Colloidal dynamics of soil clay under the effect of fine-sized biochars: Implication for biochar amendment towards preventing clay loss and soil erosion

2020 ◽  
Author(s):  
Nga T. Mai ◽  
Nga T. T. Pham ◽  
Anh T. Q. Nguyen ◽  
Anh T. N. Nguyen ◽  
Anh M. Nguyen ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Surface Charge ◽  
Clay Fraction ◽  
Test Tube ◽  
Soil Clays ◽  
Soil Clay ◽  
Ph Range ◽  
Polyelectrolyte Titration ◽  
Repulsive Forces ◽  
Biochar Amendment

<p>In soils clay loss by leaching and surface runoff is one of the initial steps increasing the risk of erosion. Here we set out to determine the effect of fine-sized biochar amendment on colloidal dynamics of soil clay, with the aim of answering whether biochar addition enhances or curbs soil erosion. Fine-sized biochar samples were prepared from fern Dicranopteris linearis’s biomass under non-biochar-oriented pyrolysis (open heating) and biochar-oriented pyrolysis (N<sub>2</sub>-supported heating) over a temperature range from 400 to 900°C. The clay fraction (< 2 µm) separated from a clay-rich soil in a hilly area of the Red River basin containing relatively high amounts of kaolinite was tested for its dispersion properties under the presence of the prepared biochars. Surface charge of biochar-soil clay mixtures was determined by polyelectrolyte titration using a particle charge detector, while corresponding colloidal properties of the mixtures were examined by the test tube method. Both, the soil clay fraction and biochar samples showed strongly negative surface charge and their surface charge was variable depending on pH. In a pH range from 3 to 10 and at an electrolyte background of 0.01 M NaCl, surface charge of the clay fraction decreased from -1.68 to -44.75 mmol<sub>c</sub> Kg<sup>-1</sup>, while the biochars surface charge varied from -0.6 to -48.8 mmol<sub>c</sub> Kg<sup>-1</sup>. Soil clays were more strongly dispersed in the presence of biochars by increasing electrostatic repulsive forces. The biochar preparation method had a crucial role for surface charge properties of biochars and in consequence colloidal dynamics of biochar-clay mixtures. The N<sub>2</sub>-supported pyrolysis at lower temperatures does not increase charge density but creates a more porous structure, thereby increasing the total negative net charges. As a result, the N<sub>2</sub>-supported biochars favor clay dispersion more effectively, while the open-pyrolysis biochars showed lesser effects. Our results indicate that fine-sized biochar amendments generally enhance the risk of clay loss, however, such techniques for creating low-charged biochars can help to decrease clay dispersibility when applying biochar for soil.</p>

Quantitative determination of the interlamellar volume in an interstratified mica-smectite soil clay

Clay Minerals ◽  
1980 ◽  
Vol 15 (2) ◽  
pp. 175-191 ◽  
Author(s):  
A. A. Jones ◽  
D. J. Greenland
Keyword(s):  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Chemical Analyses ◽  
Soil Clays ◽  
Interlamellar Water ◽  
Glycol Monoethyl Ether ◽  
The Mean ◽  
Soil Clay

AbstractTwo well-characterized soils containing substantial amounts of interstratified mica-smectite have been examined by a combination of techniques in an attempt to correlate the characteristics of the interlamellar surfaces with other properties. The techniques used included XRD and chemical analyses, determination of surface area by nitrogen sorption and by desorption of water and ethylene glycol monoethyl ether vapour, and determination of cation exchange capacity. Reasonable agreement was found between the results obtained for the proportion of expanding or smectite-like surfaces, although estimates by XRD, especially when coarser material (> 2/µm) was included, were generally lower than those obtained by the other methods. The mean density of charge on the surfaces of the soil clays appeared to be similar to that of smectite. The decrease in porosity observed for both soils dried by the critical point method was largely accounted for by the decrease in volume associated with the loss of interlamellar water from the smectite-like interlamellar surfaces included within the clay fraction.

