Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Sustainable Recovery of Critical Raw Materials From Geothermal Igneous Systems: Geochemical, Mineralogical, and Techno-Economic Insights from the Dikili-Bergama Field (Western Anatolia, Turkiye)
    (Elsevier, 2026) Ayzit, Tolga; Baba, Alper
    The sustainable co-extraction of critical raw materials (CRMs) with renewable geothermal energy offers a dual pathway to support the circular economy and low-carbon transition. In this study, an integrated geochemical and mineralogical approach is used to comprehensively assess the recoverable lithium (Li) boron (B), strontium (Sr) and other critical raw materials in the geothermal reservoirs of the Dikili-Bergama region Turkiye. A geochemical analysis was carried out by systematic sampling and multi-element testing of geothermal water and reservoir rock. Hydrogeochemical studies of the geothermal fluids indicated the presence of remarkable concentrations of B (4.6 ppm), Sr (2.8 ppm) and Li (1.2 ppm), suggesting the possibility of active leaching processes in the deposit. Mineralogical studies using X-ray diffraction (XRD) have revealed a number of secondary mineral phases, such as quartz and labradorite, indicating the interaction between water and rock. These interactions affect not only the permeability and porosity of the deposit, but also the mobilization and precipitation of CRMs. A techno-economic analysis will be used to identify potential synergies that could improve the economic feasibility of geothermal projects in the region. The Monte Carlo simulation has shown that the Dikili-Bergama geothermal reservoirs have a potential of similar to 712 tons of Li. In this study, the CRM potential that emerged during the geothermal energy exploitation process in the region was calculated. The temporality and the process of obtaining are completely related to the extraction technology. This offers the dual benefit of renewable energy and strategic mineral extraction, contributing to sustainable resource management in volcanic environments.
  • Article
    Mass Spectrometric Profiling Reveals Alterations in N-Glycans and O-Glycans in Tay-Sachs Disease Under Autophagy-Induced Conditions
    (Springer, 2025) Can, Melike; Basirli, Hande; Jin, Chunsheng; Karlsson, Niclas G.; Bojar, Daniel; Seyrantepe, Volkan
    Tay-Sachs disease is a rare neurodegenerative disorder caused by mutations in the HEXA gene. The HEXA gene encodes the alpha-subunit of the enzyme beta-hexosaminidase A, which degrades GM2 ganglioside. Previously, we identified impaired autophagy in the brains of a mouse model of Tay-Sachs disease, which exhibited neuropathological and clinical abnormalities. Moreover, we demonstrated autophagosome clearance in Tay-Sachs cells under lithium-induced conditions. Here, we further aimed to evaluate N- and O-glycan changes in these cells and examine whether glycan alterations are linked to ER stress. The profiles of N- and O-glycans were analyzed using LC-MS/MS in fibroblasts and neuroglial cells from 5-month-old Hexa-/-Neu3-/- mice and neuroglial cells from Tay-Sachs patients under lithium induction and nutrient deprivation. The expression levels of ER stress-related markers were assessed using qRT-PCR and Western blot analyses. We demonstrated higher levels of high mannose and lower levels of complex types of N-glycans, along with increased O-glycan levels in Tay-Sachs cells. Compared to control groups, we observed upregulated expression of endoplasmic reticulum (ER) stress-related markers, CHOP and ATF-6, in Tay-Sachs cells. Our study demonstrated that autophagy induction causes the degradation of accumulated high-mannose N-glycans and O-glycans, which is associated with the downregulation of ER stress-related genes in Tay-Sachs cells. Our study is the first to show this phenomenon in Tay-Sachs cells and suggests the presence of ER stress-mediated autophagy. Therefore, targeting glycans through autophagy induction could offer therapeutic benefits to patients with Tay-Sachs disease in future studies.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 23
    Lithium: an Energy Transition Element, Its Role in the Future Energy Demand and Carbon Emissions Mitigation Strategy
    (Elsevier Ltd, 2024) Chandrasekharam,D.; Şener,M.F.; Recepoğlu,Y.K.; Isık,T.; Demir,M.M.; Baba,A.
