Yazarlar
- Duran, Celal(26)
- Ozdes, Duygu(21)
- Baltaci, Cemalettin(10)
- Gundogdu, Ali(10)
- Gül, Abdulkadir(9)
- Çullu, Mustafa(8)
- Aksüt, Yavuz Selim(7)
- Baltacı, Cemalettin(7)
- Barut, Abdulkadir(7)
- Bozbeyoglu, Pinar(7)
- Erol, Ismail(7)
- Ozeken, Sengul Tugba(7)
- Peker, Iskender(7)
- Eker, Hasan(6)
- Külekçi, Gökhan(6)
- Altuner, Elif Esra(5)
- Ar, Ilker Murat(5)
- Güzel, Melih(5)
- Karahan, Selim(5)
- Karpuz, Ömer(5)
- Kıranşan, Murat(5)
- Odabaş, Halil İbrahim(5)
- Seferoğlu, Mehmet Tevfik(5)
- Uysal, Turan(5)
- Demir Şahin, Demet(4)
- Imamoglu, Mustafa(4)
- Karpuz, Omer(4)
- Top, Yener(4)
- Akar, Bülent(3)
- Akpinar, Muhammet Vefa(3)
- Akpınar, Özlem(3)
- Avci, Ibrahim(3)
- Aydoğmuş, Ercan(3)
- Bozbeyoğlu, Pınar(3)
- Cakir, Mehmet Ali(3)
- Camoglu, Aslihan Yilmaz(3)
- Cavusoglu, Ibrahim(3)
- Daulay, Amru(3)
- Ercikdi, Bayram(3)
- Komut, Osman(3)
Yayınlar
- Kitap BölümüYalnız künye2025Managing information asymmetry and conflicting interests in multi stakeholder sustainable supply chains using multi-criteria decision analysis
Şimşek, Ahmet Bahadir; Şimşek, Aybala
This chapter focuses on the challenges which information asymmetry and conflicts of interest present to multi- stakeholder sustainable supply chain design and suggests the use of MCDA to address these challenges. It looks at the ways information imbalances and divergent stakeholder priorities hamper cooperation and sustainability objectives to produce trust problems and ineffectiveness. These challenges are outlined in the chapter using theoretical underpinnings such as Game Theory and Akerlof's Market of Lemons. Next, it illustrates the MCDA's role in dealing with these problems (transparency, balancing conflicting interests and making the decision in an inclusive way). The practical application of MCDA is illustrated via a hypothetical green supply chain project that demonstrates the ability of diverse stakeholder priorities to be harmonised through systematic criteria evaluation and consensus building. The chapter concludes with a discussion of MCDA's potential for integrating environmental, social and economic goals in optimal decision making in complex supply chains.
- MakaleYayıncıda açık erişim2025Efficient extraction and determination of Au(iii) ions from acid mine drainage and water samples using silica gel immobilized with Brevibacillus borstelensis
Camoglu, Aslihan Yilmaz; Duran, Celal; Ozdes, Duygu; Nalcaoglu, Aleyna; Bektas, Kadriye Inan; Belduz, Ali Osman
The analysis of gold, which is a precious metal with limited resources, in environmental samples is crucial for the sustainable utilization of natural resources. Therefore, in the present research we have aimed to develop a novel and environmentally friendly bioadsorbent, Brevibacillus borstelensis loaded on silica gel (BB@Si), with outstanding adsorptive properties that can be implemented for quantitative recovery of Au(iii) ions via the solid phase extraction (SPE) technique. After characterizing the developed adsorbent using FTIR and SEM techniques, we conducted a detailed investigation of the critical parameters that influence the extraction performance of Au(iii) ions. Optimum parameters were observed as follows: pH 3.0, adsorption contact time 30 min, eluent type 0.1% (w/v) thiourea in 0.5 M HNO3, elution time 60 min, BB@Si amount 1.0 g L−1, and sample volume 400 mL. Some of the well-known isotherm and kinetic models were applied to the results observed from the adsorption studies. Equilibrium adsorption capacity of BB@Si was estimated to be 66.2 mg g−1 utilizing the Langmuir isotherm model while the limit of detection (LOD) and relative standard deviation (RSD%) were established as 0.99 μg L−1 and 3.7%, respectively. The developed method was utilized smoothly for the quantification of Au(iii) ions in mining wastewater, acid mine drainage (AMD), streams and seawater.
