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Öğe Boron removal by liquid-phase polymer-based retention technique using poly(glycidyl methacrylate N-methyl D-glucamine)(Wiley-Blackwell, 2013) Sanchez, Julio; Rivas, Bernabe L.; Nazar, Eliza; Bryjak, Marek; Kabay, NalanThe removal of boron was analyzed by liquid-phase polymer based retention (LPR) technique using washing and enrichment method. The extracting reagents were water-soluble polymers (WSPs) containing quaternary ammonium salts and N-methyl-D-glucamine (NMG) groups. The removal experiments of boron using the washing method were conducted at 1 bar of pressure by varying pH, polymer:boron molar ratio, and concentrations of interfering ions (chloride and sulfate). The results showed higher retention capacity for boron (60%) at pH 10 with the polymer containing NMG group. The optimal polymer:boron molar ratio was 40 : 1. Selectivity experiments showed that the presence of interfering ions did not affect the boron removal capacity. The maximal boron retention capacity was determined by the enrichment method, obtaining a value of 12 mg B/g-polymer. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013Öğe Polypropylene membranes modified with interpenetrating polymer networks for the removal of chromium ions(Wiley, 2015) Tapiero, Yesid; Rivas, Bernabe L.; Sanchez, Julio; Bryjak, Marek; Kabay, NalanPolypropylene (PP) membranes incorporating poly[(ar-vinylbenzyl) trimethylammonium chloride] P(ClVBTA), and poly[sodium (styrene sulfonate)] P(SSNa) were modified via an in situ radical polymerization synthesis. Two methods were used for impregnation of the reactive solution: pressure injection and plasma superficial activation with argon gas. The following conditions were varied: the monomer concentrations, number of injections, and cross-linked concentration. The modified polypropylene membranes were then characterized using scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform-infrared spectroscopy, electrokinetic potential, and Donnan dialysis for the chromium ions transport. The modified membranes exhibited a hydrophilic character with a water uptake capacity between 15% and 20% and a percent modification between 2.5% and 4.0%. This was compared with the results of an unmodified polypropylene membrane as the blank and the mentioned polypropylene membrane has not the capacity to uptake water because this kind of material is highly hydrophobic. Hexavalent chromium ions were efficiently transported by the modified membranes containing P(ClVBTA) via a plasma method and it achieved 59.2% extraction at pH 9.0 using a 1-mol L-1 NaCl extraction agent. Therefore, unmodified polypropylene membrane shows an extraction percentage close to 10% from the hexavalent chromium ions at pH 9.0. In the same way, the trivalent chromium transport using membranes modified with P(SSNa) achieved 49.0% extraction at pH 2.0 using 1 x 10(-1) mol L-1 HNO3 and 1 mol L-1 NaCl as the extraction agents. Moreover, the unmodified polypropylene membrane reached a value close to 10% from the trivalent chromium ions using 1 x 10(-1) mol L-1 HNO3 and 1 mol L-1 NaCl. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41953.Öğe Polypropylene membranes modified with interpenetrating polymer networks for the removal of chromium ions(Wiley, 2015) Tapiero, Yesid; Rivas, Bernabe L.; Sanchez, Julio; Bryjak, Marek; Kabay, NalanPolypropylene (PP) membranes incorporating poly[(ar-vinylbenzyl) trimethylammonium chloride] P(ClVBTA), and poly[sodium (styrene sulfonate)] P(SSNa) were modified via an in situ radical polymerization synthesis. Two methods were used for impregnation of the reactive solution: pressure injection and plasma superficial activation with argon gas. The following conditions were varied: the monomer concentrations, number of injections, and cross-linked concentration. The modified polypropylene membranes were then characterized using scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform-infrared spectroscopy, electrokinetic potential, and Donnan dialysis for the chromium ions transport. The modified membranes exhibited a hydrophilic character with a water uptake capacity between 15% and 20% and a percent modification between 2.5% and 4.0%. This was compared with the results of an unmodified polypropylene membrane as the blank and the mentioned polypropylene membrane has not the capacity to uptake water because this kind of material is highly hydrophobic. Hexavalent chromium ions were efficiently transported by the modified membranes containing P(ClVBTA) via a plasma method and it achieved 59.2% extraction at pH 9.0 using a 1-mol L-1 NaCl extraction agent. Therefore, unmodified polypropylene membrane shows an extraction percentage close to 10% from the hexavalent chromium ions at pH 9.0. In the same way, the trivalent chromium transport using membranes modified with P(SSNa) achieved 49.0% extraction at pH 2.0 using 1 x 10(-1) mol L-1 HNO3 and 1 mol L-1 NaCl as the extraction agents. Moreover, the unmodified polypropylene membrane reached a value close to 10% from the trivalent chromium ions using 1 x 10(-1) mol L-1 HNO3 and 1 mol L-1 NaCl. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41953.Öğe Polypropylene membranes modified with interpenetrating polymer networks for the removal of chromium ions(Wiley, 2015) Tapiero, Yesid; Rivas, Bernabe L.; Sanchez, Julio; Bryjak, Marek; Kabay, NalanPolypropylene (PP) membranes incorporating poly[(ar-vinylbenzyl) trimethylammonium chloride] P(ClVBTA), and poly[sodium (styrene sulfonate)] P(SSNa) were modified via an in situ radical polymerization synthesis. Two methods were used for impregnation of the reactive solution: pressure injection and plasma superficial activation with argon gas. The following conditions were varied: the monomer concentrations, number of injections, and cross-linked concentration. The modified polypropylene membranes were then characterized using scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform-infrared spectroscopy, electrokinetic potential, and Donnan dialysis for the chromium ions transport. The modified membranes exhibited a hydrophilic character with a water uptake capacity between 15% and 20% and a percent modification between 2.5% and 4.0%. This was compared with the results of an unmodified polypropylene membrane as the blank and the mentioned polypropylene membrane has not the capacity to uptake water because this kind of material is highly hydrophobic. Hexavalent chromium ions were efficiently transported by the modified membranes containing P(ClVBTA) via a plasma method and it achieved 59.2% extraction at pH 9.0 using a 1-mol L-1 NaCl extraction agent. Therefore, unmodified polypropylene membrane shows an extraction percentage close to 10% from the hexavalent chromium ions at pH 9.0. In the same way, the trivalent chromium transport using membranes modified with P(SSNa) achieved 49.0% extraction at pH 2.0 using 1 x 10(-1) mol L-1 HNO3 and 1 mol L-1 NaCl as the extraction agents. Moreover, the unmodified polypropylene membrane reached a value close to 10% from the trivalent chromium ions using 1 x 10(-1) mol L-1 HNO3 and 1 mol L-1 NaCl. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41953.Öğe Removal of Arsenic from Water by Combination of Electro-Oxidation and Polymer Enhanced Ultrafiltration(Wiley-Blackwell, 2014) Arar, Ozgur; Kabay, Nalan; Sanchez, Julio; Rivas, Bernabe L.; Bryjak, Marek; Pena, CarlosWater-soluble poly[glycidyl methacrylate N-methyl D-glucamine], P(GMA-NMG), was synthesized and purified by ultrafiltration membranes. It was subsequently used for arsenic removal by coupling electro-oxidation (EO) and polymer-enhanced ultrafiltration (PEU) processes. In the EO-PEU combined process, P(GMA-NMG) was first used as supporting electrolyte during the exhaustive electro-oxidation of As(III) to As(V) and then it was used to remove As(V) from aqueous solution through PEU. At first stage, the complete EO of As(III) to As(V) was performed with a platinum reticulated vitreous carbon (RVC)-modified electrode and the advancement of the electrolysis was monitored by analytical electrodes. After the oxidation of As(III) to As(V), the PEU was carried out by washing method using regenerate cellulose membrane and 1 bar of pressure. The effects of supporting electrolytes and pH on EO-PEU combined process were investigated. The best results showed that by using P(GMA-NMG) as supporting electrolyte during the complete electrooxidation of As(III) to As(V) followed by PEU separation, almost 80% of As(V) was removed at pH 10. (C) 2013 American Institute of Chemical Engineers Environ Prog, 33: 918-924, 2014Öğe Removal of As(V) using liquid-phase polymer-based retention (LPR) technique with regenerated cellulose membrane as a filter(Springer, 2013) Sanchez, Julio; Bastrzyk, Anna; Rivas, Bernabe L.; Bryjak, Marek; Kabay, NalanIn this study, regenerated cellulose membrane was used as a filter in liquid-phase polymer-based retention technique. The poly(4-vinyl-1-methylpyridinium bromide), P(BrVMP), was used as extracting reagent of As(V). The role of pH, polymer:As(V) molar ratio, and influence of regenerated cellulose membrane were investigated by washing method. It was observed that the efficient retention was obtained at pH 9 with 20:1 polymer:As molar ratio and it was about 100 % at Z = 10 for P(BrVMP). Experimental data showed that the regenerated cellulose membrane, compared to poly(ethersulfone) membrane, has a capacity to interact with As(V). The maximum retention capacity of P(BrVMP) was determined by enrichment method, and then, using alternately washing and enrichment methods, the charge-discharge process and recovery of P(BrVMP) were performed.