Effect of Permeable Biofilm on Micro- And Macro-Scale Flow and Transport in Bioclogged Pores

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• 作者：Wen Deng ; M. Bayani Cardenas ; Matthew F. Kirk ; Susan J. Altman ; Philip C. Bennett
• 刊名：Environmental Science & Technology
• 出版年：2013
• 出版时间：October 1, 2013
• 年：2013
• 卷：47
• 期：19
• 页码：11092-11098
• 全文大小：615K
• 年卷期：v.47,no.19(October 1, 2013)
• ISSN：1520-5851

文摘

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鈥揝tokes 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 (k_br) following a sigmoidal curve on a log鈥搇og 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 k_br and biofilm volume ratio. The simulations show that k_br has a significant impact on the shear stress distribution, and thus potentially affects biofilm erosion and detachment. The sensitivity of flow fields to k_br directly translated to effects on the transport fields by affecting the relative distribution of where advection and diffusion dominated. Both k_br and biofilm volume ratio affect the shape of breakthrough curves.