Two-phase flow in membrane processes: A technology with a future

Worldwide, the application of a (gas/liquid) two-phase flow in membrane processes has received ample scientific deliberation because of its potential to reduce concentration polarization and membrane fouling, and therefore enhance membrane flux. Gas/liquid flows are now used to promote turbulence and instabilities inside membrane modules in various membrane processes such as microfiltration, ultrafiltration, nanofiltration, reverse osmosis, membrane distillation, electrodialysis, and membrane bio-reactors. This paper provides a comprehensive and critical literature review of the state of the art in this research area. A total of 205 scientific papers published in peer-reviewed journals from 1989 to 2013 were collected. The data in 195 of these papers (published up to 2011) were compiled and analyzed. These data were analyzed and normalized based on gas and liquid superficial velocities, gas/liquid ratio and feed types, trans-membrane pressure and membrane module type in order to make a fair comparison and identify general characteristics. The objective was to identify key factors in the application of two-phase flows in aqueous separation and purification processes, deliver new insights in how to optimize operations for implementation of this technology in the industry, discuss the importance of energy saving, provide a brief overview of current commercial applications and suggest future directions for research

[1]  Martin J. Westgate,et al.  Trends and Forecasts , 2011 .

[2]  B. Min,et al.  Electricity generation using membrane and salt bridge microbial fuel cells. , 2005, Water research.

[3]  B. C. Ng,et al.  Effects of process conditions in submerged ultrafiltration for refinery wastewater treatment: Optimization of operating process by response surface methodology , 2012 .

[4]  K. Smolders,et al.  Terminology for Membrane Distillation , 1989 .

[5]  Nicolas Rios Ratkovich,et al.  Experimental Study and CFD Modelling of a Two-Phase Slug Flow for an Airlift Tubular Membrane , 2009 .

[6]  Corinne Cabassud,et al.  Air sparging with flat sheet nanofiltration: a link between wall shear stresses and flux enhancement☆ , 2002 .

[7]  Nazim Cicek,et al.  STATE-OF-THE-ART OF MEMBRANE BIOREACTORS: WORLDWIDE RESEARCH AND COMMERCIAL APPLICATIONS IN NORTH AMERICA , 2006 .

[8]  M. Mercier-Bonin Influence of a gas/liquid two-phase flow on the ultrafiltration and microfiltration performances: case of a ceramic flat sheet membrane , 2000 .

[9]  Mike Rees,et al.  5. Statistics for Spatial Data , 1993 .

[10]  D P Saroj,et al.  Impact of chemical cleaning and air-sparging on the critical and sustainable flux in a flat sheet membrane bioreactor for municipal wastewater treatment. , 2008, Water science and technology : a journal of the International Association on Water Pollution Research.

[11]  Z. Cui,et al.  Experimental study on the enhancement of yeast microfiltration with gas sparging , 2001 .

[12]  C. Cabassud,et al.  Fouling and its reversibility in relation to flow properties and module design in aerated hollow fibre modules for membrane bioreactors. , 2008, Water science and technology : a journal of the International Association on Water Pollution Research.

[13]  G. L. Sant'anna,et al.  The use of polyetherimide hollow fibres in a submerged membrane bioreactor operating with air backwashing , 2007 .

[14]  Rong Wang,et al.  Hybrid PAC-submerged membrane system for trace organics removal: I. Adsorption kinetics study of PAC in a bubbled solution , 2009 .

[15]  Feed cycling in dead end filtration , 1999 .

[16]  D. Kooij,et al.  Optimization of air/water cleaning (AWC) in spiral wound elements , 2009 .

[17]  C. Cabassud,et al.  How slug flow can improve ultrafiltration flux in organic hollow fibres , 1997 .

[18]  Alain Liné,et al.  Characterisation of hydrodynamics induced by air injection related to membrane fouling behaviour , 2010 .

[19]  Silke Schiewer,et al.  Resistance analysis for enhanced wastewater membrane filtration , 2006 .

[20]  Matthias Wessling,et al.  Flux stabilization of silicon nitride microsieves by backpulsing and surface modification with PEG moieties. , 2006, Journal of colloid and interface science.

