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cementation carbonate via vegetal issu urease

Upscaling Effects of Soil Improvement by Microbially ...

The final urease activity of the bacterial flocs was about 70 U/ml, which was then used for soil stabilisation. The cementation solution consisted of 111 g/l calcium chloride and 60 g/l urea. Fig. 2.

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Effects of environmental factors on microbial induced ...

specific organisms produce extracellular calcium carbonate which is capable of crack healing. In the present ... MICP occurs via far more complicated processes than chemically induced precipitation. The bacterial ... high potential for crack cementation of various structural formations such as granite and concrete [3, 1, 4].

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Bio-cementation of sandy soil using microbially induced ...

In ureolytic carbonate cementation, urea hydrolysis is catalyzed by the urease enzyme (urea amidohydrolase) to precipitate calcium carbonate (CaCO3) in the presence of calcium. The use of plant-derived urease offers many benefits over the use of microbially-generated urease to induce carbonate cementation (a process that has attracted much attention recently).

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Sustainable Biocement Production via Microbially Induced ...

Microbial-induced carbonate precipitation using urea hydrolysis is a relatively new improvement technique for granular soils. An important factor in achieving uniform calcite deposition (and hence consistent improvements in geomechanical properties) throughout the treated soil mass is the protocol adopted for injecting the reagents of ureolytic bacteria, urea and calcium.

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Effect of Cementation on Calcium Carbonate Precipitation ...

cementation solution concentration is a key factor in modifying the strength and permeability of MICP-treated sand. They investigated 0.5 and 1.0 M (equimolar) urea–CaCl

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Surface Percolation for Soil Improvement by Biocementation ...

The retained urease activity of bioslurry was uniformly distributed along the sand matrix, resulting in a rather uniform CaCO3 precipitation. Through repeated treatments with a cementation solution, the unconfined compressive strength of bioslurry treated sand was significantly improved due to the effective CaCO3 precipitation at the contact points of soil grains.

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Upscaling Effects of Soil Improvement by Microbially ...

- Influence of urea and urea substitute: It was observed that the optimum of urea concentration for the maximum urease activity is about 1M, but 0.33M was considered satisfactory for the cementation purposes. The urea used, for the moment, is coming by commercial fertilizer sector.

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Improving sand with microbial-induced carbonate precipitation

The use of Sporosarcina pasteurii to precipitate calcium carbonate in the anoxic subsurface via ureolysis has been proposed for reducing porosity and sealing fractures in rocks. Here we show that S. pasteurii is unable to grow anaerobically and that the ureolytic activity previously shown under anoxic conditions is a consequence of the urease enzyme already present in the cells of the ...

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Carbonate Cementation via Plant Derived Urease

Effective Use of Plant-Derived Urease in the Field of . Effective Use of Plant-Derived Urease in the Field of soil erosion control via surficial benefits over microbial urease to induce carbonate cementation....

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Soil improvement using plant-derived urease-induced ...

The use of bio-cementation via microbially induced carbonate precipitation (MICP) for improving the mechanical properties of weak soils in the laboratory has gained increased attention in recent ...

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Improving sand with microbial-induced carbonate ...

Microbially induced calcium carbonate ... which the urease secreted by microbes hydrolyzes urea to ammoniumandcarbondioxide,thuscausinganincreaseinthe surrounding pH which promotes CaCO 3 precipitation in ... cementation uid was introduced, thereby enhancing xation

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Soil improvement using plant-derived urease-induced ...

The use of bio-cementation via microbially induced carbonate precipitation (MICP) for improving the mechanical properties of weak soils in the laboratory has gained increased attention in recent ...

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Dilrukshi and Kawasaki, Civil nviron ng 21 :1 C i v i l ...

cementation solution concentration is a key factor in modifying the strength and permeability of MICP-treated sand. They investigated 0.5 and 1.0 M (equimolar) urea–CaCl

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n o g r ap h y n e a M urnal DOI: 10.4172/2572-3103 ...

In recent years, MICP technology has been widely harnessed for applications in civil engineering wherein synthesis of calcium carbonate crystals occurs at ambient temperature paving way for low energy biocement. MICP using pure urease (UA) and carbonic anhydrase (CA) producing bacteria has been promising in laboratory conditions.

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Murtala Umar* & Khairul Anuar Kassim - civil.utm.my

Microbially induced calcium carbonate ... which the urease secreted by microbes hydrolyzes urea to ammoniumandcarbondioxide,thuscausinganincreaseinthe surrounding pH which promotes CaCO 3 precipitation in ... cementation uid was introduced, thereby enhancing xation

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FINAL PUBLISHABLE REPORT - cordis ropa

Principally the carbonate produced can react with calcium provided or in the soil to form hardened lizenithne. In order to function effectively urease requires the presence of nickel ions to act as a cofactor. Each molecule of urease requires 2 nickel ions to work effectively.

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Bio-cementation through controlled dissolution and ...

Although, MICP is a widely explored biocementation method, it has some disadvantages. Plant-derived urease may offer many benefits over microbial urease to induce carbonate cementation (Kavazanjian and Karatas, 2008, Hamdan et al., 2013). Therefore, it is advantageous to further investigate different techniques, such as eco-friendly methods, for different applications in the field of geotechnical engineering as an alternative to MICP method.

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Effect of Cementation on Calcium Carbonate Precipitation ...

The retained urease activity of bioslurry was uniformly distributed along the sand matrix, resulting in a rather uniform CaCO3 precipitation. Through repeated treatments with a cementation solution, the unconfined compressive strength of bioslurry treated sand was significantly improved due to the effective CaCO3 precipitation at the contact ...

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Biomineralization of Carbonate by Terrabacter Tumescens ...

Biocement production from microbially induced calcium carbonate precipitation (MICP) is an environmentally friendly approach for construction works, but the use of calcium chloride (CaCl2) in the conventional MICP process is a cost-limiting factor. The aim of this work is to develop a method for producing soluble calcium ions through two waste sources, lizenithne powder derived from aggregate ...

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Effect of Cementation on Calcium Carbonate Precipitation ...

cementation solution concentration is a key factor in modifying the strength and permeability of MICP-treated sand. They investigated 0.5 and 1.0 M (equimolar) urea–CaCl

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Geophysical monitoring and reactive transport modeling of ...

Stabilization via grouting is the most commonly used technique in construction industry. Of these, chemical ... ammonium and carbonate is catalyzed by urease enzyme in ureolytic bacteria. The presence of ammonium rises the pH ... cementation reagent was established by varying bacterial

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Surface Percolation for Soil Improvement by Biocementation ...

The retained urease activity of bioslurry was uniformly distributed along the sand matrix, resulting in a rather uniform CaCO3 precipitation. Through repeated treatments with a cementation solution, the unconfined compressive strength of bioslurry treated sand was significantly improved due to the effective CaCO3 precipitation at the contact points of soil grains.

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Effects of environmental factors on microbial induced ...

specific organisms produce extracellular calcium carbonate which is capable of crack healing. In the present ... MICP occurs via far more complicated processes than chemically induced precipitation. The bacterial ... high potential for crack cementation of various structural formations such as granite and concrete [3, 1, 4].

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Cementation of sand soil by microbially induced calcite ...

A simple mathematical model elucidated that the cementation depth was dependent on the infiltration rate of the cementation solution and the in-situ urease activity. The model also correctly predicted that repeated treatments would enhance clogging close to the injection point.

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