Modeling biogeochemical and mass transport processes in the subsurface: Investigation of microbially induced calcite precipitation ... within the basalt flanks of the Juan de Fuca Ridge off ...

The walls of the slit nano-pore were composed of two parallel calcite surfaces, where the length along the x-axis direction and the separation distance between the mineral surfaces along the z-axis direction were fixed at 21 nm and 9 nm, respectively.The rhombohedral structure of calcite, which has space group R 3-c, and …

Fluid transport through a rough crack can be estimated through evaluation of its transmissivity (kt in m3) e.g. the fracture's permeability (k 2in m ) multiplied by the effective thickness (t in m) of the flowing fluid layer. Permeability thus corresponds to the transmissivity of a 1 m thick layer of flowing fluid (Rutter and Mecklenburgh, 2018).

Hommel et al. (2015) and Hommel et al. (2016) improved the model further by including bacteria transportation, complex solution chemistry, dissolution of calcite and the effects of biomass and ...

Transport-controlled hydrothermal replacement of calcite by Mg-carbonates. Dolomitization is one of the most important diagenetic processes, but the reaction rate and time scale of dolomitization remain a topic of controversy. We conducted experiments in which the reaction of single calcite crystals with a Mg-rich fluid at 200 °C leads to the ...

Low salinity flooding has been proposed as a promising method for enhanced oil recovery, but the underlying mechanism remains unclear especially for carbonate reservoirs.This work investigates the effect of water salinity in altering the wettability of nano-slit pores for three types of calcite surfaces (i.e., a neutral nonpolar {1 0 1-4} …

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 …

Molecular dynamics (MD) simulations at several different temperatures were run to investigate the transport, adsorption, and stability of carbon dioxide (CO2) and water phases in contact with a calcite surface. All simulated systems showed evidence of CO2 transport and interface stability heavily affected by the presence of calcite and the …

We conducted experiments in which the reaction of single calcite crystals with a Mg-rich fluid at 200 °C leads to the formation of a zoned reaction rim consisting of magnesite and, for intermediate times, Ca-rich dolomite. From detailed documentation of …

DOI: 10.1016/J.JHYDROL.2004.12.017 Corpus ID: 140653656; Reactive transport modeling of calcite dissolution in the fresh-salt water mixing zone @article{Rezaei2005ReactiveTM, title={Reactive transport modeling of calcite dissolution in the fresh-salt water mixing zone}, author={Mohsen Rezaei and Esteban Sanz and …

Simulation of calcite dissolution and porosity changes in saltwater mixing zones in coastal aquifers. Water Resources Research 25, 655–667], which used a two-step method solely transporting the amount of calcite dissolved, are essentially correct, but their solution is essentially kinetic, with a rate dependent on the time increment used.

The purpose of this study was to investigate the relationship between percolation flux and measured calcite abundances using reactive transport modeling. Our model considers the following essential factors affecting calcite precipitation: (1) infiltration, (2) the ambient geothermal gradient, (3) gaseous CO(2) diffusive transport and ...

Simulation of calcite dissolution and porosity changes in saltwater mixing zones in coastal aquifers. Water Resources Research 25, 655–667], which used a two-step method solely transporting the ...

In our formulation we assumed: the transport is advective-dispersive with nonuniform flow due to hydraulic boundaries (the porous medium is homogeneous) and with Fickian dispersion with constant dispersivity; porosity changes from biomass accumulation and calcite precipitation are minor; ureolysis is kinetically controlled and catalyzed by ...

In this study, the oil–water two-phase occurrence state and fluid transport in shale inorganic calcite nanopores are investigated utilizing molecular dynamics simulation. The multilayer sticking ...

Abstract. Geochemical reactive transport processes in natural mineral–fluid systems may produce a wide array of emergent phenomena that are difficult to predict from basic …

In an article in 1974 Berner and Morse 56 presented a theoretical analysis of the expected mass-transport dissolution rate of small calcite particles in suspension.

The structure and transport of the heavy asphaltene molecules in unconfined bulk fluids and fluids confined in a 4 nm slit-shaped nanopores of calcite and silica were studied using classical molecular dynamics simulations.The pores were filled with 7 wt% of asphaltene dissolved in an equimolar solvent of heptane and toluene.

calcite, the most common form of natural calcium carbonate (CaCO 3), a widely distributed mineral known for the beautiful development and great variety of its crystals. It is polymorphous (same chemical formula but different crystal structure) with the minerals aragonite and vaterite and with several forms that apparently exist only under …

PDF | On Mar 16, 2020, Mateo Acosta and others published Hydraulic transport through calcite bearing faults with customized roughness: Effects of normal and shear loading. | Find, read and cite ...