[21]  M. Mercier-Bonin,et al.  Application of gas/liquid two-phase flows during crossflow microfiltration of skimmed milk under constant transmembrane pressure conditions , 2003 .

[22]  Fenglin Yang,et al.  Simultaneous removal of COD and nitrogen using a novel carbon-membrane aerated biofilm reactor. , 2008, Journal of Environmental Science.

[23]  A. P. Burdukov,et al.  Local characteristics of upward gas-liquid flows , 1981 .

[24]  D. Jeison,et al.  Thermophilic treatment of acidified and partially acidified wastewater using an anaerobic submerged MBR: Factors affecting long-term operational flux. , 2007, Water research.

[25]  Runyu Ma,et al.  Concentrating the extract of traditional Chinese medicine by direct contact membrane distillation , 2008 .

[26]  Alain Liné,et al.  Spherical cap bubbles in a flat sheet nanofiltration module: experiments and numerical simulation , 2001 .

[27]  Cross-flow microfiltration of activated sludge using submerged membrane with air bubbling , 1996 .

[28]  P Cornel,et al.  Effect of mechanical cleaning with granular material on the permeability of submerged membranes in the MBR process. , 2010, Water research.

[29]  Simon Judd,et al.  Air sparging of a submerged MBR for municipal wastewater treatment , 2002 .

[30]  Pierre R. Bérubé,et al.  Shear profiles inside gas sparged submerged hollow fiber membrane modules , 2007 .

[31]  N. Bunce,et al.  Electrochemical treatment of acidic aqueous ferrous sulfate and copper sulfate as models for acid mine drainage. , 2001, Water research.

[32]  David F. Fletcher,et al.  Computational fluid dynamics simulations of taylor bubbles in tubular membranes: Model validation and application to laminar flow systems , 2005 .

[33]  S. Schiewer,et al.  Direct filtration of natural and simulated river water with air sparging and sponge ball application for fouling control , 2006 .

[34]  Donald E. Myers,et al.  Interpolation and estimation with spatially located data , 1991 .

[35]  M. V. van Loosdrecht,et al.  Impact of flow regime on pressure drop increase and biomass accumulation and morphology in membrane systems. , 2010, Water research.

[36]  H. Ngo,et al.  A mini-review on membrane fouling. , 2012, Bioresource technology.

[37]  T. Cheng,et al.  Gas-sparging cross-flow ultrafiltration in flat-plate membrane module: Effects of channel height and membrane inclination , 2007 .

[38]  S. Elmaleh,et al.  Modelling hollow-fibre ultrafiltration of biologically treated wastewater with and without gas sparging , 2004 .

[39]  C. Cabassud,et al.  Air sparging for flux enhancement in nanofiltration membranes: application to O/W stabilised and non-stabilised emulsions , 2002 .

[40]  H. Flemming,et al.  Biofouling in water systems – cases, causes and countermeasures , 2002, Applied Microbiology and Biotechnology.

[41]  Hongjun Lin,et al.  Fouling in air sparged submerged hollow fiber membranes at sub- and super-critical flux conditions , 2008 .

[42]  Jeff Penny,et al.  Hollow fiber membrane life in membrane bioreactors (MBR) , 2012 .

[43]  D. Stuckey,et al.  Saline sewage treatment using a submerged anaerobic membrane reactor (SAMBR): effects of activated carbon addition and biogas-sparging time. , 2009, Water research.

[44]  Z. Cui,et al.  Enhancement of ultrafiltration by gas sparging with flat sheet membrane modules , 1998 .

[45]  B. García-Fayos,et al.  Cleaning ultrafiltration membranes by different chemical solutions with air bubbles , 2009 .

[46]  S. Elmaleh,et al.  Dimensionless numbers for the steady-state flux of cross-flow microfiltration and ultrafiltration with gas sparging , 2000 .

[47]  C. Cabassud,et al.  Air sparging backwash in ultrafiltration hollow fibres for drinking water production , 2003 .

[48]  Sheng Chang Filtration of biomass with axial inter-fibre upward slug flow: performance and mechanisms , 2000 .

[49]  Claire Albasi,et al.  Aeration and hydrodynamics in submerged membrane bioreactors , 2011 .

[50]  T. Salmon,et al.  Gas–liquid mass transfer in a circulating jet-loop nitrifying MBR , 2005 .

