The coprecipitation of Sr2+ with calcite at 25°C and 1 atm

Pingitore, Nicholas E.; Eastman, Michael P.

doi:10.1016/0016-7037(86)90074-8

Cited by 178 publications

(98 citation statements)

References 23 publications

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“…In batch system experiments such as those described here, the logarithmic law of Doerner and Hoskins (1925) (Lorens, 1981;Pingitore and Eastman, 1986;Tesoriero and Pankow, 1996), with higher values of D EX associated with higher precipitation rates. Lorens (1981) offered an explanation related to coordination of the Sr on the calcite surface.…”

Section: Background: Sr Partitioning In Calcitementioning

confidence: 80%

“…At faster precipitation rates there is less time for equilibration, and so more Sr is trapped in the calcite lattice in partial coordination (Lorens, 1981). Pingitore and Eastman (1986) proposed another possible mechanism for the rate effect, based on the assumption that Sr can occupy both the normal lattice position of Ca and nonlattice defect sites in calcite. At higher degrees of supersaturation (e.g., faster precipitation rate), the number of crystal defects increases because surface nucleation rather than step flow is the dominant growth mechanism (Teng et al, 2000), and therefore there are more potential locations for Sr incorporation.…”

Section: Background: Sr Partitioning In Calcitementioning

confidence: 99%

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Strontium incorporation into calcite generated by bacterial ureolysis

Fujita

Redden

Ingram

et al. 2004

Geochimica et Cosmochimica Acta

214

141

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Abstract-Strontium incorporation into calcite generated by bacterial ureolysis was investigated as part of an assessment of a proposed remediation approach for 90 Sr contamination in groundwater. Urea hydrolysis produces ammonium and carbonate and elevates pH, resulting in the promotion of calcium carbonate precipitation. Urea hydrolysis by the bacterium Bacillus pasteurii in a medium designed to mimic the chemistry of the Snake River Plain Aquifer in Idaho resulted in a pH rise from 7.5 to 9.1. Measured average distribution coefficients (D EX ) for Sr in the calcite produced by ureolysis (0.5) were up to an order of magnitude higher than values reported in the literature for natural and synthetic calcites (0.02-0.4). They were also higher than values for calcite produced abiotically by ammonium carbonate addition (0.3). The precipitation of calcite in these experiments was verified by X-ray diffraction. Time-of-flight secondary ion mass spectrometry (ToF SIMS) depth profiling (up to 350 nm) suggested that the Sr was not merely sorbed on the surface, but was present at depth within the particles. X-ray absorption near edge spectra showed that Sr was present in the calcite samples as a solid solution. The extent of Sr incorporation appeared to be driven primarily by the overall rate of calcite precipitation, where faster precipitation was associated with greater Sr uptake into the solid. The presence of bacterial surfaces as potential nucleation sites in the ammonium carbonate precipitation treatment did not enhance overall precipitation or the Sr distribution coefficient. Because bacterial ureolysis can generate high rates of calcite precipitation, the application of this approach is promising for remediation of 90 Sr contamination in environments where calcite is stable over the long term.

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Section: Background: Sr Partitioning In Calcitementioning

confidence: 80%

Section: Background: Sr Partitioning In Calcitementioning

confidence: 99%

Strontium incorporation into calcite generated by bacterial ureolysis

Fujita

Redden

Ingram

et al. 2004

Geochimica et Cosmochimica Acta

214

141

View full text Add to dashboard Cite

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“…Strontium/calcium ratios have been measured in various experimental and natural samples, providing a strontium partition coefficient between calcium carbonates and fluids, relative to calcium (K Sr;Ca carbonate ) (e.g., refs. [36][37][38]. Strontium incorporation into aragonite does not strongly depend on physicochemical conditions, leading to almost constant values of strontium/calcium ratio in aragonite and fluids (36).…”

Section: Resultsmentioning

confidence: 96%

Chemical signature of magnetotactic bacteria

Amor

Busigny

Durand-Dubief

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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There are longstanding and ongoing controversies about the abiotic or biological origin of nanocrystals of magnetite. On Earth, magnetotactic bacteria perform biomineralization of intracellular magnetite nanoparticles under a controlled pathway. These bacteria are ubiquitous in modern natural environments. However, their identification in ancient geological material remains challenging. Together with physical and mineralogical properties, the chemical composition of magnetite was proposed as a promising tracer for bacterial magnetofossil identification, but this had never been explored quantitatively and systematically for many trace elements. Here, we determine the incorporation of 34 trace elements in magnetite in both cases of abiotic aqueous precipitation and of production by the magnetotactic bacterium Magnetospirillum magneticum strain AMB-1. We show that, in biomagnetite, most elements are at least 100 times less concentrated than in abiotic magnetite and we provide a quantitative pattern of this depletion. Furthermore, we propose a previously unidentified method based on strontium and calcium incorporation to identify magnetite produced by magnetotactic bacteria in the geological record.

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“…tween calcite and aqueous solution have been performed using various techniques (e.g., Holland et al, 1964;Pingitore and Eastman, 1986;Mucci and Morse, 1983;Tesoriero and Pankow, 1996;Prieto et al, 1997;Havach et al, 2001;Dietzel et al, 2004). One technique is the free-drift method in which the calcium bicarbonate solution prepared by dissolving CaCO 3 in carbonic acid water is allowed to stand to drift the initial equilibration with releasing CO 2 (e.g., Kitano et al, 1971;Pingitore and Eastman, 1986;Terakado and Masuda, 1988).…”

mentioning

confidence: 99%

A new method for the study of trace element partitioning between calcium carbonate and aqueous solution: A test case for Sr and Ba incorporation into calcite

Terakado

Taniguchi

2006

Geochem. J.

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A new experimental method (evaporation method) for calcium carbonate precipitation in aqueous solution was attempted in order to develop a convenient and controllable experimental technique for obtaining precise trace element partition coefficients. Calcite crystals were formed by evaporation of H 2 O from the aqueous mother solution using a dehumidifier, and the consumed Ca ions were supplied from a refill solution to maintain supersaturation. This method has been tested for Sr and Ba partition coefficients using NaCl (3.5%) solution under room temperature and pressure. The results of two runs give Sr partition coefficients of 0.0585 and 0.0546, and Ba partition coefficients of 0.0302 and 0.0275 for growth rates of 152 and 499 µmol·m -2 ·hr -1 , respectively. It was found that this method has several merits for partitioning experiments: (1) pH of the solution is close to the natural ones, for example, pH of 8.08 in the present case is close to that of seawater; (2) chemical composition of the mother solution can be chosen to imitate natural composition; (3) the crystal growth rate is controllable in a relatively small range and is measurable; and (4) temperature and P CO2 pressure can be controlled. The relative errors of the partition coefficients in the present study were estimated to be about 5%. The results seem to be promising, and suggest that more precise determination of partition coefficients could be possible via more careful experimental handling and improving the apparatus.

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The coprecipitation of Sr2+ with calcite at 25°C and 1 atm

Cited by 178 publications

References 23 publications

Strontium incorporation into calcite generated by bacterial ureolysis

Strontium incorporation into calcite generated by bacterial ureolysis

Chemical signature of magnetotactic bacteria

A new method for the study of trace element partitioning between calcium carbonate and aqueous solution: A test case for Sr and Ba incorporation into calcite

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