- MakaleYayıncıda açık erişim2025Chrome waste utilization in base layers: Mechanical strength and environmental risk assessment
Seferoğlu, Mehmet Tevfik; Acı, Elif Nur
This study investigates the partial substitution of natural aggregate (Na) with chrome mine waste (Crw) in highway base layers, focusing on mechanical performance and environmental safety. Crw-Na mixtures with contents from 0 % to 100 % were tested using CBR, cyclic plate loading, chemical, and leachate tests. The 15 % Crw-85 % Na mixture achieved the highest CBR (287.4 %) with limited deformation (37 mm). Although the 60 % Crw blend also met the required strength level (156.6 %), it showed higher settlement (50 mm) and three times greater vertical strain. SEM-EDX and chemical results indicated increased magnesium content and mineral changes at higher Crw ratios. Leachate tests confirmed compliance with TS266 and international water standards; all samples were categorized as neutral drainage with low metal risk. The findings show that Crw improves strength without causing environmental risk. Among tested mixtures, 15 % Crw offered the most balanced outcome in terms of field stability and performance.
- MakaleAçık Erişim2025DYE REMOVAL PERFORMANCE AND BIOLOGICAL ACTIVITIES OF IRON OXIDE NANOPARTICLES SYNTHESIZED FROM Cotoneaster sp. FRUIT EXTRACT
Akar, Bülent; Baltacı, Cemalettin; Düzgün, Azer Özad; Karpuz, Omer; Karakullukçu, Volkan; Erdoğdu, Esma Gülbahar
This work aimed to study the antioxidant, antibacterial, and dye adsorption capabilities of the aqueous extract of Cotoneaster sp. fruits (CFE) and iron oxide nanoparticles (CF-FeONP) green-synthesized from the CFE. CF-FeONPs were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The antioxidant activity of CFE and CF-FeONPs was assessed through various tests, including ABTS radical scavenging activity, DPPH radical scavenging activity, iron-reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant content (TAC). The CF-FeONPs had superior antibacterial and antioxidant activity compared to the CFEs. Furthermore, CF-FeONPs suppressed the growth of Gram-negative bacteria such as Yersinia pseudotuberculosis ATCC 911, Escherichia coli ATCC 25922, Proteus vulgaris ATCC 13315, and Pseudomonas aeruginosa ATCC 43288, as well as by Gram-positive bacteria like Streptococcus pyogenes ATCC 19615, Staphylococcus aureus ATCC 25923. and Bacillus subtilis ATCC 6633. The microdilution medium technique was used to determine the minimum inhibitory concentration (MIC) of CFE and CF-FeONPs against these bacteria strains. The adsorption rates of CF-FeONPs exhibited variability based on the quantity of adsorbent used and the specific dye type, whereas the lowest adsorption rate was 250 mg/L. CF-FeONPs demonstrated higher adsorption capacities for malachite green (MG) dye compared to methylene blue (MB) and phenol red (PR).
- MakaleYayıncıda açık erişim2025Optimization of rare earth elements recovery from Kızıldag (Karaman-Türkiye) shale ore using response surface methodology
Uysal, Turan; Ünal, Ceren Erust; Akça, Muhammet Esat; Sis, Hikmet; Erdemoğlu, Murat
In this study, the usability of bauxite-related shale ore, rich in Rare Earth Elements (REEs), to produce REEs, which have high added value and critical importance, was investigated. In this context, Kızıldag (Karaman-Türkiye) shale ore, was prepared for tests through size reduction and sampling processes. HCl leaching was performed at different acid concentrations, leaching times, leaching temperatures, and liquid/solid ratios to determine the optimum leaching conditions for the milled ore. The modeling and optimization parameters related to leaching recovery were investigated using the response surface method (RSM). The results were evaluated using analysis of variance, three-dimensional graphs were drawn, and the accuracy of the models was discussed. Accordingly, optimum values were found, and the REE leaching recovery corresponding to these optimum values was 49.13%. It was concluded that the optimization results were compatible with the experimental results, and the average error rate (6.35%) was low.