[51]  Adrian Wing-Keung Law,et al.  The relationship between performance of submerged hollow fibers and bubble-induced phenomena examined by particle image velocimetry , 2007 .

[52]  Experimental Study and Design of a Submerged Membrane Distillation Bioreactor , 2009 .

[53]  H. Prieske,et al.  Advantageous and detrimental effects of air sparging in membrane filtration: Bubble movement, exerted shear and particle classification , 2010 .

[54]  Anja Drews,et al.  Membrane fouling in membrane bioreactors—Characterisation, contradictions, cause and cures , 2010 .

[55]  R. Baker Membrane Technology and Applications , 1999 .

[56]  T. Cheng Influence of inclination on gas-sparged cross-flow ultrafiltration through an inorganic tubular membrane , 2002 .

[57]  Simon Judd,et al.  Impact of aeration, solids concentration and membrane characteristics on the hydraulic performance of a membrane bioreactor , 2003 .

[58]  K. Hwang,et al.  Selective deposition of fine particles in constant-flux submerged membrane filtration , 2010 .

[59]  Johannes S. Vrouwenvelder,et al.  Periodic air/water cleaning for control of biofouling in spiral wound membrane elements , 2007 .

[60]  Johannes S. Vrouwenvelder,et al.  The Membrane Fouling Simulator: A practical tool for fouling prediction and control , 2006 .

[61]  T. Cheng,et al.  Quantitative Flux Analysis of Gas–Liquid Two-Phase Ultrafiltration , 2003 .

[62]  M. Mercier-Bonin,et al.  How unsteady filtration conditions can improve the process efficiency during cell cultures in membrane bioreactors , 2001 .

[63]  T. Cheng,et al.  Abatement of concentration polarization in ultrafiltration using n-hexadecane/water two-phase flow , 2004 .

[64]  Abderrahim Abbas,et al.  Use of fluid instabilities to enhance membrane performance: a review , 2001 .

[65]  I. Chang,et al.  Domestic wastewater treatment by a submerged MBR (membrane bio-reactor) with enhanced air sparging. , 2003, Water science and technology : a journal of the International Association on Water Pollution Research.

[66]  Matthias Wessling,et al.  Ion conductive spacers for increased power generation in reverse electrodialysis , 2010 .

[67]  Silke Schiewer,et al.  Long-term study of an intermittent air sparged MBR for synthetic wastewater treatment , 2005 .

[68]  D. Jeison,et al.  Feasibility of Anaerobic Membrane Bioreactors for the Treatment of Wastewaters with Particulate Organic Matter , 2008 .

[69]  Simon Judd,et al.  Membrane bioreactors: Two decades of research and implementation , 2011 .

[70]  R. Lockhart Proposed Correlation of Data for Isothermal Two-Phase, Two-Component Flow in Pipes , 1949 .

[71]  K. Hwang,et al.  Effect of gas–liquid flow pattern on air-sparged cross-flow microfiltration of yeast suspension , 2009 .

[72]  Coupling air-assisted backwash and rinsing steps: a new way to improve ultrafiltration process operation for inside-out hollow fibre modules , 2009 .

[73]  Matthias Wessling,et al.  Composite hollow fiber gas–liquid membrane contactors for olefin/paraffin separation , 2004 .

[74]  A comparison of hydrodynamic methods for mitigating particle fouling in submerged membrane filtration , 2008 .

[75]  K. A. Matis,et al.  Air sparging during the solid/liquid separation by microfiltration: application of flotation , 2004 .

[76]  Feng Zhang,et al.  Experiment and calculation of filtration processes in an external-loop airlift ceramic membrane bioreactor , 2009 .

[77]  D. Jeison,et al.  Cake layer formation in anaerobic submerged membrane bioreactors (AnSMBR) for wastewater treatment , 2006 .

[78]  Zhenyu Li,et al.  Influence of gas sparging on clarification of pineapple wine by microfiltration , 2010 .

[79]  Runyu Ma,et al.  The influence of bubble characteristics on the performance of submerged hollow fiber membrane module used in microfiltration , 2008 .

[80]  J. Grace,et al.  The influence of bubble shape on the rising velocities of large bubbles , 1967 .

