University of Guelph, 50 Stone Rd. E., Guelph, ON, N1G 2W1, Canada.
Bull Math Biol. 2021 Sep 3;83(10):105. doi: 10.1007/s11538-021-00938-9.
We formulate a multiscale mathematical model that describes the bioreduction of uranium in porous media. On the mesoscale we describe the bioreduction of uranium [VI] to uranium [IV] using a multispecies one-dimensional biofilm model with suspended bacteria and thermodynamic growth inhibition. We upscale the mesoscopic (colony scale) model to the macroscale (reactor scale) and investigate the behavior of substrate utilization and production, attachment and detachment processes, and thermodynamic effects not usually considered in biofilm growth models. Simulation results of the reactor model indicate that thermodynamic inhibition quantitatively alters the dynamics of the model and neglecting thermodynamic effects may over- or underestimate chemical concentrations in the system. Furthermore, we numerically investigate uncertainties related to the specific choice of attachment and detachment rate coefficients and find that while increasing the attachment rate coefficient or decreasing the detachment rate coefficient leads to thicker biofilms, performance of the reactor remains largely unaffected.
我们提出了一个多尺度数学模型，用于描述多孔介质中铀的生物还原过程。在介观尺度上，我们使用带有悬浮细菌和热力学生长抑制的多物种一维生物膜模型来描述铀 [VI] 向铀 [IV] 的生物还原。我们将介观（菌落尺度）模型扩展到宏观（反应器尺度），并研究基质利用和产物生成、附着和脱落过程以及生物膜生长模型中通常不考虑的热力学效应的行为。反应器模型的模拟结果表明，热力学抑制定量改变了模型的动态，而忽略热力学效应可能会导致系统中的化学浓度过高或过低。此外，我们还数值研究了与附着和脱落速率系数的具体选择相关的不确定性，并发现增加附着速率系数或减小脱落速率系数会导致生物膜变厚，但反应器的性能基本不受影响。
