SDG 12 · Sorumlu Üretim ve Tüketim · SDG

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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/4701
Upcycling Agricultural Biomass into Functional Bio-Oils through Pyrolysis: Toward Sustainable Rejuvenation of Asphalt Binder
Furtana Yalcin, Beyza; Yilmaz, Mehmet; Yalçin, Erkut; Vural Kok, Baha
This study investigates the feasibility of utilizing bio-oils derived from agricultural waste materials (such as straw, olive pomace, and pine cones) as rejuvenating additives in reclaimed asphalt pavement (RAP) containing bituminous mixtures, offering a sustainable and environmentally friendly approach in asphalt technology. The primary objective of the study is to enhance the physical and mechanical properties of aged binders using ecofriendly alternatives, thereby developing high-performance asphalt mixtures without harming the environment. The bio-oils, produced through pyrolysis, were evaluated in comparison with two commercial rejuvenators. Key performance criteria, including Marshall stability, moisture damage resistance (TSR), indirect tensile stiffness modulus (ITSM), and fatigue life, were tested. The results indicate that natural rejuvenators not only soften the aged binder but also effectively balance the flexibility, strength, and deformation resistance of the mixture. Notably, straw oil exhibited superior performance in terms of both high stability and extended fatigue life, while olive pomace oil demonstrated remarkable success in moisture resistance. Although commercial additives were effective to a certain extent, they failed to achieve the same level of structural compatibility and sustainability provided by natural bio-oils. In this regard, the study provides strong evidence that agricultural biomass waste can serve as a value-added solution in asphalt pavements, in alignment with the principles of the circular economy. In conclusion revealed that mixtures containing 75% RAP rejuvenated with straw oil achieved 11% higher Marshall stability and up to 14.5 times longer fatigue life compared to virgin mixtures, while olive pomace oil-based mixtures reached a TSR value of 81.5%, demonstrating superior moisture resistance.
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/4383
An integrated process for rare earth elements recovery and silica production from Turkish bauxite-related ores
Uysal, Turan; Erüst, Ceren; Erdemoglu, Murat; Sis, Hikmet
The evaluation of bauxite-associated shales as a secondary source of rare earth elements (REEs) is strategically important for securing a sustainable supply of critical raw materials used in advanced technologies. In this study, shale ore associated with bauxite, unsuitable for aluminium production due to its high silica content, was investigated as a potential resource for valuable REEs. The effect of thermal activation on REE recovery was examined, and the potential use of the leach residue as a silica source was assessed. Based on acid leaching results, the optimum calcination temperature was identified as 700 degrees C. Under these conditions, high REE recoveries were achieved: 92.9% La, 89.9% Ce, 89.0% Pr, 88.7% Nd, and 73.0% Sm. After leaching, the residue was enriched in alumina and silica. To improve silica purity and recover remaining REEs and Al, a second-stage leaching process was applied. This resulted in a byproduct containing 55% SiO2 with a specific surface area of 48 m2 g-1, indicating its potential as a silica source. The results demonstrate that bauxite-associated shale can be sustainably valorised through intensive milling, calcination, and acid leaching, enabling efficient REE recovery and the production of a silica-rich byproduct. L'& eacute;valuation de schistes associ & eacute;s & agrave; la bauxite comme source secondaire d'& eacute;l & eacute;ments de terres rares (ETR) est strat & eacute;giquement importante pour garantir un approvisionnement durable en mati & egrave;res premi & egrave;res critiques utilis & eacute;es dans les technologies avanc & eacute;es. Dans cette & eacute;tude, on a examin & eacute; le minerai de schiste associ & eacute; & agrave; la bauxite, inappropri & eacute; & agrave; la production d'aluminium en raison de sa teneur & eacute;lev & eacute;e en silice, comme ressource potentielle d'ETR pr & eacute;cieux. On a examin & eacute; l'influence de l'activation thermique sur la r & eacute;cup & eacute;ration des ETR et l'on a & eacute;valu & eacute; l'utilisation potentielle du r & eacute;sidu de lixiviation comme source de silice. D'apr & egrave;s les r & eacute;sultats de la lixiviation acide, on a identifi & eacute; la temp & eacute;rature optimale de calcination & agrave; 700 degrees C. Dans ces conditions, on a obtenu des r & eacute;cup & eacute;rations d'ETR & eacute;lev & eacute;es: 92.9% de La, 89.9% de Ce, 89.0% de Pr, 88.7% de Nd et 73.0% de Sm. Apr & egrave;s la lixiviation, le r & eacute;sidu & eacute;tait enrichi en alumine et en silice. Afin d'am & eacute;liorer la puret & eacute; de la silice et de r & eacute;cup & eacute;rer les ETR et l'Al restants, on a appliqu & eacute; une deuxi & egrave;me & eacute;tape de lixiviation. Cela a engendr & eacute; un sous-produit contenant 55% de SiO2 et pr & eacute;sentant une surface sp & eacute;cifique de 48 m2/g, indiquant son potentiel en tant que source de silice. Les r & eacute;sultats d & eacute;montrent que le schiste associ & eacute; & agrave; la bauxite peut & ecirc;tre valoris & eacute; de mani & egrave;re durable par broyage intensif, calcination et lixiviation acide, permettant une r & eacute;cup & eacute;ration efficace des ETR et la production d'un sous-produit riche en silice.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/1537
Integrating experimental and atomistic insights into the rejuvenation of aged binder using bio-based rejuvenators
Kurban, Mustafa; Yalcin, Beyza Furtana; Yilmaz, Mehmet; Akpinar, Sinan; Kök, Baha Vural; Hekim, Seda; Özdemir, Ahmet Münir; Yalcin, Erkut; Göktaş, Fahrettin
This study integrates experimental and computational methods to evaluate the rejuvenation performance of an aged asphalt binder using two novel bio-based additives, 1T and 2T. The aged binder, sourced from reclaimed asphalt pavement (RAP), was modified with 25 wt% of each rejuvenator (denoted as 1T25 and 2T25, respectively). SARA (Saturates, Aromatics, Resins, Asphaltenes) fractionation and colloidal indices were used to assess compositional recovery. Both additives increased aromatic and resin contents while reducing asphaltenes. The 2T-modified binder achieved the highest colloidal stability (Ic = 0.29) and the most pronounced improvement in stability indicators (CI and Ic) among the tested systems. Complementary molecular dynamics (MD) simulations using the COMPASSII force field modeled the structural and thermodynamic behavior of RAP and rejuvenated systems. The 2T25 system exhibited higher density and more compact molecular packing, suggesting stronger cohesive organization and reduced free volume, whereas 1T25 showed greater molecular spacing and flexibility. RDF analysis and converged thermodynamic/structural trajectories (energy, temperature, cell length, and density stabilization) further supported rejuvenator-dependent rearrangement of packing during equilibration. Overall, MD acts as a mechanistic bridge that interprets experimental SARA/CI/Ic trends and supports design-oriented development of sustainable rejuvenators.
AtıfScopus2OpenAlex1
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/1515
Optimization, high-temperature resistance, and sulfate durability of basalt powder–blended alkali-activated slag mortars
Arslan, Furkan; Dener, Murat; Karataş, Mehmet; Benli, Ahmet
This study investigates the feasibility of using basalt powder (BP), an industrial by-product with limited reactivity, as a partial substitute for granulated blast furnace slag (GBFS) in alkali-activated systems. A comprehensive experimental program was conducted in two stages: first, a systematic optimization was performed by varying mixture parameters, including BP content, alkali dosage, activator modulus, and curing temperature to evaluate compressive strength development; second, selected binder compositions were used to produce self-compacting mortars, which were further examined for flexural strength, high-temperature resistance, and sulfate durability. The results demonstrated that moderate substitution levels (up to 20–30 % BP) could achieve satisfactory compressive strength, particularly under elevated curing temperature (60 °C) with 8 % Na2O and low to moderate modulus values. At 300 °C, mixtures with 20 % BP exhibited strength enhancement due to additional geopolymerization, demonstrating superior thermal stability compared to the control. Crucially, the incorporation of BP enhanced sulfate resistance, with the 40 % BP mixture exhibiting a slight increase in compressive strength after long-term exposure, in contrast to the marked deterioration of the GBFS-only system. Consequently, this study demonstrates that BP can be effectively utilized as a sustainable binder component, offering a practical solution for waste management while enhancing the durability of alkali-activated mortars against aggressive conditions.
