Modeling Sorbent Phase Nonideality for the Accurate Prediction of Multicomponent Ion Exchange Equilibrium with the Homogeneous Mass Action Law

2012 ◽  
Vol 57 (6) ◽  
pp. 1766-1778 ◽  
Author(s):  
José P. S. Aniceto ◽  
Patrícia F. Lito ◽  
Carlos M. Silva
Keyword(s):  
Ion Exchange ◽  
Accurate Prediction ◽  
Mass Action ◽  
Exchange Equilibrium ◽  
Sorbent Phase ◽  
Mass Action Law

Ion exchange equilibria of arsenic in the presence of high sulphate and nitrate concentrations

2005 ◽  
Vol 5 (5) ◽  
pp. 67-74 ◽  
Author(s):  
R. Baciocchi ◽  
A. Chiavola ◽  
R. Gavasci
Keyword(s):  
Ion Exchange ◽  
Equilibrium Constants ◽  
Exchange Process ◽  
Quantitative Description ◽  
Mass Action ◽  
Exchange Equilibrium ◽  
Resin Phase ◽  
Ion Exchange Process ◽  
Mass Action Law ◽  
Anionic Resin

The aim of this work was to develop a quantitative description of the ion exchange equilibria of arsenic on a strong anionic resin, in the presence of nitrates and sulphates. First, the ion exchange equilibrium data of As(V) and NO3− on a strong anionic resin in chloride form were obtained and described with a model based on the mass action law. Namely, assuming ideal behaviour for both solution and resin phase, the thermodynamic constant of the As(V)/Cl− and NO3−/Cl− ion exchange equilibria were estimated by fitting of experimental data. Then, these equilibrium constants were used to predict the ion exchange behaviour of the ternary system As(V)/NO3−/Cl−, providing a rather good agreement with experimental results. The ion exchange equilibria involving sulphate ions were also studied, showing a very high affinity to the resin phase. This behaviour did not allow a quantitative robust modelling of the equilibrium pattern. The results discussed in this paper represent a first step toward the development of a comprehensive modelling of the ion exchange process for the removal of As(V) from surface and groundwater in the presence of competitive, naturally occurring anions.

Application of the mass action law to describe ion exchange equilibrium in a fixed-bed column

2011 ◽  
Vol 172 (1) ◽  
pp. 312-320 ◽  
Author(s):  
C.E. Borba ◽  
E.A. Silva ◽  
S. Spohr ◽  
G.H.F. Santos ◽  
R. Guirardello
Keyword(s):  
Ion Exchange ◽  
Fixed Bed ◽  
Mass Action ◽  
Exchange Equilibrium ◽  
Fixed Bed Column ◽  
Mass Action Law

scholarly journals Prediction of ternary ion-exchange equilibrium using artificial neural networks and Law of Mass Action

2012 ◽  
Vol 34 (1) ◽  
Author(s):  
Rafael Luan Sehn Canevesi ◽  
Elizeu Avelino Zanella Junior ◽  
Rodrigo Augusto Barella ◽  
Tiago Dias Martins ◽  
Marcos Flávio Pinto Moreira ◽  
...  
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Ion Exchange ◽  
Mass Action ◽  
Exchange Equilibrium ◽  
Law Of Mass Action ◽  
Artificial Neural

scholarly journals Increasing the efficiency of rare earth metal recovery from technological solutions during processing of apatite raw materials

2021 ◽  
Vol 252 ◽  
pp. 1-10
Author(s):  
Maria Ponomareva ◽  
Olga Cheremisina ◽  
Yulia Mashukova ◽  
Elena Lukyantseva
Keyword(s):  
Rare Earth ◽  
Sulfuric Acid ◽  
Ion Exchange ◽  
Anion Exchanger ◽  
Raw Materials ◽  
Earth Metal ◽  
Mass Action ◽  
Exchange Equilibrium ◽  
Static Conditions ◽  
Sulfate Complexes

