The idea of biocementation, particularly the Enzyme-Induced Calcite Precipitation (EICP) method, can be implemented as natural materials for the substitution of cement. This concept utilizes the presence of urease enzyme in the urea hydrolysis process to precipitate calcite in the soil. The urease enzyme can naturally be extracted from plants ...
The calcite nanoparticles are embedded in the chitosan matrix during the mineralization process, forming a composite nanostructure (Figure 6a–d). It is clearly shown in Figure 6 a that the large nanoparticle is composed of many small particles of ~100 nm, which is very much like the particle attachment crystallization process.
The thermal decomposition process of calcite particles (0.45–3.60 mm average diameter), made up of porous agglomerates of very small CaCO 3 microcrystals, was studied in the 975–1216 K temperature range. The experiments were carried out under isothermal conditions in air atmosphere, in CO 2 atmosphere, as well as in a gas stream …
As already stated dissolution of calcite is a complex process comprising three different, simultaneously acting mechanisms: 1. Diffusion of the reactants, such as H+, H 2C03 …
As a bio-inspired calcite precipitation method, bio-grouting via enzymatic-induced calcite precipitation (EICP) uses free urease enzyme to catalyze the urea hydrolysis reaction. This soil stabilization approach is relatively new and insufficiently investigated, especially for applications involving surface layer stabilization of sandy soil …
This process can develop in specific areas of the samples, e.g. in pores and along fractures (referred to as secondary calcite) or change the entire texture of the binder (referred to as partially ...
In comparison with conventional methods, biological methods, e.g., microbially in-duced calcite precipitation (MICP), have recently gained significant attention in disaster prevention and have been extensively studied [19–21]. MICP is a promising, more eco-friendly, more sustainable alternative method in soil treatment that has wide …
The distillation waste stream from the ammonia-alkali process contains 90–120 g/L of calcium chloride. Using calcium chloride as raw material to mineralize carbon dioxide can achieve efficient utilization of calcium chloride waste and CO 2 emission reduction. This article is based on a two-step synthesis method, using ammonium …
2 is a schematic diagram showing the process flow of a method 200 for the fabrication of a calcite microfluidics cell, such as cell 100 (FIG. 1), for use in EIOR technology testing and analysis in accordance with certain embodiments.
Due to the high stability and good compatibility of microbially deposition of inorganic calcite, Le Metayer-Levrel, G. et al. (Le Metayer-Levrel et al., 1999) first proposed to do the surface protection of the southeastern tower of Saint-Médard Church using the MICP process in 1990s.The results implied that the biogenic calcium carbonate …
The calcite used in the study was from Saraburi Province, Thailand. The elemental composition analysis with an X-ray fluorescence (XRF) spectrometer indicated that the calcite was composed of CaO 97.20%, SiO 2 0.67%, Al 2 O 3 0.29%, Fe 2 O 3 0.28%, and CO 2 balance. Fresh calcite was thermally decomposed at 800 °C for 3 h.
Microbially induced calcite precipitation (MICP) is a promising, more eco-friendly alternative method for landslide prevention and foundation reinforcement. In this study, we investigated the optimization of injection methods within the MICP process in porous media to enhance calcite mass and consolidation effect. The results …
Fig. 2 a depicts the structure evolution of the sample synthesized by solvent-free method in the presence of nano calcite (Temp-SFZ) at 0–24 h. Notably, all these peaks were obtained after performing the acid treatment. ... Results show that the presence of the nano calcite hinders the crystallization process, showing by the longer period ...
method but the outcome is in small scale and associated with high costs. Moreover the hydrothermal method ... calcite to HAp. Dierent process parameters which inuence conversion were examined ...