AtıfScopus15WoS13OpenAlex10
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/1493
Effects of putrescine and MAP on quality, phenolics, and organic acids in strawberry tree fruits
Gundogdu, Muttalip; Yücel, Gül; Çolak, Ayşen Melda; Aglar, Erdal
Background: Strawberry tree (Arbutus unedo L.) fruits are rich in bioactive compounds but are highly perishable due to their high respiration rate and soft tissue structure, leading to rapid post-harvest quality losses. Therefore, developing sustainable strategies to maintain quality and extend shelf life is of great importance. Methods: In this study, the individual and combined effects of putrescine (1 mM) and modified atmosphere packaging (MAP) on the post-harvest quality and biochemical properties of strawberry tree fruits were investigated. Fruits harvested at full maturity were stored at 4 ± 1 °C and 90 ± 5% relative humidity for 15 days, and key quality parameters including weight loss, decay rate, respiration rate, soluble solids content, titratable acidity, vitamin C, organic acids, and phenolic compounds were periodically analyzed. Additionally, correlation analysis and principal component analysis (PCA) were performed to evaluate the relationships among variables. Results: Storage duration significantly increased weight loss and decay rate, while decreasing organic acids, vitamin C, and phenolic compounds (p ≤ 0.001). At the end of storage, weight loss reached 2.97% in control fruits, whereas it decreased to 1.14% in the Put + MAP treatment, representing a reduction of approximately 61.6%. Similarly, decay rate decreased from 6.55% (control) to 3.34% (Put + MAP). Respiration rate was also significantly suppressed, with the lowest values observed in the combined treatment. Furthermore, malic acid (1.38 vs. 0.80 g/100 g) and vitamin C (36.90 vs. 28.37 mg/100 g) were better preserved in Put + MAP-treated fruits compared to control at day 15. PCA results confirmed that Put + MAP treatment maintained the most balanced profile between quality attributes and biochemical stability. Conclusion: The combined application of putrescine and MAP exhibited a strong synergistic effect by simultaneously reducing respiration, limiting water loss and decay, and preserving bioactive compounds. This study demonstrates that integrating a natural bioregulator (putrescine) with an environmentally friendly packaging system (MAP) represents an innovative and practical approach for extending the shelf life and maintaining the nutritional quality of strawberry tree fruits. This strategy also has high potential for application in other highly perishable soft fruits.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1482
Sustainable self-compacting mortars: mechanical, durability and microstructural evaluation with cement replacement materials under aggressive environmental conditions
Karabulut, Büşra; Yön, Merve Şahin; Karataş, Mehmet
The aim of this study is to assess the mechanical, physical and durability properties of environmentally friendly self-compacting mortars produced using materials containing industrial waste and natural stone. The test series were produced by substituting diatomite (D) and C class fly ash (F) with Portland cement (PC) up to 30% by weight. To evaluate the workability, mechanical and durability properties of self-compacting mortars (SCM), a total of 19 series, one of which was a reference sample, were prepared. The samples, whose mechanical properties and durability properties were investigated under sulphate attack and freeze-thaw effects, were prepared as 40 × 40 × 160 mm, and the series, whose physical properties were examined, were prepared as 50 × 50 × 50 mm. Also, SEM/EDS (Scanning Electron Microscope - Energy Dispersive X-Ray) and XRD (X-Ray Diffraction) analyses were carried out to evaluate the microstructural properties of the mixtures. When the 90-day compressive strength results were examined, it was determined that the highest decrease in compressive strength compared to the control sample occurred in the D20F10 sample with a rate of 61%, and the least decrease occurred in the D5 series with a rate of 10%. When the losses in compressive strength were evaluated after 50 freeze-thaw cycles, it was determined that there was a 100% reduction in the binary and ternary series containing D15 and D20. After six months of sulphate exposure, the D5F25 sample exhibited the most significant compressive strength reduction at roughly 40%, whereas the D15F15 series experienced the least compressive strength decline at around 5%.
