Ezeuko C C, Sen A, Grigoryan A, Gates I D
Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4; telephone: 1-403-479-1254; fax: 1-403-284-4852.
Biotechnol Bioeng. 2011 Oct;108(10):2413-23. doi: 10.1002/bit.23183. Epub 2011 May 2.
The influence of bacterial biomass on hydraulic properties of porous media (bioclogging) has been explored as a viable means for optimizing subsurface bioremediation and microbial enhanced oil recovery. In this study, we present a pore network simulator for modeling biofilm evolution in porous media including hydrodynamics and nutrient transport based on coupling of advection transport with Fickian diffusion and a reaction term to account for nutrient consumption. Biofilm has non-zero permeability permitting liquid flow and transport through the biofilm itself. To handle simultaneous mass transfer in both liquid and biofilm in a pore element, a dual-diffusion mass transfer model is introduced. The influence of nutrient limitation on predicted results is explored. Nutrient concentration in the network is affected by diffusion coefficient for nutrient transfer across biofilm (compared to water/water diffusion coefficient) under advection dominated transport, represented by mass transport Péclet number >1. The model correctly predicts a dependence of rate of biomass accumulation on inlet concentration. Poor network connectivity shows a significantly large reduction of permeability, for a small biomass pore volume.
细菌生物质对多孔介质水力特性的影响（生物堵塞）已被作为优化地下生物修复和微生物强化采油的一种可行方法进行了探索。在本研究中，我们提出了一种孔隙网络模拟器，用于模拟多孔介质中的生物膜演化，包括基于平流输运与菲克扩散耦合以及一个反应项来考虑养分消耗的流体动力学和养分输运。生物膜具有非零渗透率，允许液体流动并通过生物膜本身进行输运。为了处理孔隙单元中液体和生物膜中的同时传质，引入了双扩散传质模型。探讨了养分限制对预测结果的影响。在平流主导输运下（由传质佩克莱数>1表示），网络中的养分浓度受养分跨生物膜传输的扩散系数（与水/水扩散系数相比）的影响。该模型正确地预测了生物质积累速率对入口浓度的依赖性。对于较小的生物质孔隙体积，网络连通性差会导致渗透率显著大幅降低。