- MakaleAçık Erişim2025Flexural Behavior and Sustainability of Dual-Waste Fiber-Reinforced Concrete Designed for Pavement Applications
Seferoğlu, Mehmet Tevfik; Aksüt, Yavuz Selim; Seferoğlu, Ayşegül Güneş
This study evaluates the mechanical performance and sustainability potential of fiber-reinforced concrete incorporating mine tailings as the fine aggregate and waste tire wire as the reinforcing fiber. The concrete mixtures contained 0.2%, 0.4%, and 0.6% waste tire wire with the natural fine aggregate replaced entirely with Pb-Zn-Cu tailings. The mixtures were tested for porosity, water absorption, compressive strength, splitting tensile strength, flexural strength, toughness, fracture energy, and ductility to assess their mechanical performance and durability. The mine tailings improved the microstructure and reduced water absorption, particularly with tire wire. Using waste tire wire improved the compressive, tensile, and flexural performance; in particular, W-6 showed a 18.2% rise in compressive strength and a more than twofold increase in flexural strength relative to the control mix. The flexural toughness and fracture energy rose by up to 161%, while the ductility peaked at a fiber content of 0.2%. These gains were attributed to fiber crack-bridging and post-cracking energy absorption. The dual-waste system also reduced porosity, improved durability, and demonstrated strong potential for rigid pavement applications such as highways, industrial yards, and airport runways that require high fatigue resistance and a long service life. Beyond technical performance, this approach offers a sustainable solution that lowers maintenance, reduces life-cycle costs, and aligns with circular economy principles.
- MakaleYalnız künye2025Kinetics and Isotherm Evaluation for Adsorptive Removal of Anionic and Cationic Dyes from Aqueous Media by Sulfuric Acid-Modified Beech Sawdust
Ozdes, Duygu; Ozeken, Sengul Tugba; Top, Yener; Kalkisim, Ozgun; Duran, Celal
A novel and efficient adsorbent was prepared by modifying Fagus orientalis L. (beech) sawdust with H2SO4. The adsorption behavior of H2SO4-modified beech sawdust (SMBS) was investigated by batch experiments to offer a straightforward, inexpensive, and effective method for the retention of anionic and cationic model dyes, indigo carmine (IC) and methylene blue (MB), from wastewater. The experimental conditions were optimized by investigating the effects of the initial pH, initial concentrations of IC and MB dyes, dosage of SMBS, period of the contact, and the presence of salts in the aqueous media on the adsorptive performance of SMBS. The initial pH values of the aqueous solutions, from which IC and MB dyes will be removed, were optimized as 2.0 and 6.5 (natural), respectively. The optimum contact time for the adsorption of both dyes onto SMBS was determined to be 240 min. The mechanisms in the adsorption of IC and MB onto SMBS were investigated by evaluating the experimental data through different isotherm and kinetic models. The Langmuir isotherm model and pseudo-second order kinetic model performed well in explaining the mechanism of adsorption. Langmuir monolayer adsorption capacity of SMBS adsorbent was 38.85 mg g−1 for IC and 58.82 mg g−1 for MB. As a result, CMCP exhibited excellent performance in adsorbing organic pollutants, providing a low-cost and easily prepared alternative to other adsorbents found in the literature.
- MakaleAçık Erişim2025THE REGRESSION ANALYSIS AND DETERMINATION OF MECHANICAL AND PHYSICAL PROPERTIES ON GEOPOLYMER COMPOSITES UNDER THERMAL AND WATER CURING
Cavdar, Ozlem; Temizer, Hulya
Increasing costs due to high energy consumption and the release of harmful CO2 gases in cement production have made it necessary to explore alternative binders. This study aims to investigate the physical and mechanical properties of geopolymer mortars containing different proportions of pozzolanic wastes under different cure conditions. For this objective, fly ash obtained from the Sivas/Turkey thermal power plant and blast furnace slag obtained from the Bolu/Turkey iron-steel industries were used as the binding materials. Thermal curing and water curing were applied, and three different molar ratios (8M, 10M, 12M) of NaOH solution and Na2SiO3 were used. The results showed that the reaction products, types of alkaline activators, and reaction conditions are important factors in geopolymer mortars. The highest compressive strength recorded was 84.7 MPa in the geopolymer sample which consisted of 95% blast furnace slag blast furnace slag and 5% fly ash fly ash. Furthermore, two different binder additives (marble powder and strontium) were used and their time-dependent effects on the main binder were analysed. In addition, according to the ANOVA statistical results, the R2 value of the independent variables (Molarity, main binder ratios) on the compressive strengths accepted as the dependent variable is 81.7%. The significance value is 0.007, and these results were considered quite significant.
