A proposed new reagent for the measurement of cation exchange properties of carbonate soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 633 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Calcium Carbonate ◽  
Cation Exchange ◽  
Charge Exchange ◽  
Double Layer ◽  
Aqueous Ethanol ◽  
Choline Chloride ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Layer Charge ◽  
Exchange Properties

A solution of choline chloride (1 mol L-1) in aqueous ethanol (65% by weight) is proposed as a reagent for extracting double-layer exchangeable cations from soils containing calcium carbonate, instead of the previously used solution of NH4Cl (1 mol L-1) at pH 8.5 in aqueous ethanol. This choline chloride reagent gives better estimates of double-layer exchangeable cations and of double-layer charge (exchange capacity) because it dissolves less CaCO3, and reacts less with specifically adsorbed forms of Ca, Mg and K than the NH4Cl reagent does. Because plants can use both adsorbed and exchangeable cations, the new reagent is not suitable for measuring nutrient cation availabilities. Cation exchange values for a range of Australian carbonate soils are presented to show the differences to be expected between analyses by the choline chloride and the NH4Cl reagents.

Effects of high pH solutions with large monovalent cation concentrations on cation exchange properties

Soil Research ◽  
1996 ◽  
Vol 34 (2) ◽  
pp. 229 ◽  
Author(s):  
RE Liefering ◽  
CDA Mclay
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Negative Charge ◽  
Monovalent Cation ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Ion Concentration ◽  
Exchangeable Sodium ◽  
High Ph ◽  
Exchange Properties

Disposal of strongly alkaline industrial liquid wastes, which contain large monovalent cation concentrations, by means of land treatment systems is becoming increasingly common. This study investigated the effects of solutions with large monovalent cation concentrations and high pH on cation exchange properties in four New Zealand soils with different clay mineralogies. The soils were shaken with a range of concentrations (0–0.3 M) of NaOH, KOH, NaCl, and KCl. Cation exchange capacity (CEC) and exchangeable cations (Ca2+, Mg2+, K+, and Na+) were measured following shaking and washing procedures. Although the hydroxide solutions dissolved significant amounts of organic matter from all soils, there was still a net increase in CEC measured at all hydroxide concentrations. The magnitude of the CEC increase was dependent on hydroxide concentration. The increase in CEC is attributed to newly generated negative charge on surfaces which possess variable charge (i.e. pH dependent) characteristics such as edge sites of clay minerals, sesquioxides, and the undissolved organic matter remaining in the soil. In contrast to hydroxide solutions, no increase in CEC was measured in chloride-treated samples. Increases in the concentration of all treatment solutions resulted in increases in the exchangeable ion concentration of the index cation used in the treatment solution (either Na+ or K+) and decreases in concentration of the other three exchangeable cations. In general, higher exchangeable sodium percentage (ESP) values were measured in samples treated with NaOH than samples treated with NaCl at all concentrations. Similarly, higher exchangeable potassium percentage (EPP) was measured in samples treated with KOH than samples treated with KCl at all concentrations. The higher ESP and EPP values recorded when hydroxide solutions were used as treatments are attributed to the newly generated negative charges being counter-balanced by the monovalent index cation present in the treatment solution. It is suggested that existing equations commonly used to predict ESP and EPP values are unsuccessful for accurately predicting changes when soils are treated with hydroxide solutions, due to their inability to account for the newly generated exchange sites. The equations did, however, adequately predict the effects of both chloride solutions on ESP and EPP.

Ethylene glycol and glycerol complexes of smectites and vermiculites

Clay Minerals ◽  
1966 ◽  
Vol 6 (4) ◽  
pp. 237-259 ◽  
Author(s):  
G. W. Brindley
Keyword(s):  
Chemical Analysis ◽  
Ethylene Glycol ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Layer Charge ◽  
Silicate Layers

The complexes formed by ethylene glycol, HOCH2.CH2OH, and by glycerol, HOCH2.CHOH.CH2OH, with smectites (montmorillonite-saponite group), and vermiculites have received more attention than any other group of organo-silicate complexes. This interest arose in the first place from their use for identification purposes as proposed by MacEwan (1944, 1946) and by Bradley (1945b). Over the years, increasing attention has been given to the manner in which these complexes vary with the nature of the mineral, the magnitude and source of the charge on the silicate layers, and the number and kind of the exchangeable cations between the layers. The layer charge is determined most reliably from the full chemical analysis of a mineral, but more commonly is estimated from a measurement of cation exchange capacity.