FIXATION AND RELEASE OF POTASSIUM IN RELATION TO THE MINERALOGY OF THE CLAY FRACTION OF SOME SELECTED SOIL HORIZON SAMPLES

1971 ◽  
Vol 51 (3) ◽  
pp. 449-459 ◽  
Author(s):  
A. J. MacLEAN ◽  
J. E. BRYDON
Keyword(s):  
Clay Fraction ◽  
High Capacity ◽  
Soil Horizon ◽  
Exchangeable K ◽  
High Release ◽  
Soil Clays ◽  
Activity Ratios ◽  
Plant Removal ◽  
Satisfactory Relationship ◽  
Intermediate Amount

Soil clays of 11 horizon samples of Canadian soils gave activity ratios (AReK) of 0.0003 to 0.0040, exchangeable K values of 0.18 to 1.74 meq/100 g, nonexchangeable K values of 1.54 to 6.65 meq/100 g upon leaching with 12 liters of 0.1 N BaCl2 and of 0.45 to 4.03 meq as measured by plant removal, and degrees of K-fixation of 29 to 100% of added K against extraction with 1 N NH4OAc. The amounts of exchangeable K were correlated with the activity ratios and with the amounts of non-exchangeable K removed by plants. Of the fixed K, 46 to 86% was recovered by leaching with the 0.1 N BaCl2 and 18 to 64% by cropping. Some of the clays gave a satisfactory relationship between their K behaviour and mineralogy. Two of them (Ae, Humo-Ferric Podzol), consisting of mixtures of vermiculite and montmorillonite, released native K slowly and had a high capacity to fix added K. Another corresponding sample, from the C horizon and consisting of well-ordered 2 M1 muscovite, also released native K slowly but gave the lowest degree of K-fixation. A predominantly montmorillonite clay with some mica layers (Gray Luvisol) gave a high release of native K and fixed an intermediate amount of added K. The K–mineralogy relationship in the remaining samples was less apparent, and varied with the complexity of interstratification.

scholarly journals Wien effect of Cd/Zn on soil clay fraction and their interaction

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Tingting Fan ◽  
Chengbao Li ◽  
Juan Gao ◽  
Dongmei Zhou ◽  
Marcelo Eduardo Alves ◽  
...  
Keyword(s):  
Clay Fraction ◽  
Soil Clay ◽  
Wien Effect

Surface charge on kaolinites in aqueous suspension

Soil Research ◽  
1976 ◽  
Vol 14 (2) ◽  
pp. 197 ◽  
Author(s):  
MDA Bolland ◽  
AM Posner ◽  
JP Quirk
Keyword(s):  
Surface Charge ◽  
Positive Charge ◽  
Aqueous Suspension ◽  
Isomorphous Substitution ◽  
Ph Values ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Decreasing Ph ◽  
Ph Range ◽  
Exchange Technique

The surface charge of several natural kaolinites was measured in the pH range 3-10 using an exchange technique. The positive charge was found to increase with decreasing pH and sometimes to increase with increasing ionic strength; it occurred on the kaolinites at pH values as high as 9 and 10 and was particularly evident at high ionic strengths. The positive surface charge on kaolinites is thought to be due to exposed alumina such as is found on oxide surfaces. Aluminium was found to dissolve from kaolinite at pH values beiow about 6.5. Aluminium dissolution increased with decreasing pH and time. When the proportion of dissolved aluminium ions balancing negative surface charge was taken into account, the negative and net negative surface charge on kaolinite was concluded to be largely due to pH independent charge resulting from isomorphous substitution, together with some pH dependent charge due to exposed SiOH sites. If Na+ was the index cation, dissolved aluminium ions from the clay replaced some of the Na+ balancing the negative surface charge. However, when Cs+ was the index cation, less Cs+ balancing the negative surface charge on the clay was replaced by dissolved aluminium. As the concentration of either Na+ or Cs+ was increased, less dissolved aluminium replaced the index cation as a counteraction to the negative surface charge.

