Geochemistry and reactive transport play a critical role in many fields. In particular, calcite dissolution and precipitation are chemical processes occurring ubiquitously in the Earth's subsurface. Therefore, understanding and quantifying them are necessary for various applications (e.g., water resources, reservoirs, geo-engineering). …
Large-Scale Experiments in Microbially Induced Calcite ... Reactive Transport Model Development and Prediction Mohamed K. Nassar1,2, Deviyani Gurung 1, Mehrdad Bastani, ... 2008), soil stabilization and consolidation (DeJong et al., 2010; De Muynck et al., 2010), plugging Key Points: We predictively simulate MICP in a controlled meter-scale ...
Magnesium and sulfate are each known to affect calcite growth and dissolution, but little is known about their combined effects on calcite growth rates. We grew calcite using the constant composition approach at ambient conditions, monitoring inhibition in solutions of Mg2+ and SO42– individually and together. The growth rate for pure calcite averaged …
Microbial induced calcite precipitation (MICP) has been well studied to date in the laboratory as a viable alternative soil improvement technique that harnesses a natural bacterial process to induce cementation.Specifically, MICP utilizes the microbial process of hydrolysis of urea to induce pH increase leading to calcite precipitation. The study …
This analysis suggests that under the biostimulation conditions applied here the assumption of steady state sessile biocatalyst suffices to describe the microbially mediated calcite precipitation. Design of in situ microbially induced calcite precipitation (MICP) strategies relies on a predictive capability. To date much of the mathematical …
Calcium transport from the environment to the final site of mineral deposition involves uptake from the water or the food into cells. Within the cells calcium ions are …
Abstract. Calcium transport from the environment to the final site of mineral deposition involves uptake from the water or the food into cells. Within the cells calcium ions are translocated to various organelles and vesicles where they accumulate, in such a way as to not raise the very low calcium concentrations in the cytosol.
The properties of calcite make it one of the most widely used minerals. It is used as a construction material, abrasive, agricultural soil treatment, construction aggregate, pigment, pharmaceutical and more. It has more …
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Our approach is to compare and contrast the ion pathways involving calcium, phosphate, and carbonate in three very different organisms: the enormously abundant unicellular marine …
Carbonate Sediments and Sedimentary Rocks. 1. Carbonate sediments and sedimentary rocks are formed from the accumulation of carbonate minerals precipitated either organically or inorganically from seawater. The minerals are either calcium carbonate (calcite, aragonite) or calcium-magnesium carbonates (dolomite).
Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany *
REE mineralization occurs in hydrothermal assemblages within or near carbonatites, suggesting aqueous transport of REE. We conducted experiments from 1200°C and 1.5 GPa to 200°C and 0.2 GPa using light (La) and heavy (Dy) REE, crystallizing fluorapatite intergrown with calcite through dolomite to ankerite.
Figure 5.3.1 5.3. 1: Enlarged image of frosted and rounded windblown sand grains. Medium-grained rocks composed mainly of sand are called sandstone, or sometimes arenite if well sorted. Sediment grains in sandstone can having a wide variety of mineral compositions, roundness, and sorting.
Studying the speciation and mineral-fluid partitioning of the rare earth elements (REE) allows us to delineate the key processes responsible for the formation of economic REE mineral deposits in natural systems. Hydrothermal REE-bearing calcite is typically hosted in carbonatites and alkaline rocks, such as the giant Bayan Obo REE …
To assess the long-term integrity of geologic CO 2 storage, samples modeling caprock were reacted under a supercritical CO 2-water system at 10 MPa and 40 °C.The resultant effects on their sealing performance were analyzed. The use of calcite-containing artificial samples comprising silica particles with controlled size, configuration, and …
Bacteria and enzymes are commonly utilized in biostabilization, which is a common method to encourage ureolysis, leading to calcite precipitation in the soil mass. Microbial-induced calcite precipitation (MICP) and enzyme-induced calcite precipitation (EICP) techniques are emerging trends in soil stabilization.
Design of in situ microbially induced calcite precipitation (MICP) strategies relies on a predictive capability. To date much of the mathematical modeling of MICP has focused on small-scale experiments and/or one-dimensional flow in porous media, and successful parameterizations of models in these settings may not pertain to larger scales …
Calcite is an important, relatively soluble mineral phase that can affect uranium reactive transport in subsurface sediments. This study was conducted to investigate the distribution of calcite and its influence on uranium adsorption and reactive transport in the groundwater–river mixing zone of the Hanford 300A site, Washington …
In both 2D and 3D simulations, the fluid-mineral interface was defined using the rough surface topography of a calcite single crystal measured by interferometry microscopy, published in Bibi et al. (2018).There, the surface topography of a pre-reacted (10–14) calcite face with etch pits was measured over a dissolution period of 6 h.
Flow, Transport, and Controlled Sedimentation of Salt Solutions in Porous Formations with Enhanced Structural Properties. ... Marco De La Pierre, Paolo Raiteri, Andrew G. Stack, Julian D. Gale. ... Effects of temperature and transport conditions on calcite growth in the presence of Mg2+: Implications for paleothermometry. Geochimica et ...
In addition, the microstructural evidence of dissolution and transport of calcite around the fault gouge, ... In Cahiers de l'Institut de Géologie de Neuchâtel. Série ADX vol. 1 13 (1987).
Selected results from the output for example 3 are presented in table 16.The ground water produced by part A is in equilibrium with calcite and has a log of -2.0, as specified by the input. The moles of CO 2 in the phase assemblage decreased by about 2.0 mmol, which means that about 2.0 mmol dissolved into solution. Likewise, about 1.6 mmol of calcite …
Another important ion transport process is the expulsion of excess protons, formed during calcite precipitation, back to the environment. (8) Calcium, bicarbonate, and proton transport pathways are part of the metabolism and signal transduction of every living cell, and the cellular machineries that evolved for homeostatic transport pathways ...
A column corresponding to the location of a deep borehole (WT-24) was chosen for modeling calcite deposition because measured calcite abundances (by the US Geological Survey, and reported by Fabryka-Martin, 2000) were available for …
@article{osti_1879892, title = {Emergent Behavior at the Calcite–Water Interface during Reactive Transport in a Simple Microfluidic Channel}, author = {Abdilla, Bektur and Minahan, Daniel J. and Gleghorn, Jason P. and Kim, YoungJae and Lee, Sang Soo and Fenter, Paul and Sturchio, Neil C.}, abstractNote = {Geochemical reactive …
Interpreting Self-Potential Signal during Reactive Transport: Application to Calcite Dissolution and Precipitation Flore Rembert 1,2,*, Damien Jougnot 1, Linda Luquot 3 and Roger Guérin 1
Ca 3.0 Calcite # adapt Ca to equilibrium with calcite Alkalinity 4.0 S(6) 1.0 F 0.1 Fluorite -1.0 # adapt F to SI = -1.0 for fluorite END Notes The mineral names must be spelled exactly as entered in the database under PHASES (you can copy the name after selection with CTRL+c, then paste with CTRL+v). Gas equilibria.
Indeed, the mass transport regime will change during the significant growth seen at high supersaturations, as diffusion fields will be localized to widely spaced (small) crystals but …
Calcite dissolution kinetics at the single particle scale are determined. It is demonstrated that at high undersaturation and in the absence of inhibitors the particulate mineral dissolution rate is controlled by a saturated calcite surface in local equilibrium with dissolved Ca 2+ and CO 3 2– coupled with rate determining diffusive transport of the …