undergone a change in its physiological status.
- MakaleAçık Erişim2025Su Kalitesi Parametreleri için Mann-Kendall ve Yenilikçi Trend Yöntemlerinin Karşılaştırılması
Acar, Ramazan
Günümüzde farklı veri setleri (su kalitesi, akım, yağış, sıcaklık vb.) ile eğilimlerin tespit edilmesi için pek çok yöntem mevcuttur. Bu çalışmada trend analizi çalışmalarında yaygın bir şekilde kullanılan Mann-Kendall (MK) test istatistiği ile Spearman Rho test istatistiği ve son yıllarda popüler hale gelmiş olan Şen’in yenilikçi trend yöntemi (ITA), Yenilikçi eğilim çözümlemesi için geliştirilmiş görselleştirme (IV-ITA) yöntemlerinin performansları karşılaştırılmıştır. Bu amaçla Akdeniz Bölgesi’nde yer alan Ceyhan Nehri’ne ait 20-06-00-001 numaralı istasyonundan alınan 1986-2013 su yıllarına ait yıllık ortalama ve mevsimlik ortalama 8 adet su kalitesi parametresi kullanılmıştır. Öncelikle her bir parametrenin değerleri YSKYY’nde verilen su kalite değerleriyle karşılaştırılmış ve her bir parametreye göre su kalitesi sınıfları belirlenmiştir. Daha sonra her mevsim kendi içinde ve yıllık ortalama değerlerin trendleri karşılaştırılmıştır. Bu nedenle 5 farklı trend testinin karşılaştırılması yapılmıştır. Ancak sırasıyla yapılmış olan homojenlik ve otoregresif korelasyon testi işlemlerine göre hem %95 güven aralığında homojen olmayan hem de korelasyon değeri 0.30’un üzerinde kalan bazı veriler kıyaslamada kullanılmamıştır. Makalede elde edilen sonuçlar değerlendirildiğinde farklı analizlerin birlikte yapılarak kullanılması testlerdeki yanılma payını azaltacağı kanısına varılmıştır.
AtıfOpenAlex3
İncele - MakaleAçık Erişim2025Investigation of the Benefits of the Floating Solar Power Plant to be Established on Keban Dam Lake using Penman, Linacre and Artificial Neural Networks Methods
Esen, Hikmet; Kurt, Savaş; Toka, UnalT Unal
In this study, it will be calculated how much water evaporation will be prevented if a Floating Solar Power Plant (FSPP) is installed on a certain part of the Keban Dam lake in Elazığ (38.41˚N, 39.14˚E), Türkiye by using the Penman and Linacre methods and the Artificial Neural Networks (ANN) method, which are widely used in evaporation calculation. Thus, it will be calculated how much energy can be produced with this saved water. Keban Hydroelectric Power Plant (HPP), examined in this study, is Türkiye's 3rd largest hydroelectric power plant with an installed power of 1.330 MWe. It is the fourth largest lake in Türkiye and the second largest dam lake after the Atatürk Dam. Keban Dam meets the electrical energy needs of 1.750.733 people in their daily lives with an average electricity production of 5.794.927,279 kWh. It has been calculated that thanks to a floating photovoltaic power plant that will cover 10% of the dam lake, a total of 31.305.282 m3 of water in normal water code will be prevented from evaporating annually, and thanks to this water, energy benefit will be provided with the power plant with an installed power of 6.624,84 MWe. In addition, it has been analyzed that 11.297.018 kWh of electricity can be produced from the dam turbines with the water prevented from evaporating thanks to FSPP. Approximately 72.39 MWe energy is needed for the Ağın, Pertek, Serince, Palu-Kovancılar, Uluova, Kuzova irrigation projects around the Keban Dam lake. It has been determined that the amount of water and energy needed for irrigation of these plains can be obtained thanks to FSPP.
