scholarly journals Influence of Degree of Clay-Mineral Crystallization and Free Iron Oxide Content on the Cation Exchange Capacity of Catalina and Cialitos Soils

1969 ◽  
Vol 52 (2) ◽  
pp. 148-154
Author(s):  
Raúl Pérez Escolar ◽  
M. A. Lugo López

Catalina and Cialitos soils have different cation exchange capacities, even though their organic-matter and clay contents are similar. X-ray and differential thermal analyses were made on the clay fraction to determine whether this variation in exchange capacity could be attributed to differences in clay mineral composition. The analyses revealed that, in both cases, kaolinite is the predominant clay mineral. However, it was found that, in Cialitos clay the kaolinite is poorly crystallized, whereas crystals are well defined in Catalina clay. Since the poorer the crystallinity, the higher the exchange capacity, this could account for the higher cation exchange capacity of Cialitos clay. Another factor that may also partly account for the difference in cation exchange capacity is the higher content of free iron oxides in Catalina clay. It is well known that free iron oxides block exchange positions in kaolinite clay minerals.

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  

AbstractThe adsorption properties in terms of cation exchange capacity and their relation to the soil and sediment constituents (clay minerals, Fe-, Mn-, and Al-oxyhydroxides, organic matter) were investigated in loess, soil-loess transition zone, and soil at four loess-soil sections in North-Western Croatia. Cation exchange capacity of the bulk samples, the samples after oxalate extraction of Fe, Mn and Al, and after removal of organic matter, as well as of the separated clay fraction, was determined using copper ethylenediamine. Cation exchange capacity (pH∼7) of the bulk samples ranges from 5 to 12 cmolc/kg in soil, from 7 to 15 cmolc/kg in the soil-loess transition zone, and from 12 to 20 cmolc/kg in loess. Generally, CEC values increase with depth. Oxalate extraction of Fe, Mn, and Al, and removal of organic matter cause a CEC decrease of 3–38% and 8–55%, respectively, proving a considerable influence of these constituents to the bulk CEC values. In the separated clay fraction (<2 μm) CEC values are up to several times higher relative to those in the bulk samples. The measured CEC values of the bulk samples generally correspond to the clay mineral content identified. Also, a slight increase in muscovite/illite content with depth and the vermiculite occurrence in the loess horizon are concomitant with the CEC increase in deeper horizons, irrespective of the sample pretreatment.


Clay Minerals ◽  
2012 ◽  
Vol 47 (4) ◽  
pp. 499-511 ◽  
Author(s):  
A. Mbaye ◽  
C. A. K. Diop ◽  
B. Rhouta ◽  
J. M. Brendle ◽  
F. Senocq ◽  
...  

AbstractThere is interest in exploiting and developing natural resources, particularly deposits of natural clays. Senegal has several clay mineral deposits for which chemical and mineralogical compositions have been little studied. Some of these natural materials are nowadays used in pottery and ceramics. To extend applications, a better basic knowledge is required and, for this objective, the raw clay and separated <2 μm clay fraction from Keur Saër (Senegal) were subjected to chemical and mineralogical studies. Several techniques including X-ray diffraction (XRD), thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms, cation exchange capacity (CEC) measurements and solid state nuclear magnetic resonance (NMR) have been used to characterize the material. It was found that the raw clay and the separated clay fraction consist of a mineral mixture in which kaolinite is the main component. 29Si and 27Al MAS-NMR spectra show the presence of silicon atoms linked to three other silicon atoms via an oxygen atom and six coordinated Al atoms. Significant increases in the specific surface area and cation exchange capacity were observed on purification, reaching a maximum of about 73.2 m2g–1 and 9.5 meq/100 g for the separated fine clay fraction while the values for the raw material were around 28.9 m2g–1 and 7.3 meq/100 g.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 3015
Author(s):  
Fethi Kooli ◽  
Souad Rakass ◽  
Yan Liu ◽  
Mostafa Abboudi ◽  
Hicham Oudghiri Hassani ◽  
...  

The effect of the counteranion of hexadecyltrimethylammonium salts on the physico-chemical properties of organoclays was investigated, using a selected natural clay mineral with a cation exchange capacity of 95 meq/100 g. The uptake amount of C16 cations was dependent on the hexadecyltrimethylammonium (C16) salt solution used, the organoclay prepared from C16Br salt solution exhibited a value of 1. 05 mmole/g higher than those prepared from C16Cl and C16OH salt solutions. The basal spacing of these organoclays was in the range of 1.81 nm to 2.10 nm, indicating a similar orientation of the intercalated surfactants, and could indicated that the excess amount of surfactants, above the cation exchange capacity of 0.95 meq/g could be adsorbed on the external surface of the clay mineral sheets. These organoclays were found to be stable in neutral, acidic, and basic media. The thermal stability of these organoclays was carried out using thermogravimetric analysis and in-situ X-ray diffraction (XRD) techniques. The decomposition of the surfactant occurred at a maximum temperature of 240 °C, accompanied with a decrease of the basal spacing value close to 1.42 nm. The application of these organoclays was investigated to remove an acidic dye, eosin. The removal amount was related to the initial used concentrations, the amount of the surfactants contents, and to the preheated temperatures of the organoclays. The removal was found to be endothermic process with a maximum amount of 55 mg of eosin/g of organoclay. The value decreased to 25 mg/g, when the intercalated surfactants were decomposed. The reuse of these organoclays was limited to four regeneration recycles with a reduction of 20 to 30%. However, noticeable reduction between 35% to 50% of the initial efficiency, was achieved after the fifth cycle, depending of the used organoclays.