- MakaleYalnız künye2025Application of SnO2@CTAB-modified zeolitic clay nanocatalyst for the efficient sonocatalytic degradation of methylene blue in wastewater: Structural characterization, catalytic activity, and mechanistic insights
Önen, Hakan; Kıranşan, Murat
This study investigates the sonocatalytic degradation of dyes in wastewater using SnO2 nanoparticles and a hybrid SnO2@CTAB-modified zeolitic clay (SnO2@M-ZLT) nanocatalyst. The catalysts were synthesized in solution medium and characterized by XRF, XRD, FT-IR, SEM, TEM, and nitrogen adsorption-desorption analyses, confirming their successful formation and suitable surface properties. The effects of critical parameters including initial dye concentration, catalyst dosage, pH, water matrix, and radical scavengers on the removal of methylene blue (MB) were systematically evaluated. Under optimal conditions (10 g L−1 catalyst, 10 mg L−1 MB, Ultrasonic power: 300 W/L, pH for MB: Natural pH), the SnO2@M-ZLT nanocatalyst achieved 97.40 % ± 1.12 % degradation within 120 min, while 95.05 % ± 1.25 % efficiency was observed at 5 g L−1 catalyst and 5 mg L−1 MB. The sonocatalytic degradation of MB over SnO₂@M-ZLT followed pseudo-first-order kinetics, with kapp values ranging from 0.004 to 0.082 mg L−1 min−1 depending on catalyst dosage, 0.012–0.083 mg L−1 min−1 with varying MB concentration, and 0.030–0.055 mg L−1 min−1 across different water matrices. The optimal degradation efficiency was obtained at a catalyst dosage of 2–2.5 g L−1, an initial MB concentration of 5–10 mg L−1, and in distilled water, confirming the strong dependence of the reaction rate on both operational and environmental factors. Reusability tests showed that SnO2@M-ZLT retained high catalytic activity after five cycles. These results highlight the strong potential of SnO2@M-ZLT as an efficient and stable nanocatalyst for sustainable wastewater treatment.
- MakaleYayıncıda açık erişim2025Determination of antibacterial properties and chemical composition of pyrolysis liquid from feeding wastes of mealworm Tenebrio molitor L. (Coleoptera: Tenebrionidae) adults and larvae; [ОДРЕЂИВАЊЕ АНТИБАКТЕРИЈСКЕ АКТИВНОСТИ И ХЕМИЈСКОГ САСТАВА ПИРОЛИТИЧКЕ ТЕЧНОСТИ НАСТАЛЕ ИЗ НУТРИТИВНОГ ОТПАДА ОДРАСЛОГ ЦРВА]
Özgen, İNanç; Gül, Abdulkadi̇R; Baltaci, Cemalettin; Öner, İLyas; Aydoğmuş, Ercan
This study aimed to evaluate the antibacterial properties and phytochemical composition of pyrolysis liquids obtained from the biowaste of the mealworm Tenebrio molitor L. (Coleoptera: Tenebrionidae) adults and larvae. Biowaste was subjected to pyrolysis at 295±5 °C for 7 h under a nitrogen atmosphere using a laboratory-scale system equipped with a dual condensation unit to separate light and heavy fractions. The biowaste pyrolysis liquid (BPL) were purified and analysed for their chemical content using LC–MS/MS, which identified seven key phenolic compounds, with cinnamic acid being the most abundant (358.05 µg/g), followed by salicylic acid, 4-hydroxybenzoic acid and naringenin. Notably, the most of flavonoid derivatives were either absent or below detection limits, indicating the extract’s phenolic acid-dominated profile. The antibacterial activity of BPL was assessed against two gram-negative (E. coli ATCC-25922, P. aeruginosa ATCC-27853) and two gram-positive (E. faecalis ATCC-23212, S. aureus ATCC-25923) bacterial strains using the agar well diffusion method. The results demonstrated significant antibacterial effects, particularly against S. aureus (29.5±0.3 mm) and P. aeruginosa (23.5±0.2 mm), followed by E. coli (21.7±0.1 mm). These findings highlight the potential of insect-derived pyrolysis liquids as natural antibacterial agents, driven largely by their phenolic acid content. This study underscores the value of biowaste valorisation for developing bioactive compounds with potential applications in antimicrobial therapies.