Öğe Removal of boron from water through soluble polymer based on N-methyl-D-glucamine and regenerated-cellulose membrane(Taylor & Francis Inc, 2016) Sanchez, Julio; Wolska, Joanna; Yorukoglu, Eren; Rivas, Bernabe L.; Bryjak, Marek; Kabay, NalanThis paper presents a systematic study of boron removal from simulated and real aqueous systems in northern Chile by means of polymer-enhanced ultrafiltration. Poly(glycidyl methacrylate-N-methyl-D-glucamine), P(GMA-NMG), was used to form complexes with boron, and a cellulose-regenerated membrane was used as a complex separator. The first tests were performed using two simulated water samples from northern Chile with the same pH and concentrations of boron, arsenic, and chloride. P(GMA-NMG) showed a maximum of 60% boron retention for these artificial waters. Studies of boron enrichment using P(GMA-NMG) with simulated water showed that the soluble polymer reached maximum retention capacity values between 2.0 and 4.0mg of B retained per gram of polymer. SEM images and FTIR spectroscopy confirm the deposition of the polymer on the surface of the membrane after polymer-enhanced ultrafiltration, which explains the permeate flux decay observed in retention experiments. Finally, sorption-desorption tests of boron from real water samples show that it is possible to use the polymer P(GMA-NMG) to remove boron from waters of northern Chile. It is also possible to release the retentate and regenerate the water-soluble polymer.Öğe Ultrafiltration assisted by water-soluble poly(diallyl dimethyl ammonium chloride) for As(V) removal(Springer, 2016) Sanchez, Julio; Rivas, Bernabe L.; Ozgoz, Selin; Otles, Semih; Kabay, Nalan; Bryjak, MarekArsenic is a very toxic element that must be removed efficiently from aqueous streams. Among the most promising techniques used for the removal of arsenic are separation methods using membranes. In this study, a regenerated cellulose ultrafiltration (UF) membrane and a poly(diallyl dimethyl ammonium chloride) P(DADMAC) were coupled and used in combination to remove As(V) from an aqueous solution. The influences of pH, the polymer: As(V) molar ratio, and the presence of interfering ions such as chloride and sulfate were investigated in arsenic removal via the washing method. The efficient retention of arsenic was observed at pH 7 with a 5: 1 polymer: As molar ratio and with an efficiency of approximately 85 % at Z = 10 for P(DADMAC). The maximum retention capacity of As(V) was determined by the enrichment method, and the results indicated that 194 mg of As(V) was removed per gram of polymer. Finally, using enrichment and washing methods sequentially, the sorption-desorption process and regeneration of P(DADMAC) were performed successfully.Öğe Water-Soluble Polymer and Photocatalysis for Arsenic Removal(Wiley, 2014) Yuksel, Suna; Rivas, Bernabe L.; Sanchez, Julio; Mansilla, Hector D.; Yanez, Jorge; Kochifas, Pia; Kabay, Nalan; Bryjak, MarekIn this study, the photocatalytic oxidation of hazardous arsenite (As(III)) to arsenate (As(V)) and the sequential removal of arsenate from aqueous solution by liquid-phase polymer-based retention (LPR) were investigated. The photocatalytic oxidation of arsenite was performed using TiO2 (P25 Degussa, Germany) under UV-A light. The optimal photocatalytic conditions to oxidize 10 mg L-1 of arsenite solution were achieved using a 0.5 g L-1 of catalyst at a pH value of 2. The As(III) oxidation reached 100% after 30 min of illumination with UV-A light. A water-soluble polymer containing quaternary ammonium groups, poly(3-acrylamidopropyl) trimethylammonium chloride (P(ClAPTA)), was used as an extracting reagent in the LPR process. To obtain the optimized conditions, the removal experiments were performed at various polymer : As(V) molar ratios using 10 mg L-1 of arsenate solutions. After the oxidation of As(III) to As(V), the removal of arsenate by P(ClAPTA) was obtained in a 99% yield using a 20 : 1 polymer : As(V) molar ratio at a pH value of 9. The results demonstrate that the combination of these methods is highly useful for potential applications related to the treatment of wastewater contaminated with As(III). (C) 2014 Wiley Periodicals, Inc.