    Energy transition elements (Li, Ni, Co, Fe, Cu) are gaining importance due to their ability to provide energy and play an important role as primary energy sources. Because of the energy density and power density, Li-ion batteries have the edge over other batteries. Li is distributed in various rock-forming minerals and brines, and geothermal waters. Though lithium-bearing minerals are spread over a broad geographic region, these minerals are confined to certain countries with substantial economic potential. Li is extensively used in batteries, and battery-driven vehicles are growing exponentially to meet the carbon reduction goal of the Paris agreement in 2015 and signed by more than 50 percent of the countries. Nearly 55 million cars supported by Li batteries are expected to roll out by 2030. While this is the demand, its occurrence and concentration/extraction processes are not keeping pace with this demand. The extraction of Li from its ore is an energy-intensive process involving many fossil fuel-based energies. To recover one ton of Li metal, nearly 5 to 6 tons of CO2 is emitted. The CO2 emissions of 28 kWh LFP, NMC, and LMO batteries vary from 5600 to 2705 kg CO2-eq. The end-of-life emissions of an internal combustion engine (ICE) vehicle are 400 kg CO2/vehicle, while Li Battery supports 500 kg/vehicle. The quantity of Li required for a 24 kWh average capacity leaf battery is about 137 g/kWh. While emissions are associated with the manufacturing of the batteries, emissions are also associated with a way that while they are recharged as the recharging source is fossil fuel-based energy. The best option to meet zero net carbon emissions by 2050, as envisaged by International Energy Agency (IEA), is to recover Li from geothermal brines and use geothermal energy for recharging. While hydrothermal energy sources are site-specific, enhanced geothermal system (EGS) based geothermal energy is not site-specific and is found wherever high radiogenic granites are available. High radiogenic granites are widely distributed, and heat recovered from EGS sources can provide clean energy and heat. Extraction of lithium from geothermal waters and using geothermal energy for recharging the batteries will drastically reduce CO2 emissions. It will drive the world towards Net Zero Emissions (NZE) scenario in the future. This is being practiced in Turkey. Future research should develop technology to recover Li from geothermal fluids with low concentration and support EGS development. © 2024 Elsevier Ltd
  • Article
    Citation - WoS: 15
    Citation - Scopus: 15
    Granulation of Hydrometallurgically Synthesized Spinel Lithium Manganese Oxide Using Cross-Linked Chitosan for Lithium Adsorption From Water
    (Elsevier B.V., 2024) Recepoğlu,Y.K.; Arabacı,B.; Kahvecioğlu,A.; Yüksel,A.
    A drastic increase in demand for electric vehicles and energy storage systems increases lithium (Li) need as a critical metal for the 21st century. Lithium manganese oxides stand out among inorganic adsorbents because of their high capacity, chemical stability, selectivity, and affordability for lithium recovery from aqueous media. This study investigates using hydrometallurgically synthesized lithium manganese oxide (Li1.6Mn1.6O4) in granular form coated with cross-linked chitosan for lithium recovery from water. Characterization methods such as SEM, FTIR, XRD, and BET reveal the successful synthesis of the composite adsorbent. Granular cross-linked chitosan-coated and delithiated lithium manganese oxide (CTS/HMO) adsorbent demonstrated optimal removal efficiency of 86 % at pH 12 with 4 g/L of adsorbent dosage. The Langmuir isotherm at 25 °C, which showed monolayer adsorption with a maximum capacity of 4.94 mg/g, a better fit for the adsorption behavior of CTS/HMO. Adsorption was endothermic and thermodynamically spontaneous. Lithium adsorption followed the pseudo-first-order kinetic model. © 2024
  • Article
    Citation - WoS: 4
    Citation - Scopus: 5
    Breakthrough Curve Analysis of Phosphorylated Hazelnut Shell Waste in Column Operation for Continuous Harvesting of Lithium From Water
    (Elsevier, 2024) Recepoğlu, Yaşar Kemal; Arar, Ozguer; Yuksel, Asli
