WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 6Citation - Scopus: 6The Different Impacts of g-C3N4 Nanosheets on PVDF and PSF Ultrafiltration Membranes for Remazol Black 5 Dye Rejection(Wiley, 2023-08-02) Senol-Arslan, Dilek; Gul, Ayse; Dizge, Nadir; Ocakoglu, Kasim; Uzal, NigmetMembranes combined with nanoparticles are an excellent combination capable of successfully removing various contaminants, such as dyes from wastewater while using very little energy and decreasing pollution. The present study reports an efficient approach for Remazol Black 5 (RB5) dye removal using composite graphitic carbon nitride nanosheets (g-C3N4), polysulfone (PSF), and polyvinylidene fluoride (PVDF) membranes. The membranes were prepared using the phase inversion method, with varying quantities of g-C3N4 nanosheets ranging from 0.1%, 0.2% to 0.3%. The prepared g-C3N4 nanosheets were characterized by FTIR, SEM analyses, and zeta potential measurements. FTIR and SEM studies, contact angle, water permeability, COD, and dye rejection measurements were used to characterize the g-C3N4 nanosheets embedded in PSF and PVDF membranes. After the addition of 0.3 wt% g-C3N4, the water flux of the 0.3 wt% g-C3N4 embedded PSF membrane was the highest, whereas the water flux of the 0.3 wt% g-C3N4 embedded PVDF membrane was the lowest. The ultrafiltration (UF) membrane's performance with g-C3N4 embedded showed an RB5 rejection rate of more than 80% and a COD removal efficiency of more than 45%. The results of the experimental filtration showed that RB5 rejection reached maximum values of 91.3% for 0.1 wt% g-C3N4/PSF, and 85.6% for 0.3 wt% g-C3N4/PVDF.Article Citation - WoS: 6Citation - Scopus: 6Surface Coating of Polyamide Reverse Osmosis Membranes With Zwitterionic 3-(3,4 (l-DOPA) for Forward Osmosis(Wiley, 2019-03-27) Saki, Seda; Uzal, NigmetTo overcome low permeability and fouling problems of membranes used in FO processes, modification is needed to improve the hydrophilicity, permeability and selectivity of membranes. In this work, thin film composite (TFC) commercial polyamide RO membranes (BW30-LE, SW30-HR, AG and AC) were functionalized with zwitterionicl-DOPA. The effect ofl-DOPA on the morphology of membranes was determined via SEM, FT-IR, AFM and contact angle analysis. Thel-DOPA modified BW30-LE membrane showed excellent properties with 46 degrees contact angle and 3.8 L/m(2)hbar water permeability and 0.83 L/m(2)h salt permeability. Although,l-DOPA modified BW30-LE membrane had the highest water flux and hydrophilicity,l-DOPA modified SW30-HR membrane showed higher FO flux with 9.38 L/m(2)h than BW 30 membrane with 3.5 L/m(2)h at 50 g/L NaCl draw solution. Introducing hydroxyl and carboxyl ionic groups on the membrane surface withl-DOPA coating enhanced the FO performance and water permeability which provide a new insight in FO applications.Article Citation - WoS: 5Citation - Scopus: 7Robust Multicriteria Sustainability Assessment in Urban Transportation(ASCE-Amer Soc Civil Engineers, 2023-06) Gulcimen, Sedat; Aydogan, Emel Kizilkaya; Uzal, NigmetDeveloping methodologies to facilitate the planning of sustainable transport systems for decision makers (DMs) is becoming more critical. This study proposed a methodological framework for sustainable urban transportation to make decisions during urban transportation's design and planning stages. Urban transportation alternatives were evaluated by sustainability indicators that considered a triple bottom line approach's environmental, economic, and social aspects. To choose the best alternative sustainable transportation scenarios, two multicriteria decision-making (MCDM) methods, for example, a hesitant fuzzy analytical hierarchy process (HF-AHP) and multiple attribute utility model (MAUT), were integrated. First, eight sustainable transportation indicators that considered data availability from the transport sector were selected. The weights of the selected indicators were calculated using an HF-AHP. These indicators included carbon dioxide (CO2) emissions, energy consumption, depletion of nonrenewable resources, operational and maintenance costs, fuel and taxes, the number of fatalities or injuries, and motor