Tonkul, Serhat

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Tonkul, S
Tonkul, S.
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Main Affiliation
03.06. Department of Energy Systems Engineering
Status
Former Staff
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Sustainable Development Goals

NO POVERTY1
NO POVERTY
0
Research Products
ZERO HUNGER2
ZERO HUNGER
0
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GOOD HEALTH AND WELL-BEING3
GOOD HEALTH AND WELL-BEING
0
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QUALITY EDUCATION4
QUALITY EDUCATION
0
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GENDER EQUALITY5
GENDER EQUALITY
0
Research Products
CLEAN WATER AND SANITATION6
CLEAN WATER AND SANITATION
2
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AFFORDABLE AND CLEAN ENERGY7
AFFORDABLE AND CLEAN ENERGY
5
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DECENT WORK AND ECONOMIC GROWTH8
DECENT WORK AND ECONOMIC GROWTH
0
Research Products
INDUSTRY, INNOVATION AND INFRASTRUCTURE9
INDUSTRY, INNOVATION AND INFRASTRUCTURE
1
Research Products
REDUCED INEQUALITIES10
REDUCED INEQUALITIES
0
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SUSTAINABLE CITIES AND COMMUNITIES11
SUSTAINABLE CITIES AND COMMUNITIES
1
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RESPONSIBLE CONSUMPTION AND PRODUCTION12
RESPONSIBLE CONSUMPTION AND PRODUCTION
1
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CLIMATE ACTION13
CLIMATE ACTION
2
Research Products
LIFE BELOW WATER14
LIFE BELOW WATER
0
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LIFE ON LAND15
LIFE ON LAND
0
Research Products
PEACE, JUSTICE AND STRONG INSTITUTIONS16
PEACE, JUSTICE AND STRONG INSTITUTIONS
0
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PARTNERSHIPS FOR THE GOALS17
PARTNERSHIPS FOR THE GOALS
0
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Documents

6

Citations

47

h-index

4

Documents

6

Citations

35

Scholarly Output

12

Articles

9

Views / Downloads

67302/4495

Supervised MSc Theses

1

Supervised PhD Theses

0

WoS Citation Count

35

Scopus Citation Count

47

Patents

0

Projects

0

WoS Citations per Publication

2.92

Scopus Citations per Publication

3.92

Open Access Source

9

Supervised Theses

1

JournalCount
Geothermics2
Geothermal Energy2
DSİ Teknik Bülteni1
Environmental Earth Sciences1
Environmental Monitoring and Assessment1
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Scholarly Output Search Results