[81]  C. Cabassud,et al.  Evaluation of backwash efficiency, definition of remaining fouling and characterisation of its contribution in irreversible fouling: Case of drinking water production by air-assisted ultra-filtration , 2010 .

[82]  A. James,et al.  Critical flux enhancement in gas assisted microfiltration , 2006 .

[83]  Gianni Andreottola,et al.  Flux criticality and sustainability in a hollow fibre submerged membrane bioreactor for municipal wastewater treatment , 2007 .

[84]  Menachem Elimelech,et al.  Forward with osmosis: emerging applications for greater sustainability. , 2011, Environmental science & technology.

[85]  D. Kooij,et al.  Air/water cleaning for biofouling control in spiral wound membrane elements , 2007 .

[86]  C. Cabassud,et al.  Flux enhancement by a continuous tangential gas flow in ultrafiltration hollow fibres for drinking water production: Effects of slug flow on cake structure , 1997 .

[87]  F. Fan,et al.  Interrelated effects of aeration and mixed liquor fractions on membrane fouling for submerged membrane bioreactor processes in wastewater treatment. , 2007, Environmental science & technology.

[88]  S. Sablani,et al.  Fouling of Reverse Osmosis and Ultrafiltration Membranes: A Critical Review , 2005 .

[89]  Shalom Fox,et al.  Interactions between biofilms and NF/RO flux and their implications for control—A review of recent developments , 2012 .

[90]  Z. Cui,et al.  Gas-sparged ultrafiltration using horizontal and inclined tubular membranes—A CFD study , 2006 .

[91]  Lounes Tadrist,et al.  Review on two-phase flow instabilities in narrow spaces , 2007 .

[92]  Hans-Curt Flemming,et al.  Biofouling on membranes - A microbiological approach , 1988 .

[93]  Corinne Cabassud,et al.  Gas/Liquid Two-phase Flow in a Flat Sheet Filtration Module: Measurement of Local Wall Shear Stresses , 2008 .

[94]  C. Fonade,et al.  How slug flow can enhance the ultrafiltration flux in mineral tubular membranes , 1997 .

[95]  David F. Fletcher,et al.  Fouling Control in a Submerged Flat Sheet Membrane System: Part II—Two‐Phase Flow Characterization and CFD Simulations , 2006 .

[96]  Z. Cui,et al.  Fractionation of BSA and Lysozyme Using Gas‐Sparged Ultrafiltration in Hollow Fiber Membrane Modules , 1997 .

[97]  Vicki Chen,et al.  Fibre movement induced by bubbling using submerged hollow fibre membranes , 2006 .

[98]  Jinliang Xu,et al.  Experimental study on gas–liquid two-phase flow regimes in rectangular channels with mini gaps , 1999 .

[99]  M. Abdel-Ghani Cross-flow ultrafiltration of an aqueous polymer foam solution produced by gas sparging , 2000 .

[100]  N. Cicek,et al.  Impact of shear force on the biofilm structure and performance of a membrane biofilm reactor for tertiary hydrogen-driven denitrification of municipal wastewater. , 2008, Water research.

[101]  C. Cabassud,et al.  Fouling control by air sparging inside hollow fibre membranes—effects on energy consumption , 1998 .

[102]  Effects of Air-Sparging on the Filtration Flux and Cake Properties in Cross-Flow Microfiltration of Size-Distributed Fine Particles , 2009 .

[103]  Ying An,et al.  Effect of adsorption/coagulation on membrane fouling in microfiltration process post-treating anaerobic digestion effluent. , 2009 .

[104]  Matthias Wessling,et al.  CO2 Nucleation in Membrane Spacer Channels Remove Biofilms and Fouling Deposits , 2010 .

[105]  Don W. Green,et al.  Perry's Chemical Engineers' Handbook , 2007 .

[106]  Christophe A. Serra,et al.  Use of air sparging to improve backwash efficiency in hollow-fiber modules , 1999 .

[107]  M. Jaffrin Hydrodynamic Techniques to Enhance Membrane Filtration , 2012 .

[108]  Olivier Lorain,et al.  A new membrane bioreactor generation for wastewater treatment application: Strategy of membrane aeration management by sequencing aeration cycles , 2010 .

