Browsing by Author "Uzal, Nigmet"

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Analysis of the best available techniques for wastewaters from a denim manufacturing textile mill
(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD24-28 OVAL RD, LONDON NW1 7DX, ENGLAND, 2017) Yukseler, H.; Uzal, N.; Sahinkaya, E.; Kitis, M.; Dilek, F. B.; Yetis, U.; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
The present study was undertaken as the first plant scale application and evaluation of Best Available Techniques (BAT) within the context of the Integrated Pollution Prevention and Control/Industrial Emissions Directive to a textile mill in Turkey. A "best practice example" was developed for the textile sector; and within this context, BAT requirements for one of the World's leading denim manufacturing textile mills were determined. In order to achieve a sustainable wastewater management; firstly, a detailed wastewater characterization study was conducted and the possible candidate wastewaters to be reused within the mill were identified. A wastewater management strategy was adopted to investigate the possible reuse opportunities for the dyeing and finishing process wastewaters along with the composite mill effluent. In line with this strategy, production processes were analysed in depth in accordance with the BAT Reference Document not only to treat the generated wastewaters for their possible reuse, but also to reduce the amount of water consumed and wastewater generated. As a result, several applicable BAT options and strategies were determined such as reuse of dyeing wastewaters after treatment, recovery of caustic from alkaline finishing wastewaters, reuse of biologically treated composite mill effluent after membrane processes, minimization of wash water consumption in the water softening plant, reuse of concentrate stream from reverse osmosis plant, reducing water consumption by adoption of counter-current washing in the dyeing and finishing processes. The adoption of the selected in-process BAT options for the minimization of water use provided a 30% reduction in the total specific water consumption of the mill. The treatability studies adopted for both segregated and composite wastewaters indicated that nanofiltration is satisfactory in meeting the reuse criteria for all the wastewater streams considered. (C) 2017 Elsevier Ltd. All rights reserved.
Arsenic removal by the micellar-enhanced ultrafiltration using response surface methodology
(IWA PUBLISHING, ALLIANCE HOUSE, 12 CAXTON ST, LONDON SW1H0QS, ENGLAND, 2020) Gokcek, Oznur Begum; Uzal, Nigmet; 0000-0002-0912-3459; 0000-0003-1730-2905; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü
The present research investigates the removal of arsenic (As) from aqueous solutions using micellar-enhanced ultrafiltration (MEUF) by utilizing two different surfactants: benzethonium chloride and dodecyl pyridinium chloride (BCl and DPCl). The impact of the operating variables and maximum removal efficiency were found under different conditions for BCl and DPCl surfactants. The maximum As rejection efficiency for MEUF with BCl and DPCl surfactants is 92.8% and 84.1%, respectively. In addition to this, a statistics-based experimental design with response surface methodology was used for the purpose of examining the impact of operating conditions, including initial pH, initial As concentration (ppb), and surfactant concentration (BCl, mM) in As-removal from aqueous solutions. In the analysis of the experimental data, a second-order polynomial model that was validated by statistical analysis for the BCl surfactant was used. On the basis of the response model created, the removal of As ions was acquired at optimum operating parameters, including the initial As concentration of 150 ppb, surfactant concentration of 5 mM and pH 10 for the BCl surfactant with 92.8% As-removal efficiency.
Arsenic removal from aqueous solutions by ultrafiltration assisted with polyacrylamide: an application of response surface methodology
(DESALINATION PUBL, 2015) Varol, Bekir; Uzal, Nigmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
The present work deals with removal of arsenic from aqueous solutions by ultrafiltration assisted with polyacrylamide as an environmental friendly complexing polymer. The system performance was evaluated in relation to quality of permeate in terms of operating variables as feed concentration of arsenic ions (C-o, gL(-1)), ratio of polymer to arsenic (r, w/w), and pH of feed solution. The effect of the operating variables and maximum arsenic removal efficiency was determined by adopting design of experiments and response surface methodology under different conditions for this polymer. The experimental data were analyzed with a second order polynomial model validated by statistical analysis. Based on the response model developed, the maximum removal efficiency, close to 100%, of arsenic ions has been obtained at optimum operating parameters as C-o: 150 gL(-1), r: 2, and pH 10.