- MakaleAçık Erişim2025Slag Substitution Effect on Features of Alkali-Free Accelerator-Reinforced Cemented Paste Backfill
Cavusoglu, Ibrahim
Cemented paste backfill (CPB) improves underground stability by filling mine voids, but the high cost of cement presents economic challenges for miners. While alternative binders and admixtures have been explored, the combined impact of slag substitution and alkali-free (AF) accelerators on CPB performance is not yet fully understood. This study investigates the influences of slag substitution and AF accelerators on the performance of CPB through a comprehensive experimental approach. CPB samples were prepared with slag substitution ratios of 25%, 50%, and 75%, maintaining a fixed AF accelerator content of 0.4%. Various test techniques, including unconfined comprehensive strength (UCS), mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and thermal analysis (TG/DTA), were employed to study their mechanical and microstructural properties. Monitoring tests were also conducted to thoroughly assess the performance of CPB, including suction (self-desiccation), electrical conductivity (EC), and volumetric water content (VWC) tests. The results showed that the PCI50–SL50–0.4AF sample exhibited 2.3 times higher strength than the control sample for 28 days, with this improvement attributed to enhanced pozzolanic reactions contributing to better microstructural compactness. Monitoring tests revealed accelerated hydration kinetics and reduced water content in slag-reinforced CPB, highlighting the significant role of AF accelerator in facilitating rapid setting and improving early-age mechanical strength. Microstructural findings revealed that porosity decreased and C–S–H gel formation increased in the specimen containing slag and AF accelerators, contributing to increased strength and durability. These findings highlight the potential usage of slag and AF accelerators to enhance CPB’s mechanical, microstructural, and hydration properties, offering significant benefits for mining operations by improving backfill performance, while contributing to environmental sustainability through reduced cement consumption and associated CO2 emissions.
- MakaleAçık Erişim2025The analysis of Caputo-Fabrizio fractional plastic waste model with a new numerical method; [Caputo-Fabrizio kesirli mertebeden plastik atık modelinin yeni bir sayısal yöntemle analizi]
Bingöl, Sait; Anaç, Halil
In this paper, the new numerical solutions for Caputo-Fabrizio fractional plastic waste model are derived utilizing a novel hybrid approach known as the Caputo-Fabrizio fractional q-formable homotopy analysis transform method. A novel hybrid method combining the Caputo-Fabrizio transform and the q-homotopy analysis method is introduced. A plastic waste model generally denotes a conceptual or mathematical framework employed to comprehend, simulate, or forecast the movement, accumulation, and effects of plastic trash within a system, spanning from local surroundings to the global scale. The plastic waste model is analyzed in the Caputo-Fabrizio fractional framework. The solutions for the Caputo-Fabrizio fractional plastic waste model are illustrated in the Maple program.
- MakaleYalnız künye2025Effect of mechanical milling parameters on the properties of electrolytic pure copper powders and hot pressed billets fabricated from recycled copper wastes
Akçay, Serhatcan Berk; Çuvalcı, Oğuzhan; Varol, Temel; Çuvalcı, Hamdullah; Kocaman, Mücahit; Alver, Ümit; Beder, Murat; Güler, Onur; Aksa, Hüseyin Can; Gasha, Shimelis Bihon
This study was conducted to comprehensively investigate the effect of mechanical milling parameters on the properties of electrolytic pure copper powders and hot pressed billets fabricated from recycled copper wastes. Three different milling speeds, five different milling times and three different ball to powder weight ratios were used to fully reveal the effect of the mechanical milling process on the properties of recovered Cu powders. The results show that as the milling time and milling speed increased, the initial dendritic morphology of the copper was transformed into a flake-like structure. At 400 rpm and a 5:1 BPR parameters, the average particle sizes of C3, C4, and C5 after 2, 4, and 8h were ∼52 μm, 83 μm, and 71 μm, respectively. This suggests that particle size initially increases due to shape change and cold-welding, but at longer durations, fracture becomes dominant. The I5 with d(0.5) = 69.32 μm exhibited a high flow rate of 5.88 g/s with an apparent density of 2.9 g/cm3.While the hardness value of the Cu samples (A1-bulk sample) produced by exposure to the lowest deformation during the mechanical milling is 95.02 HB, the hardness value of the Cu specimens (F5-bulk sample) showing the highest apparent density, best flow rate and highest density values is 109.31 HB. The electrical conductivity values were determined to be approximately 52.2 MS/m, 57.4 MS/m and 44.3 MS/m for A1-bulk, F5-bulk and H5-bulk, respectively. This study offers valuable insights into the relationship between milling parameters, powder characteristics, and final material properties.