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/1467
Comparative Analysis of Sequential Electrooxidation and Electrocoagulation Processes for Leachate Treatment
Ogedey, Aysenur; Oguz, Ensar
This study aims to improve the removal efficiency of chemical oxygen demand (COD), NH₃-N, and turbidity from Bingöl leachate through a sequential electrochemical process. This process includes electrooxidation (EO) with Ti/PdO-CoO anodes and stainless-steel cathodes, followed by electrocoagulation (EC) with aluminum anodes and stainless-steel cathodes. The sequential electrochemical process lasted 400 min, consisting of 360 min of EO followed by 40 min of EC process. At pH 5, COD and turbidity reached optimal removal efficiencies of 89% and 99.9%, respectively, while NH₃-N achieved 88.5% at pH 9.5. These results indicate that the sequential electrochemical process was most effective under these pH values for removing organic matter, nitrogen, and suspended solids. The sequential electrochemical process led to significant improvements in the removal efficiencies of COD, NH₃-N, and turbidity, with increases of 32.5%, 44%, and 6.9%, respectively, compared to the EO process. The sequential electrochemical process showed improvements of 9.5% in COD and NH₃-N removal, and 1.2% in turbidity removal, compared to the results of the EC process. The pseudo-first-order (PFO) reaction rates for the EO and EC processes were determined, resulting in high R2 values (0.98–0.99). Additionally, the total consumption cost of the EO process was higher than that of the EC process. After the sequential electrochemical process, the consumption cost increased from $13.586/kg COD to $24.332/kg COD as the current density increased from 15 mA/cm2 to 25 mA/cm2.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1449
A Strategic Pre-Mechanical Activation Approach for Reducing Acid Consumption and Ion Release on Acid Leaching of Lithium-Bearing Clays
Boylu, Feridun; Obuz Teker, Gülsen; Ersever Angur, Gafure; Özdemir, Orhan; Güven, Onur; Celik, Mehmet S.
The increasing demand for lithium and the limited availability of high-grade resources have accelerated interest in lithium-bearing clays as a promising alternative, despite their relatively lower lithium content. Lithium extraction from such clay minerals typically requires thermal treatment or acid leaching to disrupt the clay crystal lattice and enhance lithium solubility. The enrichment tailings from the Kırka Boron Processing Plant in Türkiye consist predominantly of dolomite-rich clay minerals and contain approximately 900–1200 ppm Li. Considering the substantial quantities of these tailings currently stored on-site, recovering lithium and converting these materials into a valuable resource would be of significant economic importance. However, due to their mineralogical composition, conventional acid leaching of these tailings demands relatively high sulfuric acid consumption (1.5–2.0 M H2SO4). This leads to excessively low solution pH and the generation of highly acidic waste streams, while also promoting the co-dissolution of iron (Fe) and aluminum (Al) ions at pH levels below 2, which negatively affects lithium recovery and downstream processing. In this study, mechanical activation was applied to the tailings prior to acid leaching. As a result, the acid requirement to achieve lithium extraction efficiencies of 90% and above was successfully reduced from 1.5 M to 1.0 M H2SO4. Moreover, solution pH was maintained near neutral (~7), and the undesirable dissolution of Fe and Al ions was effectively suppressed and kept under control.
AtıfScopus2WoS2OpenAlex2
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MakaleYalnız künye2026Scopus SJRQ1/r/munzur/1429
From trash to technology: Ai-driven waste classification with hybrid CNN-transformer approach for sustainable recycling
Utku, Anil
The increasing amount of waste globally requires more efficient recycling processes and increases the importance of intelligent, automatic classification systems. Since traditional waste separation methods are time-consuming and have high error rates, artificial intelligence-based solutions have great potential in this area. In this study, the effectiveness of deep learning-based waste classification models was investigated, and nine different waste types were classified using DenseNet121, EfficientNetB0, ResNet50, ViT, DenseNet121-ViT, EfficientNetB0-ViT, ResNet50-ViT. Experimental results show that hybrid CNN-ViT models achieved the highest accuracy rates. Mainly, the EfficientNetB0-ViT model exhibited the best performance with a 95% accuracy rate and made a balanced classification for all waste types. The model can optimize recycling processes by ensuring the correct separation of wastes and contribute to environmental sustainability by reducing misclassification. Artificial intelligence-supported waste management systems offer an effective solution in critical areas such as reducing greenhouse gas emissions, saving energy, and supporting environmentally friendly urban planning. The findings of this study reveal that deep learning-based artificial intelligence models are an important tool for sustainable environmental management.