Clay Minerals ◽  
1966 ◽  
Vol 6 (4) ◽  
pp. 341-344 ◽  
Author(s):  
W. E. Worrall ◽  
A. E. Cooper

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.


1980 ◽  
Vol 43 (331) ◽  
pp. 865-872 ◽  
Author(s):  
D. C. Bain ◽  
P. F. S. Ritchie ◽  
D. R. Clark ◽  
D. M. L. Duthie

SummaryThe chemical, mineralogical, and textural changes involved in the weathering of basalt have been traced through various stages from fresh rock (which has a cation exchange capacity of 10 meq/100 g due to the presence of a swelling chlorite mineral) to reddened basaltic rubble consisting of interstratified montmorillonite-illite, hematite, and anatase. The cation exchange capacities of the rocks increase progressively with the formation of secondary clay from labradorite as Al, Fe, and Ti accumulate and Si, Mg, Ca, and Na are depleted—much of the K is retained in the secondary clay mineral. The weathering is considered to be contemporaneous with the formation of the Antrim bauxites but not so intense.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


1969 ◽  
Vol 36 (2) ◽  
pp. 155-160
Author(s):  
M. A. Lugo López ◽  
F. Abruña ◽  
J. Roldán

The quantity of limestone required to bring the pH of various acid Puerto Rican soils to 6.5 was investigated and found to vary from several hundred to several thousands pounds per acre. To investigate the relation of clay-mineral type, clay content, cation-exchange capacity, organic-matter content, and pH to lime requirement, these properties were determined for several soils. A highly significant regression of lime requirement on pH was obtained which can be expressed by the equation: Y = 18.39 — 3.196 X, where Y is the lime requirement and X is the pH value. Multiple regressions including other factors did not significantly increase the variability which could be explained on terms of the first regression. Further analysis were made by arranging the data according to the predominant clay mineral. For kaolinitic soils highly significant correlations were obtained between lime requirement and either pH or cation exchange capacity. The regressions were: (a) Y = 15.26 — 2.632 pH, and (b) Y = 3.048 + 0.5774 (cation-exchange capacity), where Y is the lime requirement. A regression of lime requirement on both factors did not significantly increase the variability explained by the second equation. No significant regressions were obtained for beidellitic soils.


Author(s):  
Atma Sharma ◽  
Budhaditya Hazra ◽  
Giovanni Spagnoli ◽  
Sreedeep Sekharan

Specific surface area (SSA) and cation exchange capacity (CEC) are two fundamental clay properties. However, the determination of CEC and SSA is challenging due to inherent uncertainties and difficulty in experimental measurement. Popular approach is to employ transformation models for its estimation. However, most of the existing models were developed on limited sample sizes, and quantification of uncertainty associated with the estimate is not possible. Therefore this study proposes a multivariate probabilistic approach for estimation of CEC and SSA. First, a five-dimensional database (278×5) for parameters liquid limit (LL), plasticity index (PI), clay fraction (CF), CEC and SSA (labelled as CLAY/C-S/5/278) is developed. Thereafter, multivariate distribution for the five parameters in the database is constructed using vine copula approach. Implementation of the proposed approach is demonstrated by updating prior/unconditional probability density function (PDFs) of CEC and SSA given single/ multiple clay parameters using Bayes’ rule. The posterior/conditional PDFs of CEC and SSA are also summarized as practitioner friendly analytical expressions. Two geotechnical application examples are also shown. In the proposed approach, CEC and SSA are characterized by their complete joint distribution, and is, therefore, superior to the popular deterministic transformation approach in literature.


Clay Minerals ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 827-837 ◽  
Author(s):  
Y. Yukselen ◽  
A. Kaya

AbstractIn many areas of geotechnical engineering it is necessary to have an estimate of the cation exchange capacity (CEC) of a soil in order to allow preliminary design estimates. Standard methods of CEC determination are time-consuming and involve several steps (e.g. displacement of the saturating cation requires several washings with alcohol). Therefore, a rapid method of CEC estimation would be very useful. During preliminary site investigations, the soil engineering parameters can be estimated from the considerable number of correlations available in the literature. In this study, relationships between CEC and various other soil engineering properties have been investigated, resulting in a quick method for estimating CEC.Simple correlations were developed between CEC and specific surface area (SSA), soil organic matter (OM), clay fraction (CF), activity (A), Atterberg limits (liquid (LL), plastic (PL), and shrinkage (SL)), and modified free swell index (MFSI) of the soils. Strong correlations are observed between the CEC values and those for ethylene glycol monoethyl ether (EGME) uptake and methylene blue (MB) titration. However, no significant correlation was found between CEC and N2_SSA. No unique relationship was seen between CEC and CF (r2 <0.5). No relationship was observed between CEC and OM in this study. The best correlation coefficient between the CEC and Atterberg limits exists between CEC and LL (r2 = 0.61). No significant relationship was seen between CEC and PL or SL. The correlation coefficient between CEC and MFSI was 0.65. Multiple linear regression analyses were developed to investigate the contributions of different soil parameters to CEC. These analyses show that EGME_SSA, in combination with LL, accounted for 91% of the variation in CEC. Correlations between CEC and EGME_SSA, MB_SSA and LL appear to be sufficiently good to enable an indication of CEC to be estimated from these parameters.


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