- MakaleAçık Erişim2025Insight into the adsorptive removal of Cr(VI) ions and 4-chlorophenol from aqueous media on cationic surfactant-modified cucumber peels
Ozeken, Sengul Tugba; Ozdes, Duygu; Duran, Celal
A new and cost-effective adsorbent material was developed by chemical modification of cucumber peels (CP) with a cationic surfactant, cetyltrimethylammonium bromide (CTAB). The adsorptive behavior of CTAB-modified cucumber peels (CMCP) was investigated in the retention of an organic pollutant (4-chlorophenol) and an inorganic pollutant (Cr(VI)) through batch experiments. The adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscopy (SEM) technique. Influences of initial concentrations of both pollutants, dosage of CMCP, initial solution pH, contact time, and foreign ions were parameters used to specify the optimized conditions. Results of the experiments were evaluated by three kinetic models, namely pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, to find out the dominant mechanisms in the retention of 4-chlorophenol and Cr(VI). Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were applied to the adsorption data to estimate the adsorption capacity of CMCP and to describe the interactions between the species. Langmuir isotherm model fitted the data well, and the maximum Cr(VI) and 4-chlorophenol adsorption capacities of CMCP were 84.03 mg g−1 and 107.5 mg g−1, respectively. Consequently, CMCP demonstrated outstanding performance in the adsorption of both inorganic and organic pollutants, offering a low-cost, easily prepared alternative to other adsorbents reported in the literature.
- MakaleYalnız künye2025Ecological effects of energy use and tourism-induced transport modes among coastline Mediterranean countries
Cakir, Mehmet Ali; Recepoğlu, Mürşit; Alola, Uju Violet; Alola, Andrew Adewale
Purpose: Motivated by the criticality of transportations system in tourism activities, this study further uncovers the effect of the main transportation modes arising from inbound tourism activities on the ecological footprint across the panel of selected coastline Mediterranean countries (CMC). Design/methodology/approach: The study considers a suitable econometric approach for the case of CMC with the dataset that covers the period 1998–2022. Findings: While the result reveals that all the modes of transportation except air deteriorate environmental sustainability by increasing ecological footprint in the long run, higher impact of environmental woe is associated with the land transportation. Similarly, the findings further show that economic expansion and conventional energy utilization in the examined panel and in each country spurs ecological footprint, thus worsening environmental quality. Meanwhile, for the country-specific observations, ecological footprint is (1) mitigated by tourism activities associated with air, water and land transports in Spain, (2) triggered by tourism activities associated with land transport in Croatia and (3) spurred by land transport in Italy. Originality/value: Policy inference from these results suggests the need to scale up the adoption of a low-emission transportation system in the countries.
- Kitap BölümüYalnız künye2025Sustainable Development, Ecological Footprint, Carbon Footprint, Biomimicry, Permaculture, and Proactive Behavior
Şenel Tekin, Perihan; Bekar, Fevziye
The aim of this book chapter is to lay the concepts of sustainable development, ecological footprint, carbon footprint, permaculture and biomimicry, which are thought to complement one another and serve almost the same purpose, on the basis of proactive behaviors. Sustainable development means balancing ecological, social, and economic dimensions and meeting the needs of the present without consuming the resources of future generations. The ecological footprint is an indicator of sustainable development and involves calculations relevant to the world’s energy consumption, capacity and overall biomass efficiency. A carbon footprint is a type of ecological footprint, while biomimicry involves the emulation of nature to create pathways for crafting innovative designs. The discipline of permaculture derives from permanent culture and agriculture and concerns about creating sustainable living spaces. In this regard, sustainability may be ensured with the inclusion of proactive mindsets as opposed to reactive perspectives to facilitate individual ownership of sustainability within social lifestyles and business environments.
- MakaleAçık Erişim2025Utilization of desiccant silica-gel wastes for the mechanical and microstructural performances of self-compacting mortars
Yılmaz, Tekin
The existing exploratory focuses to examine the effect of relocating ordinary Portland cement (OPC) by divergent proportions (2.5–15 %, by vol.) of desiccant silica-gel waste (DSGW) on the strength/durability/microstructural traits of self-compacting mortars (SCMs). A large experimental programme comprising unconfined compressive- (UCS: 7/28/56/90 days) and flexural-strength (FS: 7/28/56/90 days), freeze-thaw (F-T: 50/100 cycles), sorptivity (Sp: 28 days), porosity (PT: 28 days) and scanning electron microscope (SEM: 28 days) tests was conducted on the fabricated SCMs. From the gathered findings, the replacing OPC by 10 % DSGW, compared to the Control, was detected to signify the most efficacious contribution on SCMs' strength (UCS/FS = +15.2/12.3 %), durability (UCS/FS-losses after 50 and 100 F-T = −4.7/−6.1 % and − 10.0/−12.7 %) behavior, which is in tune with the ameliorated microstructure (Sp = −35.2 %, PT = −19.2 % and SEM = higher C-S-H gel, less micro-crack).