Now showing 1 - 10 of 12
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Groundwater 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
    The 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
    Effect of Degassing on Scaling in Hypersaline System: Tuzla Geothermal Field, Turkey
    (Springer Science and Business Media Deutschland GmbH, 2025) Tonkul, S.; André, L.; Baba, A.; Demir, M.M.; Regenspurg, S.; Kieling, K.
    A serious issue with geothermal power plants is the loss of production and decline in power plant efficiency. Scaling, also known as mineral precipitation, is one of the frequently-observed issue that causes this loss and decreasing efficiency. It is heavily observed in the production wells when the geothermal fluid rises from the depths due to a change in the fluid’s physical and chemical properties. Scaling issue in geothermal power plants result in significant output losses and lower plant effectiveness. In rare instances, it might even result in the power plant being shut down. The chemistry of the geothermal fluid, non-condensable gases, pH, temperature and pressure changes in the process from production to reinjection, power plant type and design, and sometimes the materials used can also play an active role in the scaling that will occur in a geothermal system. ICP–MS was used to evaluate the chemical properties of the fluids. On the other hand, XRD, XRF and SEM were used to investigate the chemical and mineralogical compositions of the scale samples in analytical methods. For the numerical approach, PhreeqC and GWELL codes were used to follow the chemical reactivity of the geothermal fluid in Tuzla production well. The novelty of this study is to determine potential degassing point and to characterize the mineralogical assemblage formed in the well because of the fluid composition, temperature and pressure variations. During production, geothermal fluids degas in the wellbore. This causes a drastic modification of the chemistry of the Tuzla fluids. This is why it is focused the calculations on the nature of the minerals that are able to precipitate inside the well. According to simulation results, the degassing point is estimated to be about 105 m depth, consistent with the field observations. If a small quantity of precipitated minerals is predicted before the boiling point, degassing significantly changes the fluid chemistry, and the model predicts the deposition of calcite along with smaller elements including galena, barite, and quartz. The simulation results are consistent with the mineral composition of scaling collected in the well. © The Author(s) 2024.
  • Article
    İzotop Özelliklerinin Kullanılarak Su-kayaç Etkileşiminin İncelenmesi: Alaşehir Alt Havzası Örneği
    (DSİ, 2019) Tonkul, Serhat; Şimşek, Celalettin; Baba, Alper
    Yeraltı su kaynakları yenilenebilir kaynaklar olmasına karşın, havzalarda aşırı çekim baskısı nedeniyle akiferlerde yeterince depolanamamakta ve depolama rezervi sürekli olarak azalmaktadır. Bu bağlamda son yıllarda yeraltısuyunun sürdürülebilir verimliliğinin arttırılması için kalite ve miktarın belirlenmesine yönelik olarak yüzey ve yeraltısuyu sistemleri arasındaki ilişkinin detaylı olarak çalışılmasına ihtiyaç duyulmuştur. Yüzey ve yeraltısuları arasındaki ilişkinin ortaya konulmasında en çok kullanılan özelliklerden birisi de izotoplardır. İzotoplar yeraltısuları ile kayaçlar arasındaki etkileşimini (su-kayaç ilişkisi) anlamada büyük öneme sahiptir. İzotoplar ile suların izledikleri yollar ve kökenleri hakkında önemli bilgiler alınabilmektedir. Özellikle, jeotermal bir sistemin bulunduğu bölgede, jeotermal rezervuar sıcaklığını tahmin etmede yardımcı olabilen bu izotoplar, aynı zamanda jeotermal bir sistemin evrimini de ortaya çıkarmaktadır. Türkiye’nin batısında yer alan ve ülkenin %2’sini oluşturan Gediz Havzası, önemli bir jeotermal potansiyelin olduğu alan konumundadır. Bu çalışma kapsamında çalışma alanındaki suların fiziksel ve kimyasal özelliklerinin kullanılarak, Alaşehir alt (Manisa) havzasında yüzey ve yeraltısuyu sistemleri arasındaki ilişkinin belirlenmesi amaçlanmıştır. Bu amaçla, Alaşehir alt havzasında 25 farklı noktada araştırma kuyuları açılmış olup, bu kuyulardan yağışlı ve kurak dönemde alınan yeraltısuyu örnekleri ile bu alandaki yağmur suyu örnekleri üzerinde laboratuvar ortamında, 2017 ve 2018 yılına ait numunelerin izotopik özellikleri değerlendirilmiştir. Buna göre, çalışma sahası ve çevresinde yeraltısularının 2017 ve 2018 yıllarına ait yağışlı ve kurak dönem ? 18O, ? 2H ve ? 3H izotop dağılımlarına bakıldığında genel olarak suların önemli bir kısmının meteorik kökenli olduğu anlaşılmaktadır.
  • Article
    Alaşehir Alt Havzasının (gediz Havzası, Batı Anadolu) Nem Değişimi Yöntemine Göre Yeraltısuyu Besleniminin Değerlendirilmesi
    (2021) Durukan, Seda; Şimşek, Celalettin; Tonkul, Serhat; Baba, Alper; Tayfur, Gökmen