Clarification of Apple Juice Using New Generation Nanocomposite Membranes Fabricated with TiO2 and Al2O3 Nanoparticles
(SPRINGER, ONE NEW YORK PLAZA, SUITE 4600, NEW YORK, NY, UNITED STATES, 2020) Severcan, Solmaz Sebnem; Uzal, Nigmet; Kahraman, Kevser; 0000-0002-2786-3944; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
To enhance anti-fouling properties of polymeric membranes during apple juice clarification, PSF/PEI (20/2 wt%) ultrafiltration (UF) membranes were modified with TiO2 and Al2O3 nanoparticles using the phase inversion method. Turbid apple juice samples were clarified using cross-flow membrane filtration system. All fabricated nanocomposite UF membranes had higher apple juice flux values than PSF/PEI membrane. Membrane prepared with 0.01% TiO2 (UFT1) had the highest apple juice flux (at steady state, 44.6 L/m(2)h). The FRR (%) value of TiO2 and Al2O3 incorporated UF membranes was between 90.9-94.0% and 79.6-97.6%, respectively, and these FRR values were higher than that of PSF/PEI membrane (UF2, 60.3%). Porosity and hydrophilicity of the UF membranes significantly increased with the addition of nanoparticles and the highest porosity and hydrophilicity was achieved in the 0.01% TiO2 incorporated UF membrane (UFT1) membrane. Higher flux recovery ratio (FRR) and lower relative flux reduction (RFR) values of Al2O3 and TiO2 incorporated nanocomposite membranes, compared with the unmodified membrane, demonstrated the enhancement in the anti-fouling properties of the PSF/PEI membrane. SEM images of the nanocomposite membranes also proved the nanoparticle incorporation to the PSF/PEI matrix. Color, turbidity, total soluble solid, total phenolic content, and antioxidant capacity of the samples using nanocomposite membranes were better than that of clarified using both commercial and unmodified membranes. TiO2 incorporated nanocomposite membranes had superior performance than Al2O3 incorporated nanocomposite membranes and among these membranes, the ones prepared with the addition of 0.01 wt% TiO2 exhibit the best performance in terms of clarification of apple juice.
Clarification of pomegranate juice using PSF microfiltration membranes fabricated with nano TiO(2)and Al2O3
(WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ USA, 2020) Severcan, Solmaz Sebnem; Uzal, Nigmet; Kahraman, Kevser; 0000-0002-2786-3944; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
Microfiltration (MF) membranes were fabricated using PSF/PEI (17/2 wt%) with TiO(2)and Al(2)O(3)nanoparticles to enhance pomegranate juice clarification performance. The membrane performances were tested using dead-end filtration system. Membranes were characterized by Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), porosity, water contact angle, and pure water flux experiments. All MF membranes had higher porosity, pure water flux, and hydrophilicity.SEMimages of the membranes proved the nanoparticle incorporation to the PSF/PEI matrix. The quality of clarified pomegranate juice samples using PSF/PEI nanocomposite membranes were better than that of clarified using both commercial and unmodified membranes. The highest performance for the clarification of pomegranate juice samples was obtained for 0.05% of Al(2)O(3)incorporated PSF/PEI membranes with the highest color (5,781 +/- 4 PtCo), total soluble solid (16.2 +/- 0.0 Brix), total phenolic content (2,642.1 +/- 46.4 mg GAE/L), antioxidant activity (ABTS: 62.4 +/- 0.2 TEAC/L, DPPH: 41.3 +/- 0.0 TEAC/L) and total monomeric anthocyanin (100.7 +/- 1.7 mg/L). Practical applications Utilization of membrane technology in food industry has been increased rapidly in the past two decades. Due to their advantage in terms of saving color pigments, MF membranes are more suitable than UF ones for clarification of pomegranate juice. Incorporation of nanoparticles to the membrane matrix is one of the methods to increase the antifouling character and the strength of the membranes modified with hydrophilic polymers. There are some studies investigating the effect of TiO(2)and Al(2)O(3)nanoparticles on the properties of polymeric membranes. However, there are no reported data on the utilization of TiO(2)and Al(2)O(3)nanocomposite membranes for clarifying pomegranate juice. In this study, TiO(2)and Al(2)O(3)incorporated new generation PSF/PEI membranes were utilized in the clarification process of pomegranate juice for the first time in the literature. The results showed that Al(2)O(3)incorporation seems to be a good alternative for clarifying pomegranate juice with enhanced quality parameters.
