Reverse Osmosis Membrane Desalination Research Articles

Synthesis of ionic block polymers for desalination membranes

AbstractCopolymer containing 2‐vinylpyridine–trimethylsilyl methacrylate, styrene–2‐vinylpyridine, and styrene–trimethylsilyl methacrylate blocks as well as terpolymers containing the styrene2–vinylpyridine–trimethylsilyl methacrylate blocks were synthesized by initiation of the appropriate monomers sequentially both with butyllithium and sodium. These polymers were subjected to hydrolysis by which the acrylate ester segment is converted to the free acid and to the reaction with methyl iodide, which quaternizes the pyridine segment; finally the hydrolyzed and quaternized polymers were subjected to dehydrohalogenation with external base. The properties of these block polymers and blends of the styrene‐containing block copolymers were examined, especially in regard to their suitability as reverse osmosis desalination membranes.

Convective diffusion in axisymmetrical stagnation flow for determination of properties of membranes for reverse osmosis desalination of water

Convective diffusion in axisymmetrical stagnation flow for determination of properties of membranes for reverse osmosis desalination of water

Development and performance of some porous cellulose acetate membranes for reverse osmosis desalination

AbstractThe effects of casting solution composition and evaporation period on the performance of resulting porous cellulose acetate membranes have been studied, and the results are discussed in terms of casting solution structure, solvent evaporation rate during film formation, and the film shrinkage temperature profile. The development of Batch 316‐type porous cellulose acetate membranes is reported. At 90% level of solute separation and feed flow conditions corresponding to a mass transfer coefficient of 45 × 10−4 cm/sec, the productivities of the above membranes are 21.5 gallons/day/ft2 at 250 psig using 3500 ppm of NaCl in the feed, and 53.9 gallons/day/ft2 at 600 psig using 5000 ppm of NaCl in the feed.

Performance of some improved porous cellulose acetate membranes for low pressure reverse osmosis desalination

The performance and correlations of experimental data with respect to a new and improved class of porous cellulose acetate membranes for low pressure reverse osmosis desalination are reported. These membranes were obtained from a casting solution of the following composition (weight %): acetone 68.0, cellulose acetate (acetyl content = 39.8% ) 17.0, water 13.5, and magnesium perchlorate 1.5; the temperature of the casting solution was 0°C, and the films were cast at the laboratory temperature (23–25°C) in an ambient atmosphere in equilibrium with 30 wt.% aqueous acetone solution; the solvent evaporation time on casting was 2 minutes, and the gelation medium was ice cold water. The productivity of the films made under the above conditions for brackish water desalination was 100 to 150% higher than that of other porous cellulose acetate membranes reported earlier at operating pressures of 250 psig or less. Some comparative data at higher operating pressures are also given.

Crosslinked poly(hydroxyethyl methacrylate) membranes for desalination by reverse osmosis

AbstractA series of crosslinked hydroxyethyl methacrylate (HEMA) membranes for reverse osmosis desalination has been prepared. The crosslinkers used were trimethylol propane trimethacrylate (TPT) or ethylene glycol dimethacrylate (EGD). Membranes were synthesized by polymerizing the monomers as a thin homogeneous film. In addition to reverse osmosis tests, the membranes were also characterized by osmosis experiments and sorption measurements. The reverse osmosis water flux (1500 psi applied pressure, 4% NaCl brine, pH = 5) for these membranes decreases from 0.6 gallonmil/ft2‐day (GMFD) to 0.055 GMFD and salt rejection increase from 78% to a maximum of 94% as the amount of TPT is increased from 0 to 11 mole‐%. Water contents decrease from 42% to 15% over the same range of crosslinker, but the preferential sorption of water to salt does not vary. Thus, rises in reverse‐osmosis semipermeability were found to result from changes in water–salt diffusivity ratios. The mechanism of permselectivity has been interpreted in terms of parallel diffusive fluxes across the membrane of primary H‐bonded water and secondary water plus salt ions.

Kinetics of water and salt transport in cellulose acetate reverse osmosis desalination membranes

Kinetics of water and salt transport in cellulose acetate reverse osmosis desalination membranes

Six-Month Field Test of Reverse Osmosis Desalination Membrane

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSix-Month Field Test of Reverse Osmosis Desalination MembraneSidney Loeb and Serop ManjikianCite this: Ind. Eng. Chem. Process Des. Dev. 1965, 4, 2, 207–212Publication Date (Print):April 1, 1965Publication History Published online1 May 2002Published inissue 1 April 1965https://doi.org/10.1021/i260014a015RIGHTS & PERMISSIONSArticle Views140Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts