Yazar "Yuksel, Mithat" seçeneğine göre listele
Listeleniyor 1 - 20 / 106
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe 110th Anniversary: Transesterification of Corn Oil to Biodiesel by Ion Exchange Resins with Macroporous Structure(Amer Chemical Soc, 2019) Falizi, Nasim Jahlnejad; Madenoglu, Tulay Gungoren; Kabay, Nalan; Yuksel, MithatThis study investigated the transesterification of corn oil into fatty acid methyl esters (FAME) and free fatty acid (FFA) conversion using macroporous strong acid cationic (Purolite CT175 in H+ and Na+ forms) and strong base anionic (Purolite A500TLPIus in OH- form) resins. Taguchi experimental design was used for the optimization of molar ratio of methanol to oil (6:1, 12:1, and 18:1 mol/mol), reaction time (24, 36, 48 h), reaction temperature (63, 65, 67 degrees C), and resin loading (12, 16, 20 wt %). For both ionic forms of Purolite CT175, resin loading of 12 wt %, reaction temperature of 65 degrees C, methanol to oil (MeOH:Oil) mol ratio of 18:1, and reaction time of 24 h were found as optimum conditions. on the other hand, 12 wt % of resin loading, 65 degrees C of reaction temperature, 6:1 of methanol to oil molar ratio, and 24 h of reaction time were obtained as optimum conditions for Purolite A500TLPlus resin in OH- form. the maximal FFA conversions of approximately 80%, 81%, and 76% were achieved at optimum conditions for H- and Na+ forms of Purolite CT175 resin and OH- form of Purolite A500TLPlus resin, respectively.Öğe Anaerobic Digestion of Aquatic Plants for Biogas Production(Springer International Publishing Ag, 2020) Madenoglu, Tulay Gungoren; Falizi, Nasim Jalilnejad; Serez, Habibe; Kabay, Nalan; Gunes, Asli; Kumar, Rajeev; Yuksel, MithatLimited reserves of fossil fuel resources and negative environmental impacts increased energy demands toward renewable energy technologies. Bioenergy is one of the solutions, and biogas production from wastes and residues by anaerobic digestion (AD) is a promising technology. Municipal solid wastes, sludge from wastewater treatment plants, agricultural plant wastes, forestry residues and manure are the widely used sources in AD for biogas production. Aquatic plants can be evaluated as a renewable energy source. If waste and residues of these plants are not utilized in beneficial use, greenhouse gases (GHG) will be emitted through land-filling or direct combustion. Wastes should be converted to biogas with a high yield to decrease the quantity of wastes and biogas with a high-energy content. Substrate to inoculum ratio, temperature regime, C/N ratio, pH, volatile fatty acid and ammonia content are important process parameters for AD. Modified Gompertz, Cone and first-order equations are widely used model equations for kinetic parameters that are used in kinetic models (Monod, modified Andrew, Ratkowsky) for identification of optimum substrate concentration and temperature for each specific feed. This chapter evaluates effective process parameters on AD of aquatic plants for biogas production and application of kinetic analysis for assignment of optimum conditions.Öğe Application of adsorption-ultrafiltration hybrid method for removal of phenol from water by hypercrosslinked polymer adsorbents(Elsevier Science Bv, 2012) Ipek, Idil Yilmaz; Kabay, Nalan; Yuksel, Mithat; Yapici, Duygu; Yuksel, UmranThis study will provide a solution to the discharge of phenol containing water and wastewater problem. This could be achieved through the development of a treatment process based on the combination of adsorption and membrane filtration processes. In this study, the efficiency of phenol removal from model phenol solution was investigated using Purolite MN 200 and Purolite MN 202 hypercrosslinked macronet polymer adsorbents by using only adsorption and adsorption-ultrafiltration hybrid processes. In order to remove phenol with a percent removal of about 90% from aqueous solution, optimum amount of adsorbent was found to be 0.1 g-adsorbent/50 mL-solution and 0.2 g-adsorbent/50 mL-solution for Purolite MN 200 and Purolite MN 202, respectively. According to the results of kinetic study, phenol removal rate was found to be higher when the particle size of Purolite MN 200 is smaller due to increased surface area. The results of the hybrid system showed that the optimum operating conditions to meet the goal of discharge limit of phenol containing water by Purolite MN 200 were found when the adsorbent concentration is 3 g/L, flow rate of suspensions of saturated and fresh adsorbents 6 mL/min, and flow rate of feed and permeate 3 mL/min. Finally, the performance of Purolite MN 202 adsorbent used in adsorption-ultrafiltration hybrid system showed much promising removal rate than that of Purolite MN 200 polymer adsorbent for phenol removal. (C) 2012 Elsevier B.V. All rights reserved.