The solubility of potassium from soil illites. II. Mechanisms of potassium release

Soil Research ◽  
1964 ◽  
Vol 2 (1) ◽  
pp. 67 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Clay Minerals ◽  
Silicic Acid ◽  
Calcium Ions ◽  
Hydrogen Ion ◽  
Displacement Reaction ◽  
Potassium Release ◽  
Ph Values ◽  
Soil Clays ◽  
Mineral Structure

The release of potassium from four soil clays containing illites of different degrees of degradation was found to be independent of the solution of silicic acid or aluminium from the clay minerals. The lattice potassium is released into solution by a displacement reaction. The displacement of potassium by calcium ions is dependent on the prior release of one lattice potassium by one hydrogen ion, presumably because the entry of the hydrogen ion makes the potassium at neighbouring sites in the lattice accessible to other cations. The reaction may be written as 7Ks+ + H+ + 3Ca2+ 7K+ + 3CaS2+, where the subscript S refers to the solid (clay) phase. At pH values above pH 11, potassium is released by breakdown of the mineral structure by the action of hydroxyl ions.

The solubility of potassium from soil illites. I. The dependence of solubility on pH.

Soil Research ◽  
1964 ◽  
Vol 2 (1) ◽  
pp. 56 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Clay Mineral ◽  
Hydrogen Ions ◽  
Equilibrium Solubility ◽  
Clay Particles ◽  
Potassium Release ◽  
Ph Values ◽  
Minimum Value ◽  
Soil Clays ◽  
Mineral Structure

The equilibrium solubility of potassium from the lattice of illites in four soil clays has been measured. This solubility is related to the availability of this potassium and, when account is taken of the fineness of the clay particles, it is found to decrease as the illite structure becomes more degraded by loss of lattice potassium. The solubility depends on the pH of the system in the same way for all the clays, and a minimum value is found near to pH 11. Above this pH, potassium release is due to breakdown of the clay mineral. At lower pH values the release is due either to the instability of the clay mineral structure towards hydrogen ions or to displacement of potassium by other cations acting together with hydrogen ions.

The solubility of potassium from soil illites. IV. Rates of reaction and exchange constants

Soil Research ◽  
1967 ◽  
Vol 5 (2) ◽  
pp. 191 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Response Time ◽  
Clay Minerals ◽  
Calcium Ions ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Continuous Change ◽  
Exchangeable Potassium ◽  
Electrode Response ◽  
Soil Clays ◽  
Exchange Constants

Potassium-sensitive cationic electrodes have been used to study the rates of release of potassium from five illitic soil clays. This release was complete within a few minutes for clay-size particles and was probably controlled by diffusion. The electrode response time of 15 sec to 0.001 pK unit was too slow to permit accurate measurement of the rate of release, as the process was more than 90% complete in this time. As expected, the chemical reaction was too fast to be measured independently of diffusion. The electrodes were also used to calculate stepwise changes in Gapon constants as potassium (or sodium) was adsorbed by the clay in competition with calcium ions. The Gapon constants for potassium decreased greatly as potassium was adsorbed, but did not reach the low values expected for external exchange sites until comparatively large amounts of potassium were taken up. Potassium ions were held much more tightly thm sodium ions until the external sites began to be filled. The continuous change of Gapon constant with potassium content precluded a sharp distinction between interlayer and external exchangeable potassium. Values of the constants corresponding to the equilibrium solubilities measured in earlier work showed that the clays had a strong preference for potassium over calcium at the potassium contents in these clay preparations, and this showed that the solubility equilibria refer to potassium in the interlayer regions of the clay minerals.

Study on Influence of Silicate Morphology Based on pH Value

2012 ◽  
Vol 454 ◽  
pp. 324-328
Author(s):  
Yan He ◽  
Ya Jing Liu ◽  
Yong Lin Cao ◽  
Li Xia Zhou
Keyword(s):  
Silicic Acid ◽  
Ph Value ◽  
Colorimetric Method ◽  
Absorption Spectrometry ◽  
Degree Of Polymerization ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
The Stability

Infra-red absorption spectrometry, X-ray diffraction observations and characterization tests based on silicon molybdenum colorimetric method were used to investigate the optimal pH value controlling the stability of the silicic acid form. The experiment process was done by using sodium silicate as raw material. The results showed that the solution of silicate influenced the polymerization. The active silicic acid solution with a certain degree of polymerization was obtained by controlling the pH values.

