Experimental determination of the dissolution rates of calcite, aragonite, and bivalves

Cubillas, Pablo; Köhler, Stephan Jürgen; Prieto, M.; Chaïrat, Claire; Oelkers, Eric H.

doi:10.1016/j.chemgeo.2004.11.009

Cited by 159 publications

(126 citation statements)

References 66 publications

Supporting

Mentioning

114

Contrasting

Order By: Relevance

“…The data (20 points) give a good fit (R 2 = 0.965) to the formula R = (e x.f -e -x.b )/K where R is the net wt gain/loss, x is pH r -pH 0 (pH 0 the pH at which R = 0) and f and b are constants (comparable to reaction order or dissolution rate constants) for the forward (weight gain) and backward (weight loss) parameters and K is a constant. Growth/ dissolution results are commonly presented as a function of Ω, for example r = K(1-Ω) n (Cubillas et al 2005) but the treatment used here is similar to the approach of Lopez et al (2009) andDePaulo (2011) who regard the net calcification rate R as the sum of the forwards rate (gain) R f and backwards rate (loss) R b . The relationship between growth/dissolution and pH of a second Agaricia skeleton (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The Mediterranean coral Cladocera in low pH level did not show predicted reduced calcification (RodolfoMetalpa et al 2010(RodolfoMetalpa et al , 2011. There is a lot of information on the growth and dissolution kinetics of finely divided aragonite (Gutjahr et al, 1996, Cubillas, 2005 but little information on how dead coral behaves. Rodolfo-Metalpa et al(2011) found that dead corals did not dissolve at a pH of 7.8 and measured dissolution rates at pH 7.4 (0.3-0.6 mg.g -1 .d -1 ) and 6.8 (3.7-4.2 mg.g -1 .d -1 ).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Preliminary results with a torsion microbalance indicate that carbon dioxide and exposed carbonic anhydrase in the organic matrix are the basis of calcification on the skeleton surface of living corals

Sandeman

2015

RBT

View full text Add to dashboard Cite

Ocean acidification is altering the calcification of corals, but the mechanism is still unclear. To explore what controls calcification, small pieces from the edges of thin plates of Agaricia agaricites were suspended from a torsion microbalance into gently stirred, temperature controlled, seawater. Net calcification rates were monitored while light, temperature and pH were manipulated singly. The living coral pieces were sensitive to changes in conditions, especially light, and calcification was often suspended for one or two hours or overnight. The mean calcification rate increased from 0.06 in the dark to 0.10 mg.h -1 .cm -2 (T test, n=8, p<0.01) in low light (15 μmol.s -1 .m -2 ) and showed a positive linear relationship with temperature. With a reduction of mean pH from 8.2 to 7.6 the mean calcification rate in the light (65 μmol.s -1 .m -2 ) increased from 0.19 to 0.28 mg.h -1 .cm -2 (T test, n=8, p<0.05) indicating a dependency on carbon dioxide. After waterpiking and exposure of the skeletal surface/organic matrix to seawater, calcification showed an astonishing initial increase of more than an order of magnitude then decreased following a non-linear generalised Michaelis-Menten growth curve and reached a steady rate. Calcification rate of the freshly waterpiked coral was not influenced by light and was positively correlated with temperature. For a mean pH reduction from 8.1 to 7.6 the mean calcification rate increased from 0.18 to 0.32 mg.h -1 .cm -2 (T test, n=11, p<0.02) again indicating a dependency on carbon dioxide. Calcification ceased in the presence of the carbonic anhydrase inhibitor azolamide. Staining confirmed the presence of carbonic anhydrase, particularly on the ridges of septae. After immersion of waterpiked corals in seawater for 48 hours weight gain and loss became linear and positively correlated to temperature. When the mean pH was reduced from 8.2 to 7.5 the mean rate of weight gain decreased from 0.25 to 0.13 mg.h -1 .cm -2 (T test, n=6, p<0.05) indicating a dependence on carbonate. At a pH of 6.5 the skeleton lost weight at a rate of 1.8 mg.h -1 .cm -2 . The relationship between net calcification and pH (n=2) indicates that wt gain turns to loss at pH 7.4. These experiments confirm that calcification is a two-step process, involving secretion of a layer of organic matrix incorporating carbonic anhydrase to produce an active calcifying surface which uses carbon dioxide rather than carbonate. It is also unlikely that the calcifying surface is in direct contact with seawater. Inorganic deposition or dissolution of the skeleton in exposed dead areas of coral is a different phenomenon and is carbonate related. The wide range in results from this and other studies of calcification rate and carbon dioxide may be explainable in terms of the ratio of "live" to "dead" areas of coral. Rev. Biol. Trop. 60 (Suppl. 1): 109-126. Epub 2012 March 01.

