Macroscale Properties of Porous Media from a Network Model of Biofilm Processes
Macroscale Properties of Porous Media from a Network Model of Biofilm Processes
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生物膜过程网络模型中多孔介质的宏观特性
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
M. Allen
中科院分区：
文献类型：
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作者：
Brian J. Suchomel;B. Chen;M. Allen
我们演示了网络模型如何预测多孔介质中由于生物膜在孔隙空间中堆积而导致的孔隙率和渗透率变化。生物膜由结合在一起并附着在表面上的细菌和细胞外聚合物 (EPS) 组成。在这种情况下，表面由多孔介质的壁组成，我们将其建模为随机的管道网络。我们的模型包含五个物种。其中四种是液体相和吸附相的细菌和 EPS。第五个物质是营养物，我们假设它仅存在于流体相中。细菌和 EPS 通过吸附、侵蚀或脱落在吸附相和液相之间转移。吸附物质会影响网络中管道的有效半径，进而影响孔隙率和渗透率。我们开发了一种对控制这些物质在网络中传输的常微分方程和偏微分方程耦合系统进行积分的技术。我们使用具有相同统计数据的不同管道半径阵列检查模拟的整体平均值。这些平均值显示了生物膜传输过程中的不同速率参数如何影响浓度和渗透性曲线。
We demonstrate how a network model can predict porosity and permeability changes in a porous medium as a result of biofilm buildup in the pore spaces. A biofilm consists of bacteria and extracellular polymeric substances (EPS) bonded together and attached to a surface. In this case, the surface consists of the walls of the porous medium, which we model as a random network of pipes.Our model contains five species. Four of these are bacteria and EPS in both fluid and adsorbed phases. The fifth species is nutrient, which we assume to reside in the fluid phase only. Bacteria and EPS transfer between the adsorbed and fluid phases through adsorption and erosion or sloughing. The adsorbed species influence the effective radii of the pipes in the network, which affect the porosity and permeability.We develop a technique for integrating the coupled system of ordinary and partial differential equations that govern transport of these species in the network. We examine ensemble averages of simulations using different arrays of pipe radii having identical statistics. These averages show how different rate parameters in the biofilm transport processes affect the concentration and permeability profiles.