Civil Engineering / İnşaat Mühendisliği
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Article Citation - WoS: 40Citation - Scopus: 47Boron in Geothermal Energy: Sources, Environmental Impacts, and Management in Geothermal Fluid(Elsevier, 2022) Mott, A.; Baba, Alper; Hadi Mosleh, Mojgan; Ökten, Hatice Eser; Babaei, Masoud; Gören, Ayşegül Yağmur; Feng, C.; Recepoğlu, Yaşar Kemal; Uzelli, Taygun; Uytun, Hüseyin; Morata, Diego; Yüksel Özşen, AslıThe problem of hazardous chemicals in geothermal fluid is a critical environmental concern in geothermal energy developments. Boron is among the hazardous contaminants reported to be present at high concentrations in geothermal fluids in various countries. Poor management and inadequate treatment of geothermal fluids can release excessive boron to the environment that has toxic effects on plants, humans, and animals. Despite the importance of boron management in geothermal fluid, limited and fragmented resources exist that provide a comprehensive understanding of its sources, transport and fate, and the treatment strategies in geothermal energy context. This paper presents the first critical review from a systematic and comprehensive review on different aspects of boron in geothermal fluid including its generation, sources, toxicity, ranges and the management approaches and treatment technologies. Our research highlights the origin of boron in geothermal water to be mainly from historical water-rock interactions and magmatic intrusion. Excessive concentrations of boron in geothermal fluids have been reported (over 500 mg/L in some case studies). Our review indicated that possible boron contamination in geothermal sites are mostly due to flawed construction of production/re-injection wells and uncontrolled discharge of geothermal water to surface water. The dominancy of non-ionic H3BO3 species makes the selection of the suitable treatment method for geothermal waters limited. Combining boron selective resins and membrane technologies, hybrid systems have provided effluents suitable for irrigation. However, their high energy consumption and course structure of boron selective resins encourage further research to develop cost-effective and environmentally friendly alternatives.Article Citation - WoS: 8Citation - Scopus: 8Structural Controls and Hydrogeochemical Properties of Geothermal Fields in the Varto(TÜBİTAK Scientific & Technological Research Council Turkey, 2021) Uzelli, Taygun; Sener, Mehmet Furkan; Dolek, Iskender; Baba, Alper; Sozbilir, Hasan; Dirik, Ramazan KadirVarto and the surrounding region have important geothermal fields, developing in strike-slip tectonic setting in East Anatolia, which resulted from the collision of the Arabian and Eurasian plates. The main structural elements in the area are the NE-trending sinistral and NW-trending dextral strike-slip fault segments and N-S trending extension zones. In order to determine fault-controlled geothermal circulation, it is very important to fully characterize the structural elements in these complex environments. The widely distributed volcanic rocks have fracture and crack systems that play an important role in surface infiltration, geothermal fluid, and groundwater circulation. Especially in areas where the fault segments intersect, hot springs outlets and natural resources easily come to the surface. In order to understand the flow paths of geothermal fluid along the faults in these geothermal systems, it is necessary to determine the stress state of the faults and to map the distribution of the structural elements. For this reason, we conducted a detailed study on the Varto Fault Zone, which has important geothermal fields in Eastern Anatolia. We present conceptual models of the geothermal fields in the Varto region that show favorable geothermal activity on the intersecting fault segments, fault bends, step-overs, and accompanying fracture-crack sets. As a result, we emphasize that the planes of strike-slip faults in transtensional areas are more favorable for secondary permeability and enhances the geothermal fluid circulation, and this can be supported by hydrogeochemical data.Article Citation - WoS: 6Citation - Scopus: 6Valuing Groundwater Heritage: the Historic Wells of Kadıovacık(Springer, 2021) Yüceer, Hülya; Baba, Alper; Özcan Gönülal, Yasemin; Uştuk, Ozan; Gerçek, Deniz; Güler, Selen; Uzelli, TaygunThe consideration of the subject of water resources, seen as a part of cultural heritage, generally includes water-related architectural structures such as bridges, aqueducts, and cisterns. Groundwater resources and related structures, however, receive little attention as heritage assets, and they are mostly forgotten together with the valuable information they hold. In this sense, this study aims to provide an accurate assessment of groundwater heritage and to suggest proposals for conservation through the case of the historic wells of Kadıovacık village in the Urla district of İzmir. Although the region where the village is located is rich in groundwater resources, the residents have suffered from drought for ages due to the specific geological characteristics of the Kadıovacık polje. The limited amount of water resources in Kadıovacık village