The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method

Studies on changes of unfrozen water content in calcium bentonite from Slovakia, with various concentrations of copper ions, were carried out using the method of differential scanning calorimetry (DSC). In this study, the influence of molar concentration of copper(II) chloride solution (1 M, 0.5 M,...

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Main Authors: Edyta Nartowska, Tomasz Kozłowski
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Minerals
Subjects:
Online Access:https://www.mdpi.com/2075-163X/12/5/632
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author Edyta Nartowska
Tomasz Kozłowski
author_facet Edyta Nartowska
Tomasz Kozłowski
author_sort Edyta Nartowska
collection DOAJ
description Studies on changes of unfrozen water content in calcium bentonite from Slovakia, with various concentrations of copper ions, were carried out using the method of differential scanning calorimetry (DSC). In this study, the influence of molar concentration of copper(II) chloride solution (1 M, 0.5 M, 0.25 M, 0.1 M), used to saturate clay, was analyzed, as well as the impact of copper ions contained in bentonite and how the copper concentration affects to changes of unfrozen water content versus temperature. The results suggest that new mineral phases originate in bentonite saturated with highly concentrated solutions due to the reaction with copper(II) chloride solutions. These minerals, identified based on XRD and SEM-EDS (X-ray Diffraction and Scanning Electron Microscopy with Energy Dispersive Spectroscopy) studies, are from the atacamite group. ANOVA (Analysis of Variance) has shown a statistically significant relationship between the unfrozen water content and the molar concentration of the solution used to saturate bentonite and between the unfrozen water content and the content of copper ions in the bentonite. The analysis of multiple regression has shown that the change of unfrozen water content in copper bentonites is related to the temperature change, specific surface, and the concentration of copper ions in the clay. An empirical equation was developed to estimate the content of unfrozen water at a given negative temperature in Cu-bentonites, in which the specific surface and copper ions concentration in the bentonite are the main parameters.
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spelling doaj.art-e0c364b87cf14f4fad6dd2eacee8f3942023-11-23T12:19:44ZengMDPI AGMinerals2075-163X2022-05-0112563210.3390/min12050632The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC MethodEdyta Nartowska0Tomasz Kozłowski1Department of Geotechnical and Water Engineering, Kielce University of Technology, 25-314 Kielce, PolandDepartment of Geotechnical and Water Engineering, Kielce University of Technology, 25-314 Kielce, PolandStudies on changes of unfrozen water content in calcium bentonite from Slovakia, with various concentrations of copper ions, were carried out using the method of differential scanning calorimetry (DSC). In this study, the influence of molar concentration of copper(II) chloride solution (1 M, 0.5 M, 0.25 M, 0.1 M), used to saturate clay, was analyzed, as well as the impact of copper ions contained in bentonite and how the copper concentration affects to changes of unfrozen water content versus temperature. The results suggest that new mineral phases originate in bentonite saturated with highly concentrated solutions due to the reaction with copper(II) chloride solutions. These minerals, identified based on XRD and SEM-EDS (X-ray Diffraction and Scanning Electron Microscopy with Energy Dispersive Spectroscopy) studies, are from the atacamite group. ANOVA (Analysis of Variance) has shown a statistically significant relationship between the unfrozen water content and the molar concentration of the solution used to saturate bentonite and between the unfrozen water content and the content of copper ions in the bentonite. The analysis of multiple regression has shown that the change of unfrozen water content in copper bentonites is related to the temperature change, specific surface, and the concentration of copper ions in the clay. An empirical equation was developed to estimate the content of unfrozen water at a given negative temperature in Cu-bentonites, in which the specific surface and copper ions concentration in the bentonite are the main parameters.https://www.mdpi.com/2075-163X/12/5/632copper concentrationmolar concentrationclay mineralsunfrozen waterDSCspecific surface area
spellingShingle Edyta Nartowska
Tomasz Kozłowski
The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method
Minerals
copper concentration
molar concentration
clay minerals
unfrozen water
DSC
specific surface area
title The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method
title_full The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method
title_fullStr The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method
title_full_unstemmed The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method
title_short The Effect of the Concentration of Copper Ions on the Unfrozen Water Content in Bentonites Measured with the Use of DSC Method
title_sort effect of the concentration of copper ions on the unfrozen water content in bentonites measured with the use of dsc method
topic copper concentration
molar concentration
clay minerals
unfrozen water
DSC
specific surface area
url https://www.mdpi.com/2075-163X/12/5/632
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