    Gediz havzası Ege Bölgesinin en önemli havzalarından biridir. Çalışma alanı Gediz havzası içerisinde bulunan Alaşehir alt havzasıdır. Bu çalışma kapsamında Alaşehir alüvyon akifere çok sayıda araştırma kuyusu açılmış olup, araştırma kuyularında zemin karakterizasyonu belirlenmiş ve bazı kuyulara da zemin nem sensörleri konumlandırılarak yeraltısuyu beslenimi hesaplanmıştır. Doygun olmayan bölgedeki zeminlerde nem değişim yöntemi ile yağıştan sonra zemin nem değişimleri belirlenerek yağıştan beslenme miktarı tespit edilebilmektedir. Bu kapsamda alüvyon akifere 5 farklı noktada özel açılan kuyularda 5, 10 ve 15 m derinliklerde nem sensörleri vasıtası ile zemin nemi, sıcaklığı ve tuzluluğu ölçülmüştür. Çalışma alanında seçilen kuyularda zeminin suya doygun olmayan bölgesinde gerçekleştirilen hacimsel su içeriklerine göre mevsimsel değişiklikleri ortaya konulmuş ve yağıştan kaynaklanan beslenme miktarı belirlenmiştir. Elde edilen ölçümler sonucunda, çalışma alanındaki alüvyon akiferdeki yeraltısuyu beslenimi en az 40,81 ile en çok 77,12 mm olacak şekilde, ortalama olarak da 56,83 mm hesaplanmıştır. Ayrıca, ilk kez derin kuyular vasıtası ile yeraltısuyu besleniminde kullanılan zemin nem değişim yönteminin limitasyonları da bu çalışma kapsamında tartışılmıştır.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 20
    Groundwater Recharge Estimation Using Hydrus 1d Model in Alaşehir Sub-Basin of Gediz Basin in Turkey
    (Springer Verlag, 2019) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin; Durukan, Seda; Demirkesen, Ali Can; Tayfur, Gökmen
    Gediz Basin, located in the western part of Turkey constituting 2% land of the country, has an important groundwater potential in the area. Alasehir sub-basin, located in the southeast of the Gediz Basin and subject to the extensive withdrawal for the irrigation, constitutes the study area. Natural recharge to the sub-basin due to precipitation is numerically investigated in this study. For this purpose, 25 research wells, whose depths range from 20 to 50 m, were drilled to observe the recharge and collect the necessary field data for the numerical model. Meteorological data were collected from 3 weather stations installed in the study area. The numerical model HYDRUS was calibrated using the field water content data. Soil characterization was done on the core samples; the aquifer characterization was performed, and the alluvial aquifer recharge due to precipitation was calculated. As a result, the computed recharge value ranges from 21.78 to 68.52 mm, with an average value of 43.09 mm. According to the numerical model, this amount of recharge corresponds to 10% of the amount of annual rainfall.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 6
    Testing the Performance of Various Polymeric Antiscalants for Mitigation of Sb-Rich Precipitates Mimicking Stibnite-Based Geothermal Deposits
    (Hindawi Publishing Corporation, 2020) Çiftçi, Celal; Karaburun, Emre; Tonkul, Serhat; Baba, Alper; Demir, Mustafa Muammer; Yeşilnacar, Mehmet İrfan
    Scaling is frequently observed in geothermal fields and reduces the energy harvesting of power plants. Recently, Sb-rich deposits have developed in many fields around the world. Various polymeric macromolecules have been used as antiscalants to mitigate the formation of scale. Testing potential commercial antiscalants in field conditions is a tedious and costly process. The artificial synthesis of geothermal deposits in the lab is a more practical and economical way to test the performance of antiscalants. This study obtained a Sb-rich deposit by refluxing SbCl3 and Na2S center dot 3H(2)O in 18 h. The product was found to be a mixture of Sb2O3 and Sb2S3. We examined the performance of antiscalants such as poly(ethylene glycol), poly(vinyl pyrrolidone), Gelatin, and poly(vinyl alcohol) of various molecular weights at 5 to 100 ppm. The formation of Sb2S3 is suppressed in the presence of the polymeric antiscalants. The dosage was found to be critical for the solubilization of Sb-rich deposits. Gelatin of 5 ppm showed the highest performance under the conditions employed in this study. While low dosages improve the concentration of [Sb3+], high dosages are required to increase the solubility of [S2-]. Moreover, the amount of deposit is reduced by 12.4% compared to the reference (in the absence of any polymeric molecules). Thus, comparatively, Gelatin shows the most promising performance among the molecules employed.
  • Master Thesis
    Natural Groundwater Recharge in the Alaşehir Sub-Basin (gediz Basin, Turkey)
    (Izmir Institute of Technology, 2018) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin
    The increase in water utilization due to climate change in recent years, as well as excessively growing population causes to an increase in usage of groundwater and threatens water resources. Dams and artificial lakes are being constructed to ensure the sustainability of water resources, but there is much evaporation on large surface of these structures. Due to reason that the evaporation losses are not experienced, the groundwater recharge by direct rainfall becomes important. Groundwater recharge protects the water without too much evaporation in the basins and increases the potential of water resources and ensures sustainability. The aim of this study is to determine alluvial aquifer recharge in Alaşehir (Manisa) sub-basin using numerical and chemical methods. In addition to this aim, the mechanism of mixing of groundwater and geothermal fluid has also been examined. The Gediz Basin, located in the west of Turkey constitutes 2% of the country, has an important groundwater potential in the area where it is used. The Alasehir