Experimental Methods and Imaging for Enzymatically Induced Calcite Precipitation in a micro-fluidic cell

Abstract

 4 NH ) and bicarbonate are the dominant products of hydrolysis, see Equation 1 (Mitchell et al., 2019). However, carbon dioxide in aqueous solutions occurs as carbonic acid (H 2 CO 3 ), bicarbonate (  3 HCO ), or carbonate (  2 3CO ), depending on the pH value. Since ammonia acts as a weak base by taking up a proton and producing hydroxide, it increases the pH value and shifts the equilibrium toward carbonate ions. The additional presence of calcium ions, in our case provided by adding calcium chloride, forces calcium carbonate to precipitate. According to van Paassen ( 2009), the release of a proton (H + ) during the calcium carbonate precipitation buffers the production of hydroxide during the hydrolysis, see Equation 2. On the pore scale, precipitated calcium carbonate leads to changes in pore morphology, and on a larger scale, after averaging, this corresponds to changes in the effective quantities porosity and permeability,

Experimental Methods and Imaging for Enzymatically Induced Calcite Precipitation in a Microfluidic Cell

“…The data sets will be available in the Data Repository of the University of Stuttgart (DaRUS). Two data sets are separately published: images of optical microscopy together with the log data, including flow rates and pressure measurements, can be found in Weinhardt et al (2021). The XRCT data set is published in Vahid Dastjerdi et al (2021).…”