- MakaleAçık Erişim2025Anıtsal Taş Yapılarda Bozunmalar: Hatay-Antakya Alvan Su Kemerleri Örneği
Dal, Murat; Atay, Erol; Dolar, Ayşe
Günümüzde var olan su kemerleri, modern teknolojinin su sorununu çözmeye yönelik yenilikçi yaklaşımlarının bir sonucu olarak, bu su yapılarının işlevlerini yitirmesi ve zamanla birçok faktöre (doğal, çevresel ve insan kaynaklı) maruz kalarak yok olma tehlikesiyle karşı karşıya kalmaktadır. Çalışma, Alvan su kemeri'nin doğal taşlarında meydana gelen bozunma türlerini ve bozunmalara sebep olan etkileri belirlemeyi ve yapıyı korumanın önemine dikkat çekmeyi amaçlamaktadır. Çalışmada Hatay İli Antakya ilçesinde yer alan Alvan su kemeri’ni tehdit eden fiziksel, kimyasal ve biyolojik bozunmalar yerinde fotoğraflanarak incelenmiştir. Bugün, Asi nehrine en yakın olan ve koruma altına alınmamış olan Alvan su kemeri, yüksek seviyedeki dış etkiler nedeniyle farklı bozunma türlerine maruz kalmış, anıttaki en belirgin bozunma türlerinin özellikle sıcak-kuru iklimde sıklıkla gözlenen petekgözlülük, çatlak, derz boşalması ve malzeme kaybı gibi fiziksel bozunmalara rastlanmıştır. Kimyasal bozunmalardan renk değişimi ve kararma ile biyolojik etkilerin sebep olduğu hayvan yuvaları ve bitki oluşumu olduğu tespit edilmiştir. Çalışmada tespit edilen bozunmaların yanı sıra, rüzgâr, nem, hava kirliliği ve yetersiz bakım gibi bozunmaya katkıda bulunan unsurlar da diğer bulgular arasında yer almaktadır. Yapının mevcut durumu ile 3 yıl öncesindeki fotoğraflarda kaydedilenler arasında yapılan karşılaştırmada, 6 Şubat 2023 Kahramanmaraş depremi sonrasında ağır hasar alan Hatay ilinde bu yapının tamamen yıkıldığı tespit edilmiştir.
- MakaleAçık Erişim2025The Health Effects of Fluoride and Nitrate in Drinking Water in Tunceli (Türkiye)
Kutlu, Banu; Çetindağ, Serdar
Fluoride (F⁻) and nitrate (NO₃⁻) are common inorganic constituents of drinking water and can cause significant public health effects when present at inadequate or excessive concentrations. This study determines the levels of fluoride and nitrate in drinking water collected from 18 stations across Tunceli Province, Türkiye, during 2021, and evaluates the non-carcinogenic health risks for four age groups (infants, children, adolescents, and adults). Fluoride and nitrate concentrations were measured using spectrophotometric methods and Estimated Daily Intake (EDI) and Hazard Quotient (HQ) values were calculated. Fluoride concentrations ranged from 0.06 to 0.31 mg L⁻¹ and were below the WHO guideline value, with all HQ values <1. Nitrate concentrations varied more widely (0.45–64.38 mg L⁻¹), and exceedances of WHO limits were recorded at several rural stations. Infants and children exhibited HQ>1 values, indicating potential health risks associated with nitrate exposure. The findings highlight spatial heterogeneity in water quality across Tunceli and emphasize the need for age-specific monitoring programs and improved groundwater protection strategies.
AtıfOpenAlex1İncele - MakaleAçık Erişim2025Application of GIS in Flood Risk Analysis and Mitigation Strategies: The Case of Uluova and İkitepe Streams
Korkmaz, Meral; Uymaz, Muhammed
In recent years, the frequency and severity of floods have increased significantly due to the effects of global climate change, leading to serious economic and social losses, particularly in agricultural production areas. Floods not only damage cultivated lands but also negatively affect the livelihoods and socio-economic structures of local communities. This situation necessitates accurate identification of flood risk in agricultural areas and timely implementation of appropriate mitigation measures. In this study, flood risk was investigated in agricultural lands surrounding the Uluova Stream located between Doğankuş, Karşıbağ, and the Keban Dam and the İkitepe Stream, which flows through the center of Mollakendi in Elazığ Province, Türkiye. These areas are characterized by intensive agricultural activities. Using Geographic Information Systems (GIS), seven key parameters distance to streams, land use, aspect, slope, soil structure, precipitation, and geological features were analyzed, and corresponding thematic maps were generated. Flood risk levels were determined through spatial analysis and classification of these parameters using ArcGIS software. Based on the results, areas with high flood risk were identified, and both structural and non-structural mitigation measures were proposed for these zones. The findings offer valuable insights to support sustainable agricultural production and rural development by minimizing potential flood damages and reducing associated economic risks in the region.