vehicles for public transport per 10,000 population. Finally, sensitivity analysis was applied to validate the robustness. Based on HF-AHP results, the number of fatalities or injuries was the most significant among the eight indicators, with a 0.158 normalized weight (N-i). The results of this integrated methodology highlighted that Alternative 11, which was dominated by low-motorized vehicles (low-MVs), was the best sustainable alternative and Alternative 1 was the worst sustainable alternative, which was dominated by high-MVs with 0.69 and 0.27 total utility values, respectively. Low-motorized urban transportation alternatives showed higher sustainable performances than the motorized and high-motorized alternatives. This study proposed a novel and robust methodology for decisions on sustainable urban transportation projects and renovating current urban transportation systems.Article Citation - WoS: 10Ni-Zn Metal-Organic Framework Based Membranes for Rejection of Pb (II) Ions(Elsevier, 2022-12) Senol-Arslan, Dilek; Gul, Ayse; Uzal, Nigmet; Yavuz, EmreThe present paper describes a sustainable and affordable supply of clean, and safe water approach to investigate Ni-Zn MOF embedded membrane for rejection of Pb (II) ions in aqueous solution. Ni-Zn MOF powder was prepared by solvo-thermal method, and then the Ni-Zn MOF embedded membranes with various concentrations (0.025 wt%, 0.05 wt% and 0.1 wt%). The membranes were fabricated by a common phase inversion method. Phase solutions of Pb(II) prepared with PVP at different concentrations in aqueous solutions. Water filtration and Pb (II) rejection tests were operated on a batch scale. The prepared Ni-Zn MOF powder characterized by FTIR, SEM-EDX analyses and zeta potential measurements. Ni-Zn MOF membranes were characterized by FTIR, SEM-EDX analysis, contact angle, and water permeability measurements. The effects of important parameters on adsorption including concentration and pH were investigated. The obtained results indicated that the maximum rejection of Pb(II) was 98% for a feed solution containing 80 mg Pb/L at pH 8 and assistance with 2 % PVP for 0.05 wt% Ni-Zn MOF membrane. Additionally, it was detected that blend membranes revealed better Pb(II) rejection than pure PSF membrane.Article Citation - WoS: 46Citation - Scopus: 52Life Cycle Assessment of Lightweight Concrete Containing Recycled Plastics and Fly Ash(Taylor & Francis Ltd, 2020-06-05) Ersan, Yusuf Cagatay; Gulcimen, Sedat; Imis, Tuba Nur; Saygin, Osman; Uzal, NigmetResearchers put significant effort to decrease the environmental impact of concrete by using industrial by-products as an alternative binder. However, the considerable environmental impact still exists due to the consumption of natural resources as aggregates. Natural aggregates are the most used resources by volume in the construction sector. Therefore, it is necessary to investigate by-products as an alternative to natural aggregates as well. This study presents the environmental impact of lightweight concrete (LWC) produced by replacing natural aggregates with recycled waste plastic (polyethylene) (RWP) and partially replacing Portland cement with Class F fly ash (FA). Life Cycle Assessment (LCA) was performed to compare a conventional LWC, containing pumice as natural aggregate and Portland cement as a binder, with green LWC, containing 30% RWP as pumice replacement and 20% FA as cement replacement. These scenarios were evaluated in terms of global warming potential, abiotic depletion, ozone layer depletion, terrestrial ecotoxicity, photochemical oxidation, acidification and eutrophication. LCA was coupled with mechanical tests at 7 days and 28 days. RWPs were found to be an environment-friendly replacement material for natural lightweight aggregates with an overall decrease in all CML-IA impacts except eutrophication. Tested green mix design also provided sufficient strength for nonstructural applications.Article Citation - WoS: 3Citation - Scopus: 3Investigation of the Treatability of Pre-Coagulated Slaughterhouse Wastewater Using Dead-End Filtration(Wiley, 2021-03-15) Ozdemir, Safiye; Uzal, Nigmet; Gokcek, Oznur BegumBACKGROUND In the present study, the performance