Öğe Application of electrodeionization (EDI) for removal of boron and silica from reverse osmosis (RU) permeate of geothermal water(Elsevier, 2013) Arar, Ozgur; Yuksel, Umran; Kabay, Nalan; Yuksel, MithatIn this study, a hybrid process coupling reverse osmosis (RO) with electrodeionization (EDI) was investigated to remove boron and silica from geothermal water. The effect of applied voltage, feed flow rate, Na2SO4 concentration in the electrode compartments, membrane type and ion exchange resin bed configuration on the removal of boron and silica has been investigated. Geothermal water was obtained from the discharge lines in the geothermal plant of Izmir Geothermal Co. The RO system contained two parallel mounted brackish reverse osmosis membranes (BW-30-2540, Dow FilmTech). The RO permeate was collected using a single membrane configuration of operation by applying a 12 bar of pressure. The concentration of boron remaining in the permeate was 5.9 mg/L It was obtained that the concentration of boron decreased from 5.9 mg/L to 0.4 mg/L and silica from 03 mg Si/L to 0.1 mg Si/L with a layered bed configuration of EDI system when a 40 V of voltage was applied to the EDI system. The feed flow rate did not have any significant effect on the removal of boron and silica from the RO permeate of geothermal water by EDI. On the other hand, the transport of boron to the anode compartment of EDI system enhanced with increasing the feed flow rate. In a mixed bed EDI system, when the applied potential was 40 V. boron and silica concentrations in the product water were 1.60 mg B/L and 02 mg Si/L, respectively. The type of the membrane was found to be another important parameter on the removal of boron and silica from the RO permeate. (C) 2012 Elsevier B.V. All rights reserved.Öğe Application of electrodeionization (EDI) for removal of boron and silica from reverse osmosis (RU) permeate of geothermal water(Elsevier, 2013) Arar, Ozgur; Yuksel, Umran; Kabay, Nalan; Yuksel, MithatIn this study, a hybrid process coupling reverse osmosis (RO) with electrodeionization (EDI) was investigated to remove boron and silica from geothermal water. The effect of applied voltage, feed flow rate, Na2SO4 concentration in the electrode compartments, membrane type and ion exchange resin bed configuration on the removal of boron and silica has been investigated. Geothermal water was obtained from the discharge lines in the geothermal plant of Izmir Geothermal Co. The RO system contained two parallel mounted brackish reverse osmosis membranes (BW-30-2540, Dow FilmTech). The RO permeate was collected using a single membrane configuration of operation by applying a 12 bar of pressure. The concentration of boron remaining in the permeate was 5.9 mg/L It was obtained that the concentration of boron decreased from 5.9 mg/L to 0.4 mg/L and silica from 03 mg Si/L to 0.1 mg Si/L with a layered bed configuration of EDI system when a 40 V of voltage was applied to the EDI system. The feed flow rate did not have any significant effect on the removal of boron and silica from the RO permeate of geothermal water by EDI. On the other hand, the transport of boron to the anode compartment of EDI system enhanced with increasing the feed flow rate. In a mixed bed EDI system, when the applied potential was 40 V. boron and silica concentrations in the product water were 1.60 mg B/L and 02 mg Si/L, respectively. The type of the membrane was found to be another important parameter on the removal of boron and silica from the RO permeate. (C) 2012 Elsevier B.V. All rights reserved.