    In batch-scale operations, biosorption employing phosphorylated hazelnut shell waste (FHS) revealed excellent lithium removal and recovery efficiency. Scaling up and implementing packed bed column systems necessitates further design and performance optimization. Lithium biosorption via FHS was investigated utilizing a continuous-flow packed-bed column operated under various flow rates and bed heights to remove Li to ultra-low levels and recover it. The Li biosorption capacity of the FHS column was unaffected by the bed height, however, when the flow rate was increased, the capacity of the FHS column decreased. The breakthrough time, exhaustion time, and uptake capacity of the column bed increased with increasing column bed height, whereas they decreased with increasing influent flow rate. At flow rates of 0.25, 0.5, and 1.0 mL/min, bed volumes (BVs, mL solution/mL biosorbent) at the breakthrough point were found to be 477, 369, and 347, respectively, with the required BVs for total saturation point of 941, 911, and 829, while the total capacity was calculated as 22.29, 20.07, and 17.69 mg Li/g sorbent. In the 1.0, 1.5, and 2.0 cm height columns filled with FHS, the breakthrough times were 282, 366, and 433 min, respectively, whereas the periods required for saturation were 781, 897, and 1033 min. The three conventional breakthrough models of the Thomas, Yoon-Nelson, and Modified Dose-Response (MDR) were used to properly estimate the whole breakthrough behavior of the FHS column and the characteristic model parameters. Li's extremely favorable separation utilizing FHS was evidenced by the steep S-shape of the breakthrough curves for both parameters flow rate and bed height. The reusability of FHS was demonstrated by operating the packed bed column in multi-cycle mode, with no appreciable loss in column performance.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Cross-Linked Phosphorylated Cellulose as a Potential Sorbent for Lithium Extraction From Water: Dynamic Column Studies and Modeling
    (American Chemical Society, 2022) Recepoğlu, Yaşar Kemal; Yüksel, Aslı
    Phosphorylated functional cellulose was cross-linked with epichlorohydrin at different ratios because it is a very hydrophilic substance that instantly swells to form a hydrogel when it comes into contact with water. It was aimed to utilize a continuously packed bed column to recover lithium from water under varying operating conditions such as flow rate and bed height. The characterization results confirmed cross-linking based on morphology, structure, surface area, and thermal stability differences. Lithium recovery was more efficient with a low flow rate, but the dynamic sorption process was independent of bed height. The total capacities at the three flow rates with 1.5 cm bed height were 33.56, 30.15, and 25.54 mg g-1, and the total saturation times at the three different bed heights with 0.5 mL min-1 flow rate were 659, 1001, and 1007 min, respectively. Only 15.75 mL of 5% H2SO4 solution was required to desorb approximately 100% of Li from the saturated sorbent.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 11
    Valorization of Olive Tree Pruning Waste for Potential Utilization in Lithium Recovery From Aqueous Solutions
    (Springer, 2022) Nampeera, Jackline; Recepoğlu, Yaşar Kemal; Yüksel, Aslı
    Olive tree pruning waste, mainly composed of olive branches, was converted into a value-added and sustainable product capable of lithium as a biosorbent through alkali treatment and phosphorylation reaction. Characterization studies were performed by SEM–EDX, XPS, FTIR, and TGA. Factors affecting biosorption mechanism, i.e., sorbent dosage, pH, initial Li+ concentration and temperature, and competitive ions’ presence, were investigated the synthesized functionalized olive branches (FOB). A commercial lithium selective resin, Lewatit TP 260, was also compared with FOB in batch and column studies. The Freundlich model fits adsorption isotherms better than the Langmuir model, with a maximum adsorption capacity of 6.7 mg/g at 30 °C and pH 7–8. Kinetic studies proved fast kinetics and equilibrium were attained in 6 min, while thermodynamic studies showed an exothermic (Δ Ho= - 17.52 kJ/ mol) , spontaneous reaction Δ Go< 0 at all temperatures), and increased randomness Δ So= + 24.27 J/ mol. K) at the interaction interface. Column studies revealed that although Lewatit TP 260 resin showed higher sorption capacity, its desorption efficiency (50.42%) was lower than that of FOB (99.9%), and the degree of column utilization of FOB (56.81%) was better than Lewatit TP 260 resin’s (16.0%). The findings were encouraging in the successful synthesis of a promising biosorbent from an abundant waste in Turkey for use in sustainable lithium recovery from aqueous sources. Graphical abstract: [Figure not available: see fulltext.]
