scholarly journals Mineralogical and physico-chemical characterizations of clay from Keur Saër (Senegal)

Clay Minerals ◽  
2012 ◽  
Vol 47 (4) ◽  
pp. 499-511 ◽  
Author(s):  
A. Mbaye ◽  
C. A. K. Diop ◽  
B. Rhouta ◽  
J. M. Brendle ◽  
F. Senocq ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Raw Material ◽  
Basic Knowledge ◽  
Mineral Mixture ◽  
Fine Clay ◽  
Main Component ◽  
Adsorption Desorption

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.

Cation exchange capacity of loess and overlying soil in the non-carbonate loess sections, North-Western Croatia

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Transition Zone ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Sample Pretreatment ◽  
Loess Soil ◽  
Exchange Capacity ◽  
Oxalate Extraction ◽  
North Western

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.

Chemical fertility of krasnozems - a review

Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Published Data ◽  
Total N ◽  
Eastern Australia ◽  
Ph Buffer

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.

Corrigenda - Chemical fertility of krasnozems - a review

Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Published Data ◽  
Total N ◽  
Eastern Australia ◽  
Ph Buffer

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.

Probabilistic Estimation of Specific Surface Area and Cation Exchange Capacity: A Global Multivariate Distribution

2020 ◽  
Author(s):  
Atma Sharma ◽  
Budhaditya Hazra ◽  
Giovanni Spagnoli ◽  
Sreedeep Sekharan
Keyword(s):  
Specific Surface ◽  
Cation Exchange ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cation Exchange Capacity ◽  
Probabilistic Approach ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Liquid Limit ◽  
Vine Copula

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.

scholarly journals Prediction of cation exchange capacity from soil index properties

Clay Minerals ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 827-837 ◽  
Author(s):  
Y. Yukselen ◽  
A. Kaya
Keyword(s):  
Cation Exchange ◽  
Correlation Coefficient ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Soil Parameters ◽  
Quick Method ◽  
Swell Index

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.

scholarly journals Pedogenesis in the Barreiras Formation Under Climates of Rio Grande do Norte, Brazil

2019 ◽  
Vol 11 (16) ◽  
pp. 19
Author(s):  
Lunara G. da S. Rêgo ◽  
Jéssia J. A. da Silva ◽  
Carolina M. M. Souza ◽  
Jeane C. Portela ◽  
Isadora N. B. M. de Moura ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Rio Grande ◽  
Exchange Capacity ◽  
Climatic Conditions ◽  
The State ◽  
Sample Collection ◽  
X Ray Diffraction ◽  
Diagnostic Horizons

In Brazil, the state of Rio Grande do Norte has an important coastal zone and coastal Tableland areas along the Barreiras Formation, but there are few studies to locate and characterize soils with cohesive character. Therefore, this work was carried out to characterize pedons in the western and eastern mesoregions of the state, located in the Barreiras Formation and with different climatic conditions. The profile description and sample collection were carried out in March and April 2016. The characteristics of the profile identified were the sequence of horizons and their depth, soil color, texture, structure, consistency, and transition between horizons. The physical analyzes were of soil density and texture. The chemical analyzes consisted of: pH in water and in KCl, contents of available P, Na+, K+, Ca2+, Mg2+, potential acidity, and total organic carbon. Indices obtained were: base sum, effective cation exchange capacity, cation exchange capacity at pH 7.0, base saturation, exchangeable aluminum saturation, and exchangeable sodium percentage. The profiles were classified up to the fourth categorical level. The mineralogical assembly was identified in the clay fraction of the diagnostic horizons. The identification of the minerals was performed by X-ray diffraction. The pedons of the two regions presented distinct characteristics and pedogenesis, occurring laterization in the pedons of the western mesoregion and podzolization in the pedons of the eastern mesoregion, both without presence of cohesive character as a diagnostic attribute.

scholarly journals Genesis Pedon Tanah yang Berkembang di Atas Batuan Karbonat Wonosari Gunungkidul

2011 ◽  
Vol 25 (2) ◽  
pp. 100
Author(s):  
Djoko Mulyanto ◽  
S Subroto P.S. ◽  
Herwin Lukito
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Chemical Properties ◽  
Black Soil ◽  
Exchange Capacity ◽  
Red Soil ◽  
Organic C ◽  
Fe And Mn ◽  
Marly Limestone

