dissolved silica porewater

dissolved silica porewater

Dissolved silica concentrations and reactions in pore ...

1997-3-1  The pore water concentrations of dissolved silica in sediment cores from the continental slope offshore from Cape Hatteras, North Carolina, varied from 150 to almost 700 μ,M with depth in the top 40 cm of sediment. Sediment cores from 630 to 2010 m depth had very similar profiles of dissolved silica in their pore waters, even though these cores came from regions greatly different in slope ...

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Dissolved silica in pore waters of Lakes Ontario, Erie ...

2017-7-13  Dissolved silica in pore waters of Lakes Ontario, Erie, and Superior sediments Jerome 0. Nriagu Canada Centre for Inland Waters, Burlington, Ontario L7R 4A6 ... The pore water, in each case, was quickly acidified with two drops of HCl and stored in plastic vials for laboratory analysis. pH was determined by direct insertion ...

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Diffusivity of dissolved silica in rock pore water at 25°C ...

[1] The diffusivity of dissolved Si in rock pore water at 25°C was evaluated by through-diffusion experiments for three types of rock (Fontainebleau sandstone, Berea sandstone, and Tenjyosan rhyolite). Comparisons of the effective diffusion coefficients of Si, K +, and Cl − ( , , and ) at neutral pH (unbuffered) showed that the values obtained for the three rocks were 2.3–3.0 times ...

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Dissolution of silica and the development of concentration ...

The pore water concentrations of dissolved silica in sediment cores from the continental slope offshore from Cape Hatteras, North Carolina, varied from 150 to almost 700 mu M with depth in the top ...

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Organic matter mineralization in the pore water of a ...

The chemical composition of the pore water from the sediment of a eutrophic lake is dominated by high concentrations of total dissolved CO2 (up to 12 mM), reduced soluble iron (up to 2 mM) and dissolved silica (up to 1 mM). The pH lies within the range of 6.70 ± 0.02; this reflects that the pore water is efficiently buffered by the CO2 acid/base system. This composition is directly related to ...

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Diffusion Coefficient of Silica in Seawater Nature ...

THE diffusion coefficient of dissolved monomeric silica in seawater of 36.1% salinity has been determined at 25° C by the diaphragm cell method. The value of the coefficient D is 1.0±0.05×10− ...

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16. DIAGENESIS OF AMORPHOUS SILICA IN MIDDLE

2007-2-6  dissolved silica at depth are generally less than those calculated for equilibrium with chalcedony or quartz. Interpretation of dissolved silica data is limited by the fact that above 50°C, extraction of pore water by squeezing sediment results in lower concentrations of dissolved silica than those obtained using in-situ sampling techniques.

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Porewater nutrients from sediments collected during the ...

Porewater nutrients from sediments collected during the SWERUS-C3 expedition 2014 on the East Siberian shelf and slope Volker Brüchert, Xiaole Sun This dataset contains the major nutrients ammonium, dissolved silica, dissolved inorganic phosphate collected from the porewaters of sediment from 16 stations in the Laptev and East Siberian Sea in ...

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Revisiting the dissolution of biogenic Si in marine ...

2017-6-8  Of the ~240 × 1012 mol year−1 of biogenic silica (bSi) produced by diatoms and other silicifying organisms, only roughly 3%–4% escapes dissolution to be permanently buried. At the global scale, how, where and why bSi is preserved in sediment is not well understood. To help address this, I compile 6245 porewater dissolved Si concentrations from 453 sediment cores, to derive the ...

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THE SOLUBILITY OF BIOGENIC SILICA IN THE SEDIMENT ...

2014-7-21  The pore water distributions of DSi record early diagenetic histories that may involve chemical interactions other than the simple dissolution of the deposited BSi. Key words: biogenic silica, solubility, sediment, pore water, Prydz Bay ReleaseDate: 2014-07-21

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Dissolution of silica and the development of concentration ...

The pore water concentrations of dissolved silica in sediment cores from the continental slope offshore from Cape Hatteras, North Carolina, varied from 150 to

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Reverse weathering as a long-term stabilizer of marine pH ...

2018-8-8  As illustrated in a compilation of porewater dissolved silica concentrations (n = 6,245) from 453 sediment cores globally, the occurrence of

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Revisiting the dissolution of biogenic Si in marine ...

2017-6-8  Of the ~240 × 1012 mol year−1 of biogenic silica (bSi) produced by diatoms and other silicifying organisms, only roughly 3%–4% escapes dissolution to be permanently buried. At the global scale, how, where and why bSi is preserved in sediment is not well understood. To help address this, I compile 6245 porewater dissolved Si concentrations from 453 sediment cores,

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Organic matter mineralization in the pore water of a ...

The chemical composition of the pore water from the sediment of a eutrophic lake is dominated by high concentrations of total dissolved CO 2 (up to 12 mM), reduced soluble iron (up to 2 mM) and dissolved silica (up to 1 mM). The pH lies within the range of 6.70 ± 0.02; this reflects that the pore water is efficiently buffered by the CO 2 acid/base system.

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Diffusion Coefficient of Silica in Seawater Nature ...