of the membrane process, one of the advanced treatment methods that can enable the reuse of slaughterhouse wastewater, was evaluated. The wastewater was treated using ultrafiltration (UF) (10, 50 kDa), nanofiltration (NF) (150-300 DA) and reverse osmosis (RO) (500 kDa) membranes alone, and UF + NF, UF + RO membrane combinations at different pressures. In addition to rejection and permeate flux considerations, it was attempted to select the most effective membrane by performing scanning electron microscopy, Fourier transform infrared, contact angle, and atomic force microscopy analyses of the membranes used. RESULTS As a result of the experiments, the highest flux was observed at 5 bar for the 50 kDa UF membrane. When the performances of the sequential application of 10 and 50 kDa UF membranes followed by NF and RO membranes were evaluated, the highest flux was obtained for the sequential application of the 50 kDa UF membrane with the NF membrane as 19.68 and 9.05 L m(-2) h, respectively. CONCLUSION The highest chemical oxygen demand (COD) removal was obtained for the RO membrane at 20 bar as 88.67%, and for the 50 kDa UF + RO sequential application, the COD removal was increased from 70% to 88.67%. (c) 2021 Society of Chemical Industry (SCI).Article Citation - WoS: 11Citation - Scopus: 13Fabrication and Characterization of Silane-Functionalized Na-Bentonite Polysulfone/Polyethylenimine Nanocomposite Membranes for Dye Removal(Wiley, 2020-02-04) Saki, Seda; Senol-Arslan, Dilek; Uzal, NigmetIn this study, tetraethoxysilane (TEOS)-functionalized Na-bentonite incorporated into polysulfone/polyethylenimine (PSF/PEI) membranes were fabricated by phase inversion method for the efficient removal of methylene blue dye. For the preparation of PSF/PEI nanocomposite membranes, silane-functionalized Na-bentonite and pure Na-bentonite were used at three different concentrations (0.5, 1, and 2 wt%). The prepared membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, porosity, hydrophilicity, and water permeability measurements. Antifouling behaviors and methylene blue dye rejections of the PSF/PEI nanocomposite membranes were also tested. The obtained results showed that the addition of pure Na-bentonite and silane-functionalized Na-bentonite both increased the water permeability of the membranes. The PSF/PEI membrane containing 2 wt% silane-functionalized Na-bentonite showed the highest water flux of 105 L m(-2) h(-1), while the lowest water flux of 1.2 L m(-2) h(-1) was recorded for pure PSF membrane. Filtration results demonstrated that the antifouling capacity was significantly increased due to the negatively charged surface of the newly generated silane-functionalized Na-bentonite PSF/PEI membranes. In summary, TEOS-functionalized Na-bentonite can be used to fabricate PSF/PEI nanocomposite membranes with effective filtration ability, antifouling capacity with lower decay ratio, higher flux recovery ratio, and 99% methylene blue dye removal performance.Article Citation - WoS: 9Citation - Scopus: 11Evaluation of Diatomite Substitute With Thermal Power Plant Waste Fly Ash in Sustainable Geopolymer Through Life Cycle Assessment(Springer, 2025-02-28) Ilkentapar, Serhan; Orklemez, Ezgi; Durak, Ugur; Gulcimen, Sedat; Bayram, Savas; Uzal, Nigmet; Atis, Cengiz DuranThis research demonstrates the potential of diatomite as a fly ash replacement to improve mechanical properties and environmental sustainability and presents it as a viable alternative for sustainable construction. Additionally, a life cycle assessment (LCA) was conducted on the produced mortars to quantitatively compare their environmental impacts using a cradle-to-gate approach. In mixtures, it was used by replacing the diatomite in the ratios of 1%, 2%, 3%, 4%, and 5% by weight of the fly ash. Workability, unit weight, flexural and compressive strength, abrasion resistance, elevated temperature resistance and microstructure analysis were carried out. The results indicated that replacing 1%, 2%, and 3% diatomite increased the compressive and flexural strength of mortars due to their higher specific surface area. Two percent replacement of diatomite provided the best results. FESEM results