Adsorption of aluminium ions by montmorillonite: influence on aluminium speciation.

Bruggenwert, M.G.M.; Keizer, P.; Koorevaar, P.

doi:10.18174/njas.v35i3.16723

Cited by 6 publications

(5 citation statements)

References 12 publications

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“…The Davies equation was used to calculate the activity coefficients. The ECOSAT program used the equilibrium constants for hydrolysis products of Na, Al and Zn (Lindsay, 1979), Na, Al and Zn chloride complexes (Lindsay, 1979), and the solubility product of 10 −33 for AlHO on clay, defined as (Al 3+ )(OH – ) 3 (Turner & Brydon, 1965; Bruggenwert et al ., 1987).…”

Section: Methodsmentioning

confidence: 99%

Zinc ion adsorption on montmorillonite–Al hydroxide polymer systems

Janssen

Bruggenwert

Riemsdijk

2003

European J Soil Science

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Summary Clay–Al hydroxide polymers (CAlHO) can bind heavy metals effectively and may play an important role in the adsorption behaviour and metal binding capacity of soils. We studied the dependence of Al loading and pH on the adsorption of Zn on Na‐saturated montmorillonite–Al hydroxide polymer systems. The available binding sites on Al hydroxide polymers (AlHO) had a very strong affinity for Zn ions. Zinc binding on the clay surface became important when the binding sites on the AlHO were nearly all occupied. The pH had a very strong effect on the Zn binding. At pH 6.6 much more Zn could be adsorbed to the AlHO than at pH 5.0. The effect of the Al:clay ratio on Zn binding was influenced by pH. At pH 6.6, Zn binding to the AlHO, expressed per mole AlHO, was independent of the Al:clay ratio, whereas at pH 5.0 this relation was dependent. This is related to the constant charge of the AlHO at pH 6.6, whereas at pH 5.0 the charge decreases with increasing Al:clay ratio. If clay–Al hydroxide polymers are present in the soil their Zn binding to the AlHO will strongly influence the availability of the Zn.

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Section: Methodsmentioning

confidence: 99%

Zinc ion adsorption on montmorillonite–Al hydroxide polymer systems

Janssen

Bruggenwert

Riemsdijk

2003

European J Soil Science

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“…A realistic scenario, with dissolution at low pH and subsequent increase of the pH would involve simultaneous interaction of the dissolved components. The interaction of aluminum ions with montmorillonite has been previously discussed by Bruggenwert et al [ 12 ] who also provide a concise overview on the interactions of aluminum and clay minerals. While the main discussion is about the effect of the clays on aluminum, the issue of irreversibly bound aluminum is also discussed.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of dissolved aluminum on sapphire-c and kaolinite: implications for points of zero charge of clay minerals

et al. 2014

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We have studied the impact of dissolved aluminum on interfacial properties of two aluminum bearing minerals, corundum and kaolinite. The effect of intentionally adding dissolved aluminum on electrokinetic potential of basal plane surfaces of sapphire was studied by streaming potential measurements as a function of pH and was complemented by a second harmonic generation (SHG) study at pH 6. The electrokinetic data show a similar trend as the SHG data, suggesting that the SHG electric field correlates to zeta-potential. A comparable study was carried out on kaolinite particles. In this case electrophoretic mobility was measured as a function of pH. In both systems the addition of dissolved aluminum caused significant changes in the charging behavior. The isoelectric point consistently shifted to higher pH values, the extent of the shift depending on the amount of aluminum present or added. The experimental results imply that published isoelectric points of clay minerals may have been affected by this phenomenon. The presence of dissolved aluminum in experimental studies may be caused by particular pre-treatment methods (such as washing in acids and subsequent adsorption of dissolved aluminum) or even simply by starting a series of measurements from extreme pH (causing dissolution), and subsequently varying the pH in the very same batch. This results in interactions of dissolved aluminum with the target surface.A possible interpretation of the experimental results could be that at low aluminum concentrations adatoms of aluminum (we will refer to adsorbed mineral constituents as adatoms) can form at the sapphire basal plane, which can be rather easily removed. Simultaneously, once the surface has been exposed to sufficiently high aluminum concentration, a visible change of the surface is seen by AFM which is attributed to a surface precipitate that cannot be removed under the conditions employed in the current study.In conclusion, whenever pre-treatment or the starting point of an experiment favor the dissolution of aluminum, dissolved Al may remain in the experimental system and interact with the target surfaces. The systems are then no longer pristine and points of zero charge or sorption data are those of aluminum-bearing systems.