Öğe Application of nanofiltration for reuse of municipal wastewater and quality analysis of product water(Elsevier Science Bv, 2013) Bunani, Samuel; Yorukoglu, Eren; Sert, Gokhan; Yuksel, Umran; Yuksel, Mithat; Kabay, NalanIn this study, the municipal wastewater treated by biological methods was used for further treatment by nanofiltration method for wastewater reuse. For this purpose, different nanofiltration (NF) membranes, such as CK. NF-90, and NF-270 were employed. The quality analysis of product water was carried out using various analytical techniques. The results revealed that the NF-90 membrane can produce the best water quality compared to other two membranes. The CK membrane showed also a good rejection property after NF-90 membrane but its big inconvenience is that it gave a lower water flux. Despite the good water flux by NF-270, the permeate quality obtained with this membrane was not as good as obtained with the NF-90 and CK membranes. (C) 2012 Elsevier B.V. All rights reserved.Öğe Application of nanofiltration for reuse of wastewater(Inderscience Enterprises Ltd, 2014) Bunani, Samuel; Yorukoglu, Eren; Yuksel, Umran; Kabay, Nalan; Yuksel, Mithat; Sert, Gokhan; Pek, Taylan OzgurThe present research is a part of efforts to reuse wastewater by applying nanofiltration (NF) method for the secondary treatment of bio-treated wastewater and to check the quality of product water as irrigation water by using various analytical methods. For this, the performances of three different NF membranes (CK, GE-Osmonics; NF-270 and NF-90, Dow-FilmTech) were investigated using a cross-flow flat-sheet membrane test unit (SEPA CF-II, GE). The bio-treated wastewater obtained from ITOB-OSB Wastewater Treatment Plant, Izmir where membrane bioreactor (MBR) technology is employed as a treatment process has a high salinity and a high conductivity which make the treated water unsuitable for irrigation purposes. After applying NF separation for the three membranes at 10 bar as operating pressure, it was concluded that NF-90 gave the best quality of product water for almost all analysed parameters such as salinity calcium, magnesium, sodium, potassium, bicarbonate, chloride, sulphate, phosphate-phosphorous, nitrate-nitrogen, and conductivity.Öğe Application of reverse osmosis for reuse of secondary treated urban wastewater in agricultural irrigation(Elsevier Science Bv, 2015) Bunani, Samuel; Yorukoglu, Eren; Yuksel, Umran; Kabay, Nalan; Yuksel, Mithat; Sert, GokhanSecondary treated urban wastewater was further polished by reverse osmosis (RO) membranes and the water quality of RO permeates was assessed for their utilizations in agricultural irrigation. The performances of brackish water reverse osmosis (AK-BWRO) and seawater reverse osmosis (AD-SWRO) membranes were investigated at 10 bar as applied pressure. The AD-SWRO membrane was tested also at 20 bar. Conductivity, salinity, chemical oxygen demand (COD), total organic carbon (TOC) and color were rejected by AK-BWRO membrane with average values of 94.6%, 95.2%, 85.8%, 76.4% and 91.3%, respectively, whereas the same contaminants were rejected with average values of 98.3%, 98.3%, 84.6%, 69.7% and 86.6%, respectively with AD-SWRO membrane. Except for TOC, AD-SWRO membrane showed similar rejections at 10 bar and at 20 bar of applied pressures. Although their rejection efficiencies were similar, AK-BWRO and AD-SWRO membranes revealed differences in their permeate flux which is 38.0 L/hm(2) for AK-BWRO membrane and 3.81 L/hm(2) for AD-SWRO membrane. An average value of permeate flux was 14.8 L/hm(2) at 20 bar for AD-SWRO membrane. Assessment of water quality of product water obtained by blending of the two effluents (secondary treated urban wastewater and RO permeate) based on salinity, electrical conductivity, specific ionic toxicity and miscellaneous hazards proved that blending of 20-30% of secondary treated effluent and 80-70% of RO permeate is a good strategy to minimize the unwanted components in treated water for its reuse in agricultural irrigation. (C) 2014 Elsevier B.V. All rights reserved.