In the present work, we have developed a numerical analysis to understand the influence that the Damköhler number has on the consumption of hydrogen sulfide (H₂S) that develops on the surface of a biofilm for a mixture composed of methane gas and hydrogen sulfide that circulates laminarly through a thin microchannel. For this multiscale problem, because we are treating two physical regions, the dimensionless conservation equations are written for the mixture and the biofilm, considering that the only reactive stage occurs on the surface of the biofilm in contact with the flow. In this manner, we use the well-known law of Monod to characterize the chemical kinetics. The system of equations was numerically solved with the aid of the COMSOL Multiphysics software. As usual in these types of studies, the main results consist of the prediction of the H₂S concentration profile along the microchannel and how it also changes along with the biofilm, as well as the estimation of the dimensionless gradient of the hydrogen sulfide concentration on the biofilm surface or local Sherwood number. This hydrogen sulfide concentration is substantially increased if the Damköhler number increases and therefore allows us to establish under which fluid-dynamic and reactive conditions the operation of a bioreactor can be improved.

中文翻译：

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共轭传质在DAMKÖHLER数的影响下去除均质生物膜上微通道中硫化氢气体的循环

在本工作中，我们已经进行了数值分析，以了解Damköhler数对硫化氢（H _2）消耗的影响。S）在生物膜表面上形成，由甲烷气体和硫化氢组成的混合物通过薄的微通道层流循环。对于这个多尺度问题，因为我们正在处理两个物理区域，所以考虑到唯一的反应阶段发生在与流动接触的生物膜表面上，因此为混合物和生物膜写了无量纲的守恒方程。通过这种方式，我们使用Monod的著名定律来表征化学动力学。借助COMSOL Multiphysics软件对方程组进行了数值求解。与这些类型的研究一样，主要结果包括对H ₂的预测沿微通道的S浓度分布及其与生物膜的关系如何变化，以及对生物膜表面上的硫化氢浓度的无量纲梯度或局部Sherwood数的估计。如果Damköhler数增加，则硫化氢的浓度会大大增加，因此使我们能够确定在哪种流体动力学和反应条件下可以改善生物反应器的运行。