Comparative life cycle assessment of retort pouch and aluminum can for ready-to-eat bean packaging
(SPRINGER, 2023) Gulcimen, Sedat; Ozcan, Ozlem; Cevik, Selin Babacan; Kahraman, Kevser; Uzal, Nigmet; 0000-0002-8967-3484; 0000-0002-2786-3944; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Gulcimen, Sedat; Ozcan, Ozlem; Kahraman, Kevser; Uzal, Nigmet
Since 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.
Determining the priority waste in aluminum manufacturing sector using the smaa-2 method: A case study of kayseri
(Computers and Industrial Engineering, 2014) Aydogan, Emel Kizilkaya; Ates, Nuray; Uzal, Nigmet; Ozmen, Mihrimah; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
Small and medium-sized enterprises (SMEs) constitute a major part of the Turkish economy, accounting for a large proportion of the country's businesses and total employment. Although the SMEs are known as important contributors to environmental pollution, the relative contribution of SMEs to the total environmental impacts of industrial is unknown. The most important environmental issues related with aluminum industries are emission of gases, wastewater and solid wastes from aluminum production. In multi-criteria decision making (MCDM) problems in some situations, decision makers (DMs) don't or can't express their preferences obviously. In these situations for decision making, stochastic multi-criteria acceptability analysis (SMAA-2) can be applied. In this study, a multi-criteria decision making model is presented to determine higher priority waste types (air and solid wastes, wastewaters) among the three firms. We used stochastic data by applying and the SMAA-2 results are given.
Developing a Decision-Support System for Waste Management in Aluminum Production
(SPRINGERVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2016) Ozmen, Mihrimah; Aydogan, Emel Kizilkaya; Ates, Nuray; Uzal, Nigmet; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
Industrial 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.
The different impacts of g-C3N4 nanosheets on PVDF and PSF ultrafiltration membranes for Remazol black 5 dye rejection
(WILEY, 2023) Senol-Arslan, Dilek; Gul, Ayse; Dizge, Nadir; Ocakoglu, Kasim; Uzal, Nigmet; 0000-0001-9639-2843; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Senol-Arslan, Dilek; Uzal, Nigmet
Membranes 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.
Effluent treatment in denim and jeans manufacture
(ELSEVIER, 2015) Uzal, Nigmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
This chapter discusses the major strategies that should be considered in the treatment of denim dyeing and jeans processing wastewater. It first gives an overview of wastewater characteristics and further elaborates on the different techniques currently available for treating wastewater. There follow the strategies to be adopted for water reuse and the recovery of dyes and chemicals. Also emphasised is the utilisation of novel technologies that provide waste minimisation, recovery and reuse opportunities and pollution prevention, instead of end of pipe approaches for treating this highly polluted wastewater.
Enhanced hydrophilicity and mechanical robustness of polysulfone nanofiber membranes by addition of polyethyleneimine and Al2O3 nanoparticles
(ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2017) Uzal, Nigmet; Ates, Nuray; Saki, Seda; Bulbul, Y. Emre; Chen, Yongsheng; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
A novel hydrophilic and mechanically robust polysulfone (PSF) nanofiber membrane (NFM) was prepared by electrospinning of a PSF solution blended with polyethyleneimine (PEI) and Al2O3 nanoparticles. The influence of PEI and Al2O3 nanoparticles concentration on the NFM characteristics was studied using scanning electron microscopy (SEM), Fourier transform infrared FT-IR spectroscopy, porosity, water contact angle measurement, and tensile strength test. Filtration performance of the nanofiber membranes (NFMs) were evaluated by the measurement of pure water flux (PWF) and bovine serum albumin (BSA) rejection tests. According to the results, blending PSF solution with 2 wt.% PEI and 0.05 wt.% Al2O3 nanoparticles resulted in formation of NFMs with high porosity and increased mechanical strength, which exhibited a low water contact angle of 23.5 and high water flux of 28,456 L/m(2) h. On the other hand, incorporation of nanoparticles and PEI in the PSF membrane matrix led to increasing of tensile strength that it was changed from 0.15 to 0.69 for pure PSF and PSF/PEI/Al2O3, respectively. A-24 and 48% BSA rejection performances were obtained by nanoparticle incorporated PSF membranes. In conclusion, the studies strongly suggest that blending with hydrophilic additives of NFMs can enhance the hydrophilicity and mechanical strength of PSF membranes and these NFMs can be effectively used in water based membrane systems. (C) 2017 Elsevier B.V. All rights reserved.