sub-basin, located in the southeast of the Gediz Basin and having extensive withdrawal for irrigation, constitutes the study area. Alluvial aquifer is the main groundwater bearing lithological unit in the plain. Twenty-five research wells, which is ranging from 20 m to 50 m in depth, were opened for the calculation of the recharge of the aquifer. Soil characterization was done on the core samples and the aquifer characterization was performed and the alluvial aquifer recharge was calculated. As a result, the recharge value of annual precipitation is range from 21.78 mm to 68.52 mm and average recharge from precipitation is 43.09 mm in the wells which are opened into the alluvium aquifer. According to the numerical model, this amount of recharge corresponds to 10% of the amount of annual rainfall. This estimated recharge ratio directly represents recharge from precipitation into the aquifer. According to the results of the chemical method, it is understood that the average recharge value from precipitation is 16.38%. In addition, the mixing ratio of the groundwater and geothermal fluid is 17% in the sub-basin. Keywords Aquifer Characterization, Alaşehir, Precipitation Recharge, Numerical Modelling
  • Conference Object
    Akifere Yağıştan Süzülme Miktarının Sondaj Verileri Kullanılarak Tahmin Edilmesi: Alaşehir (manisa) Havzası
    (TMMOB Jeoloji Mühendisleri Odası, 2018) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin; Tayfur, Gökmen; Durukan, Seda; Kumanlıoğlu, Ahmet; Demirkesen, Ali Can
    Son yıllarda iklim değişikliğine bağlı su kullanımının artması ve buna ek olarak aşırı nüfus artışı, yeraltısuyu kullanımını arttırmakta ve su kaynaklarını tehdit etmektedir. Su kaynaklarının sürdürülebilirliğinin sağlanması için barajlar ve yapay göller inşa edilmekte, ancak bu yapıların geniş yüzey alanlarında çok fazla buharlaşma görülmektedir. Dolayısı ile yeraltı suyunun, buharlaşma kayıplarının yaşanmadığı direkt yağış ile beslenen yapay beslenmesi önem kazanmaktadır. Yapay beslenme, havzalardaki suyu fazla buharlaşmadan korur ve su kaynaklarının potansiyelini artırıp, sürdürülebilirliğini sağlar. Bu çalışma kapsamında nümerik metotlar kullanılarak, Alaşehir (Manisa) havzasında alüvyon akiferin beslenmesinin belirlenmesi amaçlanmıştır. Türkiye’nin batısında yer alan ve ülkenin %2’sini oluşturan Gediz Havzası, önemli bir yeraltı suyu potansiyelinin olduğu ve kullanıldığı alan konumundadır.
  • Article
    Fluid-CO2 Injection in a Hypersaline Volcanic Systems: A Reactive Transport and Experimental Evaluation with Application to the Tuzla Geothermal Field, Turkiye
    (Springer, 2026) Tonkul, Serhat; Erol, Selcuk; Baba, Alper; Regenspurg, Simona
    This study evaluates the CO2 sequestration capability of the Tuzla Geothermal Field (TGF) in northwest T & uuml;rkiye under reservoir conditions (200 degrees C and 4.4 MPa). While ongoing studies at TGF have investigated CO2 co-injection primarily for geothermal heat extraction, the present study focuses on the associated potential for long-term CO2 storage. To this end, CO2-brine-rock interactions were examined through batch reactor experiments and reaction path modeling using the PhreeqC geochemical tool. The experiments revealed complex dissolution/precipitation reactions that altered reservoir properties, with mineralogical analyses (XRD, XRF, SEM, and EDS) showing the formation of secondary phases such as calcite, kaolinite, and Ca-rich aluminosilicates. These results indicate that the Tuzla reservoir rocks provide sufficient divalent cations to support mineral trapping under reservoir conditions. Overall, our findings highlight that, in addition to its promise for heat extraction, CO2 co-injection at TGF offers an opportunity for permanent geological storage, thereby strengthening the dual benefits of this approach.
  • Conference Object
    Investigation of Groundwater Recharges Mechanism in Alasehir Plain: From Physical Characterization To Modelling
    (International Water Association, 2017) Şimşek, Celalettin; Baba, Alper; Aksoy, Niyazi; Demirkıran, Zülfü; Hasözbek, Altuğ; Tayfur, Gökmen; Kumanlıoğlu, Ahmet; Durukan, Seda; Demirkesen, Ali Can; Murathan, Alim; Çağıran, Ömer; Akdeğirmen, Özgün; Tonkul, Serhat
    Characteristics of aquifer that allows the flow of groundwater, recharge and discharge mechanism effect the available groundwater potential. In order to determine the available potential of groundwater, the budget components are the most important parameters. In general, different analogical methods are applied in different countries, instead of using measurable data. Determination of the groundwater recharge is the most difficult parameter to be measured among the hydrological budget parameters. In general, the analogical methods are insufficient to determine the groundwater recharge rate. Precipitation, evaporation-transportation and runoff can be measured from the surface meteorological station. However, estimation of groundwater recharge cannot be measured directly. At the moment of climate change, visualization of the spatial distribution of the groundwater recharge estimation and mapping are needed. Therefore, improvements of easy groundwater recharge techniques are very important tools for groundwater basins to develop the water management planning.