- MakaleYalnız künye2025Scopus SJRQ2Green synthesis of environmentally friendly Ag/AgCl nanoparticles for use as solid phase extraction materials
Kurnaz Yetim, Nurdan; Hasanoğlu Özkan, Elvan; Aslan, Naim; Koç, Mümin Mehmet; Nartop, Dilek; Özcan, Cemile
Green synthesis is a prominent procedure used to easily and environmentally friendly fabricate nanostructures and nanoparticles (NPs), without complex instrumentation, intricate procedures, and harmful chemicals. This study investigated the green synthesis of silver NPs (AgNPs), with Aronia melanocarpa fruit extract as the reducing agent. Following synthesis optimization, AgNPs were characterized using a range of analytical techniques, including UV–Vis, XRD, SEM-EDX, BET, and TEM analyses. Based on the characterization results, an Ag/AgCl hybrid structure was formed. The Ag/AgCl NPs obtained were utilized as adsorbents to remove Cd(II) and Pb(II) heavy metals. The experimental factors that were optimized included pH (5.5), sample volume (5 mL), eluent type and concentration (2 M HNO3), adsorbent amount (5 mg), and extraction time (30 min). Under optimized conditions, the limits of detection were determined to be 9.6 and 4.8 µg/L for Pb(II) and Cd(II), respectively. These limits were established within a concentration range of 50–3,000 µg/L.
AtıfScopus3WoS3OpenAlex3
İncele - MakaleYayıncıda açık erişim2025Scopus SJRQ2Determination of Toxic Effects of Copper in Navicula cryptocephala var. veneta by Biomarkers and Bioaccumulation Quantification
Aydın, Ayşe Nur; Serdar, Osman; Ölçülü, Abdüllatif; Çimen, Işıl Canan Çiçek; Ak, Tuba Parlak; Derman, Taner; Sevim, Ayşegül; Yıldırım, Nuran Cikcikoğlu
As a result of the increased use of metals such as copper (Cu), copper pollution in the environment is also increasing. In order to investigate the effect of copper mixed into the water environment and on aquatic biota, the microalga Navicula cryptocephala var. veneta was chosen as a model organism. N. cryptocephala var. veneta it was aimed to determine the accumulation and elimination amounts and some biomarker responses. Metal accumulation amounts in the organisms used in the study. The amount of metal accumulated in relation to the wet weight mass of the samples was determined using Atomic Absorption Spectophotometry (AAS) mass spectrometry. In the bioassays conducted within the scope of the study, lipid peroxidation (TBARS) and reduced glutathione (GSH) levels, superoxide dismutase (SOD) enzyme activity, glutathione peroxidase (GSH-Px) enzyme activity and catalase (CAT) enzyme activity were determined with an ELISA microplate reader at 24, 48, 72, 96 and 120 hours. According to the study data, it was observed that Cu metal accumulated in Navicula cryptocephala var. veneta and caused oxidative stress in the organism, affecting the organism by causing changes in TBARS, GSH levels and antioxidant enzymes SOD, CAT and GPx activities. Additionally, it was observed that different elimination levels occurred in the application groups.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ4The effect of the pesticide Klaxon on the oxidative stress and the antioxidant responses of the Zebra mussel (Dreissena polymorpha); [El efecto del pesticida Klaxon sobre el estrés oxidativo y las respuestas antioxidantes del mejillón cebra (Dreissena polymorpha)]
Ozcan, Ebru Ifakat
Klaxon pesticide represents a novel generation of insecticide employed in the control of diseases, pests and weeds in select agricultural regions. Pesticides that enter the aquatic environment indirectly have a detrimental impact on the organisms that inhabit this environment, and humans are ultimately exposed to these chemicals through the food chain. The present study investigated the toxicity of the klaxon pesticide in Dreissena polymorpha, a suitable bioindicator of water pollution, through the analysis of oxidative stress and metabolic biomarkers. The effects of klaxon at concentrations of 0.01, 0.15 and 0.30 mg·L-1 on oxidative stress and antioxidant changes in D. polymorpha were determined over a 24 – and 96–hour period. Enzyme–linked immunosorbent assay (ELISA) kits were employed to quantify the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and thiobarbituric acid (TBARS), as well as to assess the levels of reduced glutathione (GSH). ELISA kits were used to determine results. Statistical evaluation of biomarker analyzes was performed using the SPSS 24.0 package program one–way ANOVA (Duncan 0.05) test. Significant decreases in GSH levels (P<0.05); significant increases in TBARS levels (P<0.05) were observed. Significant decreases (P<0.05) in SOD, CAT and GPx activities were observed. Considering the study data, it was determined that the klaxon pesticide penetrating the body of the living organism caused oxidative stress and changes in enzyme activities in D. polymorpha.