- MakaleAçık Erişim2025Sulfur Removal From Low-Grade Turkish Kaolin Clay
Erkan, Ilker; Alp, Ibrahim
This study investigated the effects of NaOH direct leaching for sulfur removal from a kaolin ore from the Balıkesir region, Turkey. Characterization studies were undertaken before sulfur removal studies to enlighten the structure and originate the source of sulfur. The characterization studies revealed that the ore was mainly composed of quartz, with sulfur originating from alunite minerals with opal inclusions. The leaching process was tested under varying NaOH concentrations (1.5–2 M), temperatures (95 ± 2°C), and durations (2 h) in temperature-controlled closed systems to maintain consistency. Results demonstrated complete (100%) sulfur removal from alunite under optimal conditions. However, significant mass losses (18.15%–45%) occurred because of the dissolution of kaolinite along with alunite, indicating the method's effectiveness in sulfur removal but also its potential drawbacks for kaolinite retention.
- MakaleAçık Erişim2025Valorisation of bread wastes via the bacterial cellulose production
Güzel, Melih
The short shelf life of bread can be attributed to changes in its textural and sensory properties, a process termed staling, and large amounts of bread residue and waste are generated daily. Because the main component of bread is starch, the use of bread wastes as a substrate for bacterial cellulose (BC) production can significantly contribute to valorisation and reuse of wastes. This study aimed to investigate the BC production potential of various stale breads, convert these wastes into usable forms for food and other industries, and increase their economic value. Stale breads were hydrolyzed with dilute acid, and BC-producing bacteria from Kombucha tea were isolated and identified as Gluconobacter oxydans MG2021 (GO). BCs were produced from bread hydrolysates with GO and Komagataeibacter hansenii GA2016 (KH), and their properties were examined. The results indicated that stale breads represented a good source for BC production, as high BC yields were obtained using GO (8.81%–25.02%) and all BCs had superior properties such as high crystallinity (75.96%–91.39%), thermal stability, liquid holding capacity, and fine fibers (40.16–85.39 nm). This study demonstrated that bread wastes could be used as a low-cost substrate for large-scale BC production, and the abundance of bread wastes demonstrated their potential as a resource for commercial BC producers.
- MakaleAçık Erişim2025Sol–Gel Synthesized CuFe2O4-Modified Biochar Derived from Tea Waste for Efficient Ni(II) Removal: Adsorption, Regeneration, and ANN Modeling
Duran, Celal; Ozeken, Sengul Tugba; Seker, Serdal; Ozdes, Duygu
In the present research, a novel magnetic adsorbent was developed via the sol–gel method by coating CuFe2O4 nanoparticles on biochar sourced from brewed tea waste. The synthesized adsorbent was utilized for the removal of Ni(II) ions from aqueous media. The adsorption efficiency of Ni(II) ions was assessed under crucial experimental conditions such as initial solution pH, contact time, adsorbent dosage, and initial Ni(II) concentration. The adsorbent exhibited rapid adsorption kinetics, achieving equilibrium in approximately 15 min, and maintained high efficiency across a wide pH range. Adsorption experiments were conducted for Ni(II) solutions at their natural pH (5.6) to minimize chemical usage and enhance process simplicity. An impressive maximum adsorption capacity of 232.6 mg g−1 was recorded, outperforming many previously reported adsorbents. Furthermore, desorption studies demonstrated nearly 100% recovery of Ni(II) ions using 1.0 M HCl solution, indicating excellent regeneration potential of the adsorbent. Additionally, the prediction performance of an artificial neural network (ANN) model was evaluated to predict Ni(II) removal efficiency based on experimental variables, showing strong agreement with experimental data. Isotherm and kinetic models were also applied to the data to estimate the adsorption mechanisms. These findings demonstrate the promise of CuFe2O4-modified tea waste biochar for sustainable water treatment applications.