The results were used to refine a process-based calcite growth kinetics model. 7 The refined growth model includes distinct step velocities for acute versus obtuse growth steps and is able to reproduce experimentally observed variability in bulk growth rates in relation to topographical variations. Methods Computational methods
Therefore, in this study, natural pyrite and calcite were used to investigate the effect of calcite on the thermal decomposition of pyrite. The desulfurization mechanism of calcite was investigated using thermodynamics, TG, XRD, and SEM-EDS. In addition, the reaction kinetics were analyzed using the methods recommended by ICTAC.
Calcite ores typically contain metal sulphide, silicate, or other calcium-containing impurity minerals, which can be removed by flotation. A tremendous amount of research has been performed on …
The weathering of monumental stones is a complex process inserted in the more general 'matter transformation cycle' operated by physical, chemical and biological factors. ... In this case the parameter is the newly formed calcite inside a stone. At the moment no NDT methods exist to directly evaluate calcite growth. However, the ...
The method based on the microbially induced calcite precipitation (MICP) appeared in recent years as a promising process that proved its efficiency. The feasibility of the MICP technique to
Simplified method for producing calcite powder via MICP and Sporosarcina pasteurii, with optimal conditions identified for production. ... To optimize the cost-effectiveness of the calcite production process, a detailed analysis was conducted to evaluate the cost of the chemicals used and the amount of calcite produced.
This study aims to review the potential for microbial calcium carbonate precipitation (MCP) as an effective method for environmental remediation and its application in construction restoration. This review aims to provide in-depth knowledge of microbial calcium carbonate precipitation through the concrete denitrification process. …
The following findings can be reached based on the review conducted in this paper, MICP is a bio-cementation process that occurred in natural environment, implement this process to improve geotechnical properties of soil is to be an economical, design feasible, sustainable and eco-friendly method. This process can improve shear …
The MICP process provides a novel and promising option for the remediation and self-healing of concrete with microcracks; it involves manipulating microbial metabolic processes to induce the generation of calcite precipitates to improve the physical and mechanical properties of recycled aggregates, repair of cracks in concrete and …
Even though the precursor material has less surface area, the HAp formed showed better surface area due to the dissolution precipitation process during the formation process 25. The current synthesis method using calcite and diammonium phosphate uses less energy by avoiding the hydration and calcination steps and is …
Calcite is known for its distinct physical properties, which contribute to its identification and utility in various applications. Here are some of the key physical properties of calcite: 1. Color and Transparency:Calcite can occur in a wide range of colors, including colorless, white, gray, yellow, green, blue, and even shades o…
Results and discussion Characteristics of calcite treatment process. In a conventional F − removal process, Ca 2+ ions are added into the wastewater to create CaF 2 precipitate and the remaining F − concentration is mainly determined by the remaining Ca 2+ concentration according to the solubility product of fluorite as shown in equation …
The process of using enzyme urease instead of bacteria to hydrolyze urea and produce calcite precipitations is called Enzyme induced calcite precipitation (EICP). …
The crystals synthesized by this method are rhombohedral and cubic calcite. The synthesis of the calcite phase is not affected by high pressure, minor fluctuations in …
In this process, ACC in a high-temperature acidic co-polymerization network released the CO 2 gas, creating a porous structure and transforming it into stable calcite crystals uniformly dispersed within the hydrogel matrix. The integration of hard calcite crystals with a flexible hydrogel network significantly enhanced the fatigue resistance of ...
In addition to immobilizing heavy metals, bio-mediated calcite precipitation methods can also improve the strength of contaminated soils. The process involves the introduction of microorganisms that produce calcite or other minerals, which bind the soil particles together and create a more stable structure . This can be especially useful in ...
The dynamic process of microbial calcium carbonate precipitation revealed that B. lentus CP28 precipitated calcite crystals through the enzymatic hydrolysis of …
The primary methods used to extract minerals from the ground are: Underground miningSurface (open pit) miningPlacer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.Higher-grade …
slurries. Recently, this process has been more interesting for industrial purposes to produce large quantities of calcite. The optimum conditions of the calcite synthesis in various sizes from ...