AtıfScopus1WoS1OpenAlex3
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/1423
Optimization of native plant selection for phytomining of strategic/critical raw materials using Artificial Bee Colony algorithm
Arslan Topal, E. Işıl; Topal, Murat; Çelik, Erdal; Öbek, Erdal
This study investigates the potential of native plant species (NPs) as secondary sources for strategic/critical raw materials (SCRMs) through phytomining, aiming to identify the most efficient accumulator for sustainable element recovery. To achieve high-precision results, the Artificial Bee Colony (ABC) algorithm, a robust meta-heuristic optimization technique inspired by the foraging behavior of honeybees, was utilized to minimize the error between experimental data and predicted models to optimize the accumulation of key elements including cobalt (Co), strontium (Sr), antimony (Sb), vanadium (V), phosphorus (P), lanthanum (La), magnesium (Mg), titanium (Ti), aluminum (Al), and scandium (Sc). The research focused on three NP species—Musk thistle (MT), curly dock (CD), and Juncus (JS)—collected from a geothermal hot spring area. Methodological validation was performed through comparative statistical analysis and the calculation of bioconcentration factor (BCF) and translocation factor (TF) to assess phytoremediation efficiency. The ABC optimization results revealed that MT exhibited the most significant accumulation capacity, particularly for Mg, reaching a peak concentration of 3,910 mg/kgdw in the leaves. The concentration range (lowest to highest value) was between 0.01 (for La) and 3,910 mg/kgdw for the studied plants. Principal component analysis (PCA) corroborated these findings, explaining cumulative variances of 80.4% (MT), 89.4% (CD), and 76.4% (JS). The innovation of this study lies in the application of the ABC algorithm to the field of phytomining, which offers a more dynamic and flexible alternative to traditional regression-based models. The primary advantage of this proposed method is its superior global search capability and ability to handle multi-elemental interactions with high predictive accuracy. However, a potential disadvantage remains the computational complexity and the requirement for fine-tuning control parameters to ensure consistent convergence. Overall, MT is identified as a highly promising candidate for the phytomining of SCRMs, with Mg emerging as the most effectively accumulated element under the optimized ABC model.
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/1377
Adsorption of Reactive Red 120 dye from aqueous solutions using sepiolite clay with a channel-structured morphology: Mechanism, kinetics, isotherm, and thermodynamic studies
Fırat, Tülay
The effective treatment of dye-containing wastewater remains a major environmental challenge due to the high stability and solubility of reactive dyes. In this study, the adsorption behavior of Reactive Red 120 (RR120), an anionic reactive azo dye, from aqueous solutions was investigated using natural sepiolite clay possessing a channel-structured morphology. Batch adsorption experiments were performed to evaluate the effects of contact time (1–200 min), initial dye concentration (50–500 mg L−1), adsorbent dosage (0.1–1.5 g), solution pH (2–10), and temperature (25–50°C). The adsorption equilibrium was reached within approximately 75 min. The Langmuir isotherm provided the best fit to the equilibrium data, yielding a maximum monolayer adsorption capacity of 168.4 mg g−1 at 298 K. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic, with an activation energy of 32.41 kJ mol−1. Adsorption kinetics were analyzed using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, while equilibrium data were evaluated using Langmuir, Freundlich, and Temkin isotherm models. The kinetic data were best described by the pseudo-second-order model, while thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. FTIR and XRD analyses further supported the important role of the channel-structured framework of sepiolite in RR120 adsorption. Unlike many clay-based adsorbents that require chemical modification, natural sepiolite exhibited high adsorption performance due to its intrinsic fibrous morphology, nano-channel structure, and high surface area. These findings demonstrate that natural sepiolite is a promising, low-cost, and sustainable adsorbent for the treatment of dye-contaminated wastewater.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1294
Multifunctional PLA/PHA-Based films incorporating Moluccella spinosa extract for sustainable and antimicrobial food packaging applications
Selcuk Pekdemir, Sibel; Gurler, Nedim; Yilmaz Sancar, Pelin; Karagulle, Burcu; Kok, Mediha; Pekdemir, Mustafa Ersin; Qader, Ibrahim Nazem
In this study, a novel plant-based shape memory biocomposite was developed for sustainable food packaging applications. A poly(lactic acid)/poly(hydroxyalkanoate) (PLA/PHA) blend was reinforced with the ethanolic extract of Moluccella spinosa, a plant recognized for its bioactive constituents. Structural and thermal analyses confirmed the successful incorporation of the extract without compromising the polymer matrix integrity. The results demonstrated improved barrier performance, characterized by lower water vapor permeability, reduced moisture content, and slightly increased opacity with increasing concentrations of M. spinosa extract. In addition, the composite films exhibited enhanced shape memory behavior, which became more pronounced at higher extract concentrations. Antimicrobial assays revealed a limited and selective inhibitory effect, primarily against Gram-positive bacteria (Enterococcus faecalis and Clostridium perfringens), while no notable activity was observed against Escherichia coli and Staphylococcus aureus. These findings indicate a preliminary antimicrobial potential, likely associated with a sustained-release mechanism rather than strong bactericidal activity. Overall, the integration of M. spinosa extract into the PLA/PHA matrix offers a promising route to design multifunctional, biodegradable packaging materials with shape memory capability, where antimicrobial functionality serves as a complementary feature, contributing to the advancement of environmentally friendly and active food packaging technologies.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1264
