Yazar "Uzal, Nigmet" seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    Arsenic removal by the micellar-enhanced ultrafiltration using response surface methodology
    (Iwa Publishing, 2020) Gokcek, Oznur Begum; Uzal, Nigmet
    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.
  • Küçük Resim Yok
    Öğe
    Efficiency of L-DOPA+TiO2 modified RO membrane on salinity gradient energy generation by pressure retarded osmosis
    (Pamukkale Univ, 2024) Ates, Nuray; Saki, Seda; Gokcek, Murat; Uzal, Nigmet
    Harvesting energy from the salinity gradient of seawater and river water using pressure retarded osmosis (PRO) has been a major research topic of recent years. However, there is a need for efficient PRO membranes that can generate high power density and are pressure resistant, as the performance of current membranes on the market is poor. In this study, specific energy potential of PRO process using LDOPA+TiO2 modified BW30-LE membrane was evaluated on synthetic and real water samples. Polyamide BW30-LE RO membrane was modified by L-DOPA, L-DOPA+0.5 wt% TiO2 and L-DOPA+1 wt% TiO2. The effect of hydraulic pressure and temperature on generation of power density were evaluated for 5, 10, and 15 bar pressures, as well as 10 degrees C, 20 degrees C, and 30 degrees C degrees. The incorporation of TiO2 nanoparticles with L-DOPA increased the water flux by increasing the surface hydrophilicity and roughness of the membrane surface. The maximum specific power was observed as 1.6 W/m(2) for L-DOPA+1 wt% TiO2 modified BW30-LE membrane at 15 bar pressure. Besides, Mediterranean and Aegean, Black Sea water samples were used as draw solution and Seyhan, Ceyhan, Buyuk Menderes, Gediz, Yesilirmak, and Kizilirmak Rivers were used as feed solution. The highest osmotic power density was obtained by using L-DOPA+1 wt% TiO2 modified BW30-LE membrane with Ceyhan River as feed and Mediterranean Sea water as draw solution, which have the highest differences in salinity. In the mixture of Mediterranean and Ceyhan River, the highest power density was obtained at 10 bar pressure at 30 +/- 5 degrees C with 0.70 W/m(2).
  • Küçük Resim Yok
    Öğe
    Investigation of the treatability of pre-coagulated slaughterhouse wastewater using dead-end filtration
    (Wiley, 2021) Ozdemir, Safiye; Uzal, Nigmet; Gokcek, Oznur Begum
    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).
  • Küçük Resim Yok
    Öğe
    Nanofiltration and Reverse Osmosis for Reuse of Indigo Dye Rinsing Waters
    (TAYLOR & FRANCIS INC, 2010) Uzal, Nigmet; Yilmaz, Levent; Yetis, Ulku
    A membrane based treatment strategy was developed for the possible recycling of rinsing wastewater from indigo dyeing to the process itself. Performances of three different nanofiltration (NF) (NF 270 and NF 90, Dow Film Tech, USA and NF 99, Alfa Laval, Denmark) and two different reverse osmosis (RO) (HR 98 PP and CA 995 PE, Alfa Laval, Denmark) membranes were investigated with wastewater collected from the first post-rinsing tank of indigo dyeing process of a denim manufacturing plant. Dead-end microfiltration with a 5 mu m filter was employed to remove coarse particles and minimize fouling of further NF and RO membranes. For NF and RO, a lab scale plate-and-frame membrane module was operated at a pressure of 5.07bar and at a 0.62m/s cross-flow velocity. The permeate quality from all the tested NF and RO membranes was acceptable for reuse in terms of COD and color. However, only the permeate from HR 98 PP RO and NF 90 membranes were with an acceptable conductivity. On the other hand, NF 270 membrane was superior to all the other NF and RO membranes in terms of the permeation rate. Flux declines obtained for all membranes were higher than 50% but fouling was not considerable and completely reversible. The good performance of NF 270 in terms of permeate quality (permeate conductivity, color, and COD values were 4.3mS/cm, 8 Pt-Co, and 87mg/L, respectively) together with a higher flux makes this membrane preferable over the other membranes to recycle denim textile rinsing wastewaters.
  • Küçük Resim Yok
    Öğe
    Sustainable waste management system and reverse logistic network design in plastic industry: A case study of Turkey
    (IGI Global, 2013) Aydogan, Emel Kizilkaya; Uzal, Nigmet; Ates, Nuray; Zaral, Fulya; Papajorgji, Petraq
    The shortage of natural sources and the threat of the bad trend have forced the industries to find environmentally- friendly alternatives and ecological approaches in their production line. In some countries, regulations have been issued for industries about this subject. Due to these reasons and more of them, logistic firms have been forced to take into consideration decreasing material and energy consumption and minimizing waste production in planning their network designs. In practice, it might be necessary to simultaneously optimize more than one conflicting objective to obtain effective and realistic solutions. In this chapter, current logistics network design of a plastic industry in Turkey has been investigated and reverse logistics network design has been developed to minimize waste production and to achieve green production. This chapter presents a mathematical model which is a fuzzy goal programming model for imprecise goals for reverse logistic network design with multiple objectives in plastic sector. The considered objectives are to reduce cost in reverse logistics, to improve product quality, and to provide environmental benefits by minimizing waste production. © 2014, IGI Global.