DEM simulations of initial deposition of colloidal particles around non-woven membrane spacers

The modelling of the initial deposition on membrane spacers of colloidal size particles immersed in a liquid is investigated using the Discrete Element Method (DEM) coupled to Computational Fluid Dynamics (CFD). The ability of this method to model surface interactions allows the modelling of aggregation and deposition at the particle scale. The numerical model adopts a mechanistic approach to represent the forces involved in colloidal suspension by including near wall drag retardation, surface interaction and Brownian forces. The model is implemented using commercially available software, so that results can be replicated in a standard and user-friendly framework. The effect of different spacer orientation with respect to feed direction is examined and results show that deposition of particles is increased around the spacer joints when feed orientation bisects the spacers' angle; when one of the spacer filaments is aligned with the feed inflow deposition occurs exclusively and uniformly on it. Simulation results demonstrate the validity of the method to describe the small-scale behaviour of micro-particles around spacers. The incipient fouling of particles in this size range is analogous to incipient bio-fouling of membrane spacers.

[1]  Herve Morvan,et al.  CFD simulations of flow and concentration polarization in spacer-filled channels for application to water desalination , 2008 .

[2]  M. V. van Loosdrecht,et al.  Biofouling of spiral-wound nanofiltration and reverse osmosis membranes: a feed spacer problem. , 2009, Water research.

[3]  M. Elimelech,et al.  Direct microscopic observation of particle deposition in porous media: Role of the secondary energy minimum , 2007 .

[4]  E. Verwey,et al.  Theory of the stability of lyophobic colloids. , 1955, The Journal of physical and colloid chemistry.

[5]  Matthias Wessling,et al.  Particle deposition and biofilm formation on microstructured membranes , 2010 .

[6]  M. Crapper,et al.  DEM-CFD Modelling of Voidage and Heat Transfer in Fluidized Beds , 2009 .

[7]  J. A. V. BUTLER,et al.  Theory of the Stability of Lyophobic Colloids , 1948, Nature.

[8]  Andrea I. Schäfer,et al.  Nanofiltration: Principles and Applications , 2004 .

[9]  Arthur T. Andrews,et al.  Multiscale modeling of gas-fluidized beds , 2006 .

[10]  Dianne E. Wiley,et al.  CFD simulations of net-type turbulence promoters in a narrow channel , 2001 .

[11]  R. G. Cox,et al.  Slow viscous motion of a sphere parallel to a plane wall—I Motion through a quiescent fluid , 1967 .

[12]  G. Evans,et al.  Exact and approximate expressions for resistance coefficients of a colloidal sphere approaching a solid surface at intermediate Reynolds numbers , 2007 .

[13]  A. B. de Haan,et al.  Optimization of commercial net spacers in spiral wound membrane modules , 2002 .

[14]  V. Kottke,et al.  Effects of spacer geometry on pressure drop, mass transfer, mixing behavior, and residence time distribution , 1996 .

[15]  C. Tien,et al.  Chapter 8 - The process of particle deposition in granular media: Description and formulation , 2007 .

[16]  S. Maharudrayya,et al.  Pressure losses in laminar flow through serpentine channels in fuel cell stacks , 2004 .

[17]  Pierre Aimar,et al.  Model for colloidal fouling of membranes , 1995 .

[18]  Goodarz Ahmadi,et al.  Brownian diffusion of submicrometer particles in the viscous sublayer , 1991 .

[19]  R. G. Cox,et al.  Slow viscous motion of a sphere parallel to a plane wall , 1967 .

[20]  Kok Keong Lau,et al.  Integrated CFD simulation of concentration polarization in narrow membrane channel , 2005, Comput. Chem. Eng..

[21]  J. Gregory,et al.  Approximate expressions for retarded van der waals interaction , 1981 .

[22]  P. A. Cundall,et al.  FORMULATION OF A THREE-DIMENSIONAL DISTINCT ELEMENT MODEL - PART I. A SCHEME TO DETECT AND REPRESENT CONTACTS IN A SYSTEM COMPOSED OF MANY POLYHEDRAL BLOCKS , 1988 .

[23]  Abdul Latif Ahmad,et al.  Impact of different spacer filaments geometries on 2D unsteady hydrodynamics and concentration polarization in spiral wound membrane channel , 2006 .

[24]  J. Costerton,et al.  Bacterial biofilms: a common cause of persistent infections. , 1999, Science.

[25]  Johannes S. Vrouwenvelder,et al.  Biofouling in spiral wound membrane systems: Three-dimensional CFD model based evaluation of experimental data , 2010 .

[26]  F. Li,et al.  Experimental validation of CFD mass transfer simulations in flat channels with non-woven net spacers , 2004 .

[27]  Masoud Rahimi,et al.  CFD modeling of permeate flux in cross-flow microfiltration membrane , 2005 .

[28]  H C van der Mei,et al.  Physico-chemistry of initial microbial adhesive interactions--its mechanisms and methods for study. , 1999, FEMS microbiology reviews.

[29]  David F. Fletcher,et al.  Techniques for computational fluid dynamics modelling of flow in membrane channels , 2003 .

[30]  M. Shakaib,et al.  CFD modeling for flow and mass transfer in spacer-obstructed membrane feed channels , 2009 .

[31]  Masoud Rahimi,et al.  CFD and experimental studies of fouling of a microfiltration membrane , 2009 .

[32]  Dianne E. Wiley,et al.  Spacer characterization and pressure drop modelling in spacer-filled channels for ultrafiltration☆ , 1994 .

[33]  Chi Tien,et al.  Trajectory analysis of deep‐bed filtration with the sphere‐in‐cell porous media model , 1976 .

[34]  Weeratunge Malalasekera,et al.  An introduction to computational fluid dynamics - the finite volume method , 2007 .

[35]  M. Shakaib,et al.  Study on the effects of spacer geometry in membrane feed channels using three-dimensional computational flow modeling , 2007 .

[36]  Julien Pedel,et al.  Hemispheres-in-cell geometry to predict colloid deposition in porous media. , 2009, Environmental science & technology.

[37]  M. Loosdrecht,et al.  A critical flux to avoid biofouling of spiral wound nanofiltration and reverse osmosis membranes: Fact or fiction? , 2009 .

[38]  Kuo-Lun Tung,et al.  CFD simulation of fluid flow through spacer-filled membrane module : selecting suitable cell types for periodic boundary conditions , 2008 .

[39]  S. Hosseinalipour,et al.  CFD modeling of porous membranes , 2008 .

[40]  Robert H. Davis,et al.  Deposition of foulant particles during tangential flow filtration , 2006 .

[41]  Sandeep K. Karode,et al.  Flow visualization through spacer filled channels by computational fluid dynamics I. , 2001 .

[42]  H. Brenner.  The slow motion of a sphere through a viscous fluid towards a plane surface , 1961 .

[43]  A. Sangani,et al.  An O(N) algorithm for Stokes and Laplace interactions of particles , 1996 .

[44]  V. Naumov.  Influence of Saffman's lift force on the motion of a particle in a Couette layer , 1995 .

[45]  H. D. Stensel,et al.  Wastewater Engineering: Treatment and Reuse , 2002 .

[46]  P. R. Neal,et al.  The effect of filament orientation on critical flux and particle deposition in spacer-filled channels , 2003 .