Concentration-Dependent Diffusion Coefficients and Sorption Isotherms. Application to Ion Exchange Processes As an Example

1996 ◽  
Vol 100 (30) ◽  
pp. 12569-12573 ◽  
Author(s):  
N. F. E. I. Nestle ◽  
R. Kimmich
Keyword(s):  
Ion Exchange ◽  
Diffusion Coefficients ◽  
Sorption Isotherms ◽  
Exchange Processes

scholarly journals Theoretical Modelling of Ion Exchange Processes in Glass: Advances and Challenges

2021 ◽  
Vol 11 (11) ◽  
pp. 5070
Author(s):  
Xesús Prieto-Blanco ◽  
Carlos Montero-Orille
Keyword(s):  
Ion Exchange ◽  
Diffusion Coefficients ◽  
Molten Salts ◽  
Theoretical Modelling ◽  
Copper Films ◽  
Theoretical Frameworks ◽  
Self Diffusion ◽  
Exchange Processes ◽  
The One ◽  
Made In

In the last few years, some advances have been made in the theoretical modelling of ion exchange processes in glass. On the one hand, the equations that describe the evolution of the cation concentration were rewritten in a more rigorous manner. This was made into two theoretical frameworks. In the first one, the self-diffusion coefficients were assumed to be constant, whereas, in the second one, a more realistic cation behaviour was considered by taking into account the so-called mixed ion effect. Along with these equations, the boundary conditions for the usual ion exchange processes from molten salts, silver and copper films and metallic cathodes were accordingly established. On the other hand, the modelling of some ion exchange processes that have attracted a great deal of attention in recent years, including glass poling, electro-diffusion of multivalent metals and the formation/dissolution of silver nanoparticles, has been addressed. In such processes, the usual approximations that are made in ion exchange modelling are not always valid. An overview of the progress made and the remaining challenges in the modelling of these unique processes is provided at the end of this review.

scholarly journals Contribution of Ion-Exchange and Non-Ion-Exchange Reactions to Sorption of Ammonium Ions by Natural and Activated Aluminosilicate Sorbent

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Larisa Belchinskaya ◽  
Lyudmila Novikova ◽  
Vladimir Khokhlov ◽  
Jen Ly Tkhi
Keyword(s):  
Ion Exchange ◽  
Adsorption Capacity ◽  
Sorption Isotherms ◽  
Exchange Reactions ◽  
Ammonium Ions ◽  
Alkaline Activation ◽  
Exchange Processes ◽  
Natural Aluminosilicate ◽  
Silica Alumina ◽  
Alkali Activated

The effect of acid and alkaline activation of complex natural aluminosilicate sorbent on its chemical composition, surface properties, and adsorption capacity towards ammonium ions was studied. An increase in specific surface area of the sorbent by 1.3 times after acid treatment and by 1.5 times after alkaline activation was shown. The change of ion-exchange complex of sorbent as a result of activation was observed. Sorption isotherms of ammonium ions on natural and activated samples were obtained and were satisfactorily described by the Langmuir equation. The evaluation and comparison of desorbed cations of alkali and alkaline earth metals were carried out. It was confirmed that ion-exchange processes primarily contributed to sorption of ammonium ions by natural and acid-activated silica-alumina, in contrast to alkali-activated one, for which absorption of nonexchangeable ammonium ions increased adsorption capacity of ammonium ions by 1.5 times.

Advancement in Ion Exchange Processes for Municipal Wastewater Nutrient Recovery

2013 ◽  
Vol 2013 (7) ◽  
pp. 6474-6485 ◽  
Author(s):  
Allen T. Williams ◽  
Brooke K. Mayer
Keyword(s):  
Ion Exchange ◽  
Municipal Wastewater ◽  
Nutrient Recovery ◽  
Exchange Processes

Ion exchange processes in aqueous-organic media

1969 ◽  
Vol 41 (14) ◽  
pp. 2047-2050 ◽  
Author(s):  
J. L. Pauley ◽  
D. D. Vietti ◽  
C. C. Ou-Yang ◽  
D. A. Wood ◽  
R. D. Sherrill
Keyword(s):  
Ion Exchange ◽  
Organic Media ◽  
Exchange Processes

A novel utilisation of principal component analysis to optimise sorption isotherms and determine diffusion coefficients of five naphthalimide disperse dyes on polyester fibres

2013 ◽  
Vol 92 (3) ◽  
pp. 553-562 ◽  
Author(s):  
Seyamack Jafari ◽  
Alireza Khosravi ◽  
Kamaladin Gharanjig ◽  
Siamak Moradian ◽  
Saeed Pourmahdian
Keyword(s):  
Principal Component Analysis ◽  
Diffusion Coefficients ◽  
Sorption Isotherms ◽  
Principal Component ◽  
Component Analysis ◽  
Disperse Dyes

Ion-exchange processes

1991 ◽  
Vol 10 (1) ◽  
pp. 7-8
Author(s):  
A. Dyer
Keyword(s):  
Ion Exchange ◽  
Exchange Processes

scholarly journals Chemical composition of groundwaters in the Hornsund region, southern Spitsbergen

2012 ◽  
Vol 44 (1) ◽  
pp. 117-130 ◽  
Author(s):  
Tomasz Olichwer ◽  
Robert Tarka ◽  
Magdalena Modelska
Keyword(s):  
Chemical Composition ◽  
Ion Exchange ◽  
Shallow Groundwater ◽  
Mineralogical Composition ◽  
Deep Groundwater ◽  
Exchange Processes ◽  
Groundwater Circulation ◽  
Initial Chemical Composition ◽  
The University ◽  
Intermediate System

Chemical composition of groundwaters was investigated in the region of the Hornsund fjord (southern Spitsbergen). The investigations were conducted during polar expeditions organized by the University of Wroclaw in two summer seasons of 2003 and 2006. Three zones of groundwater circulation: suprapermafrost, intrapermafrost and subpermafrost, were identified in areas of perennial permafrost in the region of Hornsund. The zone of shallow circulation occurs in non-glaciated (suprapermafrost) and subglacial areas. In this zone, the chemical composition of groundwater originates from initial chemical composition of precipitation, mineralogical composition of bedrock, oxidation of sulphides and dissolution of carbonates. The intermediate system of circulation is connected with water flow inside and below perennial permafrost (intrapermafrost and subpermafrost). In this zone, the chemical composition of groundwater is mainly controlled by dissolution of carbonates, ion exchange processes involving Ca2+ substitution by Na+, and oxidation of sulphides under oxygen-depleted conditions. The subpermafrost zone (deep groundwater circulation) occurs in deep-tectonic fractures, which are likely conduits for the descent of shallow groundwater to deeper depths. In this zone, the groundwater shows lower mineralization comparing to intrapermafrost zone and has a multi-ion nature Cl–HCO3–Na-Ca–Mg.

Water as an Eluting Agent for Ion-Exchange Processes

2018 ◽  
pp. 93-98
Author(s):  
C. Calmon
Keyword(s):  
Ion Exchange ◽  
Exchange Processes
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