Particle size of wyoming bentonite and its relation to the cation exchange capacity and the homogeneity of the charge density

1976 ◽  
Vol 72 (0) ◽  
pp. 376 ◽  
Author(s):  
P. Rengasamy ◽  
Jan B. van Assche ◽  
Jan B. Uytterhoeven
Keyword(s):  
Particle Size ◽  
Charge Density ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Wyoming Bentonite

Dehydration of the montmorillonite minerals

1955 ◽  
Vol 30 (228) ◽  
pp. 604-615 ◽  
Author(s):  
R. Greene-Kelly
Keyword(s):  
Charge Density ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
The Other ◽  
Hydration Energy ◽  
Interlayer Cations ◽  
Potassium Fixation ◽  
Exchange Cations ◽  
Silicate Layers

Studies of the effect of dehydration at temperatures greater than 150° on sorption by montmorillonites have shown that small interlayer cations such as lithium and magnesium promote an irreversible decrease in the amount of interlamellar sorption and a consequent marked fall in the cation exchange capacity as measured by conventional methods (1, 2, 3, 4). The other minerals of the group do not show this property (4), which is quite distinct from the supposed 'potassium fixation' reported in these minerals (5). This latter effect, which is small for montmorillonite, refers to the decreased rate of exchange of potassium as compared with smaller exchange cations especially after the potassium-saturated mineral has been dried at ]00° C., and has been shown to be much more marked in mica-like minerals with silicate layers of higher charge density (e.g. illites and vermiculites (6)). The amount of water sorbed by potassium-saturated montmorillonite is not significantly affected by drying at temperatures below 400° C. although it is less than that of most other montmorilIonites (3), due probably to the low hydration energy of the potassium ion (7).

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

1968 ◽  
Vol 48 (1) ◽  
pp. 53-63 ◽  
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.

Reaction of mixed magnesium–aluminum and calcium–aluminum hydroxides with Wyoming bentonite

1969 ◽  
Vol 6 (1) ◽  
pp. 47-53
Author(s):  
J. S. Clark ◽  
G. J. Ross
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Marked Reduction ◽  
Exchange Capacity ◽  
Reaction Products ◽  
Aluminum Hydroxides ◽  
Wyoming Bentonite

Excess AlCl3 was reacted with Mg(OH)2 and Ca(OH)2 in suspensions of Wyoming bentonite and the nature of the reaction products formed and their effect on the cation-exchange capacity (CEC) of the clay was determined. Reaction of Mg(OH)2 and AlCl3 with the clay produced marked decreases of the CEC in the bentonite, whereas much smaller decreases were observed in the Ca–Al–clay preparations. The decreases in the CEC were attributed to the formation of mixed Mg–Al and Ca–Al hydroxide clay complexes. The greater stability of the mixed Mg–Al hydroxide complexes with the clay appeared to account for the marked reduction of CEC in these systems.

Cation and Anion Sorption Capability of Organophilic Bentonite

1997 ◽  
Vol 506 ◽  
Author(s):  
J. Bors ◽  
St. Dultz ◽  
B. Riebe
Keyword(s):  
Cation Exchange ◽  
Surface Charge ◽  
Cation Exchange Capacity ◽  
Particle Surface ◽  
Exchange Capacity ◽  
Negative Particle ◽  
Strontium Ions ◽  
Wyoming Bentonite

ABSTRACTSorption experiments were performed with iodide, cesium and strontium ions on MX-80 Wyoming-bentonite treated with hexadecylpyridinium (HDPy+) in amounts equivalent to 0.2 - 4.0 times the cation exchange capacity (CEC) using 125I- 134Cs+ and 85Sr2+ as tracers. In HDPy-bentonite, iodide exhibited increasing adsorption, while cesium and strontium ions showed decreasing adsorption with increasing organophilicity. It was also found that the Cs+affinity to original and HDPy-bentonite was considerably higher than that of Sr2+ ions. HDPy+ uptake in increasing concentrations resulted in a pronounced expansion of the basal spacings (d002 reflex at 2.78 nm) and in a change of the negative particle surface charge to positive values.

