Effect of Permeable Biofilm on Micro-and Macro-Scale Flow and Transport in Bioclogged Pores
Simulations of coupled flow around and inside biofilms in pores were conducted to study the effect of porous biofilm on micro-and macro-scale flow and transport. The simulations solved the Navier-Stokes equations coupled with the Brinkman equation representing flow in the pore space and biofilm, respectively, and the advection-diffusion equation. Biofilm structure and distribution were obtained from confocal microscope images. The bulk permeability (k) of bioclogged porous media depends on biofilm permeability (kbr) following a sigmoidal curve on a log-log scale. The upper and lower limits of the curve are the k of biofilm-free media and of bioclogged media with impermeable biofilms, respectively. On the basis of this, a model is developed that predicts k based solely on kbr and biofilm volume ratio. The simulations show that kbr has a significant impact on the shear stress distribution, and thus potentially affects biofilm erosion and detachment. The sensitivity of flow fields to kbr directly translated to effects on the transport fields by affecting the relative distribution of where advection and diffusion dominated. Both kbr and biofilm volume ratio affect the shape of breakthrough curves.
W. Deng et al., "Effect of Permeable Biofilm on Micro-and Macro-Scale Flow and Transport in Bioclogged Pores," Environmental Science and Technology, vol. 47, no. 19, pp. 11092 - 11098, American Chemical Society (ACS), Oct 2013.
The definitive version is available at https://doi.org/10.1021/es402596v
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Advection and diffusions; Advection-diffusion equation; Biofilm permeabilities; Biofilm structure; Break through curve; Brinkman equation; Confocal microscope images; Flow and transport; Advection; Navier Stokes equations; Porous materials; Biofilms; Breakthrough curve; Navier-Stokes equations; Numerical model; Permeability; Pore space; Porous medium; Shear stress; Article; Bioclogging; Confocal microscopy; Controlled study; Diffusion; Membrane permeability; Membrane structure; Membrane transport; Prediction; Simulation; Transport kinetics; Models; Theoretical; Porosity; Pseudomonas fluorescens
International Standard Serial Number (ISSN)
Article - Journal
© 2013 American Chemical Society (ACS), All rights reserved.
01 Oct 2013