Fabrication and characterization of silane-functionalized Na-bentonite polysulfone/polyethylenimine nanocomposite membranes for dye removal
(WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ USA, 2020) Saki, Seda; Senol-Arslan, Dilek; Uzal, Nigmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü
In 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.
Fabrication of Gd2O3/PSF Membranes via Aqueous Phase Inversion Method
(HİTİT ÜNİVERSİTESİ, 2022) Gül, Ayşe; Şenol Arslan, Dilek; Uzal, Nigmet; 0000-0001-9639-2843; 0000-0002-2305-6408; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Gül, Ayşe; Şenol Arslan, Dilek; Uzal, Nigmet
The purpose of this study was to look into the effect of Gadolinium oxide (Gd2O3) concentration (0.5%, 1%, and 2%) on the performance of newly developed Gd2 O3 /PSF membranes A common phase inversion method was used to create the membranes. Pure water flux and bovine serum albumin (BSA) permeation tests were used to evaluate membrane performance. FTIR and contact angle measurements were used to characterize the membranes that were manufactured. The greatest percentage of BSA rejection was 53%. In this work, the optimum membrane (2% wt Gd2O3/17% wt PSF) successfully demonstrated 53% rejection with filtrate flux for about 8.7 L/m2.h at a pressure of 10 bar.
A holistic sustainability assessment of a university campus using life cycle approach
(Institute for Ionics, 2023) Gulcimen, Sedat; Qadri, Zakee; Dönmez, Rasim; Uzal, Nigmet; 0000-0002-8967-3484; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Gulcimen, Sedat; Qadri, Zakee; Uzal, Nigmet; Dönmez, Rasim
The sustainability performances of campuses are of importance as it could model the efective sustainable initiatives that could be then applied to campuses by decision-makers and designers. Studies have been conducted on the environmental and economic assessment of campuses in specifcation with the identifcation of their carbon footprint and cost analysis, respectively. The studies have lacked a showcase of an ideal sustainable campus along with its urban and architectural features, facilities, and services through analyzing their social aspects as well. The objective of this study was to evaluate the sustainability of the Abdullah Gul University Sumer Campus to model a sustainable campus integrating the Environmental Life Cycle Assessment(E-LCA), the Life Cycle Costing (LCC) and the Social Life Cycle Assessment using life cycle sustainability assessment approaches for the use-phase analysis of the campus. E-LCA was applied to quantify the global warming potential and cumulative energy demand based on International Organization for Standardization 14,040 and 14,044 by considering the gate-to-gate approach. The environmental assessment results showed that the global warming potential of the campus was 2.92 tCO2 eq./person, and the cumulative energy demand was found as 15.4 GJ/person. In LCC, the total cost of the campus was calculated as 200 US Dollars/person, and the energy cost is found as a major contributor with 86% of the total cost for the year of 2019. In the social performance assessment, it is found that the university has a weak social performance for the local community, the consumer, the worker, and the society
İnce Film Kompozit Membranlar ile Basınç Geciktirmeli Ozmos (PRO) Prosesi Kullanılarak Sürdürülebilir Enerji Üretimi
(TUBİTAK, 2018) Uzal, Nigmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