Résumé (eng) Calcite dissolution experiments performed with a rotating disc apparatus reveal that at low pH (< i 4) the dissolution process is transport controlled and almost di¬ rectly proportional to the H+-concentration. At higher pH (> . 5.5) the dissolution is independent of the H+-concentration and controlled by mixed kinetics, where ...

The calcite concentration at positions near to the bottom remains lower than that at the positions close to the top, even though after 17 h the urea/calcium concentration remains overall constant at 1.1 kmol/m 3. The axial gradient of the calcite concentration in the sample reveals the time effects in the reaction system.

Here we conducted fluid transport experiments on Carrara marble fractures with a novel customized surface topography. Transmissivity measurements were conducted under mechanical loading conditions representative of deep geothermal reservoirs (normal stresses from 20 to 70 MPa and shear stresses from 0 to 30 MPa).

The hydrothermal replacement of calcite by magnesium carbonate has been reported in the presence of high MgCl 2 contents (1 M) at elevated temperature (200 C) and pressure (Jonas et al. 2015 ...

Data collected from 15° to 30°C yield an activation energy for calcite precipitation of 33 kJ/mol for solutions with [Mg] = 5 × 10-5 molal. Electron microprobe analyses of large hillocks grown at corresponding conditions demonstrate that Mg has a strong preference for incorporation at negative (acute) step edges, rather than at positive ...

This study indicates that reactive transport modeling of calcite deposition can yield important constraints on the unsaturated zone infiltration-percolation …

This study links direct measurement of Mg-calcite growth kinetics with high-spatial-resolution analysis of Mg contents in experimental crystals, with particular attention to the effects of temperature on growth rate and reactant transport conditions on Mg distribution. In contrast to previous experiments on Mg partitioning into calcite, here the layer-growth …

Fig. 1 a displays the calcite saturation distribution in a non-reactive medium for a mixture of saline groundwater in equilibrium with calcite (P CO2 =10 −1.96) and freshwater (P CO2 =10 −2.0) (solutions 3 and 4, respectively, Table 1).This distribution is compared with the curve of cumulative change in calcite volumetric fraction (expressed …

Bio-geochemical reactive transport modeling of microbial induced calcite precipitation to predict the treatment of sand in one-dimensional flow ... The dispersion coefficient is constructed following the formulation developed by De Marsily [9] comprised The parameter, ZHt, represents the total urease enzyme present of longitudinal and ...

The comparison of methane transport in graphene, quartz, and calcite nanopores suggests that this behavior arises from the strong attractive potential and the lack of atomically ultrasmooth surface in calcite, thus leading to the presence of particles sticking at the interface. ... San-Netz.de; Technical University of Munich (TUM) …

Besides, the reaction-transport model for calcite precipitation has also been evaluated in the field of geology in which scientists attempted to setup the hydrological modeling of Yucca Mountain ...

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 …

Semantic Scholar extracted view of "Effects of temperature and transport conditions on calcite growth in the presence of Mg2+: Implications for paleothermometry" by L. Wasylenki et al. ... Implications for paleothermometry}, author={Laura E. Wasylenki and Patricia M. Dove and James De Yoreo}, journal={Geochimica et Cosmochimica …

Water Resources Research 25, 655–667], which used a two-step method solely transporting the amount of calcite dissolved, are essentially correct, but their …

Reaction rates involving growth or dissolution of calcite can be either transport- or surface-controlled (Morse, 1983; Lasaga, 1998). This distinction potentially has important ramifications for the Mg contents of natural calcite samples, especially where biomineralization in different organisms is concerned.

Our analytical results and schematic model fill this gap and show that calcite dissolution and silica precipitation are linked by a fluid-mediated replacement process …

Request PDF | On Nov 29, 2018, Jin Zhao and others published Molecular dynamics investigation of substrate wettability alteration and oil transport in a calcite nanopore | Find, read and cite all ...

Semantic Scholar extracted view of "Bio-geochemical reactive transport modeling of microbial induced calcite precipitation to predict the treatment of sand in one-dimensional flow" by B. C. Martinez et al.