Sedimentary Carbonate Minerals

Lippmann, F.

doi:10.1007/978-3-642-65474-9

Cited by 521 publications

(357 citation statements)

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“…The formation of Mn-rich calcites at high supersaturations seems to be associated with poorly organised and defective surfaces. This has been demonstrated by the diffuseness of X-ray patterns (Goldsmith and Graf, 1957) that can be related to random inclusions of water molecules in the structure (Lippmann, 1973) and by the observation of crystals with rounded and rough faces (Feman dez-Gonzalez and Prieto, 1999). Evidence of the accumulation of defects on calcite {lOI4} surfaces containing Mn was ob tained by passing deionised water over a surface after growth from an Mn 2 + _Ca 2 + -CO/ -solution (solution 1).…”

Section: Discussionmentioning

confidence: 96%

Molecular-scale surface processes during the growth of calcite in the presence of manganese

Astilleros

Pina

Fernndez-daz

et al. 2002

Geochimica et Cosmochimica Acta

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Abstract-This paper deals with the growth behaviour of the Mn-Ca-C0 3 -H 2 0 solid solution-aqueous solution system on calcite {1O I 4} surfaces. This system represents a model example, which allows us to study the effect of a number of controlling factors on the crystallisation: (1) the supersaturation function, (3(x), and nucleation rate function, J(x), for the Mn-Ca-C0 3 -H 2 0 system, (2) the relationship of such functions to the molecular scale growth mechanisms operating on growing surfaces, and (3) the surface structure of the calcite {1O I 4} faces. In situ atomic force microscopy (AFM) growth experiments revealed a wide variety of surface phenomena, such as the transition between growth mechanisms, anisotropic changes in the step rates, and the influence of the Mn-bearing newly formed surface on subsequent growth (step stoppage followed by the formation of two-dimensional nuclei and the reproduction of the original calcite {1014} surface microtopog raphy). These phenomena result from the interplay between the controlling parameters and are explained in those terms.

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Section: Discussionmentioning

confidence: 96%

Molecular-scale surface processes during the growth of calcite in the presence of manganese

Astilleros

Pina

Fernndez-daz

et al. 2002

Geochimica et Cosmochimica Acta

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“…The structural mineralogy of dolomite is very similar to the calcite structure, except that Mg substitutes for Ca in every other cation layer, which results in lower symmetry. Lippmann (1973) and Reeder (1983) point out the dolomite structure can be visualized as alternating layers of calcite and magnesite. The tendency for Ca and Mg to exist in separate layers stems from the Large difference in ionic radii of those metal ions (0.99 vs. 0.66 A, respectively).…”

Section: Introductionmentioning

confidence: 99%

Metal sorption to dolomite surfaces

Brady

Papenguth

Kelly

1999

Applied Geochemistry

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Potential human intrusion into the Waste Isolation Pilot Plant (WIPP) might release actinides into the Culebra Dolomite where sorption reactions will affect of radiotoxicity from the repository. Using a limited residence time reactor the authors have measured Ca, Mg, Nd adsorption/exchange as a function of ionic strength, Pcoz, and pH at 25°C. By the same approach, but using as input radioactive tracers, adsorption/exchange of Am, Pu, U, and Np on dolomite were measured as a function of ionic strength, Pcoz, and PH at 25"C. Metal adsorption is tYPical@ favored at high pH. Calcium and Mg adsorb in near-stoichiometric proportions except at high pH. Adsorption of Ca and Mg is diminished at high ionic strengths (e.g., 0.5M NaCl) pointing to association of Na + with the dolomite surflce, and the possibility that Ca and Mg sorb as hydrated, outer-sphere complexes. Sulfate amplifies sorption of Ca and Mg, and possibly Nd as well. Exchange of Nd for surface Ca is favored at high pH, and when Ca levels are low. Exchange for Ca appears to control attachment of actinides to dolomite as well, and high levels of Ca2 + in solution will decrease Kds. At the same time, t~the extent that high Pcojs increase Ca2 + levels, &S will decrease with C02 levels as well, but only if sorbing actinide-carbonate complexes are not observed to form (Amcarbonate complexes appear to sorb; Pu-complexes might sorb as well. U-carbonate complexation leads to resorption). This indirect C02 effect is observed primarily at, and above, neutral pH. High NaCl levels do not appear to atTect to actinide Kds

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“…Very coarse and very fine soils like gravel and silts respectively also take a much longer time to increase shear wave velocity due to the limited rate of permeability in fine soils and the limited number of particle contacts in the very coarse soils. Calcium carbonate forms three anhydrous polymorphs named as calcite, aragonite and vaterite, three other hydrated crystalline phases named as mono hydrocalcite (CaCO 3 •H 2 O), ikaite (CaCO 3 •6H 2 O), and amorphous calcium carbonate (ACC) with differences in short range order and degree of hydration [93][94][95][96][97]. Rodrigues-Navarro et al explains that the efficiency of bio deposition treatment depends on the type and structure of the precipitated CaCO 3 polymorphs (Vaterite or calcite).…”

Section: Caco 3 Precipitationmentioning

confidence: 99%

Effective Use of Plant-Derived Urease in the Field of Geoenvironmental/ Geotechnical Engineering

Ran¹,

Kawasaki²

2016

J Civil Environ Eng

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Geotechnical and geo-environmental engineering applications currently being explored through bio mineralization process include cementation of sands to improve mechanical properties and hence, to enhance bearing capacity and liquefaction resistance, sequestration of carbon, soil erosion control via surficial stabilization, groundwater flow control and remediation of soil and groundwater impacted by metals and radionuclides. Bio mediated system broadly refers to a chemical reaction series that are managed and controlled through biological activities and byproducts resulting from those reactions alter the properties of material in the system. Bio mediated methods such as microbial induced calcite precipitation (MICP), biofilm formation, biogas generation and biopolymers have been developed by injecting or stimulating microbes. MICP is the most widely explored method. Microbes having urease activity enhance the hydrolysis of urea and it helps to control the pH and to precipitate carbonate. Although it is a widely explored bio mediated method it has some disadvantages.The plant-derived urease may offer many benefits over microbial urease to induce carbonate cementation. Therefore, it is advantageous to explore the knowledge regarding such a technique as an eco-friendly method for different applications in the fields of geoenvironmental/geotechnical Engineering. The main objective of this paper is to provide an overview of the importance of plant-derived urease for different applications in the fields of geoenvironmental/ geotechnical engineering. The information presented in this paper may be important for biotechnologists/geoengineers to have wide ranging updates on the current situation.

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Sedimentary Carbonate Minerals

Cited by 521 publications

References 0 publications

Molecular-scale surface processes during the growth of calcite in the presence of manganese

Molecular-scale surface processes during the growth of calcite in the presence of manganese

Metal sorption to dolomite surfaces

Effective Use of Plant-Derived Urease in the Field of Geoenvironmental/ Geotechnical Engineering

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