Publication: Novel porous composite hydrophobic/hydrophilic polysulfone membranes for desalination by direct contact membrane distillation
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2009-09-30
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Elsevier B. V.
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Novel composite membrane distillation membranes were prepared by blending the hydrophilic polysulfone with hydrophobic surface modifying macromolecules (SMMs). Three different types of SMMs were tested. These SMMs were synthesized and characterized for fluorine content, molecular weights and glass transition temperature. Phase inversion method in a single casting step was used to prepare the composite membranes. The membranes were characterized by means of different techniques such as contact angle measurement, gas permeation test, liquid entry pressure of water and scanning electron microscopy. Finally, these membranes were tested for desalination by direct contact membrane distillation (DCMD). Different membrane preparation conditions affecting membrane morphology, structure and DCMD performance were investigated. The parameters studied were the SMMs type, polysulfone concentration, solvent type and non-solvent additive concentration in the casting solution. Attempts linking the membrane morphology to its DCMD performance have been made. it was found that increasing the polymer concentration or the non-solvent additive concentration decreased the permeate flux of the porous composite hydrophobic/hydrophilic membranes since the liquid entry pressure of water increased and the ratio of the membrane pore size time the porosity over the effective pore length (r epsilon/L(p)) decreased. Furthermore, the stoichiometric ratio of the SMMs, type of SMMs, was found to affect considerably the characteristics and permeate flux of the composite membranes. In general, the composite membranes with higher liquid entry pressure of water exhibited smaller permeate fluxes. Moreover, the obtained results were compared to those of a commercial polytetrafluoroethylene membrane and it was observed that some of the SMMs blended polysulfone membranes achieved better DCMD fluxes than those of the commercial membrane. A permeate flux 43% higher than that of the commercial membrane was achieved with 99.9% NaCl separation factor.
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© 2009 Elsevier B.V. One of the authors (M. Qtaishat) is thankful to the Middle East Desalination Research Centre for the grant that partially supported this Study.
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[1] K.W. Lawson, D.R. Lloyd, Membrane distillation, J. Membr. Sci. 124 (1997) 1–25.
[2] J.I. Mengual, L. Peña, Membrane distillation, Curr. Top. Colloid Interface Sci. 1 (1997) 17–29.
[3] A. Burgoyne, M.M. Vahdati, Direct contact membrane distillation, Sep. Sci. Technol. 35 (2000) 1257–1284.
[4] A.M. Alklaibi, N. Lior,Membrane-distillation desalination: status and potential, Desalination 171 (2004) 111–131.
[5] E. Curcio, E. Drioli, Membrane distillation and related operations—a review, Sep. Purif. Rev. 34 (2005) 35–86.
[6] M.S. El-Bourawi, Z. Ding, R. Ma,M. Khayet, A framework for better understanding membrane distillation separation process, J. Membr. Sci. 285 (2006) 4–29.
[7] P. Peng, A.G. Fane, X. Li, Desalination by membrane distillation adopting a hydrophilic membrane, Desalination 173 (2005) 45–54.
[8] C. Feng, B. Shi, G. Li, Y. Wu, Preparation and properties of microporous membrane from poly(vinylidene fluoride-co-tetrafluoroethylene) (F2.4) for membrane distillation, J. Membr. Sci. 237 (2004) 15–24.
[9] C. Feng, R. Wang, B. Shi, G. Li, Y. Wu, Factors affecting pore structure and performance of poly(vinylidene fluoride-co-hexafluoro propylene) asymmetric porous membrane, J. Membr. Sci. 277 (2006) 55–64.
[10] B. Li, K.K. Sirkar, Novel membrane and device for vacuum membrane distillation-based desalination process, J. Membr. Sci. 257 (2005) 60–75.
[11] L. Song, B. Li, K.K. Sirkar, J.L. Girlon, Direct contact membrane distillation-based desalination: novel membranes, devices, larger-scale studies, and a model, Ind. Eng. Chem. Res. 46 (2007) 2307–2323.
[12] J. Girlon, L. Song, K.K. Sirkar, Design for cascade of crossflow direct contact membrane distillation, Ind. Eng. Chem. Res. 46 (2007) 2324–2334.
[13] S. Bonyadi, T.S. Chung, Flux enhancement in membrane distillation by fabrication of dual layer hydrophilic–hydrophobic hollow fiber membranes, J. Membr. Sci. 306 (2007) 134–146.
[14] M. Khayet, T. Matsuura, Application of surface modifying macromolecules for the preparation of membranes for membrane distillation, Desalination 158 (2003) 51–56.
[15] M. Khayet, J.I. Mengual, T. Matsuura, Porous hydrophobic/hydrophilic composite membranes: application in desalination using direct contact membrane distillation, J. Membr. Sci. 252 (2005) 101–113