scholarly journals Cesium adsorption/desorption behavior of clay minerals considering actual contamination conditions in Fukushima

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Hiroki Mukai ◽  
Atsushi Hirose ◽  
Satoko Motai ◽  
Ryosuke Kikuchi ◽  
Keitaro Tanoi ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Adsorption Desorption

scholarly journals Guidelines to Study the Adsorption of Pesticides onto Clay Minerals Aiming at a Straightforward Evaluation of Their Removal Performance

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1282
Author(s):  
Jorge Cesar Masini ◽  
Gilberto Abate
Keyword(s):  
Clay Minerals ◽  
Total Concentration ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Adsorption Parameters ◽  
Experimental Conditions ◽  
Inorganic Particles ◽  
Analytical Technique ◽  
Modified Clay ◽  
Adsorption Desorption

Natural and modified clay minerals have been extensively used for the adsorption/desorption of organic substances, especially pesticides, from waters and wastewater, aiming at pollution control and more efficient use of the herbicides through controlled release. While natural clay minerals efficiently remove organic cations such as paraquat and diquat, the adsorption of anionic or neutral species demands surface chemical modification with, for instance, quaternary ammonium salts containing long alkyl chains. Basic pesticides, on the other hand, are better absorbed in clay minerals modified with polycations. Kinetic studies and adsorption/desorption isotherms provide the parameters needed to evaluate the clay mineral’s adsorptive performance towards the pollutant target. However, the direct comparison of these parameters is complicated because the experimental conditions, the analytical techniques, the kinetic and isotherm models, and the numerical fitting method differ among the various studies. The free-energy-related Langmuir constant depends on the degree of site occupation; that is, it depends on the concentration window used to construct the adsorption isotherm and, consequently, on the analytical technique used to quantify the free concentrations. This paper reviews pesticides’ adsorption on natural and modified clay minerals and proposes guidelines for designing batch adsorption/desorption studies to obtain easily comparable and meaningful adsorption parameters. Articles should clearly describe the experimental conditions such as temperature, contact time, total concentration window, the solution to adsorbent ratio, the analytical technique, and its detection and quantification limits, besides the fitting models. Research should also evaluate the competitive effects of humic substances, colloidal inorganic particles, and ionic strength to emulate real-world adsorption experiments.

scholarly journals Adsorption of Uranium (VI) from Aqueous Solutions by Amino-functionalized Clay Minerals

2019 ◽  
Vol 3 (1) ◽  
pp. 41 ◽  
Author(s):  
Victoria Tobilko ◽  
Larysa Spasonova ◽  
Iryna Kovalchuk ◽  
Borys Kornilovych ◽  
Yurij Kholodko
Keyword(s):  
Thermal Analysis ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Clay Minerals ◽  
Powder Diffraction ◽  
Nitrogen Adsorption ◽  
Layer Silicate ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Adsorption Desorption

Silylation of clay minerals from Cherkasy deposit (Ukraine) montmorillonite (layer silicate) and palygorskite (fibrous silicate) was performed using organosilane (3-aminopropyl)triethoxysilane (APTES). Solvents with different polarity (ethanol, toluene) were used in synthesis. The structure of modified minerals was characterized by complex of methods (X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption at −196 °C and thermal analysis). Studies of adsorption characteristics of APTES-modified clay minerals were carried out in relation to uranium (VI). The results indicated that modified montmorillonite and palygorskite were effective materials for water purification from UO22+.

Adsorption/desorption of hydrocarbons on clay minerals

Chemosphere ◽  
1994 ◽  
Vol 28 (3) ◽  
pp. 627-638 ◽  
Author(s):  
Yuncong Li ◽  
Gian Gupta
Keyword(s):  
Clay Minerals ◽  
Adsorption Desorption

Adsorption–Desorption Behavior of Acrylic–Maleic Acid Copolymer at Clay Minerals

1997 ◽  
Vol 186 (2) ◽  
pp. 234-247 ◽  
Author(s):  
F. Blockhaus ◽  
J.-M. Séquaris ◽  
H.D. Narres ◽  
M.J. Schwuger
Keyword(s):  
Clay Minerals ◽  
Maleic Acid ◽  
Acid Copolymer ◽  
Adsorption Desorption ◽  
Maleic Acid Copolymer

Chitosan-smectite composite on the urea adsorption–desorption study for slow-release fertilizer application

2018 ◽  
Vol 15 (2) ◽  
pp. 292-297
Author(s):  
Is Fatimah ◽  
Dwiarso Rubiyanto ◽  
Septian Perwira Yudha ◽  
Gunarti Pratiwi ◽  
Ayu Puspita
Keyword(s):  
Clay Minerals ◽  
Slow Release ◽  
Water Solution ◽  
Physicochemical Characterization ◽  
Fertilizer Application ◽  
Chromatography Method ◽  
Content Type ◽  
Slow Release Fertilizer ◽  
Desorption Study ◽  
Adsorption Desorption

Purpose The purpose of this study is to prepare composite of chitosan-modified smectite clays consisting of montmorillonite and saponite clay minerals and their urea adsorption–desorption study. Prepared materials were designed for slow-release fertilizer application. Design/methodology/approach Preparation of the composites was conducted by a simple intercalation of chitosan solution and clay suspension followed by hydrogel beads formation. Physicochemical characterization of materials was performed by X-ray diffraction, gas sorption analysis by using Brunauer–Emmett–Teller surface areas and pore volume, water absorbency and Fourier transform-infrared. Urea adsorption and desorption studies of prepared materials were conducted by using batch method, and the adsorbed and desorbed urea content was analyzed by using high-performance liquid chromatography method. Findings The results revealed that the composites have higher absorptivity and lower absorptivity toward urea from and into water solution compared to raw clay minerals. Adsorption capacity and slow desorption rate of urea from the composites suggested the potential application of the composites as slow urea-releasing agent. Originality/value There are many papers that study the formation of chitosan-clay composites, but the study on the urea adsorption–desorption properties based on chitosan-smectite minerals have not been reported. Intensive study related to physicochemical properties and its related kinetics study is an important basic finding for further applications.

Effect of the modification of natural clay minerals with hexadecylpyridinium cation on the adsorption–desorption of fungicides

2004 ◽  
Vol 84 (1-3) ◽  
pp. 133-141 ◽  
Author(s):  
M. Soledad Andrades ◽  
M. Sonia Rodríguez-Cruz ◽  
M. Jesús Sánchez-Martín ◽  
Maria Sánchez-Camazano
Keyword(s):  
Clay Minerals ◽  
Natural Clay ◽  
Adsorption Desorption

Adsorption/Desorption of toluene on clay minerals

1994 ◽  
Vol 3 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Yuncong Li ◽  
Gian Gupta
Keyword(s):  
Clay Minerals ◽  
Adsorption Desorption

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

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