scholarly journals Kinetics of Sr2+ sorption on clinoptilolite-containing tuffs of different deposits from the surface drinking water

2018 ◽  
Vol 17 (6) ◽  
pp. 886-892
Author(s):  
Tatyana G. Kuzmina ◽  
Valentina A. Nikashina ◽  
Nadezhda Lichareva ◽  
Irina N. Gromjak ◽  
Inna B. Serova ◽  
...  
Keyword(s):  
Drinking Water ◽  
Ion Exchange ◽  
Exchange Process ◽  
Linear Part ◽  
Distribution Coefficients ◽  
Permeable Reactive Barrier ◽  
Particle Diffusion ◽  
Sorption Dynamic ◽  
Dynamic Conditions ◽  
Ion Exchange Process

Previously Sr2+ion-exchange isotherms were obtained from the surface drinking water and the corresponding Sr2+ distribution coefficients (Kd) were calculated for linear part of the isotherms of the studied CLT. The comparative kinetic data of Sr2+ ion-exchange sorption on NH4+- forms of the clinoptilolite-containing tuffs from deposits of Russia and Bulgaria on the sample of the surface drinking water was investigated in detail with the known method of the "thin layer". It was shown, that the kinetic process of the Sr-sorption on the clinoptilolite- containing tuffs is characterized with the features and includes 3 stages. The first stage is described with the particle diffusion law, the second stage –a slowing down, the ion-exchange process reaches a plateau, then an increase of Sr2+ sorption is observed again. The particle diffusion coefficients of Sr2+ describing the first stage of the sorption process on CLT of different deposits were calculated. The obtained data are the initial one for the development of a mathematical model of the dynamic ion-exchange process on NH4+-form of the clinoptilolite- containing tuffs from the surface drinking waters, that makes possible to generate the computer program and thereupon to calculate the break-through curves of Sr2+ sorption on NH4+- clinoptilolite- containing tuffs for the different dynamic conditions, including the sorption dynamic conditions on the permeable reactive barrier

Determination of the adsorption mechanism of imidazolium-type ionic liquids onto kaolinite: implications for their fate and transport in the soil environment

2008 ◽  
Vol 5 (4) ◽  
pp. 299 ◽  
Author(s):  
Wojciech Mrozik ◽  
Christian Jungnickel ◽  
Michał Skup ◽  
Piotr Urbaszek ◽  
Piotr Stepnowski
Keyword(s):  
Ionic Liquids ◽  
Ion Exchange ◽  
Adsorption Mechanism ◽  
Exchange Process ◽  
Sorption Process ◽  
Distribution Coefficients ◽  
Van Der Waals Interactions ◽  
Kaolinite Clay ◽  
Chain Molecules ◽  
Ion Exchange Process

Environmental context. The present paper looks at the possible spreading of a new class of chemicals, namely, ionic liquids in soils. These ionic liquids have gained increasing attention, and their environmental impact and fate needs to be determined before accidental release. The paper specifically focusses on the adhesion mechanisms of these chemicals onto a type of clay, kaolinite. It was found that a multilayer adhesion mechanism occurs. Sorption of ionic liquids on kaolinite indicates that these chemicals can modify the clay surfaces, which may lead to changes in its natural geochemical cycles. Abstract. In the present study, the mechanism of sorption of ionic liquids onto kaolinite clay mineral has been investigated in detail. Results obtained indicate a multilayer type of adsorption. At final saturations, the highest distribution coefficients were found for the long alkyl chain molecules. The mean free energy values obtained are below values of a typical ion-exchange process, which thus suggests that the adsorption mechanism is a combination of electrostatic interaction and physical sorption. At the beginning of the binding process (formation of a monolayer), ion-exchange and van der Waals interactions are predominantly responsible for the process, whereas at higher concentrations of ionic liquids, dispersive interactions become dominant. Thermodynamic parameters were also calculated from graphical interpretation of experimental data. Negative values of ΔG indicate a spontaneous sorption process for ionic liquids. Standard heats of adsorption were found to be exothermic and entropy contributions were negative in all cases studied.

SIX®: A New Resin Treatment Technology for Drinking Water

2009 ◽  
Vol 4 (4) ◽  
Author(s):  
Gilbert Galjaard ◽  
Peer C. Kamp ◽  
Erik Koreman
Keyword(s):  
Drinking Water ◽  
Ion Exchange ◽  
Large Scale ◽  
Exchange Process ◽  
Polymeric Materials ◽  
Treatment Technology ◽  
Ion Exchange Process ◽  
New Process ◽  
History Of ◽  
Research Facilities

The history of ion exchange is marked by many important milestones, notably the development of novel polymeric materials and considerable advances in our understanding of the underlying fundamental principles. Separately, there have been major advances in the design and development of the apparatus and equipment required to perform industrial ion exchange and also for large scale applications in the production of drinking water, like the MIEX® process from Orica. This paper reviews the progress that has been made during the last three years within the research facilities of PWN which have resulted in a new ion exchange process for the direct treatment of water containing high amounts of suspended matter such as surface waters. This new process has been called SIX® and will most likely be operational at a flow of 4000 m3/h by 2012.

Removal of Toxic Dyestuffs from Aqueous Solution by Amphoteric Bioadsorbent

2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Dye Removal ◽  
Exchange Process ◽  
Cationic Dyes ◽  
Carboxyl Groups ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Isotherm ◽  
Ion Exchange Process ◽  
Dyes And Pigments

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.

Chromate ion-exchange process at alkaline pH

1986 ◽  
Vol 20 (9) ◽  
pp. 1177-1184 ◽  
Author(s):  
Arup K. Sengupta ◽  
Dennis Clifford ◽  
Suresh Subramonian
Keyword(s):  
Ion Exchange ◽  
Exchange Process ◽  
Alkaline Ph ◽  
Ion Exchange Process ◽  
Chromate Ion

The Application of ß“-Alumina As A Solid State Laser Host

1985 ◽  
Vol 60 ◽  
Author(s):  
J. D. Barrie ◽  
D. L. Yang ◽  
B. Dunn ◽  
O. M. Stafsudd
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Ion Exchange ◽  
Exchange Process ◽  
Laser Action ◽  
Solid State Laser ◽  
Host Crystal ◽  
State Laser ◽  
Ion Exchange Process ◽  
Single Host

AbstractIon exchanged ß“-aluminas display a number of interesting optical properties which suggest that the material is well suited for application as a solid state laser host. Small platelets of Nd3+ Ion exchanged β“-alumina exhibit laser action with gain coefficients many times greater than YAG. The versatility of the ion exchange process enables one to form a wide variety of compounds with different active ions and concentrations, thereby allowing the study of many different effects within a single host crystal.

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