Ultrafiltration (UF) is one of the significant advanced processes for oily wastewater treatment due to its clear advantages, for instance, ease in operation and efficient separation. The main drawback of these processes is the fouling problem and many researchers' effort on fabrication of high-performance membranes with higher hydrophilicity and antifouling properties. In this study, flat-sheet polysulfone (PSF)/polyethylenimine (PEI)/CaCO nanocomposite membranes were prepared by phase inversion method for oil/water emulsion separation. Structural properties of membranes were characterized by SEM, FT-IR, contact angle, tensile strength, and atomic force microscopy analysis. Increasing the CaCO nanoparticle loading exhibited the increased the water flux and BSA rejection. PSF/PEI/10 wt% CaCO nanocomposite membranes have 145 L/m h water flux at 2 bar with a contact angle of 84° and with 92% BSA rejection. All prepared CaCO nanocomposite membranes reached similar oil rejections at above 90%. Besides the higher water flux and oil removal efficiencies, 10 wt% of CaCO nanoparticle-blended PSF membranes has notable antifouling capacity with the highest flux recovery ratio (FRR) and lowest flux decay ratio (DR) values. The results showed that there is a great potential to use PSF/PEI/CaCO nanocomposite membranes for the treatment of oil water emulsions with higher permeability and antifouling capacity.

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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.

a b s t r ac tNanocomposite membranes have attracted attention for their high permeability, rejection efficiency, and thermal and mechanical stability. In this study, novel flat-sheet polysulfone nanocomposite membranes were prepared by a phase inversion method with polyethylenimine and Al 2 O 3 nanoparticles to increase the flux and hydrophilicity. Al 2 O 3 nanoparticles were added to the membrane matrix to enhance the permeability, selectivity, and mechanical resistance. Two different sizes of Al 2 O 3 nanoparticles (20 and 80 nm) were used with different weight percentages of 0.2, 1, and 5 wt%. The effects of the size and concentration of the nanoparticles on the structural properties and filtration performance of the membranes were investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy, porosity, water contact angle, thermogravimetric analysis, viscosity, and tensile strength measurements were used to characterize the prepared membranes. The membrane performance was evaluated with water flux and bovine serum albumin rejection tests. According to the results, the membrane containing 15 wt% polysulfone, 1 wt% polyethylenimine, and 5 wt% 20 nm Al 2 O 3 showed the highest pure water flux, porosity, viscosity, and morphological stability. This membrane may have potential uses in water treatment applications.

Pressure 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 m3/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. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13085, 2019