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Preliminary results with a torsion microbalance indicate that carbon dioxide and exposed carbonic anhydrase in the organic matrix are the basis of calcification on the skeleton surface of living corals

Sandeman

2015

RBT

View full text Add to dashboard Cite

show abstract

“…These organic components likely provide the shell some protection from dissolution, relative to pure mineral. Ground biogenic calcium carbonate minerals have been found to dissolve faster than pure mineral phases due to differences in surface area for dissolution and the bacterial degradation of the organic matrix into which carbonate minerals are precipitated (Glover & Kidwell 1993, Cubillas et al 2005. As a result, the saturation indices used to determine solubility of pure calcium carbonate minerals only approximate the response of shell material in live bivalves and other metazoan calcifiers.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Size-dependent pH effect on calcification in post-larval hard clam Mercenaria spp.

Waldbusser

Bergschneider²,

Green³

2010

Mar. Ecol. Prog. Ser.

105

View full text Add to dashboard Cite

Increasing atmospheric carbon dioxide threatens to decrease pH in the world's oceans. Coastal and estuarine calcifying organisms of significant ecological and economical importance are at risk; however, several biogeochemical processes drive pH in these habitats. In particular, coastal and estuarine sediments are frequently undersaturated with respect to calcium carbonate due to high rates of organic matter remineralization, even when overlying waters are saturated. As a result, the post-larval stages of infaunal marine bivalves must be able to deposit new shell material in conditions that are corrosive to shell. We measured calcification rates on the hard clam, Mercenaria spp., in 5 post-larval size classes (0.39, 0.56, 0.78, 0.98, and 2.90 mm shell height) using the alkalinity anomaly method. Acidity of experimental water was controlled by bubbling with air-CO 2 blends to obtain pH values of 8.02, 7.64, and 7.41, corresponding to pCO 2 values of 424, 1120, and 1950 µatm. These pH values are typical of those found in many near-shore terrigenous marine sediments. Our results show that calcification rate decreased with lower pH in all 5 size classes measured. We also found a significant effect of size on calcification rate, with the smaller post-larval sizes unable to overcome dissolution pressure. Increased calcification rate with size allowed the larger sizes to overcome dissolution pressure and deposit new shell material under corrosive conditions. Size dependency of pH effects on calcification is likely due to organogenesis and developmental shifts in shell mineralogy occurring through the post-larval stage. Furthermore, we found significantly different calcification rates between the 2 sources of hard clams we used for these experiments, most likely due to genotypic differences. Our findings confirm the susceptibility of the early life stages of this important bivalve to decreasing pH and reveal mechanisms behind the increased mortality in post-larval juvenile hard clams related to dissolution pressure, that has been found in previous studies.KEY WORDS: Calcification · Acidification · Size-dependent · Hard clam · Post-larval Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 417: [171][172][173][174][175][176][177][178][179][180][181][182] 2010 dation of reduced metabolites in sediments during bioirrigation and particle reworking processes (Green et al. 2004b). As a result, estuarine or coastal pH is far more variable than that of the open ocean and subject to multiple processes making it difficult to parameterize, measure, and predict (Blackford & Gilbert 2007, Soetaert et al. 2007, Borges & Gypens 2010. However, gradual shifting-baseline type decreases in carbonate saturation state of coastal sediment pore waters due to rising atmospheric CO 2 has been noted (Andersson et al. 2006). Determining the potential ecological and economic consequences of acidification on living resources in coastal areas requires additional empirical data of shell producti...