A method to study the effect of chemical dissolution on the morphology of soil clay

Clay Minerals ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 315-318
Author(s):  
M. Hagiwara
Keyword(s):  
Electron Microscopy ◽  
Infrared Spectroscopy ◽  
Inorganic Material ◽  
Morphological Changes ◽  
The Other ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Chemical Dissolution ◽  
Soil Clays ◽  
Soil Clay

Soil clays contain a relatively large amount of disordered inorganic material. Chemical dissolution has been used for the removal of this material (Jackson, 1956; Hashimoto & Jackson, 1960; Follett et al, 1965 a,b; Wada & Greenland, 1970). On the other hand, Farmer et al. (1977) claimed that dissolution of allophane and imogolite with hot 5% Na2CO3 for periods of 2-100 h led to new phases which could be distinguished from the starting material by infrared spectroscopy. It is clear, therefore, that chemical dissolution can alter soil clays. This note suggests an electron microscopy specimen preparation technique to study the morphological changes. Collodion films containing densely arranged minute hollows are used for specimen supports.

The influence of organic matter extracted from humified clover on the properties of amorphous aluminosilicates. I. Surface charge

Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 327 ◽  
Author(s):  
KW Perrott
Keyword(s):  
Surface Charge ◽  
Negative Charge ◽  
Positive Charge ◽  
Degree Of Polymerization ◽  
Aqueous Extracts ◽  
Hydrous Oxides ◽  
Soil Clays ◽  
Charge Balancing ◽  
Inorganic Components ◽  
Allophanic Soil

A series of synthetic amorphous aluminosilicates, hydrous oxides and allophanic soil clays were treated with aqueous extracts of humified clover. The resulting changes in surface charge due to organic treatment were determined by comparing the charge characteristics of these organic treated samples and samples treated with a synthetic mixture of the inorganic components of the humified clover extract. Organic treatment caused a change of net surface charge to more negative values. The change in surface charge varied with the mole ratio Al/(Al+Si) of the aluminosilicate, being largest at low values of Al/(Al+Si). Where the aluminosilicates contain positive charges these are reduced by the organic treatment. This is a major contributor to the alteration of net surface charge in the more aluminous samples. The effect of organic treatment on the charge characteristics of allophanic soil clays was similar to that for the synthetic aluminosilicates of intermediate composition. The inorganic treatments also caused an increase in negative charge, and this is attributed to the neutralization of positive charge by the adsorption of phosphate and the removal of charge-balancing aluminium-hydroxy material. The effect of the organic and inorganic treatments on the positive and negative charge components of amorphous aluminosilicates is discussed in terms of the degree of polymerization of chargebalancing hydroxy-aluminium as envisaged in current models of the structure of amorphous aluminosilicates.

Mineralogical composition of the clay fraction of two fluvio-glacial sediments from east Greenland

Clay Minerals ◽  
1980 ◽  
Vol 15 (2) ◽  
pp. 135-145 ◽  
Author(s):  
L. Petersen ◽  
K. Rasmussen
Keyword(s):  
Clay Fraction ◽  
Mineralogical Composition ◽  
Cold Climate ◽  
High Rate ◽  
Degree Of Crystallinity ◽  
Metamorphic Rocks ◽  
Glacial Sediments ◽  
East Greenland ◽  
Soil Clays ◽  
High Degree

AbstractThe < 2 µm fractions of two fluvio-glacial sediments from East Greenland have been analysed chemically and by XRD and Mössbauer spectroscopy. The bulk of each < 2 µm fraction consists of feldspars and micas (biotite) which are important constituents of the Precambrian igneous and metamorphic rocks of the area. Significant amounts of vermiculitic and smectitic minerals are also present. Compared with similar minerals present in Danish soil clays, the Greenland vermiculite and smectite are characterized by a high degree of crystallinity and it is concluded that these minerals have been formed from biotite through K release and lattice expansion. These processes appear to have proceeded at a sufficiently high rate to yield significant amounts of vermiculite and smectite despite the cold climate prevailing in the area.