  • Article
    Citation - WoS: 17
    Citation - Scopus: 16
    Synthesis, Characterization and Adsorption Studies of Phosphorylated Cellulose for the Recovery of Lithium From Aqueous Solutions
    (Editura Acad Romane, 2021) Recepoğlu, Yaşar Kemal; Yüksel, Aslı
    In this study, pristine cellulose was functionalized by the phosphorylation reaction to make it suitable for lithium separation. After characterization studies of the synthesized adsorbent with SEM, EDX, FTIR, TGA and XPS, the effects of various parameters on the lithium uptake capacity of the adsorbent were examined. The analysis of equilibrium data by several adsorption models showed that maximum adsorption capacity of the adsorbent was found to be 9.60 mg/g at 25 degrees C by the Langmuir model. As initial concentration and contact time increased, adsorption capacity also increased, however, mild temperature (25-35 degrees C) and pH (5-6) were better for the adsorption of lithium. 80% of lithium adsorption within three minutes proved the fast kinetic nature of the adsorbent. A 99.5% desorption efficiency of lithium was achieved with 0.5 M H2SO4, among HCl and NaCl with different molarities. Phosphorylated cellulose was shown to be a favorable adsorbent for the recovery of lithium from aqueous solutions.
  • Article
    Citation - WoS: 25
    Citation - Scopus: 26
    Phosphorylated Hazelnut Shell Waste for Sustainable Lithium Recovery Application as Biosorbent
    (Springer, 2021) Recepoğlu, Yaşar Kemal; Yüksel, Aslı
    Hazelnut shell waste was phosphorylated to develop a novel biosorbent based on natural renewable resource for the recovery of lithium from aqueous solution. For the synthesized biosorbent, the surface morphology and mapping by SEM-EDS, chemical properties by FTIR, elemental analysis by XPS, specific surface area by BET, crystallinity by XRD and thermal properties by TGA were elucidated elaborately. The influence of biosorbent dosage, initial concentration, temperature, contact time, pH and coexisting ions were investigated. The equilibrium sorption capacity reached 6.03 mg/g under optimal conditions (i.e., biosorbent dosage of 12.0 g/L, initial Li concentration of 100 mg/L, pH value of 5.8, sorption temperature of 25 degrees C, and sorption time of 6 min). According to the sorption behavior of the phosphorylated hazelnut shell waste the Freundlich model proved to be more suitable than the Langmuir model indicating maximum sorption capacity as 7.71 mg/g at 25 degrees C. Thermodynamic parameters obtained by different isokinetic temperatures disclosed that the ion exchange reaction was feasible, spontaneous, and exothermic where the interaction between biosorbent surface and solvent plays an important role. A preliminary test on the Li recovery from geothermal water was also performed to check its applicability in a real brine. Desorption studies at 25 degrees C revealed that relatively higher desorption efficiency and capacity were achieved at 97.4% and 5.93 mg/g, respectively with a 1.0 M H2SO4 among other regenerants (i.e., HCl and NaCl). Concentrations of Li and the other cations were determined via ICP-OES. Due to such outstanding features, the novel phosphorylated hazelnut shell waste had great potential for lithium recovery from aqueous solution by being added value as a waste and recovering a strategic element of modern life simultaneously. [GRAPHICS] .
  • Article
    Citation - WoS: 17
    Citation - Scopus: 19
    Effect of Operational Conditions on Separation of Lithium From Geothermal Water by ?-Mno2 Using Ion Exchange–membrane Filtration Hybrid Process
    (Taylor and Francis Ltd., 2018) Recepoğlu, Yaşar Kemal; Kabay, Nalan; Yoshizuka, Kazuharu; Nishihama, Syouhei; Yılmaz İpek, İdil; Arda, Müşerref; Yüksel, Mithat
    A hybrid system coupling ion exchange and ultrafiltration (UF) was employed to separate lithium from lithium-spiked geothermal water. The effect of process parameters such as adsorbent type, adsorbent dosage, permeate flow rate, and replacement speeds of fresh and saturated adsorbents have been evaluated to determine the efficiency of the hybrid system. According to the results obtained using λ-MnO2 derived from spinel-type lithium manganese dioxide, the optimal operating conditions to separate lithium from geothermal water were found with powdery λ-MnO2 with an adsorbent concentration of 1.5 g adsorbent/L solution, replacement rates of fresh and saturated adsorbents of 6.0 mL/min, and a permeate flow rate of 5.0 mL/min. The ion exchange–UF hybrid system providing an advantage to work with very fine particles easily can be considered as a favorable process for the separation of lithium from geothermal water.