[109]  P. Bérubé,et al.  Distribution of surface shear forces and bubble characteristics in full-scale gas sparged submerged hollow fiber membrane modules , 2011 .

[110]  Zhongwei Ding,et al.  The use of intermittent gas bubbling to control membrane fouling in concentrating TCM extract by mem , 2011 .

[111]  Jian Yu,et al.  Hydrodynamics and mass transfer in a novel multi-airlifting membrane bioreactor , 2008 .

[112]  A. Fane,et al.  The use of gas bubbling to enhance membrane processes , 2003 .

[113]  Marianne Nyström,et al.  Drawbacks of applying nanofiltration and how to avoid them: A review , 2008 .

[114]  M. Nyström,et al.  Fouling and retention of nanofiltration membranes , 1995 .

[115]  W. Samhaber,et al.  Impact of gas bubbling and backflushing on fouling control and membrane cleaning , 2011 .

[116]  Roger Woodard,et al.  Interpolation of Spatial Data: Some Theory for Kriging , 1999, Technometrics.

[117]  C. Cabassud,et al.  Air sparging in ultrafiltration hollow fibers: relationship between flux enhancement, cake characteristics and hydrodynamic parameters , 2001 .

[118]  Z. Cui,et al.  Fractionation of BSA and lysozyme using ultrafiltration: Effect of gas sparging , 1998 .

[119]  N. V. Ndinisa,et al.  Fouling Control in a Submerged Flat Sheet Membrane System: Part I – Bubbling and Hydrodynamic Effects , 2006 .

[120]  I Nopens,et al.  Analysis of shear stress and energy consumption in a tubular airlift membrane system. , 2011, Water science and technology : a journal of the International Association on Water Pollution Research.

[121]  H. Prieske,et al.  Optimised hydrodynamics for membrane bioreactors with immersed flat sheet membrane modules , 2010 .

[122]  Pierre R. Bérubé,et al.  Quantifying the shear at the surface of submerged hollow fiber membranes , 2006 .

[123]  Gas-slug enhanced hollow fibre ultrafiltration—an experimental study , 2004 .

[124]  R. Clift,et al.  Bubbles, Drops, and Particles , 1978 .

[125]  S. Schiewer,et al.  Long-term flux improvement by air sparging and backflushing for a membrane bioreactor, and modeling permeability decline , 2008 .

[126]  Anthony G. Fane,et al.  Membrane bioreactor with bubble‐size transformer: Design and fouling control , 2007 .

[128]  D. C. Nijmeijer,et al.  Influence of feed spacer geometries on air/water cleaning in spiral wound membrane elements , 2012 .

[129]  Sunando DasGupta,et al.  FLUX ENHANCEMENT IN NANOFILTRATION OF DYE SOLUTION USING TURBULENT PROMOTERS , 2004 .

[130]  H. Yeh,et al.  Effects of gas slugs and inclination angle on the ultrafiltration flux in tubular membrane module , 1999 .

[131]  S. Schiewer,et al.  Anti-fouling application of air sparging and backflushing for MBR , 2006 .

[132]  Anthony G. Fane,et al.  Factors affecting flux in crossflow filtration , 1985 .

[133]  S. Schiewer,et al.  Dimensionless numbers for the analysis of air sparging aimed to reduce fouling in tubular membranes of a membrane bioreactor , 2006 .

[134]  Mehmet Kitis,et al.  Impacts of membrane flux enhancers on activated sludge respiration and nutrient removal in MBRs. , 2009, Water research.

[135]  Z. Cui,et al.  Fractionation of HSA and IgG by gas sparged ultrafiltration , 1997 .

[136]  Kerry J. Howe,et al.  Fouling of microfiltration and ultrafiltration membranes by natural waters. , 2002, Environmental science & technology.

[137]  Jyeshtharaj B. Joshi,et al.  Bubble Formation and Bubble Rise Velocity in Gas−Liquid Systems: A Review , 2005 .

[138]  B. Lesjean,et al.  Survey of the European MBR market: trends and perspectives , 2008 .

[139]  J. Georgiadis,et al.  Science and technology for water purification in the coming decades , 2008, Nature.

[140]  Robert W. Field,et al.  Critical and sustainable fluxes: Theory, experiments and applications , 2006 .