AtıfScopus1WoS1İncele - MakaleYalnız künye2025Scopus SJRQ4Bioaccumulation of copper by Gammarus pulex (L., 1758): monitoring through a statistical modelling approach
Pala, Aysegul; Ince, Muharrem; Serdar, Osman
The aim of this study is to test freshwater gammarids as ecotoxicological biomarkers. Gammarids were collected from fresh water and adapted to the laboratory environment. Then, the influence of various variables was investigated. For monitoring and detecting the bioaccumulation level in Gammarus pulex exposed to controlled copper ions and to evaluate potential human and ecological risks, the use of G. pulex as sentinel indicators of water quality is one rational approach. Copper bioaccumulation rate and fate are currently not sufficiently studied. For optimization, the experimental conditions to ensure bioaccumulation level and to find the effects of various variables on proses, a Box–Behnken experimental design was performed. Used mentioned model with statistical underpinnings for Cu2+ ions bioaccumulation have been analyzed, tested and verified and the viability of G. pulex as a biomonitor. The variables’ optimum levels (temperature; 18.1, pH; 4.3, initial concentration of Cu2+ ions, mg L−1; 11.2 and exposure time, h; 42.2) were achieved by employing the quadratic regression model. Critical role of G. pulex in freshwater biomonitoring and their potential to be evaluated as biomarkers for Cu2+ ions was confirmed. It was also explored to see if G. pulex may serve as a potential tool for estimating aquatic quality.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ3Assessments of heavy metal contaminations of surface water and sediment of Pülümür Stream (Türkiye)
Kutlu, Banu; Çevik, Fatma; Çetindağ, Serdar
The primary considerations within aquatic ecosystems are water and sediment quality, rendering it imperative to assess their concentrations, pollution levels, origins, and ecological hazards. In this study, heavy metal concentrations in surface waters and sediments of the Pülümür Stream were investigated to assess the level, distribution, source of pollution and the associated human risks. Water and sediment samples from the river were collected monthly from February 2021 to January 2022 and examined using the Inductively Coupled Plasma Mass Spectrometry (ICP– MS) technique. Metal concentrations in the sediment followed a decreasing or derivative sequence of Fe > Al > Mn > Ni > Cr > Zn > Cu > Pb > As >Cd > Hg. The ecological indices of the stream water have low degrees of contamination by heavy metals. Igeo and EF showed that most of the sites are moderately to highly polluted due to Ni, and Cr, while PLI and PERI showed a progressive deterioration of the environment at site 9. Moreover, the modified hazard quotient (mHQ) indicates low ecological risk for Cu, Pb, Zn, Cd, Hg metals, while Ni, As and Cr reach high pollution at sediment sites. Pearson correlation analysis revealed that the presence of Zn, Cu, Pb, Hg, and Mn metals in the sediment analysis has a lithogenic source, and As, Ni, Cd, and Cr accumulate due to human activities, mainly domestic and agricultural irrigation wastes and mining wastes, all of which affect the aquatic environment. According to this study, more attention should be paid to the comprehensive monitoring of metals in the water and sediment for both aquatic biota and human risk of the Pülümür River.
AtıfScopus6WoS5OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ2Determination of the Effect of Nanoparticle Copper on Navicula cryptocephala var. veneta by Biomarkers and Bioaccumulation Amounts
Serdar, Osman; Aydın, Ayşe Nur; Ölçülü, Abdüllatif; Çiçek Çimen, Işıl Canan; Parlak Ak, Tuba; Derman, Taner; Pala, Ayşegül; Yıldırım, Nuran Cikcikoğlu
Pollutants such as copper nanoparticles (CuNP), which form residues in the environment, especially in water environments, cause serious damage to the environment and the organisms living in the environment. In this study, Navicula cryptocephala var. veneta was selected as a model organism. The EC50 values of CuNP on Navicula cryptocephala var. veneta were determined as 4.94 mg\L and 3 different application concentrations were determined considering this ratio. The experiments were carried out in 3 replicates and samples were taken at 24 and 96 hours. At the end of 120 hours, samples were taken to determine the elimination values. CuNP accumulation amounts in the samples were measured by electrothermal atomic absorption spectrophotometer (ETAAS). For biomarker analysis, thiobarbituric acid (TBARS) and glutathione (GSH) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities were performed using CAYMAN ELISA kit. According to the study data, as CuNP concentration and application time increased, the amount of accumulation in Navicula cryptocephala also increased. Increasing-decreasing changes were observed in elimination. CuNP caused oxidative stress in N. cryptocephala and caused changes in TBARS and GSH levels. In addition, it caused increases in SOD activities and statistically significant decreases (P<0.05) in CAT and GPx activities.