show abstract

“…A-8 permits calculation of the intrinsic dissolution-rate constant, k rxn , from the experimental measurements of r A . Namely, k rxn equals the measured reaction rate (Plummer et al 1978;Chou et al 1989;Lasaga and Luttge 2001;Morse and Arvidson 2002;Palandri and Kharaka 2004;Cubillas et al 2005) after division by the square root of the calcium-carbonate-solubility product, or…”

Section: ðA-1þmentioning

confidence: 99%

Bulk and Surface Aqueous Speciation of Calcite: Implications for Low-Salinity Waterflooding of Carbonate Reservoirs

Yutkin¹,

Mishra²,

Radke³

et al. 2016

SPE Kingdom of Saudi Arabia Annual Technical Symposium and Exhibition

View full text Add to dashboard Cite

SummaryLow-salinity waterflooding (LSW) is ineffective when reservoir rock is strongly water-wet or when crude oil is not asphaltenic. Success of LSW relies heavily on the ability of injected brine to alter surface chemistry of reservoir crude-oil brine/rock (COBR) interfaces. Implementation of LSW in carbonate reservoirs is especially challenging because of high reservoir-brine salinity and, more importantly, because of high reactivity of the rock minerals. Both features complicate understanding of the COBR surface chemistries pertinent to successful LSW. Here, we tackle the complex physicochemical processes in chemically active carbonates flooded with diluted brine that is saturated with atmospheric carbon dioxide (CO 2 ) and possibly supplemented with additional ionic species, such as sulfates or phosphates.When waterflooding carbonate reservoirs, rock equilibrates with the injected brine over short distances. Injected-brine ion speciation is shifted substantially in the presence of reactive carbonate rock. Our new calculations demonstrate that rock-equilibrated aqueous pH is slightly alkaline quite independent of injected-brine pH. We establish, for the first time, that CO 2 content of a carbonate reservoir, originating from CO 2 -rich crude oil and gas, plays a dominant role in setting aqueous pH and rock-surface speciation.A simple ion-complexing model predicts the calcite-surface charge as a function of composition of reservoir brine. The surface charge of calcite may be positive or negative, depending on speciation of reservoir brine in contact with the calcite. There is no single point of zero charge; all dissolved aqueous species are charge determining. Rock-equilibrated aqueous composition controls the calcitesurface ion-exchange behavior, not the injected-brine composition. At high ionic strength, the electrical double layer collapses and is no longer diffuse. All surface charges are located directly in the inner and outer Helmholtz planes.Our evaluation of calcite bulk and surface equilibria draws several important inferences about the proposed LSW oil-recovery mechanisms. Diffuse double-layer expansion (DLE) is impossible for brine ionic strength greater than 0.1 molar. Because of rapid rock/brine equilibration, the dissolution mechanism for releasing adhered oil is eliminated. Also, fines mobilization and concomitant oil release cannot occur because there are few loose fines and clays in a majority of carbonates. LSW cannot be a low-interfacial-tension alkaline flood because carbonate dissolution exhausts all injected base near the wellbore and lowers pH to that set by the rock and by formation CO 2 . In spite of diffuse double-layer collapse in carbonate reservoirs, surface ion-exchange oil release remains feasible, but unproved.Introduction LSW refers to improved oil recovery achieved by waterflooding a reservoir with brine of lower salinity than that of the field brine. The process is alluring because of simplicity, favorable economics, and large potential. In some applications, seawater is inj...

show abstract

Experimental determination of the dissolution rates of calcite, aragonite, and bivalves

Cited by 159 publications

References 66 publications

Preliminary results with a torsion microbalance indicate that carbon dioxide and exposed carbonic anhydrase in the organic matrix are the basis of calcification on the skeleton surface of living corals

Preliminary results with a torsion microbalance indicate that carbon dioxide and exposed carbonic anhydrase in the organic matrix are the basis of calcification on the skeleton surface of living corals

Size-dependent pH effect on calcification in post-larval hard clam Mercenaria spp.

Bulk and Surface Aqueous Speciation of Calcite: Implications for Low-Salinity Waterflooding of Carbonate Reservoirs

Contact Info

Product

Resources

About