[141]  Zhanfeng Cui,et al.  Flux enhancements with gas sparging in downwards crossflow ultrafiltration: performance and mechanism , 1996 .

[142]  Ng Niels Deen,et al.  Bubbles in spacers: Direct observation of bubble behavior in spacer filled membrane channels , 2009 .

[143]  R. Wakeman,et al.  Shear stress-based modelling of steady state permeate flux in microfiltration enhanced by two-phase flows , 2004 .

[144]  S. Adham,et al.  PERFORMANCE OF NEW GENERATION CERAMIC MEMBRANES USING HYBRID COAGULATION PRETREATMENT , 2008 .

[145]  Guibai Li,et al.  Air bubbling for alleviating membrane fouling of immersed hollow-fiber membrane for ultrafiltration of river water ☆ , 2010 .

[146]  Christopher E. Brennen,et al.  Fundamentals of Multiphase Flow , 2005 .

[147]  Simon Judd,et al.  The MBR Book: Principles and Applications of Membrane Bioreactors for Water and Wastewater Treatment , 2006 .

[148]  J. Wesselingh,et al.  Single Particles, Bubbles and Drops , 1999 .

[149]  S. Judd The status of membrane bioreactor technology. , 2008, Trends in biotechnology.

[150]  TorOve Leiknes,et al.  Impact of aeration rates on particle colloidal fraction in the biofilm membrane bioreactor (BF-MBR) , 2008 .

[151]  K. Hwang,et al.  Flux enhancement and cake formation in air-sparged cross-flow microfiltration , 2008 .

[152]  Enhancement of membrane permeability by gas-sparging in submerged hollow fibre ultrafiltration of macromolecular solutions: Role of module design , 2006 .

[153]  Zhanfeng Cui,et al.  Gas sparging to enhance permeate flux in ultrafiltration using hollow fibre membranes , 1996 .

[154]  Z. Cui,et al.  Effect of bubble size and frequency on mass transfer in flat sheet MBR , 2009 .

[155]  O. Monroy,et al.  Experimental and theoretical study of membrane-aerated biofilm reactor behavior under different modes of oxygen supply for the treatment of synthetic wastewater , 2006 .

[156]  W. Gao,et al.  Membrane fouling control in ultrafiltration technology for drinking water production: A review , 2011 .

[157]  Ng Niels Deen,et al.  Use of particle imaging velocimetry to measure liquid velocity profiles in liquid and liquid/gas flows through spacer filled channels , 2010 .

[158]  R. Nerenberg,et al.  Total nitrogen removal in a hybrid, membrane-aerated activated sludge process. , 2008, Water research.

[159]  S. Rouhani,et al.  Two-phase flow patterns: A review of research results , 1983 .

[160]  Evaluation of bubble flow properties between flat sheet membranes in membrane bioreactor , 2010 .

[161]  J. V. Dijk,et al.  Air sparging in capillary nanofiltration , 2006 .

[162]  G. Ducom,et al.  Possible effects of air sparging for nanofiltration of salted solutions , 2003 .

[163]  H. Futselaar,et al.  Direct capillary nanofiltration: a new high-grade purification concept , 2002 .

[164]  C. Brepols,et al.  An aeration energy model for an immersed membrane bioreactor. , 2008, Water research.

[165]  J. Verberk,et al.  Research on AirFlush®: distribution of water and air in tubular and capillary membrane modules , 2003 .

[166]  D. Sabatini,et al.  Packed Column and Hollow Fiber Air Stripping of a Contaminant-Surfactant Stream , 2004 .

[167]  M. Ishii,et al.  Two-phase flow regimes in narrow rectangular vertical and horizontal channels , 1994 .

[168]  Anthony G. Fane,et al.  Low pressure membrane processes - doing more with less energy , 2005 .

[169]  Z. Cui,et al.  Airlift crossflow membrane filtration — a feasibility study with dextran ultrafiltration , 1997 .

[170]  S. Taha,et al.  The effect of a static mixer on the ultrafiltration of a two-phase flow , 2000 .

[171]  I. Eames,et al.  The Motion of High-Reynolds-Number Bubbles in Inhomogeneous Flows , 2000 .

[172]  David Jeison,et al.  Feasibility of thermophilic anaerobic submerged membrane bioreactors (AnSMBR) for wastewater treatment , 2007 .