Öğe Application of reverse osmosis for reuse of secondary treated urban wastewater in agricultural irrigation(Elsevier Science Bv, 2015) Bunani, Samuel; Yorukoglu, Eren; Yuksel, Umran; Kabay, Nalan; Yuksel, Mithat; Sert, GokhanSecondary treated urban wastewater was further polished by reverse osmosis (RO) membranes and the water quality of RO permeates was assessed for their utilizations in agricultural irrigation. The performances of brackish water reverse osmosis (AK-BWRO) and seawater reverse osmosis (AD-SWRO) membranes were investigated at 10 bar as applied pressure. The AD-SWRO membrane was tested also at 20 bar. Conductivity, salinity, chemical oxygen demand (COD), total organic carbon (TOC) and color were rejected by AK-BWRO membrane with average values of 94.6%, 95.2%, 85.8%, 76.4% and 91.3%, respectively, whereas the same contaminants were rejected with average values of 98.3%, 98.3%, 84.6%, 69.7% and 86.6%, respectively with AD-SWRO membrane. Except for TOC, AD-SWRO membrane showed similar rejections at 10 bar and at 20 bar of applied pressures. Although their rejection efficiencies were similar, AK-BWRO and AD-SWRO membranes revealed differences in their permeate flux which is 38.0 L/hm(2) for AK-BWRO membrane and 3.81 L/hm(2) for AD-SWRO membrane. An average value of permeate flux was 14.8 L/hm(2) at 20 bar for AD-SWRO membrane. Assessment of water quality of product water obtained by blending of the two effluents (secondary treated urban wastewater and RO permeate) based on salinity, electrical conductivity, specific ionic toxicity and miscellaneous hazards proved that blending of 20-30% of secondary treated effluent and 80-70% of RO permeate is a good strategy to minimize the unwanted components in treated water for its reuse in agricultural irrigation. (C) 2014 Elsevier B.V. All rights reserved.Öğe Application of reverse osmosis for reuse of secondary treated urban wastewater in agricultural irrigation(Elsevier Science Bv, 2015) Bunani, Samuel; Yorukoglu, Eren; Yuksel, Umran; Kabay, Nalan; Yuksel, Mithat; Sert, GokhanSecondary treated urban wastewater was further polished by reverse osmosis (RO) membranes and the water quality of RO permeates was assessed for their utilizations in agricultural irrigation. The performances of brackish water reverse osmosis (AK-BWRO) and seawater reverse osmosis (AD-SWRO) membranes were investigated at 10 bar as applied pressure. The AD-SWRO membrane was tested also at 20 bar. Conductivity, salinity, chemical oxygen demand (COD), total organic carbon (TOC) and color were rejected by AK-BWRO membrane with average values of 94.6%, 95.2%, 85.8%, 76.4% and 91.3%, respectively, whereas the same contaminants were rejected with average values of 98.3%, 98.3%, 84.6%, 69.7% and 86.6%, respectively with AD-SWRO membrane. Except for TOC, AD-SWRO membrane showed similar rejections at 10 bar and at 20 bar of applied pressures. Although their rejection efficiencies were similar, AK-BWRO and AD-SWRO membranes revealed differences in their permeate flux which is 38.0 L/hm(2) for AK-BWRO membrane and 3.81 L/hm(2) for AD-SWRO membrane. An average value of permeate flux was 14.8 L/hm(2) at 20 bar for AD-SWRO membrane. Assessment of water quality of product water obtained by blending of the two effluents (secondary treated urban wastewater and RO permeate) based on salinity, electrical conductivity, specific ionic toxicity and miscellaneous hazards proved that blending of 20-30% of secondary treated effluent and 80-70% of RO permeate is a good strategy to minimize the unwanted components in treated water for its reuse in agricultural irrigation. (C) 2014 Elsevier B.V. All rights reserved.Öğe Aromatic sulfonic acid-catalyzed conversion of safflower stalk into levulinic acid(Springer Heidelberg, 2022) Yuksel, Dogan Emre; Ballice, Levent; Cengiz, Nihal; Saglam, Mehmet; Yuksel, MithatSafflower stalk is a suitable lignocellulosic biomass that can replace fossil resources for the production of platform chemicals. In this study, the production of levulinic acid (LA) from safflower stalk using aromatic sulfonic acids as environmentally friendly catalysts was investigated. A Taguchi experimental design was used to determine the conditions for the highest product yield. The variations of valuable by-products such as 5-HMF, formic acid, and acetic acid, which may occur depending on the reaction conditions were also analyzed. Optimum conditions for maximum LA yield were found using para-toluenesulfonic acid (PTSA) with concentration of 0.3 M, solvent/biomass ratio as 20 at a temperature of 200 degrees C. Experiments were also carried out to verify the optimum LA yield found using analysis of variance (ANOVA). Comparison experiments were performed with sulfuric acid (H2SO4) under optimum conditions, and it was concluded that PTSA could be an alternative catalyst to H2SO4 in terms of LA yield.