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“…This result is what we expected, because the concentration of Al 3+ in a solution at pH 6.6 in equilibrium with Al(OH) 3 is very small and it cannot compete effectively with the Na + ions, which are present in a large excess. Assuming a solubility constant of 10 −33 for AlHO on clay (Turner & Brydon, 1965; Bruggenwert et al ., 1987), we can calculate the excess of Na + over Al 3+ to be roughly 10 8.8 times. Treatment with the unbuffered salt solution La(NO 3 ) 3 does not lead to Al being released if it is present as AlHO.…”

Section: Resultsmentioning

confidence: 99%

“…The Davies equation was used to calculate the activity coefficients. The ECOSAT program used the equilibrium constants for hydrolysis products of Ca, Na, Al, Zn and Pb (Lindsay, 1979), Ca, Na, Al, Zn and Pb chloride, and nitrate complexes (Lindsay, 1979), and the solubility product of 10 −33 for AlHO on clay, defined as (Al 3+ )(OH – ) 3 (Turner & Brydon, 1965; Bruggenwert et al ., 1987).…”

Section: Methodsmentioning

confidence: 99%

Effect of Al hydroxide polymers on cation exchange of montmorillonite

Janssen

Bruggenwert

Riemsdijk

2003

European J Soil Science

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Summary Al hydroxide polymers (AlHO) can significantly influence the cation exchange behaviour of clays. We have determined the effect of synthesized AlHO on Ca–Na, Zn–Na and Pb–Na exchange for a series of exchanger compositions and two Al loadings at pH 6.0 and an ionic strength of 0.01 m. The preference for Ca on the siloxane surface of the clay–AlHO system (CAlHO) was greater than for the pure clay, and the average KV (Vanselow selectivity coefficient) was determined to be 2.16 and 1.24, respectively. The selectivity coefficients for the exchange reactions Zn–Na and Pb–Na were not directly determined in CAlHO systems, because heavy‐metal ions bind as well to the clay surface as to the AlHO over a wide range of pH. We have estimated the effect of the presence of AlHO on the selectivity coefficients of Zn–Na and Pb–Na exchange by extrapolation of the experimental results of Ca–Na, Zn–Na and Pb–Na exchange for pure clay and Ca–Na exchange for CAlHO. The average KV was increased by the presence of the AlHO from 1.23 to 2.16 for Zn–Na exchange and from 1.59 to 2.77 for Pb–Na exchange. The increase in the preference for the divalent cations is probably caused by parallel alignment of clay platelets by sorption of AlHO. Increasing the amount of AlHO did not change the selectivity for Ca–Na exchange, and probably the structure of the system or the arrangement of the clay platelets and AlHO particles was not substantially changed. This was supported by the linear reduction of the cation exchange capacity with amount of AlHO present at pH 6.6. It seems likely that the selectivity coefficients for Ca–Na, Zn–Na and Pb–Na exchange that we found apply in naturally occurring montmorillonite–AlHO systems.

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Adsorption of aluminium ions by montmorillonite: influence on aluminium speciation.

Cited by 6 publications

References 12 publications

Zinc ion adsorption on montmorillonite–Al hydroxide polymer systems

Zinc ion adsorption on montmorillonite–Al hydroxide polymer systems

Adsorption of dissolved aluminum on sapphire-c and kaolinite: implications for points of zero charge of clay minerals

Effect of Al hydroxide polymers on cation exchange of montmorillonite

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