Sustainable epoxy based biocomposites reinforced with Melilotus officinalis: Structural, mechanical, thermal, and dielectric performance evaluation
Solmaz, Adnan; Açar, Mikail; Demirel, Maruf Hurşit; Deniz, Şermin; Aydoğmuş, Ercan
The aim of this study is to investigate the manufacturability of Melilotus officinalis (L.) reinforced epoxy biocomposites as a renewable biofiller and to characterize the mechanical, thermal, and dielectric properties of these materials. For this purpose, composites containing biomass at 0, 3, 6, and 9 wt.% were prepared; the samples were examined by tensile testing, FTIR, SEM, EDX, XRD, Shore D hardness, thermal conductivity, and dielectric analysis. The findings showed that with increasing M. officinalis content, tensile strength, hardness, and density decreased, while ductility and elongation at break improved. The significant decrease in thermal conductivity revealed an increase in heat insulation efficiency. Dielectric analyses showed that strong interfacial polarization occurred at low frequencies, and the dielectric constant and loss values decreased as the frequency increased. SEM examinations confirmed that the plant-derived filler was homogeneously distributed and formed acceptable interfacial adhesion with the matrix. In conclusion, although the use of synthetic epoxy matrix and the decrease in mechanical strength limit load-bearing structural applications, M. officinalis is a promising biofiller for lightweight and partially bio-based epoxy composites thanks to its increased ductility and improved thermal insulation properties. © The Author(s) 2026. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
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MakaleAçık Erişim2026Scopus SJRQ3/r/munzur/1238
Optimized bioleaching of spent FCC catalysts for the recovery of critical metals
Erust, Ceren; Altındaş, Mediha Demet Okudan
Spent fluid catalytic cracking (FCC) catalysts, generated in large volumes by petroleum refining, represent a promising secondary source of critical metals such as lanthanum, cerium, titanium, and vanadium. In this study, a biohydrometallurgical approach was applied to recover these metals using Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans. The spent FCC catalyst, supplied by petroleum refinery, was characterized through WD-XRF, XRD, SEM-EDS, and ICP-OES analyses, confirming significant concentrations of La2O3 (1.44%), TiO2 (1.43%), and CeO2 (0.23%). Bioleaching experiments were conducted under varying initial ferrous ion concentrations (1–9 g/L) and pulp densities (5–20% w/v) at 35°C over 14 days. Results revealed that the optimal conditions for maximum recovery occurred at 5 g/L Fe2+ and 10% pulp density, achieving leaching efficiencies of 95.5% for La, 90.5% for Ce, 92.5% for Ti, and 60.8% for V within seven days. Beyond this period, efficiency decreased due to jarosite formation and microbial activity constraints. The findings confirm that bioleaching is a cost-effective and sustainable route that aligns with circular economy principles by reducing reliance on virgin rare earth mining while mitigating the environmental impact of catalyst disposal.
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MakaleAçık Erişim2026Scopus SJRQ1/r/munzur/1224
Sustainable material pathways: Utilizing biomass-derived bio-oils from agricultural wastes to restore aged asphalt binder properties
Yalcin, Beyza Furtana; Yilmaz, Mehmet; Yalcin, Erkut; Kok, Baha Vural
This study explores the valorization of agricultural biomass wastes into high-value bio-based materials by evaluating the performance of pyrolysis-derived bio-oils obtained from straw, pine cone, and olive pomace for the rejuvenation of aged asphalt binders. The effectiveness of these biomass-derived bio-oils was comparatively assessed against two commercial rejuvenators to enhance binder reusability using renewable resources. The optimum rejuvenator dosages were determined through penetration, viscosity, and dynamic shear rheometer (DSR) tests, while the associated physical and chemical modifications were investigated using FTIR, SEM-EDS, and elemental analyses. Penetration and viscosity results indicated that all rejuvenators significantly reduced binder stiffness and improved fluidity. DSR analysis indicated that increasing rejuvenator content reduced G∗/sin δ values, reflecting a decrease in binder stiffness and a softening effect of the rejuvenators, which contributes to restoring the viscoelastic balance of the aged binder. FTIR results demonstrated that biomass-derived bio-oils, particularly those from pine cone and straw, effectively reduced carbonyl (C=O) and sulfoxide (S=O) functional groups, indicating strong chemical rejuvenation. SEM-EDS analyses showed that the heterogeneous and porous morphology of bio-oils promoted improved interaction with the asphalt binder. Based on the combined results of the three experimental approaches, the optimum rejuvenator dosages were identified as 25% for commercial products, 35% for pine cone and olive pomace bio-oils, and 45% for straw bio-oil. Overall, the findings highlight that biomass-derived bio-oils produced via pyrolysis offer a sustainable and performance-effective pathway for converting agricultural residues into value-added materials, supporting circular bioenergy and biomass utilization strategies.