[173]  Analysis of Particle Fouling in Constant Pressure Submerged Membrane Filtration , 2010 .

[174]  Marcel Mulder,et al.  Basic Principles of Membrane Technology , 1991 .

[175]  Fenglin Yang,et al.  Post‐treatment of upflow anaerobic sludge blanket effluent by combining the membrane filtration process: fouling control by intermittent permeation and air sparging , 2010 .

[176]  Shaohua Chen,et al.  Survey of MBR market: Trends and perspectives in China ☆ , 2010 .

[177]  Z. Cui,et al.  Gas—liquid two-phase cross-flow ultrafiltration of BSA and dextran solutions☆ , 1994 .

[178]  Matthias Wessling,et al.  Towards spacer free electrodialysis , 2009 .

[179]  M. Mercier-Bonin,et al.  Hydrodynamics of slug flow applied to cross‐flow filtration in narrow tubes , 2000 .

[180]  S. Elmaleh,et al.  Enhancing microfiltration through an inorganic tubular membrane by gas sparging , 2000 .

[181]  Zhanfeng Cui,et al.  CFD modelling of gas-sparged ultrafiltration in tubular membranes , 2002 .

[182]  Predicting the performance of gas-sparged and non-gas-sparged ultrafiltration , 2006 .

[183]  M. Hashim,et al.  Effects of colloidal fouling and gas sparging on microfiltration of yeast suspension , 2005, Bioprocess and biosystems engineering.

[184]  Tzahi Y. Cath,et al.  Membrane contactor processes for wastewater reclamation in space: II. Combined direct osmosis, osmotic distillation, and membrane distillation for treatment of metabolic wastewater , 2005 .

[185]  L. Martinelli,et al.  Experimental analysis of mechanisms induced by a spherical cap bubble injection in submerged hollow-fibre bioreactor , 2006 .

[186]  Hee-Deung Park,et al.  Reduction of membrane fouling by simultaneous upward and downward air sparging in a pilot-scale submerged membrane bioreactor treating municipal wastewater. , 2010 .

[187]  Ben Freeman,et al.  HYDRAcap® MAX: innovative micro-filtration for reverse osmosis pretreatment and water reuse , 2013 .

[188]  J. Wesselingh,et al.  The velocity of particles, drops and bubbles , 1987 .

[189]  C. H. Lee,et al.  Flux enhancement with gas injection in crossflow ultrafiltration of oily wastewater. , 2001, Water research.

[190]  A. E. Dukler,et al.  Modelling flow pattern transitions for steady upward gas‐liquid flow in vertical tubes , 1980 .

[191]  E. McAdam,et al.  Evaluation of intermittent air sparging in an anoxic denitrification membrane bioreactor. , 2010, Water science and technology : a journal of the International Association on Water Pollution Research.

[192]  N. Mostoufi,et al.  Analyze and control fouling in an airlift membrane bioreactor: CFD simulation and experimental studies , 2011 .

[193]  Z. Cui,et al.  Analysis of developing laminar pipe flow¿an application to gas slug enhanced hollow fibre ultrafiltration , 2004 .

[194]  Z. Cui,et al.  Enhancement of microfiltration of yeast suspensions using gas sparging – effect of feed conditions , 2005 .

[195]  D. Jeison,et al.  Cake formation and consolidation: Main factors governing the applicable flux in anaerobic submerged membrane bioreactors (AnSMBR) treating acidified wastewaters , 2007 .

[196]  M. Mercier-Bonin,et al.  Application of gas/liquid two-phase flows during crossflow microfiltration of skimmed milk under constant flux conditions , 2004 .

[197]  M. Hashim,et al.  The Effect of Gas Sparging in Cross‐Flow Microfiltration of 2,3‐Butanediol Fermentation Broth , 2005 .

[198]  K. Fukushi,et al.  Nitrate removal and biofilm characteristics in methanotrophic membrane biofilm reactors with various gas supply regimes. , 2010, Water research.

[199]  K. Kaufman,et al.  The effects of bubble size on microflotation , 1975 .

[200]  Xianghua Wen,et al.  Critical flux enhancements with air sparging in axial hollow fibers cross-flow microfiltration of biologically treated wastewater , 2003 .

