Mass transfer mechanisms and transport resistances in direct contact membrane distillation process

Abstract The objective of the present work was to investigate the mass transport and fouling mechanism of direct contact membrane distillation (DCMD) process. The experiments were performed on a flat sheet module using pure water and humic acid solution as feeds. The membrane employed was hydrophobic PVDF of pore size 0.22 μm. The mass transfer models based on Dusty gas model were applied to fit the flux data and the pressure blocking filtration laws were employed to explain the membrane fouling. The results showed that molecular diffusion was the most suitable model for predicting fluxes of both laminar and turbulent flow. Fouling of the membrane by humic acid aggregates can be described by cake filtration model. The transport resistance of the feed boundary layer was higher than other resistances, and fouling resistance increased significantly with time.

[1]  Anthony G. Fane,et al.  Gas and vapour transport through microporous membranes. I. Knudsen-Poiseuille transition , 1990 .

[2]  R. Field,et al.  Critical flux concept for microfiltration fouling , 1995 .

[3]  D. R. Lloyd,et al.  Membrane distillation. I. Module design and performance evaluation using vacuum membrane distillation , 1996 .

[4]  Anthony G. Fane,et al.  Factors affecting flux in membrane distillation , 1990 .

[5]  Giulio C. Sarti,et al.  Low temperature distillation through hydrophobic membranes , 1987 .

[6]  Investigation of fouling mechanisms governing permeate flux in the crossflow microfiltration of beer , 1997 .

[7]  Mohamed Khayet,et al.  Direct contact membrane distillation of humic acid solutions , 2004 .

[8]  P. Prádanos,et al.  Fouling kinetics and associated dynamics of structural modifications , 1998 .

[9]  M. Vázquez-González,et al.  Water distillation through poly(tetrafluoroethylene) hydrophobic membranes in a stirred cell , 1994 .

[10]  Kim Dam-Johansen,et al.  Characterization of microporous membranes for use in membrane contactors , 1997 .

[11]  L. Martinez-diez,et al.  Temperature and concentration polarization in membrane distillation of aqueous salt solutions , 1999 .

[12]  Anthony G. Fane,et al.  Humic acid fouling in the membrane distillation process , 2005 .

[13]  D. R. Lloyd,et al.  Membrane distillation. II. Direct contact MD , 1996 .

[14]  Giulio C. Sarti,et al.  Role of heat and mass transfer in membrane distillation process , 1991 .

[15]  J. Hermia,et al.  Constant Pressure Blocking Filtration Laws - Application To Power-law Non-newtonian Fluids , 1982 .

[16]  Mohamed Khayet,et al.  Characterization of membranes for membrane distillation by atomic force microscopy and estimation of their water vapor transfer coefficients in vacuum membrane distillation process , 2004 .

[17]  K.S.M.S. Raghavarao,et al.  Mass transfer in osmotic membrane distillation , 2006 .

[18]  J. Mengual,et al.  Concentration of Bovine Serum Albumin Aqueous Solutions by Membrane Distillation , 1998 .

[19]  Andrew L. Zydney,et al.  Analysis of humic acid fouling during microfiltration using a pore blockage-cake filtration model , 2002 .

[20]  F. J. Florido-Díaz,et al.  Theoretical and experimental studies on desalination using membrane distillation , 2001 .

[21]  Anthony G. Fane,et al.  Heat and mass transfer in membrane distillation , 1987 .

[22]  Antoni W. Morawski,et al.  Membrane distillation of NaCl solution containing natural organic matter , 2001 .

[23]  E. Tipping,et al.  Aggregation of aquatic humic substances , 1984 .

[24]  S. T. Hsu,et al.  Seawater desalination by direct contact membrane distillation , 2002 .

[25]  A. Zydney,et al.  HUMIC ACID FOULING DURING MICROFILTRATION , 1999 .

[26]  Tomasz Winnicki,et al.  Analysis of membrane fouling in the treatment of water solutions containing humic acids and mineral salts , 1999 .