Fosil yakıtlara bağımlılığın azalması için alternatif yenilenebilir ve temiz enerji kaynaklarının bulunmasına yönelik araştırmalar gün geçtikçe artmakta ve önem kazanmaktadır. Son yıllarda oldukça ilgi çeken “tuzluluk gradyanı esaslı ozmotik enerji” veya “mavi enerji” olarak da bilinen enerji kaynağı, artan enerji ihtiyacını karşılamada farklı bir yenilenebilir kaynak olarak ortaya çıkmıştır. Ülkemizdeki tuzluluk gradyanı esaslı enerji potansiyelinin değerlendirilmesine yönelik ilk çalışma niteliğine olan bu projede öncelikle Devlet Su İşlerinden (DSİ) elde edilen nehir debi ve tuzluluk değerleri esas alınarak teorik enerji potansiyeli hesaplamaları gerçekleştirilmiştir. Teorik hesaplamalar tamamlandıktan sonra, enerji potansiyelinin deneysel olarak belirlenmesi için sentetik ve gerçek su örnekleri kullanılarak basınç geciktirmeli ozmos (PRO) prosesinde deneysel çalışmalar gerçekleştirilmiştir. Bu amaçla dört farklı (BW30-LE, SW30-HR, AG, AC) ticari ince film kompozit (TFC) ters osmos membran 3-(3,4-Dihydroxyphenyl)-L-alanine (L-DOPA) ve LDOPA ile birlikte nanomalzemeler (MWCNT, TiO2, SiO2, Al2O3) kullanılarak modifiye edilmiş ve PRO sisteminde işletilerek enerji üretim performansı lab-ölçekli deneyler ile belirlenmiştir. TFC yapıdaki RO membranların modifikasyonu sonrası aktif yüzeylerinde meydana gelen yapısal değişiklerin belirlenmesinde SEM, FTIR, temas açısı, ve AFM analizleri gerçekleştirilmiştir. Deney sonuçları ışığında L-DOPA ile birlikte %1wt TiO2 nanomalzeme ile modifiye edilmiş BW30-LEmembranı 1,61 W/ m2 en yüksek PRO güç üretim potansiyelini göstermiştir. Gerçek su örnekleri ile gerçekleştirilen PRO deneylerinde Akdeniz, Karadeniz, Marmara ve Ege Denizlerinden deniz suyu ve bu denizlere dökülen Seyhan, Ceyhan, Büyük Menderes, Gediz, Susurluk, Kızılırmak ve Yeşilırmak nehirlerinin karıştığı noktalardan örnekler alınarak ülkemizde tuzluluk gradyanı esaslı bu enerjiye ilişkin potansiyel belirlenmiştir. Geçek su numunelerinde en yüksek enerji üretim performansı 56,8 mS/cm iletkenliğe sahip Akdeniz ile 586 µS/cm iletkenliğe sahip Ceyhan ve Seyhan nehrinin PRO prosesi uygulamasından 5 ve 10 barda sırasıyla 0,47 ve 0,68 W/m2 olarak bulunmuştur.
Integration of direct microfiltration and reverse osmosis process for resource recovery from municipal wastewater
(DESALINATION PUBL, 2023) Ozcan, Ozlem; Sahinkaya, Erkan; Uzal, Nigmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Ozcan, Ozlem; Uzal, Nigmet
For the sustainability of water resources, the recovery of water, organic matter (OM), energy, and nutrients from municipal wastewater become very attractive resources. As direct application of water, nutrient, and energy recovery from municipal wastewater cannot be feasible, the wastewater needed to be concentrated. In this study, the molecular weight distribution of OM content was determined in wastewater samples, up-concentration potential of direct microfiltration (DMF) of municipal wastewater and water recovery were investigated. In OM fractionation studies, around 52% of the chemical oxygen demand (COD) in wastewater was particulate or colloidal (>10 kDa) and 48% was soluble (<300 Da). In DMF tests, the COD concentration was concentrated up to 1,573 mg/L after sequential DMF experiments. Additionally, the theoretic total energy requirement of the DMF process was found around 0.3 kWh/m3 and it would be potentially energy positive. In crossflow experiments, the reverse osmosis (RO) process was performed using DMF effluent. When microfiltration and RO membranes were chemically cleaned, flux recovery rates of 100% and 99% were achieved, respectively. However, the foulants could not be completely removed during the cleaning according to scanning electron microscopy, atomic force microscopy, and attenuated total reflection-Fourier-transform infrared spectroscopy results of the virgin, fouled, and cleaned membranes. This study reveals that the DMF+RO p
Investigation of the treatability of pre-coagulated slaughterhouse wastewater using dead-end filtration
(WILEY111 RIVER ST, HOBOKEN 07030-5774, NJ, 2021) Ozdemir, Safiye; Uzal, Nigmet; Gokcek, Oznur Begum; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
BACKGROUND 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).
