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: 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: 4Citation - Scopus: 5Predicting Potential of Pressure Retarded Osmosis Power for Different Estuaries in Turkey(Wiley, 2018-11-29) Saki, Seda; Uzal, Nigmet; Gokcek, Murat; Ates, NurayPressure retarded osmosis (PRO) is an alternative renewable energy source recovered from the salinity gradient between the fresh water (feed solution) and salty water (draw solution). In order to implement osmotic power, the site-specific characteristics including the river and sea salinity, annual flow rates, ecological restrictions were taken into account. This study revealed a comprehensive analysis for a theoretical potential of PRO process for different estuaries in Turkey. In this study, the power potential prediction of PRO process for the Ceyhan, Sakarya, and Meric Rivers were analyzed via Gibbs free energy calculations. The net annual energy production is projected to be 167, 164, and 208 GWh/y for Ceyhan, Sakarya, and Meric Rivers, respectively. Meric River has the highest energy production of 208 GWh/yr with 186 m(3)/s mean flow rate and 245 mg/L salinity. These results clearly show that Turkey's rivers having high salinity and flow rate are feasible and applicable for making the osmotic power plant economically. Thereby, it is providing essential direction to the improvement of its design, installation, and operation. The developed methodology for the evaluation of the osmotic power potential of other rivers can be considered as a basis to assess the whole potential on a worldwide level. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38:e13085, 2019Article 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.