INFLUENCE OF CLAY MINERALS ON MICROORGANISMS: III. EFFECT OF PARTICLE SIZE, CATION EXCHANGE CAPACITY, AND SURFACE AREA ON BACTERIA

1966 ◽  
Vol 12 (6) ◽  
pp. 1235-1246 ◽  
Author(s):  
G. Stotzky
Keyword(s):  
Particle Size ◽  
Cation Exchange ◽  
Surface Area ◽  
Clay Minerals ◽  
Cation Exchange Capacity ◽  
Physicochemical Characteristics ◽  
Exchange Capacity ◽  
Bacterial Respiration ◽  
Effect Of Particle Size ◽  
Stimulation Of

The stimulation of bacterial respiration by clay minerals was related to certain physicochemical characteristics of clays. Respiration increased with an increase in the cation exchange capacity and surface area of the particles. The importance of surface area, however, could not be unequivocally established, as some of the methods used to determine this characteristic on certain clay species were questionable. Particle size did not appear to be a critical characteristic. The implications of the cation exchange capacity of clay minerals in the activity, ecology, and population dynamics of microorganisms in nature are discussed.

scholarly journals Influence of Pine Bark Particle Size and pH on Cation Exchange Capacity

2014 ◽  
Vol 24 (5) ◽  
pp. 554-559 ◽  
Author(s):  
James E. Altland ◽  
James C. Locke ◽  
Charles R. Krause
Keyword(s):  
Particle Size ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Fine Particles ◽  
Exchange Capacity ◽  
Pine Bark ◽  
Sphagnum Peat ◽  
Maximum Quantity ◽  
Particle Size Classes ◽  
Substrate Ph

Cation exchange capacity (CEC) describes the maximum quantity of cations a soil or substrate can hold while being exchangeable with the soil solution. Although CEC has been studied for peatmoss-based substrates, relatively little work has documented factors that affect CEC of pine bark substrates. The objective of this research was to determine the variability of CEC in different batches of pine bark and determine the influence of particle size, substrate pH, and peat amendment on pine bark CEC. Four batches of nursery-grade pine bark were collected from two nurseries, and a single source of sphagnum moss was obtained, separated in to several particle size classes, and measured for CEC. Pine bark was also amended with varying rates of elemental sulfur and dolomitic limestone to generate varying levels of substrate pH. The CEC varied with pine bark batch. Part of this variation is attributed to differences in particle size of the bark batches. Pine bark and peatmoss CEC increased with decreasing particle size, although the change in CEC from coarse to fine particles was greater with pine bark than peatmoss. Substrate pH from 4.02 to 6.37 had no effect on pine bark CEC. The pine bark batch with the highest CEC had similar CEC to sphagnum peat. Amending this batch of pine bark with sphagnum peat had no effect on composite CEC.

Particle-size distribution, cation exchange capacity and charge density of deferrated montmorillonites

Clay Minerals ◽  
1982 ◽  
Vol 17 (2) ◽  
pp. 209-216 ◽  
Author(s):  
M. S. Stul ◽  
L. Van Leemput
Keyword(s):  
Charge Density ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Particle Sizes ◽  
Citrate Solution ◽  
Interlayer Cation ◽  
The Mean ◽  
Mean Charge ◽  
Wyoming Bentonite ◽  
By Products

AbstractDifferent montmorillonites (Otay, Chambers, Marnia, Camp Berteau, Moosburg, Greek White, Wyoming bentonite were deferrated with a dithionite/citrate solution; iron sulphide by-products were eliminated with an HCl washing and citrates with an H2O2 oxidation. The smaller CEC after deferration could not be assigned to either (i) the occurrence of a positive correlation between CEC and particle sizes smaller than 0.2 µm or (ii) to the mean charge density of these sub-fractions. All sub-fractions had a heterogeneous interlayer cation density distribution.

scholarly journals SOME PROPERTIES OF ALUMINUM HYDROXIDE PRECIPITATED IN THE PRESENCE OF CLAYS

1965 ◽  
Vol 45 (3) ◽  
pp. 331-336 ◽  
Author(s):  
R. C. Turner
Keyword(s):  
Cation Exchange ◽  
Aluminum Hydroxide ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
The Other ◽  
Wyoming Bentonite

With Arizona bentonite, Wyoming bentonite, Fithian illite, and Georgia kaolin it was found that the OH/Al ratio of the aluminum hydroxide precipitated was about 2.7, providing the initial OH/Al ratio was not greater than 2.7. When the initial OH/Al ratio was increased to 3.0 the OH/Al ratio of the precipitate also increased to 3.0. The decrease in cation exchange capacity of the clays per milliequivalent of Al in the precipitate was independent of the initial OH/Al ratio when the ratio was varied from 1.0 to 2.7. When this ratio was increased beyond 2.7, however, inactivation of the exchange sites decreased, until with an initial OH/Al ratio of 3.0 there was very little decrease in exchange capacity. It required less precipitated Al to decrease the exchange capacity of Arizona bentonite than it did for the other three clays.

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