AtıfScopus2WoS1İncele - MakaleYayıncıda açık erişim2025Scopus SJRQ1Experimental analysis of a double-slope solar still integrated with parabolic trough solar collector using nanofluid
Tuğan, Volkan; İnallı, Mustafa; Işık, Erdem
The use of solar energy in the treatment of saline water offers a sustainable and low-cost solution to the increasing global fresh water demand. In this direction, solar still systems separate water vapor from saline water by directly using solar radiation and then condense it to obtain pure water. However, their fresh water productivity is relatively low. Therefore, in this study, the fresh water productivity and thermal efficiency of the double slope solar distillation unit integrated with parabolic trough solar collector, which operates completely on solar energy, were investigated experimentally. In addition, the effect of water-based nanofluid containing multi-walled carbon nanotubes on the performance of the solar still was investigated. All the stills produced were compared in terms of fresh water productivity and thermal efficiency. According to the results obtained from the study, the highest daily productivity was found to be 1963.8 g/m2/day, 2008.5 g/m2/day, 2592.0 g/m2/day and 2937.6 g/m2/day for SSSS, DSSS, PTSC integrated DSSS and both NF and PTSC integrated DSSS, respectively. It was observed that the daily productivity of DSSS, DSSS with integrated PTSC, and DSSS with both PTSC and NF were 6.6 %, 42.2 %, and 49.6 % higher than SSSS, respectively. Additionally, it was observed that the thermal efficiency of DSSS using PTSC and NF was lower compared to SSSS due to its larger system area.
AtıfScopus13WoS8OpenAlex10İncele - MakaleAçık Erişim2025Scopus SJRQ4Adsorption of RB-5 Dyestuff onto Boric Acid-Zinc Nanoalloys: Isotherm, Kinetic, and Thermodynamic Investigations
İlhan, Hasan; Güler, Ömer; Şi̇mşek, Tuncay; Alkan, Salih
In this study, boric acid-zinc (BA-Zn) nanoalloys were employed as an adsorbent for the removal of RB-5 dyestuff from aqueous solutions. The investigation focused on analyzing the impact of the initial dyestuff concentration, solution pH, temperature, and equilibrium contact time on the adsorption process of RB-5. The adsorption behavior of RB-5 onto the surface of BA-Zn-nanoalloys was explored, with a particular emphasis on the influence of initial dyestuff concentration and solution pH. The adsorption equilibrium data were subjected to analysis using Langmuir, Freundlich, DRK, and Temkin isotherm models. The results revealed a consistent alignment of RB-5 adsorption with both Langmuir and Temkin isotherms. Notably, the Langmuir adsorption capacity of BA-Zn-nanoparticles for RB-5 adsorption was determined to be 11.77mg / g at a temperature of 25°C. In the Temkin isotherm model, an adsorption constant (AT) of 1.003 was obtained. The calculated adsorption energy from the DR adsorption model was 1.09kJ / mol, implying a physical interaction-driven adsorption process. The empirical data further exhibited conformity with the pseudo-second order kinetic model, reflecting the rate-limiting step and overall kinetics of the adsorption process. Complementary to this, thermodynamic parameters such as enthalpy (ΔH0), Gibbs free energy (ΔG0), and entropy (ΔS0) were evaluated to discern the energetics of BA-Zn-nanoparticle RB-5 adsorption. This study not only underscores the effectiveness of BA-Zn nanoalloys as a potential adsorbent for RB-5 dyestuff removal but also contributes to the understanding of the underlying adsorption mechanisms and energetics. The insights gained hold implications for the development of sustainable and efficient strategies for wastewater treatment and environmental protection.