Collaborative Study of the Cation Exchange Capacity of Peat Materials

1973 ◽  
Vol 56 (1) ◽  
pp. 154-157 ◽  
Author(s):  
Virginia A Thorpe
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Collaborative Study ◽  
Statistical Treatment ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Satisfactory Degree ◽  
Modified Method ◽  
Precision And Accuracy

Abstract To provide a measure of the total amount of exchangeable cations that can be held by peat expressed as mequiv./100 g air-dried peat, the modified method of Puustjärvi for cation exchange capacity has been proposed and studied collaboratively. The statistical treatment of the collaborators’ results indicate a satisfactory degree of precision and accuracy for the 3 products considered, moss, humus, and reed-sedge. The method for cation exchange capacity of peat materials, with the description of the transfer technique included, has been adopted as official first action. The 7 ASTM methods have been adopted as procedures.

scholarly journals Influence of clay minerals and exchangeable cations on the formation of humic-like substances (melanoidins) from D-glucose and L-tyrosine

Clay Minerals ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 487-497 ◽  
Author(s):  
P. Arfaioli ◽  
O. L. Pantani ◽  
M. Bosetto ◽  
G. G. Ristori
Keyword(s):  
Cation Exchange ◽  
Clay Minerals ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Reaction Conditions ◽  
Polymeric Compounds

AbstractThe ability to produce humic-like polymeric compounds, with D-glucose and L-tyrosine as starting materials, was evaluated in different mineral systems: (1) Ca-, Al- and Cu(II)-saturated montmorillonite; (2) Ca-, Al- and Cu(II)-saturated kaolinite; (3) quartz in the presence of two different amounts of the same cations (according to the cation exchange capacity of the clays); and (4) untreated quartz (as control). All systems proved to be effective in the formation of humic-like compounds, particularly quartz, in the presence of cations. The effectiveness in promoting humification reactions was strictly related to the amounts of added cations. In the reaction conditions considered, the humification appears to be due more to the cations than to the type of clay minerals. The clayey systems synthesized more complex (aromatic) substances than the quartz ones.

Comparison of Cation Exchange in Ganophyllite and [Na + Al]-Substituted Tobermorite: Crystal-Chemical Implications

1988 ◽  
Vol 52 (366) ◽  
pp. 371-375 ◽  
Author(s):  
Sridhar Komarneni ◽  
Stephen Guggenheim
Keyword(s):  
Cation Exchange ◽  
Exchangeable Cations ◽  
Cross Linking ◽  
Crystal Chemical ◽  
Layer Silicates ◽  
Residual Charge ◽  
Interlayer Region ◽  
Exchange Properties ◽  
Charge Configuration

AbstractGanophyllite and [Na+ + Al3+]-substituted tobermorite exhibited similar cation exchange properties and, in particular, selective cesium exchange. [Na+ + Al3+]-substituted tobermorite and ganophyllite showed a selective Cs exchange of 10.77 and 8.71 meq/100 g from 0.02N NaCl and of 11.08 and 9.04 meq/100 g from 0.02N CaCl2, respectively. The [Na+ + Al3+]-substituted tobermorite is structurally similar to ganophyllite: both are roughly analogous to 2:1 layer silicates, both have cross-linking tetrahedra across the interlayer region, and both have exchangeable cations located in zeolite-like sites in the interlayer region. The similarities in cation exchange properties imply that the residual charge configuration of the analogue 2 : 1 layer must be approximately equivalent also.

Acid character of nontronite: permanent and pH-dependent charge components of cation exchange capacity

Clay Minerals ◽  
1972 ◽  
Vol 9 (4) ◽  
pp. 425-433
Author(s):  
B. S. Kapoor
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Dependent Component ◽  
Ph Dependent ◽  
The Difference ◽  
The Cost ◽  
Fe Ions ◽  
Acid Character

AbstractThe cation exchange capacity (C.E.C.) of nontronite was determined by titrating the acid clay, prepared by the action of H-resin on nontronite, in water and some nonaqueous solvents. The base-titratable acidities of the acid nontronite, freshly prepared as well as aged, were found to be greater than the acidities extractable with 1 N NaCl; the difference was attributed to the non-exchangeable pH-dependent component of C.E.C. In the freshly prepared sample, H+ and Fe3+ ions were the only exchangeable cations. Ageing produced basic Fe ions which were exchangeable and whose amount increased at the cost of H− and Fe3+ ions. Whatever the age, the total quantity of these exchangeable cations corresponding to the total isomorphous charge, remained constant. The amount of the pH-dependent acidity also remained unchanged. A likely mechanism to account for the observed pH-dependent component of the C.E.C, of nontronite is suggested.

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