Adsorption of Organic Compounds on Refined Latvian Clay

2018 ◽  
Vol 788 ◽  
pp. 83-88
Author(s):  
Oskars Leščinskis ◽  
Ruta Švinka ◽  
Visvaldis Švinka
Keyword(s):  
Methyl Orange ◽  
Zeta Potential ◽  
Adsorption Capacity ◽  
Clay Minerals ◽  
Organic Compounds ◽  
Clay Mineral ◽  
Rhodamine B ◽  
Ph Value ◽  
Ftir Spectra ◽  
Ph Values

Clays are materials consisting of clay minerals and non-clay minerals. Clay mineral fraction is considered to be a nanofraction. Clay minerals can be used for water purification and treatment. Description and characterization of 3 different Latvian clay nanosized minerals from 3 different geological periods (clay Liepa from Devonian period, clay Vadakste from Triassic period and clay Apriki from Quaternary period) as well as their adsorption capacity concerning organic compounds such as methyl orange and rhodamine B are summarized. Nanosized clay mineral particles were obtained using sedimentation method. Particle size distribution, zeta potential and FTIR spectra is given. The adsorption tests of above mentioned organic compounds were carried out in water solutions at 3 different pH values. The adsorption values were determined by means of UV-spectrophotometric technique. Zeta potential values for clay minerals Apriki, Liepa and Vadakste are -40.9 mV, -49.6 mV and -43.0 mV, respectively. FTIR spectra show similar tendencies for all 3 clay minerals. The best adsorption capacity concerning methyl orange and rhodamine B were in solutions with a pH value of 2, whereas at neutral and alkaline pH values adsorption in 24 hours was not observed.

scholarly journals Vermiculture as a biotechnological method of recultivation of disturbed lands in the post-mining system

2021 ◽  
Vol 315 ◽  
pp. 02008
Author(s):  
Andrei Babenko ◽  
Dmitrij Bezrukov ◽  
Saulet Karimova ◽  
Akmaral Mametova ◽  
Ludmila Zakonnova
Keyword(s):  
Leaf Litter ◽  
Calcium Ions ◽  
Tap Water ◽  
Mining System ◽  
Mining Areas ◽  
Ph Values ◽  
Disturbed Areas ◽  
Agrochemical Properties ◽  
Plant Waste ◽  
Poplar Leaf

The article shows the prospects of using the technology of vermicomposting for the biological re-cultivation of disturbed mining areas. The valuable properties of vermicompost as a component of soil-substituting mixtures for use in the re-cultivation of disturbed areas are considered. The expediency of using plant waste for the preparation of soil-substituting substrates is shown. The presence of special agrochemical properties of vermicompost obtained during the processing of plant waste (leaf litter) by the Eisenia fetida Savigny culture is experimentally established. The pH values and the content of calcium ions in the vermicompost based on poplar leaf litter were significantly higher than in the vermicompost based on horse manure – 7.61 vs. 6.98 and 112.3 vs. 83 mg-eq. / kg, respectively. Germination of wheat seeds on extracts from vermicompost obtained from poplar litter led to a statistically significant increase in the mass of the formed roots compared to seeds germinated on tap water.

THE ELECTRODE POTENTIAL OF IRON IN RELATION TO HYDROGEN ION CONCENTRATION

1936 ◽  
Vol 14b (1) ◽  
pp. 31-40 ◽  
Author(s):  
J. W. Shipley ◽  
J. H. Shipley
Keyword(s):  
Electrode Potential ◽  
Chloride Ion ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Iron Electrode ◽  
General Corrosion ◽  
Citrate Buffer ◽  
Hydrogen Ion Concentration ◽  
Electrically Conducting ◽  
Ph Values

The electrode potential of iron immersed in phosphate, borate and citrate buffers of varying hydrogen ion concentration was measured, using a normal calomel electrode as the second half of the cell. Breaks in the potential of the iron electrode amounting to as much as 0.7 volts were found to occur at definite pH values for each series of buffers. The electrode exhibited an "initial" and "final" potential depending on the pH of the electrolyte and the time of immersion, the "final" value requiring several days to become established. The "final" break in the electrode potential of 0.74 volts in the pure phosphate buffer occurred between a pH of 3.1 and 4.0, that in the pure borate buffer, of 0.75 volts, occurred between a pH of 4.3 and 4.6, and in the pure citrate buffer, of 0.77 volts, between a pH of 10.1 and 10.9. The effect of chloride ion and de-aeration on the electrode potential was observed. It is suggested that the potential of the iron electrode is determined by the presence or absence of a non electrically conducting film or deposit on the iron, the formation of which is a function of the nature of the electrolyte and its hydrogen ion concentration. De-aeration apparently had no effect on the electrode potential, but the presence of chloride ion affected the establishing of the "final" potential and caused the break in voltage to appear irregularly at a much lower hydrogen ion concentration.At pH values below that at which the break in potential occurred, corrosion of the iron electrode was marked, and the electrode potential remained high, while, at pH values above the break, corrosion was virtually inhibited or confined to local spots on the electrode, and the electrode potential remained low. The presence of the chloride ion stimulated local corrosion and permitted general corrosion to proceed at a lower hydrogen ion concentration.

Studies on Silicic Acid Gels. IV. The Effect of the Hydrogen-ion Concentration upon the Time of Set.

1934 ◽  
Vol 38 (5) ◽  
pp. 663-674 ◽  
Author(s):  
Charles B. Hurd ◽  
C. Lawrence Raymond ◽  
P. Schuyler Miller
Keyword(s):  
Silicic Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration
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