Method for the preparation of cellulose acetate flat sheet composite membranes for forward osmosis—Desalination using MgSO4 draw solution

Abstract A lab scale method for the preparation of defect free flat sheet composite membranes for forward osmosis (FO) has been developed. Membranes containing a thin layer of cellulose acetate (CA) cast on a nylon fabric of 50 μm thick were prepared by phase inversion in water. Cellulose acetate (CA) membranes with an overall thickness of 70–80 μm have been prepared with lactic acid, maleic acid and zinc chloride as pore forming agents, at different annealing temperatures, for forward osmosis. These membranes have been tested in the desalination of saline feeds (35 g·L − 1 of NaCl) using magnesium sulphate solution (150 g·L − 1 ) as the draw solution. The water flux, and rejection of NaCl, were compared with those of commercially available membranes tested under the same FO conditions. The commercially available FO membrane from Hydration Technologies Inc, OR (M1) has a permeability of 0.13 L·h − 1 ·m − 2 ·bar − 1 with a NaCl rejection of 97% when tested with 150 g·L − 1 of MgSO 4 in the draw solution. Another commercially available membrane for FO from Hydration Technologies Inc, OR, M2 has a water permeability of 0.014 L·h − 1 ·m − 2 ·bar − 1 with NaCl rejection of 100%. The flux and rejection of the CA membranes prepared in this work are found to be dependent on the nature of the pore forming agent, and annealing temperature. Impregnation of an inorganic filler, sodium montmorrillonite in CA membranes and coating of CA membranes with hydrophilic PVA did not enhance the flux of base CA membranes. Cellulose acetate membranes cast from dope solutions containing acetone/isopropanol and lactic acid, maleic acid and zinc chloride as pore forming agents have water permeabilities of 0.13, 0.09 and 0.68 L·h − 1 ·m − 2 ·bar − 1 respectively, with NaCl rejections of 97.7, 99.3 and 88% when annealed at 50 °C. CA membranes prepared with zinc chloride as a pore forming agent have good permeability of 0.27 L·h − 1 ·m − 2 ·bar − 1 with a NaCl rejection of 95% when annealed at 70 °C.

[1]  Robert L McGinnis,et al.  Desalination by ammonia–carbon dioxide forward osmosis: Influence of draw and feed solution concentrations on process performance , 2006 .

[2]  C. Grigoropoulos,et al.  Fast Mass Transport Through Sub-2-Nanometer Carbon Nanotubes , 2006, Science.

[3]  S. Loeb,et al.  Effect of porous support fabric on osmosis through a Loeb-Sourirajan type asymmetric membrane , 1997 .

[4]  H. Lonsdale,et al.  Reverse Osmosis Membrane Research , 2012 .

[5]  Amy E. Childress,et al.  Forward osmosis: Principles, applications, and recent developments , 2006 .

[6]  K. Richau,et al.  Annealing effect in porous cellulose acetate membranes , 1987 .

[7]  Robert Y. M. Huang,et al.  Pervaporation separation of aqueous mixtures using crosslinked poly(vinyl alcohol)(pva). II. Permeation of ethanol-water mixtures , 1990 .

[8]  Lei Li,et al.  Polyamide thin film composite membranes prepared from isomeric biphenyl tetraacyl chloride and m-phenylenediamine , 2008 .

[9]  T. Scheper,et al.  Structural development of asymmetric cellulose acetate microfiltration membranes prepared by a single-layer dry-casting method , 2007 .

[10]  R. Kesting,et al.  Semipermeable membranes of cellulose acetate for desalination in the process of reverse osmosis. II. Parameters affecting membrane gel structure , 1965 .

[11]  J. McCutcheon,et al.  Internal concentration polarization in forward osmosis: role of membrane orientation , 2006 .

[12]  Andrew G. Livingston,et al.  In search of a standard method for the characterisation of organic solvent nanofiltration membranes , 2007 .

[13]  Richard E. Kravath,et al.  Desalination of sea water by direct osmosis , 1975 .

[14]  S. Loeb,et al.  Internal polarization in the porous substructure of a semipermeable membrane under pressure-retarded osmosis , 1978 .

[15]  A. Haute,et al.  The use of direct osmosis tests as complementary experiments to determine the water and salt permeabilities of reinforced cellulose acetate membranes , 1978 .

[16]  Eric M.V. Hoek,et al.  Interfacial polymerization of thin film nanocomposites: A new concept for reverse osmosis membranes , 2007 .

[17]  C. A. Smolders,et al.  Formation of asymmetric cellulose acetate membranes , 1981 .

[18]  M. D. Pinho.  Annealing effect of cellulose acetate membranes on ethanol and glucose reverse osmosis separation , 1988 .

[19]  R. Kesting.  Synthetic Polymeric Membranes: A Structural Perspective , 1985 .

[20]  J. Hao,et al.  Influence of quench medium on the structure and gas permeation properties of cellulose acetate membranes , 1998 .

[21]  S. Loeb,et al.  Performance of permasep B-9 and B-10 membranes in various osmotic regions and at high osmotic pressures , 1978 .

[22]  Qian Yang,et al.  Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall , 2009 .

[23]  Menachem Elimelech,et al.  Influence of membrane support layer hydrophobicity on water flux in osmotically driven membrane processes , 2008 .

[24]  Sidney Loeb,et al.  Industrial processing with membranes , 1972 .

[25]  G. Wakley,et al.  The structure of cellulose acetate membranes for reverse osmosis. Part 2. Transmission and scanning electron microscopy of membranes cast from an acetone-formamide dope , 1973 .

[26]  Kai Yu Wang,et al.  Polybenzimidazole (PBI) nanofiltration hollow fiber membranes applied in forward osmosis process , 2007 .

[27]  R. Kesting.  Semipermeable membranes of cellulose acetate for desalination in the process of reverse osmosis. I. Lyotropic swelling of secondary cellulose acetate , 1965 .

[28]  J. E. Cadotte,et al.  A new thin-film composite seawater reverse osmosis membrane , 1980 .

[29]  B. Kunst,et al.  Asymmetric membrane formation. Is the evaporation step necessary , 1987 .

[30]  T. Aminabhavi,et al.  Different viscosity grade sodium alginate and modified sodium alginate membranes in pervaporation separation of water + acetic acid and water + isopropanol mixtures , 2004 .

[31]  Menachem Elimelech,et al.  A novel ammonia-carbon dioxide forward (direct) osmosis desalination process , 2005 .

[32]  Tzahi Y Cath,et al.  Forward osmosis for concentration of anaerobic digester centrate. , 2007, Water research.

[33]  B. Kunst,et al.  On the skinned cellulose triacetate membranes formation , 1991 .

[34]  J. Hao,et al.  Calculation of alcohol‐acetone‐cellulose acetate ternary phase diagram and their relevance to membrane formation , 2001 .

[35]  G. Wakley,et al.  The structure of cellulose acetate membranes for reverse osmosis. Part I. Membranes prepared from a dioxan based dope , 1970 .

[36]  T. Matsuura,et al.  Effect of shrinkage on pore size and pore size distribution of cellulose acetate reverse osmosis membranes , 1984 .

[37]  Qian Yang,et al.  Cellulose acetate nanofiltration hollow fiber membranes for forward osmosis processes , 2010 .

[38]  A. Fane,et al.  Influence of solvent on the structure and performance of cellulose acetate membranes , 2006 .