- MakaleYalnız künye2025Scopus SJRQ2Chromium removal with walnut shells and oak branches, adsorption studies, and kinetics
Fırat, Tülay
This study investigates the chromium sorption properties of walnut shells (WS) and oak branches (OB), both of which were modified using NaOH and lactic acid treatments. The characterization of these adsorbents was carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), point of zero charge (pHpzc) analysis, and Brunauer–Emmett–Teller (BET) surface area measurements. According to BET results, WS exhibited higher surface area values compared to OB. The pH and pHpzc measurements revealed that acidic functional groups are more prevalent than basic ones on both adsorbents. Batch experiments were conducted to evaluate the chromium ion sorption capacities of WS and OB. To further understand the adsorption mechanism, the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were analyzed, with the Langmuir and Freundlich models being widely recognized for describing adsorption in single-solute systems. The equilibrium data aligned best with the Langmuir isotherm, while the kinetic data were modeled using pseudo-first-order and pseudo-second-order kinetics. The maximum chromium sorption capacity for WS was determined to be 30.51 mg/g. The energy values calculated from the D-R equation for chromium adsorption onto WS and OB were 13.49 kJ/mol and 15.71 kJ/mol, respectively, indicating that the adsorption process is primarily driven by physical adsorption.
AtıfScopus3WoS3OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Monitoring of organic micropollutant behavior and fate in a full-scale conventional biological urban wastewater treatment plant
Demirbilek, D.; İpek, U.; Yetis, U.
Organic micropollutants, found at trace levels in nature, are causing significant concern due to their toxic, carcinogenic, and mutagenic effects. In this study, the fate and removal of organic micropollutants were monitored covering all seasons in an urban wastewater treatment plant in Turkey. The plant influent, effluent, and aeration basin were sampled seven times in the years of 2019–2020; and three surfactants (linear alkylbenzene sulfonate, nonylphenol mono-di-ethoxylate, nonylphenol), polychlorinated biphenyls and polyaromatic hydrocarbons were monitored in this context. The plant was being operated in the endogenous respiration phase during the monitoring period without sludge removal. Results obtained showed that the highest NH3-N removal (41%) of the study period was realized in March when the lowest mixed liquid volatile suspended solids value (380 mg/L) and the lowest sludge age were observed. In this month, the highest organic micropollutants removal efficiency was obtained in relation to the increased metabolic activity. On the other hand, in August, when the highest mixed liquid volatile suspended solids value (1,750 mg/L) was observed, the lowest organic micropollutants removal was recorded, with the lowest NH3-N removal (6%). The removal of linear alkylbenzene sulfonate and nonylphenol mono-di-ethoxylate was high during the period, and microorganisms could metabolize these pollutants efficiently. Polychlorinated biphenyls, polyaromatic hydrocarbons, and nonylphenol were resistant to metabolic degradation, so they were present in high amounts at various stages of the treatment process. Due to the poor plant treatment performance, a high quantity of organic micropollutants was discharged into the receiving environment.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2025Scopus SJRQ1Rainfall trends in the transboundary Euphrates-Tigris River Basin
Acar, Ramazan; Akbas, Ergun; Koycegiz, Cihangir; Esit, Musa
Climate change and anthropogenic factors have a significant impact on rainfall variability. In this study, the trends of monthly total precipitation in the transboundary Euphrates-Tigris River Basin (ETRB), where these effects are intensely observed, were analyzed by trend analysis methods with various perspectives. After decomposing the monthly total rainfall series (1964–2021) obtained from 18 stations representing 12 months of the year, statistical (Mann-Kendall, Wilcoxon, Onyutha), graphical (Innovative Polygon Trend Analysis, IPTA), Trend Polygon Star Concept, TPSC), sub-trend (Onyutha) and spatial trend analyses were performed. Based on the results, it was observed that rainfall in the basin has significant spatial and temporal variability. A monotonic strong decreasing trend was observed in cold months with high rainfall, while an increasing trend was observed in warm months with low rainfall. Extreme rainfall during the winter months has shifted towards the end of the cold months. Graphical and statistical analysis methods have shown strong consistency in identifying monotonic trends. However, the implementation of various methods provides specific insight (transition, sub-trend, etc.) into the temporal and spatial variability of rainfall. Sub-trend analysis shows that rainfall characteristics in the cold months show a significant change before and after the 1990–2000 period. In warmer months, this variability is significantly affected by local and global driving forces. The central and marginal parts of the ETRB have different rainfall characteristics. During cold months, the monotonic trend (decreasing) is significant in the central part. In warm months, the monotonic trend (increasing) increases its intensity in the eastern parts.