Öğe Biocompatibility and biomechanical characteristics of loofah based scaffolds combined with hydroxyapatite, cellulose, poly-L-lactic acid with chondrocyte-like cells(Elsevier Science Bv, 2016) Cecen, Berivan; Kozaci, Leyla Didem; Yuksel, Mithat; Ustun, Ozcan; Ergur, Bekir Ugur; Havitcioglu, HasanThe current study reports the biocompatibility and biomechanical characteristics of loofah-based scaffolds combined with hydroxyapatite (HA), cellulose, poly-L-lactic acid (PLLA) with chondrocytes-like cells. Scanning electron microscope (SEM) micrographs of the scaffolds showed that the addition of PLLA usually resulted in an increase in cell's attachment on scaffolds. Mechanical and elemental analyzes were assessed using tensile test and Energy Dispersive X-ray spectrometry (EDS), respectively. In summary, we showed that the loofah + PLLA + HA scaffolds perform significantly better than other loofah-based scaffolds employed in terms of increasing a diversity of mechanical properties including tensile strength and Young's modulus. Based on the analysis of the differential scanning calorimetry (DSC) thermograms and EDS spectrums that give an idea about the calcium phosphate (CaP) ratios, the improvement in the mechanical properties could principally be recognized to the strong interaction formed between loofah, PLLA and HA. The viability of chondrocytes on loofah-based scaffolds was analyzed by XTT tests. However, none of the scaffolds have proved to be toxic in metabolic activity. The histological evaluation obtained by hematoxylin and eosin (H&E), Masson trichrome, toluidine blue and immunohistochemistry methods showed that cells in all scaffolds produced extracellular matrix that defined proteoglycan and type I-II collagens. The results of this study suggest that the loofah-based scaffold with desirable properties can be considered as an ideal candidate for cartilage tissue engineering applications. (C) 2016 Elsevier B.V. All rights reserved.Öğe Biocompatibility of MG-63 cells on collagen, poly-L-lactic acid, hydroxyapatite scaffolds with different parameters(Wichtig Publishing, 2015) Cecen, Berivan; Kozaci, Didem; Yuksel, Mithat; Erdemli, Diler; Bagriyanik, Alper; Havitcioglu, HasanPurpose: In this study, osteoblast-like MG-63 cells were cultured on 3 different scaffold types composed of (a) collagen + poly-L-lactic acid (PLLA), (b) collagen + hydroxyapatite (HA; 30 degrees C) or (c) collagen + hydroxyapatite (HA; 37 degrees C) and produced with different porosities. Methods: Biomechanical properties of the scaffolds were characterized by tensile strength measurements. Properties of the cell-seeded scaffolds were evaluated with scanning electron microscopy (SEM). Cell adhesion and proliferation capacities were evaluated. Alkaline phosphatase (ALP) levels in media were measured. Transmission electron microscopy (TEM) and histological analyses were used to assess morphological characteristics. Results: Our results showed that collagen-based PLLA and HA scaffolds have good cell biocompatibility. MTT test showed that the scaffolds exhibited no cytotoxicity. According to the force and displacement data, collagen + HA at 37 degrees C showed the highest mechanical strength and displacement. Conclusion: The results suggest that collagen-based PLLA and HA scaffolds might improve osteoblastic growth in vitro and have biomaterial integration potential in possible therapeutic approaches for future clinical studies.Öğe Catalytic gasification of mannose for hydrogen production in near- and super-critical water(Elsevier Science Bv, 2016) Madenoglu, Tulay Gungoren; Cengiz, Nihal Uremek; Saglam, Mehmet; Yuksel, Mithat; Ballice, LeventHydrothermal decomposition of mannose (8 wt.