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MakaleAçık Erişim2026Scopus SJRQ2/r/munzur/1209
Synergistic Effect of Cylindrical Fins and Phase Change Material on the Thermal and Economic Performance of a Double-Slope Solar Distillation Device Under Tunceli Climatic Conditions
Tuğan, Volkan; Işık, Erdem; İnallı, Mustafa
Global water scarcity driven by population growth, climate variability, and rising freshwater demand increases the need for more efficient solar desalination systems. In this study, a double-slope solar distillation device supported by a phase change material pool was developed to improve freshwater production. The phase change material layer was placed directly beneath the absorber plate to store excess thermal energy during peak solar radiation and release it during low-radiation periods. To strengthen thermal interaction between the absorber surface and the storage medium, cylindrical fins were embedded within the phase change material pool. The development of a double-slope solar distillation device integrated with a finned phase change material pool, and the simultaneous comparison of the thermal efficiency and economic analyses of single-slope and double-slope solar distillation devices under the same climatic conditions, are the prominent features of this study. Additionally, the performance of solar distillation devices has not previously been investigated under the climatic conditions of Tunceli, which further motivates this research. The developed system reached a peak freshwater productivity of 2459.2 g/m2/day, providing a 21.4% enhancement over the conventional configuration. In addition, the thermal efficiency increased from 17.7% in the conventional unit to 21.4% in the phase change material-assisted design. The economic analysis showed that the cost of distilled water was $0.097/kg for the conventional system and $0.105/kg for the proposed system, with the corresponding payback periods being approximately 11 and 12 months, respectively.
AtıfScopus2WoS2OpenAlex2
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MakaleAçık Erişim2026Scopus SJRQ4/r/munzur/1198
Solvent Extraction of Copper from Sulfate Solutions Using Acorga OPT5510; [Extracción de cobre de soluciones de sulfato mediante solventes con Acorga OPT5510]
Karacahan, Mehmet Kayra
This study used a solvent extraction technique with AcorgaOPT5510 extractant in kerosene to examine the extraction of copper ions from the actual leach solution produced after leaching malachite ore in sulfuric acid solutions. On the Cu/Fe separation factor and the effectiveness of copper extraction, the impacts of significant parameters, including stirring speed, contact duration, extractant concentration, beginning solution pH, and temperature, were examined. The following values were chosen as the optimal ones: 1:1, 1.5, 12%, 20 °C, 10 min, 10 min, and 500 rpm for maximum Cu2+ extraction from the aqueous-phase, aqueous/organic phase ratio, equilibrium pH of the aqueous phase, extractant concentration, temperature, contact time, settling time, and stirring speed. Under these conditions, 94% of the copper in the leach solution was removed, yielding about 40.09 Cu/Fe separation factor. A McCabe-Thiele plot was revealed, and it was shown that a two-step extraction procedure would yield the best results. Furthermore, employing a sulfuric acid concentration of 4 mol·L-1 for 10 minutes, the loaded organic phase was stripped and recovered 91% copper.
