Microbial-induced carbonate precipitation (MICP) in porous media is a two-step procedure: First, the suspension of bacteria is injected and some of the bacteria get stuck on the grains. The second stage consists in the injection of a calcifying solution that triggers the calcite precipitation and creates a calcite shell around the bacteria. In the present article, we describe a novel method to measure the adhesion rate of Sporosarcina pasteurii bacteria on sandstone and that, additionally, allows to obtain information about local position of the calcite crystals on the sandstone grains. The method is based on the detection of the crystals developed on grains placed inside a microfluidic cell. The potential of the technique was evaluated and demonstrated by studying the influence of the injection time and ionic strength on the adhesion rate and on the spatial distribution of the crystals. The values of the adhesion rates are in good agreement with values determined using column experiments. We find, for example, an increase in the adhesion rate with the NaCl in solution, with a rate of the order of 0.005 min-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{-1}$$\end{document} for a concentration of 3 g/L. with a maximum of 0.03 min-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{-1}$$\end{document} for experiments realized with a salt concentration of 20 g/L. Our work shows it is possible to use small volumes of fluid to determine quantities accurately, such as adhesion rate or crystals spatial repartition, avoiding the waste of a large quantity of fluids. The method also opens the possibility to screen different fluid compositions and flow conditions to optimize the MICP process.

中文翻译：

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使用微流控装置测定砂岩上巴氏孢子菌细菌的吸附率

多孔介质中的微生物诱导碳酸盐沉淀 (MICP) 是一个两步程序：首先，注入细菌悬浮液，一些细菌会粘在颗粒上。第二阶段包括注入钙化溶液，触发方解石沉淀并在细菌周围形成方解石壳。在本文中，我们描述了一种新的方法来测量 Sporosarcina pasteurii 细菌在砂岩上的粘附率，此外，还可以获得有关方解石晶体在砂岩颗粒上的局部位置的信息。该方法基于对放置在微流体单元内的晶粒上形成的晶体的检测。通过研究注射时间和离子强度对粘附率和晶体空间分布的影响，评估和证明了该技术的潜力。粘附率的值与使用柱实验确定的值非常一致。例如，我们发现溶液中 NaCl 的粘附率增加，速率为 0.005 min-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{ amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{-1}$$\end{document } 浓度为 3 g/L。最大为 0。03 min-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{ \oddsidemargin}{-69pt} \begin{document}$$^{-1}$$\end{document} 用于以 20 g/L 的盐浓度实现的实验。我们的工作表明，可以使用少量流体来准确确定数量，例如粘附率或晶体空间重新分配，避免浪费大量流体。该方法还开启了筛选不同流体成分和流动条件以优化 MICP 工艺的可能性。我们的工作表明，可以使用少量流体来准确确定数量，例如粘附率或晶体空间重新分配，避免浪费大量流体。该方法还开启了筛选不同流体成分和流动条件以优化 MICP 工艺的可能性。我们的工作表明，可以使用少量流体来准确确定数量，例如粘附率或晶体空间重新分配，避免浪费大量流体。该方法还开启了筛选不同流体成分和流动条件以优化 MICP 工艺的可能性。