%) in near- and super-critical water was investigated at 500-700 degrees C and 20.0-42.5 MPa with a reaction time of 1 h in the absence and presence of alkali catalyst (K2CO3). Gaseous products, aqueous products, and residue were observed in the batch reactor. The produced gases were carbon dioxide, methane, hydrogen, carbon monoxide, and C-2-C-4 hydrocarbons. The effect of operating parameters (temperature and pressure) on the product distribution was examined in the absence and presence of potassium carbonate. The gaseous product yields were compared with the theoretical equilibrium values that are estimated by Gibbs free energy minimization. In the absence of catalyst, the hydrogen yield was 5.82 mol H-2/mol mannose at 700 degrees C and 20.0 MPa. At this condition, theoretical equilibrium yield of hydrogen was found as 5.78 mol H-2/mol mannose which was very close to the experimental value and addition of K3CO3 increased the hydrogen yield to 10.34 mol H-2/mol mannose. The hydrogen yield increased with increasing temperature and decreasing pressure. Acetic acid was the major component of the aqueous product in gasification of mannose. (C) 2015 Elsevier B.V. All rights reserved.Öğe Catalytic Treatment of Opium Alkaloid Wastewater via Hydrothermal Gasification(Springer International Publishing Ag, 2020) Cengiz, Nihal U.; Saglam, Mehmet; Yuksel, Mithat; Ballice, LeventThe wastewater from an opium processing plant should meet the standards as specified in the 'Water Pollution Control Regulation (WPCR), 2004' before being discharged safely into the receiving medium. Treatment of opium alkaloid wastewater is not sufficient using the existing combined methods of aerobic/anaerobic and chemical treatment. Hydrothermal gasification (HTG) is proposed as an alternative treatment in this study. the other aim of this study is to show the ability to manufacture CH4 and H-2 as renewable energy sources and to determine to what extent the removal of chemical oxygen demand (COD) is. Studies were carried out in batch autoclave reactor systems without catalyst, with original red mud (RM), activated RM, and nickel-impregnated (10, 20, and 30%) forms. Reduction with NaBH4 was done to the nickel-impregnated forms of RM to increase the catalytic activity. Yields of CH4 and H-2 increased from 16.8 to 28.6 mol CH4/kg C in wastewater and from 20.3 to 33.3 mol H-2/kgC in wastewater with 20% impregnated nickel and reduced red mud as the highest at 500 degrees C. the COD of the wastewater was lowered by 81-85% approximately while the TOC content decreased by 85-90%.Öğe Characterisation of products from pyrolysis of waste sludges(Elsevier Sci Ltd, 2006) Karayildirim, Tamer; Yanik, Jale; Yuksel, Mithat; Bockhorn, HenningThe pyrolysis of waste sludges was investigated using thermogravimetry/mass spectrometry (TG/MS) and a fixed-bed reactor. Two types of sludge were used, namely mixed sludge and oil sludge. In TGA/MS measurements, two degradation steps were observed. Degradation of organic structures, in sludge took place in the first step, while inorganic materials in sludge were mainly decomposed in a second step (above 500 degrees C). In a fixed-bed reactor, the catalytic effect of inorganic matter in addition to organic matter was monitored the quality and yield of products from pyrolysis. Pyrolysis of oil sludge produced a larger amount of oil containing more aliphatic compounds and a high calorific value. On the other hand, pyrolysis of mixed sludge gave a smaller amount of oil being rich in polar compounds. The gaseous products from pyrolysis consist of high amount of combustable gases. Landfilling was found to be the best alternative to dispose off the pyrolytic char obtained from pyrolysis. (C) 2005 Elsevier Ltd. All rights reserved.