[201]  Raja Ghosh,et al.  Mass transfer in gas-sparged ultrafiltration: upward slug flow in tubular membranes , 1999 .

[202]  Silke Schiewer,et al.  Critical flux aspect of air sparging and backflushing on membrane bioreactors , 2005 .

[203]  Zhichao Wu,et al.  Distribution and transformation of molecular weight of organic matters in membrane bioreactor and conventional activated sludge process , 2009 .

[204]  G. Vatai,et al.  Combining air sparging and the use of a static mixer in cross-flow ultrafiltration of oil/water emulsion , 2007 .

[205]  Jack P. C. Kleijnen,et al.  Kriging Metamodeling in Simulation: A Review , 2007, Eur. J. Oper. Res..

[206]  H. Fadaei,et al.  Comparative assessment of the efficiencies of gas sparging and back-flushing to improve yeast microfiltration using tubular ceramic membranes , 2007 .

[207]  K. A. Matis,et al.  Removal of phosphates from water by a hybrid flotation- membrane filtration cell , 2006 .

[208]  Michael T. Brunelle Colloidal fouling of reverse osmosis membranes , 1980 .

[209]  Z. Cui,et al.  Upper- and Lower-Bound Estimates of Flux for Gas-Sparged Ultrafiltration with Hollow Fiber Membranes , 2005 .

[210]  D. J. Nicklin,et al.  Two-phase bubble flow , 1962 .

[211]  T. Cheng,et al.  Characteristics of gas–liquid two-phase flow in small diameter inclined tubes , 2001 .

[212]  T. Cheng,et al.  A study on cross-flow ultrafiltration with various membrane orientations , 2004 .

[213]  C. Fonade,et al.  Yeast suspension filtration: flux enhancement using an upward gas/liquid slug flow-application to continuous alcoholic fermentation with cell recycle. , 1998, Biotechnology and bioengineering.

[214]  A. E. Bergles,et al.  Review of two-phase flow instability , 1973 .

[215]  C. Cabassud,et al.  Characterisation of gas–liquid two-phase flow inside capillaries , 1999 .

[216]  Georges Belfort,et al.  Fluid mechanics in membrane filtration: Recent developments☆ , 1989 .

[217]  A. H-Kittikun,et al.  Separation of protease from yellowfin tuna spleen extract by ultrafiltration: Effect of hydrodynamics and gas sparging on flux enhancement and selectivity , 2008 .

[218]  Ling Chen,et al.  Effect of air-sparging on the cross-flow microfiltration of microbe/protein bio-suspension , 2010 .

[219]  K. A. Matis,et al.  A hybrid flotation–microfiltration cell for solid/liquid separation: operational characteristics , 2006 .

[220]  David Jeison,et al.  On-line cake-layer management by trans-membrane pressure steady state assessment in Anaerobic Membrane Bioreactors for wastewater treatment , 2006 .

[221]  S. Vigneswaran,et al.  Experimental assessment of filtration of biomass with transverse and axial fibres , 2002 .

[222]  Jia Yue,et al.  Study on air-bubbling strengthened membrane distillation process , 2011 .

[223]  M. Nyström,et al.  Humic acid as a fouling agent in filtration , 1996 .

[224]  Pierre R. Bérubé,et al.  The effect of hydrodynamic conditions and system configurations on the permeate flux in a submerged hollow fiber membrane system , 2006 .

[225]  A. Grasmick,et al.  Ultrafiltration enhanced by coagulation in an immersed membrane system , 2002 .

[226]  Zhanfeng Cui,et al.  Effect of bubble size and frequency on the permeate flux of gas sparged ultrafiltration with tubular membranes , 1997 .

[228]  Weiyi Li,et al.  A three mechanism model to describe fouling of microfiltration membranes , 2006 .

[229]  N. Cicek,et al.  Achieving biofilm control in a membrane biofilm reactor removing total nitrogen. , 2010, Water research.

[230]  Maurice A. Bergougnou,et al.  Measurements and CFD simulations of gas holdup and liquid velocity in novel airlift membrane contactor , 2006 .

[231]  E. Cornelissen,et al.  Air/water cleaning for the control of particulate fouling , 2010 .