The variation of soil color that developed on carbonate rocks which are generally white, very interesting to be studied. The aim of the study is to examine the formation of two pedons of black soil and red soil by hue 10 YR and hue 5 to 2.5 YR which successively developed on marly limestones and calcarenite. Analysis of mineral properties consist of the total minerals of sand fraction, clay fraction and rock powders. Soil chemical properties include: pH, organic C, exchangeable cations and cation exchange capacity, CaCO3, the amorphous-crystalline of Fe and Mn, the total of Fe and Mn, the analysis of physical properties is the texture of seven fractions. The results showed that the development of the red soil is much more developed than black soil that shown by intensively decalcification process of red soil that impact on the low of pH, base saturation and cation exchange capacity, whereas the development of black soil is inhibited. The formation of black soil is more inherited of clay bearing marly limestone after carbonate dissolution, whereas the red soil development through rubification and illuviation.

Soil properties and mineralogy in relation to land use on a sedimentary toposequence in south-eastern Nigeria

1989 ◽  
Vol 112 (3) ◽  
pp. 377-386 ◽  
Author(s):  
E. T. Eshett ◽  
J. A. I. Omueti ◽  
A. S. R. Juo
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Base Saturation ◽  
Valley Bottom ◽  
Fine Grained ◽  
South Eastern ◽  
Transmission Electron ◽  
Upland Soils

SummaryThe mineralogy of the clay fraction (<2 μm) of nine soil samples representing three physiographic positions of a toposequence in Ochon, south-eastern Nigeria, was determined by transmission electron microscopy and X-ray diffraction.Soils in the crest and middle slopes (pedons TE1 and TE2, respectively) of the toposequence, formed over fine-grained sandstone, were coarse-textured, well-drained and acidic and had low effective cation exchange capacity and percentage base saturation. Kaolinite, mica, quartz, goethite and gibbsite were the principal minerals identified in the clay fraction of these soils. Soils in the valley bottom (pedon TE3) formed over arenaceous shale were, on the other hand, fine-textured, poorly drained and weakly acidic with higher cation exchange capacity and percentage base saturation. Their clay fraction mineralogy was similar to that of the well-drained upland soils but additionally included feldspar and smectite/vermiculite mixed layer minerals.Mixed cropping of yam, cassava, maize and other annuals under traditional methods was carried out on the drier, well-drained crest and upper slopes while sole cropping of lowland rice occurred in the poorly drained, more fertile valley-bottom site. The valley-bottom soils show greater potential for improvement in agricultural productivity under good management than the upland soils.

scholarly journals Application of sorption tests to estimate selected properties of alluvial soils in Żuławy Elbląskie

2011 ◽  
Vol 15 (1) ◽  
pp. 167-177
Author(s):  
Andrzej Olchawa ◽  
Jerzy Terlikowski
Keyword(s):  
Specific Surface ◽  
Cation Exchange ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cation Exchange Capacity ◽  
Mineral Soil ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Alluvial Soils

Application of sorption tests to estimate selected properties of alluvial soils in Żuławy Elbląskie The specific surface area and hence the sorption or desorption moisture at constant water vapour pressure will increase with increasing content of humus and clay fraction in soils. Adopting such an assumption, preliminary experimental studies were performed to assess the possibility of using sorption/desorption tests to determine some features of alluvial soils from Żuławy such as cation exchange capacity CEC and the specific external surface area Se. Results of the sorption tests were compared with the analyses of the same soil properties determined with standard methods to evaluate the usefulness of the former. Preliminary studies showed a high similarity in the determination of CEC and Se with both methods. Confirmed usefulness of sorption/desorption methods for determination of the specific surface area of mineral soil particles and particularly for analyses of cation exchange capacity would bring a significant simplification of studies and a possibility of their dissemination due to the ease of such analyses. Determination of the specific surface area with the sorption and desorption method does not require sophisticated equipment and laborious and costly preliminary procedures. Dissemination of this method and recognition it as a reference one would, however, need further studies on various soil types.

Sign in / Sign up

Export Citation Format

Share Document