of 3% diatomite inclusion showed more intense and compact microstructure of geopolymer. Diatomite inclusion increased the abrasion resistance of geopolymer. Since 2% diatomite replacement was found to be optimum, the LCA results showed that geopolymer mortar with 2% diatomite has 25% lower impacts in terms of global warming potential and 10% lower impacts in terms of terrestrial ecotoxicity than conventional Portland cement mortar.Article Citation - WoS: 12Citation - Scopus: 14Developing a Decision-Support System for Waste Management in Aluminum Production(Springer, 2016-04-13) Ozmen, Mihrimah; Aydogan, Emel Kizilkaya; Ates, Nuray; Uzal, NigmetIndustrial enterprises constitute a major portion of the world's economy, as well as a large proportion of a country's businesses and total employment. In Turkey, industrial enterprises are underdeveloped in terms of knowledge, skill, capital, and particularly accessing and benefiting from the advantages provided by modern information and communication technologies. Aluminum manufacturing has been reported to be the largest industry in Turkey with respect to production volumes and application fields. However, aluminum production is known to be an important contributor to environmental pollution, and the relative contribution of other related enterprises to the total industrial environmental impact is unknown. Environmental pollution sources can typically be classified into three categories: gaseous emissions, solid wastes, and wastewaters. The types of wastes produced by aluminum production vary based on the process line used, the variety of target products produced, and the production capacity of a given plant. As the capacities of facilities grow, the type and amount of waste become more variable. Therefore, the primary objective of this study is to determine the priority of each waste type in aluminum manufacturing industries. This study was conducted in the Industrial Zone of Kayseri in Turkey. Three different facilities that range in size from large to small based on their production volume, plant capacity, and variety of production are selected for this study. The priority of waste types was determined by combining the AHP and PROMETHEE II multicriteria decision methods. While wastewater was categorized as having the highest priority in large facilities, solid waste was determined to be the highest priority in medium and small facilities.Article Citation - WoS: 6Citation - Scopus: 6Comparative Life Cycle Assessment of Retort Pouch and Aluminum Can for Ready-to Bean Packaging(Springer, 2023-09-12) Gulcimen, Sedat; Ozcan, Ozlem; Cevik, Selin Babacan; Kahraman, Kevser; Uzal, NigmetSince packaging contributes to severe environmental impacts in food production, alternatives of packaging materials that satisfy customer needs while minimizing environmental impacts in a cost-effective manner should be preferred for food product sustainability. This paper compares two different packaging materials (aluminum cans and retort pouches) with a life cycle approach to assess the environmental impacts of ready-to-eat bean packaging. The life cycle assessment (LCA) was used to define and compare the environmental performance of ready-to-eat beans in aluminum cans and retort pouches. The gate-to-gate approach was used in the LCA, with a functional unit of 1 kg of packaged ready-to-eat bean product. Inventory for packaging in retort pouch was created in collaboration with Duru Bulgur Company (Karaman, Turkey) and the data for ready-to-eat beans in the aluminum can were gathered from the literature. The findings show that ready-to-eat beans in retort pouches have lower environmental impacts than ready-to-eat beans in aluminum cans. The packaging and washing processes for both ready-to-eat beans packaged in aluminum cans and retort pouches had the greatest environmental impact. In ready-to-eat beans production, retort pouch provides 87% better environmental performance than aluminum can in terms of global warming (GW). Overall, the results demonstrated that replacing aluminum cans with retort pouches in ready-to-eat bean production can significantly reduce environmental effects in all impact categories. [Graphics] .