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MakaleAçık Erişim2026Scopus SJRQ3/r/munzur/1106
Effect of mechanical activation on lithium and alkali cation release from dolomitic clay wastes of boron processing plant
Boylu, Feridun; Teker, Gülsen Obuz; Angur, Gafure Ersever; Ozdemir, Orhan; Çelik, Mehmet Sabri
With the significant increase in lithium demand and production, alternative resources such as lithium-bearing clays have increasingly attracted attention and have been considered as a potential source. In addition to conventional Li recovery methods such as acid treatment and roasting, more economical and environmentally friendly techniques such as mechanical activation followed by water leaching are also being considered. In Türkiye, wastes from boron processing plants, containing approximately 900 ppm of lithium and mainly of dolomitic clays and unrecovered boron minerals (~10-13% of waste), are considered as a potential lithium source. However, due to high dolomite and boron mineral contents, the waste material may release significant amounts of alkaline earth ions such as Na+, K+, Mg2+, Ca2+, and B2O3 during leaching, which may interfere with lithium extraction from the solution. In this study, the leaching behavior of lithium, alkali ions, and other possible elements (e.g., B2O3, Fe3+, and Al3+) from both raw clay waste and mechanically activated forms of this waste material was investigated in detail. The results showed that water leaching without sodium salt of activated waste samples achieves about 44.7–57.7% lithium recovery, yielding high lithium concentrations (80–115 ppm), low levels of alkali ions (4430 ppm Na+, 114 ppm K+, 20 ppm Ca2+, and 7 ppm Mg2+), and almost no detectable Fe3+ (<0.2 ppm) or Al3+ (0.07 ppm) ions. On the other hand, a single problem was encountered where 0.95 % of B2O3 concentrations did not decrease in water leaching at even room temperature.
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MakaleYalnız künye2026Scopus SJRQ2/r/munzur/1079
Oxalic Acid–MAP Synergy in Maintaining Postharvest Grape Quality and Biochemical Content
Küçüker, Emine; Ağlar, Erdal; Sümbül, Ahmet; Demir, Selda; Özcengiz, Ceyda Kizgin; Güzel, Sedat
This study was conducted to investigate the effects of oxalic acid (OA) and modified atmosphere packaging (MAP) applications, both alone and in combination, on the preservation of postharvest quality characteristics of grapes. All samples were stored at 4 ± 1 °C and approximately 80–85% relative humidity for 28 days. The OA + MAP treatment most effectively limited weight loss (10.49%), soluble solids content (SSC; 20.62°Bx), and decay rate (1.78%), while providing the best preservation of total phenolic content (68.25% change), antioxidant activity (53.19% change), and individual phenolic compounds at the end of the storage period. A decrease in color parameters, including L* and a* values, was observed, with OA treatment particularly prominent in preserving the red color. Principal component analysis and hierarchical heatmap analysis confirmed distinct clustering of treatments from the control, highlighting the process efficiency of packaging-based interventions. The combination of OA and MAP treatments was more effective than either treatment alone in reducing quality losses in grapes during storage. Therefore, the widespread use of OA + MAP in commercial storage and marketing processes is recommended.
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MakaleYalnız künye2026Scopus SJRQ1/r/munzur/1071
Enhancing durability of slag-based alkali-activated composites with dunite sand and carbon fiber: Sulfate, freeze–thaw, and thermal resistance optimization
Benli, Ahmet; Bürlükkara, Sadullah; Öz, Ali; Karataş, Mehmet; Kaplan, Gökhan
The replacement of natural river sand with sustainable alternatives is essential to reduce environmental degradation associated with aggregate extraction. In this context, dunite sand (DS), a magnesium-rich ultramafic mineral, was investigated as an eco-efficient fine aggregate in thermally cured slag-based alkali-activated composites (AACs), in combination with carbon fiber (CF) reinforcement. The study aims to clarify how aggregate substitution and fiber addition interact to control matrix densification, crack-bridging efficiency, and durability under aggressive conditions. Sixteen mixtures incorporating varying DS (0–100%) and CF (0–1.00%) contents were prepared and cured at 80°C to promote rapid slag activation and microstructural development. Mechanical performance, high-temperature resistance, sulfate durability, and freeze–thaw behavior were systematically evaluated. The results demonstrate that moderate DS substitution (~25%) significantly improves matrix compactness and interfacial quality through a micro-filler effect, leading to enhanced strength and durability. CF effectively bridge micro cracks and improve flexural and thermal performance; however, excessive fiber contents impair workability and increase porosity due to fiber clustering. Durability results confirm that optimized DS–CF combinations reduce thermal degradation, limit sulfate-induced deterioration, and enhance resistance to cyclic freezing. Overall, 25% DS replacement combined with limited CF content (≤0.50%) provides the best balance between mechanical performance and durability. The findings highlight the importance of controlling aggregate–fiber synergy and curing strategy to develop durable, thermally stable, and sustainable alkali-activated composites for harsh service environments.
AtıfScopus5WoS4OpenAlex4
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