High-spacing irregularly interstratified layer-silicates in the alluvial soil clays of Meerut, India

Clay Minerals ◽  
1985 ◽  
Vol 20 (1) ◽  
pp. 115-124 ◽  
Author(s):  
K. P. Tomar
Keyword(s):  
Alluvial Soil ◽  
Clay Fraction ◽  
Alluvial Plain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Soil Clays ◽  
Ap Horizon ◽  
Fine Clay ◽  
Xrd Patterns

AbstractThe mineralogy of the fine clay fraction (<0·2 μm) of two soil pedons (Aquic and Udic Haplustalfs) representing the wheat-sugarcane belt of the Indo-Gangetic alluvial plain was studied by X-ray diffraction, differential thermal analysis, transmission electron microscopy, and by chemical analysis. The XRD patterns are characterized by unusually high spacings which are interpreted in terms of an interstratification comprising smectite, illite and ‘chlorite’ components. The CEC data (Ca/Mg and K/NH4) also indicate the possible presence of vermiculite. A plateau bridging the 7–10 Å maxima in K-saturated specimens heated at 300°C suggests interstratification of kaolinite and smectite, although this may not be part of the above interstratification. The diffuse bands shown by Mg-glycerol-solvated Ap-horizon clays at ∼21 Å, and the increasing elimination of XRD peaks in the > 10 Å region with distance from the surface, suggests that the expanding layers have a slight tendency to segregate in Ap horizon samples and that randomization tends to increase with depth. Discrete illite and small amounts of kaolinite were also detected.

Deflocculation of Alumina Suspensions Using Polyelectrolyte Dispersants

2007 ◽  
Vol 352 ◽  
pp. 81-84
Author(s):  
Yang Qiao Liu ◽  
Lian Gao
Keyword(s):  
Acrylic Acid ◽  
Zeta Potential ◽  
Synergistic Effect ◽  
Surface Charge ◽  
Functional Groups ◽  
Ph Value ◽  
Rheological Measurements ◽  
Gel Casting ◽  
Ph Range ◽  
Poly Acrylic Acid

In this paper, the dispersing abilities of three polyelectrolytes, poly (acrylic acid), poly (acrylic acid-co-acrylate), and a four-member copolymer containing various anionic functional groups were tested for aqueous Al2O3 suspensions. The influence of the dispersants on the surface charge of the powder was evaluated by measuring the zeta potential in dilute Al2O3 suspensions. It was found that all the three dispersants shifted the isoelectric point to a lower pH value. Rheological measurements showed that the four-member dispersant decreased the viscosity in the widest pH range, which should be ascribed to the synergistic effect of different functional groups. The 58vol% concentrated Al2O3 slurry using the four-member dispersant was further consolidated using gel casting and was fully sintered at 1600oC.

An analytical tool for understanding the properties and behaviour of variable charge soils

Soil Research ◽  
2007 ◽  
Vol 45 (2) ◽  
pp. 83 ◽  
Author(s):  
G. P. Gillman
Keyword(s):  
Surface Charge ◽  
Large Scale ◽  
Graphical Representation ◽  
Resource Assessment ◽  
Ideal Condition ◽  
Soil Resource ◽  
Variable Charge ◽  
Ph Range ◽  
Soil Resource Assessment ◽  
Insight Into

Routine analyses for soil cation exchange properties usually give only limited insight into the properties and management of soils containing significant amounts of variable charge. In this paper a procedure for determining a soil Charge Fingerprint is fully described, a model developed from simplified theory to underpin the methodology is discussed, and examples of the usefulness of the approach are given. Operationally defined cation and anion exchange capacities (CEC and AEC) are determined over an appropriate pH range (pH 4 to pH 6 is suggested) using Ca and Cl as the index cations. At low pH, Ca does not always fully saturate the CEC, so that it is necessary to distinguish a Basic CEC (Ca ads.) from the Total CEC (Ca + Al ads.). The graphical representation of CECT, CECB, and AEC v. pH constitutes the Charge Fingerprint. Though not intended as a routine instrument, its determination on key samples in a characterisation exercise places routinely determined basic and acidic cations in context. Examples are given of large scale characterisation studies that link soils from different continents having similar surface charge characteristics; of the assessment of the success or otherwise of producing permanent positive charge in synthetically prepared Ti-substituted goethites; and of the evaluation of the effect of adding crushed basic rock amendment on the surface charge properties of a variable charge soil. The formulation of a Depreciation Index, which classifies soils in terms of their departure in basic cation content from an arbitrarily defined ‘ideal’ condition, is suggested for use in soil resource assessment.

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