Öğe Characterization of products evolved from supercritical water gasification of xylose (principal sugar in hemicellulose)(Taylor & Francis Inc, 2016) Gokkaya, Dilek Selvi; Saglam, Mehmet; Yuksel, Mithat; Madenoglu, Tulay Gungoren; Ballice, LeventThe catalyst decomposition of xylose (the principal sugar in hemicellulose) was examined in supercritical water for temperature from 400 to 600 degrees C. Experiments were performed in the absence and presence of three main types of catalysts [alkali catalysts (K2CO3 and KOH) and metal impregnated activated carbons (Ni/AC) and (Ru/AC)] with a reaction time of 1h. Gasification yield reaches maximum values by using K2CO3 and KOH at the highest temperature of 600 degrees C. The highest H-2 yield and the highest CH4 yield were obtained by using Ru/AC and Ni/AC, respectively. Acetic acid and 5-methyl furfural were determined as the main aqueous products and reached maximum value by using Ru/AC.Öğe A comparative study for boron removal from seawater by two types of polyamide thin film composite SWRO membranes(Elsevier Science Bv, 2011) Guler, Enver; Kabay, Nalan; Yuksel, Mithat; Yavuz, Emre; Yuksel, UmranIn this paper, field performance of a small-scale seawater reverse osmosis unit installed in Urla Bay-lzmir, Turkey was analyzed and presented. The design of SWRO system in Urla consists of two types of FilmTec polyamide thin film composite spiral wound seawater reverse osmosis membranes (high rejection FILMTEC XUS SW30XHR-2540 RO membrane and FILMTEC SW30-2540 RO membrane) which could be operated in parallel. To make a comparative study between two types of membranes regarding their desalination performances and boron rejections, each membrane was operated individually for each set of experiments. This comparison was made via investigation of the effects of feed seawater temperature (10-16 degrees C), operating pressure (55, 60 and 62 bar), and pH adjustment on the feed side (pH 7.0-7.5). (C) 2010 Elsevier B.V. All rights reserved.Öğe A comparative study for the removal of boron and silica from geothermal water by cross-flow flat sheet reverse osmosis method(Elsevier Science Bv, 2011) Oner, S. Gorkem; Kabay, Nalan; Guler, Enver; Kitis, Mehmet; Yuksel, MithatThis study focused on the application of laboratory scale cross-flow flat sheet reverse osmosis (RO) method for boron, salt and silica removal from geothermal water. Most important operating parameters of RO process such as membrane type, operating pressure and feed flow rate (thus the cross-flow velocity) that govern permeate flux, boron, silica and salt removals were investigated. Four different RO membranes, AD-SWRO (GE Osmonics), AG-BWRO (GE Osmonics), BW-30-BWRO (FILMTEC) and AK-BWRO (GE Osmonics) were used to compare their performances. In order to examine the effects of pressure and cross-flow velocity, system was operated at pressures ranging from 15 to 30 bar and cross-flow velocities of 0.16 and 0.33 m/s. Obtained permeate boron concentrations were evaluated according to drinking and irrigation water standards. (C) 2011 Elsevier B.V. All rights reserved.Öğe A comparative study of removal of endocrine disrupting compounds (EDCs) from treated wastewater using highly crosslinked polymeric adsorbents and activated carbon(Wiley-Blackwell, 2014) Solak, Seyhan; Vakondios, Nikos; Tzatzimaki, Ioanna; Diamadopoulos, Evan; Arda, Muserref; Kabay, Nalan; Yuksel, MithatBACKGROUNDRemoval of some EDCs, such as triclosan including its metabolites (2,4-dichloro phenol and 2,3,4-trichloro phenol), estrogens (estrone, 17--estradiol and 17--ethinyl estradiol) and some pharmaceuticals (clofibric acid, clofibrate, clofibrate methyl ester, carbamazepine) from water and treated wastewater by commercial highly crosslinked polymer adsorbents (Diaion SP207, Diaion SP825, Dowex L493) and activated carbon was investigated using batch adsorption. The analyses of EDCs were performed by solid phase micro-extraction (SPME) coupled with gas chromatography/mass spectrometry. RESULTSThe optimum dosages of polymer adsorbents were in the range 0.2-1.2 g L-1, while the respective values for activated carbon were in the range 0.05-0.2 g L-1. When treated municipal wastewater was used as the water matrix, removal rates of EDCs for activated carbon clearly deteriorated compared with pure water solutions. However, when the synthetic resins were tested in treated effluent, most substances exhibited similar or even higher removals. CONCLUSIONSPolymer adsorbents exhibited good performance for removal of EDCs from water. Their use in biologically treated effluent for EDCs removal is also a viable option. (c) 2014 Society of Chemical Industry.
