Do clay mineral dissolution rates reach steady state?

Köhler, Stephan Jürgen; Bosbach, Dirk; Oelkers, Eric H.

doi:10.1016/j.gca.2004.10.015

Cited by 93 publications

(51 citation statements)

References 48 publications

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“…The soluble content of K, Si and Mg were higher than that of Al and Fe, and in general the release increased with increasing pH under acidic conditions, minimizing at near neutral pH and increasing with increasing pH at alkaline conditions. Previous reports on dissolution rates found similar results (Huertas et al 1999;Cama et al 2000;Köhler et al 2005;Rozalén et al 2008). On the other hand, Kalinowski and Schweda (1996) reported dissolution rates of muscovite at Table 3 minerals and, therefore, the adsorption capacity may be affected by dissolution processes.…”

Section: Release Of Different Elements During Arsenate Adsorptionsupporting

confidence: 76%

Arsenate adsorption at the sediment–water interface: sorption experiments and modelling

2011

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Arsenate adsorption was studied in three clastic sediments, as a function of solution pH (4.0-9.0) and arsenate concentration. Using known mineral values, protolytic constants obtained from the literature and K ads values (obtained by fitting experimental adsorption data with empirical adsorption model), the constant capacitance surface complexation model was used to explain the adsorption behavior. The experimental and modelling approaches indicate that arsenate adsorption increases with increased pH, exhibiting a maximum adsorption value before decreasing at higher pH. Per unit mass, sample S 3 (smectitequartz/muscovite-illite sample) adsorbs more arsenate in the pH range 5-8.5, with 98% of sites occupied at pH 6. S 1 and S 2 have less adsorption capacity with maxima adsorption in the pH ranges of 6-8.5 and 4-6, respectively. The calculation of saturation indices by PHREEQC at different pH reveals that the solution was undersaturated with respect to aluminum arsenate (AlAsO 4 2H 2 O), scorodite (FeAsO 4 2H 2 O), brucite and silica, and supersaturated with respect to gibbsite, kaolinite, illite and montmorillonite (for S 3 sample). Increased arsenate concentration (in isotherm experiments) may not produce new solid phases, such as AlAsO 4 2H 2 O and/or FeAsO 4 2H 2 O.

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Section: Release Of Different Elements During Arsenate Adsorptionsupporting

confidence: 76%

Arsenate adsorption at the sediment–water interface: sorption experiments and modelling

2011

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“…The relatively fast dissolution of minerals during the early stages of clay dissolution observed in this study is consistent with the results from studies conducted on pure clay minerals (Bibi et al, 2011c;Kohler et al, 2005;Rozalen et al, 2008). Such results have been attributed to several processes including: (i) rapid dissolution of ultra-fine particles present in the mineral sample; (ii) enhanced availability of highly reactive sites on the mineral surfaces created during sample pre-treatment procedures; and (iii) dissolution of cations from highly strained areas on large particles or defects (Stillings and Brantley, 1995).…”

Section: Initial Release Of Si Al K Fe and Mgsupporting

confidence: 91%

Dissolution kinetics of soil clays in sulfuric acid solutions: Ionic strength and temperature effects

Bibi

Singh

Silvester

2014

Applied Geochemistry

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“…The final dissolution rates that we observe are indeed similar to those observed in mineral dissolution experiments and field measurements ( Fig. 7) (Fraysse et al, 2009;Goddéris et al, 2006;Golubev et al, 2005;Golubev et al, 2006;Köhler et al, 2003;Köhler et al, 2005). Given the fact that observed k-values are similar, it is reasonable to assume that mineral dissolution is also the main contributor to Si release towards the end of the experiments for A cb horizon samples and during the whole experiment for the Ac lv horizon samples.…”

Section: Time Dependency Of Dsi Concentrationssupporting

confidence: 85%

Factors controlling Si export from soils: A soil column approach

Ronchi

Barão

Clymans

et al. 2015

CATENA

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The release of dissolved silicon (DSi) from A and B horizons was investigated with leaching tests on unsaturated columns. As forest A horizons have larger biogenic Si (BSi) pools than arable lands, we compared the Si release from a forest and a cropland from the same geographical region developed on a Luvisol in Belgium and a Cambisol in Sweden. The A horizons released a quickly dissolving Si fraction in contrast to the B horizons, which did contain no or only little amounts of BSi and released lower Si concentrations. Our experiments show that Si export from forest soils is high because of the presence of a large reservoir of soluble BSi as well as due to the acidity of the soil (pH b 4). Leaching at two different water fluxes revealed that export in forest soils was transport controlled while cropland soils were in equilibrium.

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Do clay mineral dissolution rates reach steady state?

Cited by 93 publications

References 48 publications

Arsenate adsorption at the sediment–water interface: sorption experiments and modelling

Arsenate adsorption at the sediment–water interface: sorption experiments and modelling

Dissolution kinetics of soil clays in sulfuric acid solutions: Ionic strength and temperature effects

Factors controlling Si export from soils: A soil column approach

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