AtıfScopus12WoS10OpenAlex14İncele - MakaleYalnız künye2025Scopus SJRQ2Using Meta-Heuristic Optimization Algorithms to Determine Baseflow and Comparing Their Temporal Performance
Acar, Ramazan; Sapliogu, Kemal
Accurate and simple determination of baseflow is an extremely important issue. In this study, the baseflow levels of Göksu station number 1805 in the Seyhan basin were determined by calibrating the Lyne and Hollick, Chapman, Chapman and Maxwell methods available in the literature using meta-heuristic optimization methods. The meta-heuristic algorithms used for calibration in the study were run thirty times each. Thus the reliability, the reliability of the algorithms was tested with the standard deviations obtained. The study also measured the temporal performance of the algorithms. In addition, the baseflows of Göksu station were determined and their percentage rates were found separately according to all three methods and intuitive methods, and the results obtained were compared. By examining the results obtained in this section, the average baseflow rate of the basin was also determined. Furthermore, each phase of the study was repeated over a five-year period, with the objective of measuring its sustainability. Consequently, it has been demonstrated that the method can be employed over extended periods.
AtıfOpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ3Experimental and Theoretical Study on the Freshwater Productivity of a Single-Slope Solar Still
Tuğan, Volkan; Işık, Erdem; İnallı, Mustafa
Converting saline water into freshwater using renewable energy resources is crucial to address global shortages of freshwater. This study aims to investigate the freshwater productivity of a single-slope solar still (SSS) operating with solar energy, one of the renewable energy sources. The main motivation of this study is to evaluate the experimental, theoretical, and economic performance of the solar still under climate conditions that have not been sufficiently studied before. Experimental analyses were conducted under the climatic conditions of Tunceli, a city located in the Eastern Anatolia Region of Türkiye. In addition, a comprehensive theoretical analysis was carried out using energy equations, and the experimental and theoretical results were compared with each other. Finally, the economic feasibility of the system was evaluated through a cost analysis. The SSS's experimental and theoretical productivity were found to be 1883.9 and 2458.7 g/m2/day, respectively. The experimental thermal efficiency for this still was 15.1%, whereas the theoretical thermal efficiency was 19.7%. It was concluded that the theoretical productivity and efficiency values were close to the experimental values and the difference between them originated from the assumptions of theoretical calculations. The cost of water distilled by the single-slope solar distillation unit was found to be $0.077/kg, and the payback period was found to be 9 months.
AtıfScopus2WoS3OpenAlex2İncele - MakaleAçık Erişim2025Scopus SJRQ1Site Fidelity, Home Range Size and Movement Patterns of a Mega-Fish, Luciobarbus esocinus, in Keban Reservoir, Euphrates River
Alp, Ahmet; Akyüz, Adil; Gündüz, Fatih; Demirol, Ferhat; Çoban, Mehmet Zülfü; Yüksel, Fahrettin; Yerli, Sedat Vahdet
Luciobarbus esocinus (mangar), a critically endangered mega-fish species (≤ 140 kg) endemic to the Euphrates and Tigris river systems, faces severe threats due to habitat fragmentation. To assess its spatial ecology in the Keban Reservoir, 30 individuals were acoustically tagged and monitored for 218–437 days using 18 receivers deployed in the reservoir. The tagged fish exhibited low site fidelity, with station residency indices (RI) ranging from 0.00 to 0.46 and detection periods lasting 59–153 days. Depth and temperature data (115,318 and 112,789 records, respectively) revealed seasonal habitat shifts: individuals occupied deeper waters in winter (mean 10.1 m), shallower depths in spring (4.4 m) and summer (3.8 m), and tolerated temperatures of 7.4°C–28.4°C. Although depth use was weakly correlated with temperature, trends indicated shallower occupancy during warmer periods. Home range analyses showed a maximum linear home range (LHR) of 36.5 km and the areal home range estimated via minimum convex polygon (MCP) was 6422.8 ha. In addition, kernel density (KD) analysis revealed the 95% KD area was 2877.0 ha, the 75% KD area was 67.7 ha and the 50% KD area was 33.8 ha. Seasonal migrations spanned 25–30 km upstream/downstream from release sites, particularly toward tributaries in spring. Around the Keban Reservoir, 14 hydroelectric power plants (HPPs) present and most of these HPP are not designed suitable fish passages. Urgent conservation measures are needed, including Fish Conservation Zones in critical habitats and connectivity restoration via functional fishways, to safeguard this imperilled species in fragmented river-reservoir ecosystems.
