Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests

In the treatment of industrial polluted sites and the construction of landfill sites, anti-pollution barriers are usually used to prevent the diffusion of pollutants. In this paper, the adsorption characteristics of Zn ions by the rock-bentonite anti-pollution barrier were observed by means of stati...

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Main Authors: Sifa Xu, Yajun Fu, Weiwei Wei, Cuifeng Li, Mengdan Bian, Zhe Wang
Format: Article
Language:English
Published: MDPI AG 2021-04-01
Series:Processes
Subjects:
Online Access:https://www.mdpi.com/2227-9717/9/4/619
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spelling doaj-3f15e21d646d4e55a1a69793f4acf1ea2021-04-01T23:05:59ZengMDPI AGProcesses2227-97172021-04-01961961910.3390/pr9040619Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic TestsSifa Xu0Yajun Fu1Weiwei Wei2Cuifeng Li3Mengdan Bian4Zhe Wang5Institute of Geotechnical Engineering, Zhejiang University of Technology, Hangzhou 310023, ChinaInstitute of Geotechnical Engineering, Zhejiang University of Technology, Hangzhou 310023, ChinaZhongtian Construction Group Co., LTD., Dongyang 322100, ChinaState Grid Ningbo Power Supply Company, Ningbo 315000, ChinaLibrary, Zhejiang University of Technology, Hangzhou 310014, ChinaInstitute of Geotechnical Engineering, Zhejiang University of Technology, Hangzhou 310023, ChinaIn the treatment of industrial polluted sites and the construction of landfill sites, anti-pollution barriers are usually used to prevent the diffusion of pollutants. In this paper, the adsorption characteristics of Zn ions by the rock-bentonite anti-pollution barrier were observed by means of static equilibrium and dynamic adsorption tests. The experimental results showed that the adsorption of Zn by stone chips—bentonite was close to the nonlinear Freundlich and Langmuir models. When the concentration of Zn ion is constant, the adsorption capacity increases with the increase in temperature. At a certain temperature, the adsorption removal rate decreases with the increase in concentration. Further study found that the adsorption of Zn from mixed soil was mainly an ion exchange process, and the adsorption mode of Zn from mixed soil was controlled by both intra-particle diffusion and membrane diffusion. Zeta potential, X-ray diffraction (XRD) and The Fourier Transform Infrared spectroscopy (FTIR) showed that with the increase in concentration, the mixed soil adsorbed more metal ions, and the thickness of the double electric layer decreased. Moreover, the adsorption of Zn<sup>2+</sup> by bentonite was mainly interlayer adsorption and ion exchange. As an anti-pollution barrier material, the mixed soil of stone chips -bentonite can prevent the diffusion of pollutants, which has certain reference significance for engineering construction.https://www.mdpi.com/2227-9717/9/4/619stone-bentoniteheavy metal of Znequilibrium isothermal adsorptiondynamic isothermal adsorptionzeta potential
collection DOAJ
language English
format Article
sources DOAJ
author Sifa Xu
Yajun Fu
Weiwei Wei
Cuifeng Li
Mengdan Bian
Zhe Wang
spellingShingle Sifa Xu
Yajun Fu
Weiwei Wei
Cuifeng Li
Mengdan Bian
Zhe Wang
Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests
Processes
stone-bentonite
heavy metal of Zn
equilibrium isothermal adsorption
dynamic isothermal adsorption
zeta potential
author_facet Sifa Xu
Yajun Fu
Weiwei Wei
Cuifeng Li
Mengdan Bian
Zhe Wang
author_sort Sifa Xu
title Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests
title_short Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests
title_full Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests
title_fullStr Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests
title_full_unstemmed Adsorption Characteristics of Stone-Bentonite Mixtures towards Zn: Equilibrium and Kinetic Tests
title_sort adsorption characteristics of stone-bentonite mixtures towards zn: equilibrium and kinetic tests
publisher MDPI AG
series Processes
issn 2227-9717
publishDate 2021-04-01
description In the treatment of industrial polluted sites and the construction of landfill sites, anti-pollution barriers are usually used to prevent the diffusion of pollutants. In this paper, the adsorption characteristics of Zn ions by the rock-bentonite anti-pollution barrier were observed by means of static equilibrium and dynamic adsorption tests. The experimental results showed that the adsorption of Zn by stone chips—bentonite was close to the nonlinear Freundlich and Langmuir models. When the concentration of Zn ion is constant, the adsorption capacity increases with the increase in temperature. At a certain temperature, the adsorption removal rate decreases with the increase in concentration. Further study found that the adsorption of Zn from mixed soil was mainly an ion exchange process, and the adsorption mode of Zn from mixed soil was controlled by both intra-particle diffusion and membrane diffusion. Zeta potential, X-ray diffraction (XRD) and The Fourier Transform Infrared spectroscopy (FTIR) showed that with the increase in concentration, the mixed soil adsorbed more metal ions, and the thickness of the double electric layer decreased. Moreover, the adsorption of Zn<sup>2+</sup> by bentonite was mainly interlayer adsorption and ion exchange. As an anti-pollution barrier material, the mixed soil of stone chips -bentonite can prevent the diffusion of pollutants, which has certain reference significance for engineering construction.
topic stone-bentonite
heavy metal of Zn
equilibrium isothermal adsorption
dynamic isothermal adsorption
zeta potential
url https://www.mdpi.com/2227-9717/9/4/619
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AT yajunfu adsorptioncharacteristicsofstonebentonitemixturestowardsznequilibriumandkinetictests
AT weiweiwei adsorptioncharacteristicsofstonebentonitemixturestowardsznequilibriumandkinetictests
AT cuifengli adsorptioncharacteristicsofstonebentonitemixturestowardsznequilibriumandkinetictests
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AT zhewang adsorptioncharacteristicsofstonebentonitemixturestowardsznequilibriumandkinetictests
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