RELATION OF COLLOIDAL HYDROUS OXIDES TO THE HIGH CATION-EXCHANGE CAPACITY OF SOME TROPICAL SOILS OF THE COOK ISLANDS

Conducting binary-exchange experiments is a common way to identify cationic preferences of exchangeable phases in soil. Cation exchange reactions and thermodynamic studies of Pb2+/Ca2+, Cd2+/Ca2+, and Zn2+/Ca2+were carried out on three surface (0–30 cm) soil samples from Adamawa and Niger States in Nigeria using the batch method. The physicochemical properties studies of the soils showed that the soils have neutral pH values, low organic matter contents, low exchangeable bases, and low effective cation exchange capacity (mean: 3.27 cmolc kg−1) but relatively high base saturations (≫50%) with an average of 75.9%. The amount of cations sorbed in all cases did not exceed the soils cation exchange capacity (CEC) values, except for Pb sorption in the entisol-AD2 and alfisol-AD3, where the CEC were exceeded at high Pb loading. Calculated selectivity coefficients were greater than unity across a wide range of exchanger phase composition, indicating a preference for these cations over Ca2+. TheKeqvalues obtained in this work were all positive, indicating that the exchange reactions were favoured and equally feasible. These values indicated that the Ca/soil systems were readily converted to the cation/soil system. The thermodynamic parameters calculated for the exchange of these cations were generally low, but values suggest spontaneous reactions.

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Cation exchange capacity of an oxisol amended with an effluent from domestic sewage treatment

Scientia Agricola ◽

10.1590/s0103-90162005000600007 ◽

2005 ◽

Vol 62 (6) ◽

pp. 552-558 ◽

Cited By ~ 7

Author(s):

Adriel Ferreira da Fonseca ◽

Luís Reynaldo Ferracciú Alleoni ◽

Adolpho José Melfi ◽

Célia Regina Montes

Keyword(s):

Cation Exchange ◽

Cation Exchange Capacity ◽

Sewage Treatment ◽

Barium Chloride ◽

Dry Weight ◽

Tropical Soils ◽

Exchange Capacity ◽

Strong Positive Correlation ◽

Ionic Force ◽

Barium Chloride Solution

The addition of Na-rich anthropogenic residues to tropical soils has stimulated the scientific community to study the role of sodium in both the soil solution and the exchange complex. In this study, several different methods were used to calculate the concentration of exchangeable and soluble cations and this data was then used to establish correlations between the level of these cations and both the accumulation of various elements and the dry weight of maize grown in a greenhouse under different conditions. In the closed environments of the pots, the most suitable method for calculating the effective cation exchange capacity (ECEC) was the cation exchange capacity calculated by cations removed with barium chloride solution (CEC S). Then again, the actual cation exchange capacity (CEC A) should be measured by using Mg adsorption to prevent ionic force from influencing electric charges. A strong positive correlation was obtained between the concentrations of Na in the 1:2 soil:water extracts and the accumulation of Na in the maize plants, indicating saline or double acid extractors are not needed when monitoring the Na concentration only.

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Modeling of solid-state cultivation of Trichoderma in order to obtain natural substances with high cation exchange capacity

New Biotechnology ◽

10.1016/j.nbt.2012.08.576 ◽

2012 ◽

Vol 29 ◽

pp. S205

Author(s):

Gergana Angelova ◽

Konstantin Chakalov ◽

Todorka Popova ◽

Valentin Savov

Keyword(s):

Solid State ◽

Cation Exchange ◽

Cation Exchange Capacity ◽

Exchange Capacity ◽

Natural Substances ◽

High Cation Exchange Capacity

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ESTIMATION OF THE INORGANIC AND ORGANIC pH-DEPENDENT CATION EXCHANGE CAPACITY OF THE B HORIZONS OF PODZOLIC AND BRUNISOLIC SOILS

Canadian Journal of Soil Science ◽

10.4141/cjss68-008 ◽

1968 ◽

Vol 48 (1) ◽

pp. 53-63 ◽

Cited By ~ 4

Author(s):

J. S. Clark ◽

W. E. Nichol

Keyword(s):

Organic Matter ◽

Cation Exchange ◽

Cation Exchange Capacity ◽

Acid Soils ◽

Exchange Capacity ◽

Hydrous Oxides ◽

Before And After ◽

Ph Dependent ◽

The Difference ◽

Wyoming Bentonite

Heating in hydrogen peroxide, dilute oxalic acid, and dilute aluminum oxalate did not change the effective cation exchange capacity (CEC) or the pH-7 CEC of Wyoming bentonite and Alberni clay soil containing excess Al(OH)x. This indicated that treatment of soils with H2O2 to oxidize organic matter and the possible production of oxalates during oxidation did not change the CEC values of the inorganic fraction of soils even if some clay exchange sites were blocked by hydrous oxides of Al.With soils of pH less than approximately 5.4, oxidation of organic matter did not change the effective CECs although the pH-7 CEC values were decreased. Thus, organic matter in acid soils appeared to have little or no effective CEC. Because of this and the negligible effect of H2O2 oxidation on the CEC values of clays, the difference of the pH-7 CEC of soils before and after H2O2 oxidation provided a simple means of estimating the amount of organic pH-dependent CEC in acid soils.The amount of organically derived pH-dependent CEC was determined in a number of soils by means of peroxide oxidation. The technique provided a useful indication of the quantities of sesquioxide–organic matter complexes accumulated in medium- and fine-textured soils.

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Ionic composition of a disordered kaolinite

Clay Minerals ◽

10.1180/claymin.1966.006.4.08 ◽

1966 ◽

Vol 6 (4) ◽

pp. 341-344 ◽

Cited By ~ 4

Author(s):

W. E. Worrall ◽

A. E. Cooper

Keyword(s):

Cation Exchange ◽

Clay Mineral ◽

Cation Exchange Capacity ◽

Ionic Composition ◽

Exchange Capacity ◽

Plastic Clay ◽

High Cation Exchange Capacity

AbstractA white-burning, highly-plastic clay from Jamaica, containing mainly disordered kaolinite, was examined recently. It was unusual in that it was practically free from fine mica, and therefore could be purified readily by standard sedimentation techniques.The cation exchange capacity was abnormally high, and the purified clay mineral, on analysis and calculation of the ionic composition, was found to be deficient in aluminium, but contained magnesium and iron.The results confirmed the view, previously expressed, that disorder in kaolinites is associated with a high cation exchange capacity and a substituted lattice.

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