Life cycle assessment of lightweight concrete containing recycled plastics and fly ash
(TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND, 2020) Ersan, Yusuf Cagatay; Gulcimen, Sedat; Imis, Tuba Nur; Saygin, Osman; Uzal, Nigmet; 0000-0003-4128-0195; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü
Researchers 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.
Life Cycle Assessment of the Neutralization Process in a Textile WWTP
(Erciyes Üniversitesi, 2020) Şener Fidan, Fatma; Kızılkaya Aydoğan, Emel; Uzal, Niğmet; 0000-0002-0912-3459; 0000-0003-0927-6698; 0000-0002-2397-3628; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Uzal, Nigmet
Although industrial wastewater treatment plants (WWTP) have become an important part of textile facilities in reducing environmental pollution problems, they also produce sludge and various emissions such as high chemical oxygen demand, color and conductivity which have serious negative impacts on the environment. One of the processes with enormous chemical consumption in industrial WWTP of textile facilities is the neutralization process, which aims to adjust the pH of the wastewater. Neutralization processes needed to be optimized in order to determine its overall environmental impacts and then identify the most environmentally appropriate options. The aim of this study is to compare the environmental impacts of carbon dioxide and sulfuric acid, which are two alternative chemicals used in the neutralization process of textile facilities, using Life Cycle Assessment (LCA) approach. The environmental impacts resulting from the use of these two chemicals proposed according to the Reference document on Best Available Techniques (BREF) Document for Textile Industry were revealed by the CML-IA method and the gate-to-gate method. According to the results, using carbon dioxide instead of sulfuric acid, the best improvement was in the abiotic depletion category with 92%, while the least improvement was in the eutrophication potential with 39%. No improvement was observed in the global warming potential and human toxicity impacts.
Life cycle sustainability assessment of a light rail transit system: Integration of environmental, economic, and social impacts
(WILEY111 RIVER ST, HOBOKEN 07030-5774, NJ, 2021) Gulcimen, Sedat; Aydogan, Emel K.; Uzal, Nigmet; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Gulcimen, Sedat; Uzal, Nigmet
The transition toward sustainable urban transportation has gained importance in recent decades. However, urban transportation has not been addressed for all dimensions of sustainability. This study presents a life cycle sustainability assessment of a light rail transit system in Kayseri, Turkey, by integrating environmental, economic, and social aspects. The sustainability performance of the light rail transit system is evaluated using a cradle-to-grave approach to assess three aspects of sustainability. For the environmental evaluation, a life cycle assessment was applied using SimaPro 8.4.1 PhD version based on ISO 14040 and 14044. The method, which includes nine environmental impact categories, was employed to assess the environmental performance of the light rail transit system with a functional unit of 1 passenger-km. For the economic assessment, life cycle costing was utilized with the functional unit of USD for 1 passenger-km. A social life cycle assessment was applied to assess the social performance of the light rail transit system based on guidelines published by the United Nations Environment Programme in collaboration with the Society of Environmental Toxicology and Chemistry. For the determination of social impacts, 11 subcategories and 18 social indicators were selected. The results showed that the global warming potential and abiotic depletion potential of the light rail system per passenger-km were 2.4E - 02 kg CO2 eq. and 2.7E - 01 MJ, respectively, with a service life of 50 years. The total life cycle cost of the light rail system was calculated as 0.046 USD for 1 passenger-km. The results also revealed that the main contributor to the total life cycle cost was energy cost, with 92% (2.88E + 08 USD) of the total cost. In the social performance evaluation, it is found that the industry performs well for society, the local community, and workers but has a weaker social performance for the consumer due to a weak feedback mechanism. Integr Environ Assess Manag 2021;00:1-13. (c) 2021 SETAC