THE diffusion coefficient of dissolved monomeric silica in seawater of 36.1% salinity has been determined at 25° C by the diaphragm cell method. The

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Biogenic silica in tidal freshwater marsh sediments and ...

study of silica content in porewater, sediment and veg-etation, in order to gain a complete picture of the amounts of silica stored in the freshwater marsh eco-system and to explore seasonal variability in Si storage. MATERIALS AND METHODS Study site.The Schelde estuary (Fig. 1), in northern Belgium (Flanders) and SW Netherlands, has a history

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THE SOLUBILITY OF BIOGENIC SILICA IN THE SEDIMENT ...

2014-7-21  The pore water distributions of DSi record early diagenetic histories that may involve chemical interactions other than the simple dissolution of the deposited BSi. Key words: biogenic silica, solubility, sediment, pore water, Prydz Bay ReleaseDate: 2014-07-21

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Regeneration of dissolved substances in a seasonally ...

2017-7-31  NH4+, dissolved reactive P (DRP), reactive silica (RSi), total Fe, and Mn are given else- where (Carignan 1984). Total Fe and Mn were assumed to occur entirely as reduced Fe(II) and Mn(I1). In the anoxic hypolim- nion and pore waters of this lake, DRP is essentially equivalent to P043- as shown by

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Minerals Free Full-Text Effect of Dissolved Silica on ...

2018-2-24  The effect of silica on the immobilization reaction of boron by magnesium oxide was investigated by laboratory experiments. In the absence of silica, due to dissolution of the magnesium oxide, boron was removed from

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Geochemical data supporting investigation of solute and ...

2021-2-16  Assessment of geochemical cycling within tidal wetlands and measurement of fluxes of dissolved and particulate constituents between wetlands and coastal water bodies are critical to evaluating ecosystem function, service, and status. The U.S. Geological Survey and collaborators collected surface water and porewater geochemical data from a tidal wetland located on the

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Diffusivity of dissolved silica in rock pore water at 25°C ...

[1] The diffusivity of dissolved Si in rock pore water at 25°C was evaluated by through-diffusion experiments for three types of rock (Fontainebleau sandstone, Berea sandstone, and Tenjyosan rhyolite). Comparisons of the effective diffusion coefficients of Si, K+, and Cl− ( De,Si , De,K+, and De,Cl−) at neutral pH (unbuffered) showed that the De,Si values obtained for the three rocks were ...

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(PDF) Freshwater marshes as dissolved silica recyclers in ...

Freshwater marshes as dissolved silica recyclers in an estuarine environment (Schelde estuary, Belgium) ... pore water) along these estuaries and to quantify. the fluxes between these compartments.

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Ocean dissolved silica concentrations in bottom waters ...

To help address this, I compile 6245 porewater dissolved Si concentrations from 453 sediment cores, to derive the concentration gradient at the sediment–water interface and thus diffusive fluxes ...

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Dissolved silica in the subterranean estuary and the ...

Dissolved silicon (DSi) is a key nutrient in the oceans, but there are few data available regarding Si isotopes in coastal aquifers. Here we investigate the Si isotopic composition of 12 fresh and ...

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Revisiting the dissolution of biogenic Si in marine ...

2017-6-8  Of the ~240 × 10 12 mol year −1 of biogenic silica (bSi) produced by diatoms and other silicifying organisms, only roughly 3%–4% escapes dissolution to be permanently buried. At the global scale, how, where and why bSi is preserved in sediment is not well understood. To help address this, I compile 6245 porewater dissolved Si concentrations from 453 sediment cores, to derive the ...

Read More
16. DIAGENESIS OF AMORPHOUS SILICA IN MIDDLE

2007-2-6  dissolved silica at depth are generally less than those calculated for equilibrium with chalcedony or quartz. Interpretation of dissolved silica data is limited by the fact that above 50°C, extraction of pore water by squeezing sediment results in lower concentrations of dissolved silica than those obtained using in-situ sampling techniques.

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Magnetite dissolution in siliceous sediments - Florindo ...

2003-7-5  In biogenic silica-rich sediments, rapid recrystallization of diatom and radiolaria frustules can result in pore water dissolved silica concentrations up to 1250 μmol kg −1 [Dixit et al., 2001]. Similarly, the reactive nature of volcanic ash can also result in high pore

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Freshwater marshes as dissolved silica recyclers in an ...

The marsh was shown to act as silica recycler, resupplying biologically available dissolved Si to the estuarine ecosystem. Extrapolations show that during summer and spring months, when dissolved silica is depleted due to diatom growth, almost half of the total dissolved silica load in the main river channel could result from marsh recycling.

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THE SOLUBILITY OF BIOGENIC SILICA IN THE SEDIMENT ...

2014-7-21  The pore water distributions of DSi record early diagenetic histories that may involve chemical interactions other than the simple dissolution of the deposited BSi. Key words: biogenic silica, solubility, sediment, pore water, Prydz Bay ReleaseDate: 2014-07-21

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The diffusion coefficient of dissolved silica revisited ...

The diffusion coefficient of dissolved silica was determined for two different salinities, 36 and 0, at temperatures ranging from 2 °C to 30 °C and at an average pH value of 8.1.

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