have karstic characteristics and have shaped the life and topography of the region. To access and harvest this limited groundwater, a group of wells had been constructed on the ridge of the hill. These wells have been idle since 1980s with the supply of city main water. In line with the aim, a comprehensive heritage valuation by an interdisciplinary group of experts is essential to reveal the significance of the relatively humble wells. Accordingly, a multi-method system is used, including historical, social, cultural, architectural, geological, hydrogeological, and environmental aspects. The results show that although the wells are generally considered to be less important as heritage assets in terms of their physical features, an in-depth evaluation demonstrates their high significance for the village community.Article Citation - WoS: 4Citation - Scopus: 15Effects of Seismic Activity on Groundwater Level and Geothermal Systems in İzmir, Western Anatolia, Turkey: the Case Study From October 30, 2020 Samos Earthquake(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2021) Uzelli, Taygun; Bilgiç, Esra; Öztürk, Bahadır; Baba, Alper; Sözbilir, Hasan; Tatar, OrhanThe October 30, 2020 Samos earthquake (Mw 6.6) affected the Aegean Sea and environs, caused destruction and loss of life in the city of İzmir located 70 km away from the earthquake epicenter. Before this earthquake, water resources were monitored in the areas of Bayraklı, Gülbahçe, and Seferihisar. For this purpose, 10 groundwater monitoring wells were drilled in the Bayraklı area, where groundwater level, temperature, and electrical conductivity changes were monitored at 1-h intervals in 5 wells. Besides physical parameters such as groundwater levels, temperatures and electrical conductivities, hydrogeochemical cations, and anions measured in the study area. Change in the groundwater levels was observed before, during, and after the Samos earthquake. A trend of rising groundwater level was observed two days before the mainshock, to a height of 10 cm, and the level was maintained till the end of the earthquake. The water levels returned to its original height after about 7 to 10 days of the earthquake. Moreover, electrical conductivity (EC) values were changed because of the interaction with the surrounding rocks and well walls, mixing with different waters during the earthquake shaking. The essential anomalies were observed in the geothermal fields of Gülbahçe and Seferihisar. Due to this earthquake, new geothermal springs emerged along the NE-SW trending Gülbahçe and Tuzla faults, located about 50 to 20 km from the Samos earthquake epicenter, respectively. The new geothermal waters are in Na-Cl composition and similar to other geothermal springs in the region. While the recorded water temperatures in the new geothermal springs vary from 40 to 45 °C in Seferihisar, it was measured between 35 and 40 °C in Gülbahçe. Due to these anomalies, it is found essential to monitor the effect of the earthquake on the physical and chemical characteristics of the groundwater and its usefulness in earthquake predictions.Article Citation - WoS: 40Citation - Scopus: 44Geological and Hydrogeochemical Properties of Geothermal Systems in the Southeastern Region of Turkey(Elsevier Ltd., 2019) Baba, Alper; Şaroğlu, Fuat; Akkuş, I.; Özel, Nedret; Yeşilnacar, Mehmet İrfan; Nalbantçılar, Mahmut Tahir; Demir, Mustafa Muammer; Gökçen, Gülden; Arslan, Ş.; Dursun, N.; Uzelli, Taygun; Yazdani, HamidrezaThe Anatolia region is one of the most seismically active regions in the world. It has a considerably high level of geothermal energy potential thanks to its geological and tectonic settings. The Southeastern Anatolia Region (GAP) is located in the south of Bitlis-Zagros Suture Zone (BZSZ) which is in the Arabian foreland. During the neotectonic period, the folded structures have been developed under the influence of tectonic compression from the Upper Miocene in the GAP Region where it is closely related to active tectonics. These tectonic activities produce more geothermal resources. Few studies have been carried out in this region for geothermal energy. Limited portions of the geothermal resources have been used both for thermal tourism and greenhouses in the GAP region. The aim of this study is to determine geological, tectonic and hydrogeochemical properties of a geothermal system in the GAP Region. The result indicates that the surface temperatures of geothermal fluids are from 20 to 84.5 °C A large number of abandoned oil wells, whose temperature reaches 140 °C, are found in the region. Also, hydrogeochemical results show that deep circulated geothermal fluids are enriched with Na-Cl and shallow geothermal system fluids have Na−HCO 3 and Ca-SO 4 characters because of cold water mixing and water-rock interaction. Cold waters are generally of Ca-Mg−HCO 3 and Ca−HCO 3 type. Cation geothermometers were used for determining reservoir temperature of the geothermal resources in the region. The results show that the reservoir temperature of these geothermal resources ranges from 50 °C to 200 °C. The isotope data (oxygen-18, deuterium and tritium) suggests that geothermal fluid is formed by local recharge and deep circulation.