The issues of complex processing of mineral resources are relevant due to the depletion of available raw materials. So, it is necessary to involve technological waste, generated during the processing of raw materials, to obtain valuable components. In the process flow of apatite concentrate treatment using the sulfuric acid method, a large amount of phosphogypsum is produced with an average content of light rare earth metals (REMs) reaching 0.032-0.45 %. When phosphogypsum is treated with sulfuric acid solutions, a part of REMs is transferred to the sulfate solution, from which it can be extracted by means of ion exchange method. The study focuses on sorption recovery of light REMs (praseodymium, neodymium and samarium) in the form of anionic sulfate complexes of the composition [ln(SO4)2]– on polystyrene anion exchanger AN-31. The experiments were performed under static conditions at a liquid-to-solid ratio of 1:1, pH value of 2, temperature of 298 K and initial REM concentration in the solutions ranging from 0.83 to 226.31 mmol/kg. Thermodynamic description of sorption isotherms was carried out by the method based on linearization of the mass action equation, modified for the ion exchange reaction. As a result of performed calculations, the authors obtained the constants of ion exchange equilibrium for Pr, Nd and Sm, as well as the values of the change in the Gibbs energy for the ion exchange of REM sulfate complexes on the AN-31 anion exchanger and the values of total capacity of the anion exchanger. Calculated separation factors indicated low selectivity of AN-31 anionite exchanger for light REMs; however, the anion exchanger is suitable for effective recovery of a sum of light REMs. Based on the average value of ion exchange equilibrium constant for light REMs, parameters of a sorption unit with a fluidized bed of anion exchanger were estimated.

Ion exchange in felspathoids as a solid-state reaction

1956 ◽  
Vol 236 (1205) ◽  
pp. 227-249 ◽  
Keyword(s):  
Ion Exchange ◽  
Metal Ion ◽  
Mass Action ◽  
Simple Explanation ◽  
Exchange Diffusion ◽  
Membrane Hydrolysis ◽  
Mass Action Law ◽  
Temperature Variable ◽  
Observed Behaviour ◽  
End Members

A quantitative investigation has been made of ion-exchange diffusion and equilibria in the felspathoids, basic cancrinite ( M 2 O. Al 2 O 2 . 2.4SiO 2 . 0.6 M OH. x H 2 O), basic sodalite ( M 2 O. Al 2 O 3 . 2.5SiO 2 . 0.34 M OH. x H 2 O) and K and Rb analcite ( M 2 O. Al 2 O 3 . 4SiO 2 ). The isotherm contours were of three kinds: an ‘ideal’ form obeying the mass action law K = ( B c A s / A c B s ) (Na–Li, Na–K , Li–K and Na–Ag in basic sodalite); a sigmoid form obeying the equation log 10 K = log 10 ( B c A s / A c B s ) + C(1 — 2 B c ) where the constant C takes a negative value (Na–Li in basic cancrinite); and a form exhibiting hysteresis (Na–Ag and Li–Ag in basic cancrinite and K–Rb in analcite). The hysteresis was shown to be due to limited mutual solid solubility of the end-members of the exchange and to an associated difficulty in nucleating crystallites of one growing phase on or in a matrix of the other. This effect is most strikingly found in the Rb–K exchange in analcite, for which various scanning loops were traversed. A quantitative approach to the theory of the above types of exchange isotherm has been given, and applied to the present and to earlier results obtained with crystalline exchangers. This gives a possible theoretical basis of the equation log 10 K = log 10 ( B c A s / A c B s ) + C (1 — 2 B c ) and for Kielland’s equation log 10 f A c = CB 2 c . Examination of selectivity coefficients shows that the crystalline exchangers may possess very high selectivities towards one alkali metal ion as against another or for heavy metal ions such as Ag or Tl. These selectivities may change radically as one crystal is substituted for another. Ion sieve effects, partial or complete, were observed and can bring about a Donnan membrane hydrolysis of salts even of strong acids or bases, such as CsCl. Comparison has been made of the exchange diffusion coefficients evaluated in these laboratories for several kinds of crystal. A feature of exchanges where the temperature variable has been studied is the normally small temperature coefficient of the exchange equilibria and so a small value of the heat of exchange. A model has been proposed which regards the reactions as an interchange of ions between two inert dielectrics. This interpretation provides a simple explanation of the observed behaviour.

Studies on Activator Formation in Human Plasma with Streptokinase

1973 ◽  
Vol 30 (02) ◽  
pp. 381-392
Author(s):  
M Martin ◽  
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Mass Action ◽  
Activator Concentration ◽  
Kinetic Effect ◽  
Mass Action Law

SummaryThe plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation.The activator is probably a dissociated complex of the formulaStreptokinase + Plasminogen ⇄ Activator.The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.

Maize Stalk as Natural Ion Exchanger for Hazardous Pollutants

2017 ◽  
Vol 68 (8) ◽  
pp. 1726-1731
Author(s):  
Nicoleta Mirela Marin ◽  
Luoana Florentina Pascu ◽  
Ioana Stanculescu ◽  
Ovidiu Iordache ◽  
Denisa Jianu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Kinetic Models ◽  
High Selectivity ◽  
Ion Exchanger ◽  
Exchange Equilibrium ◽  
Waste Waters ◽  
Cationic Species ◽  
Hazardous Pollutants ◽  
Tailing Ponds

This paper recommends maize stalk as a cheap natural ion exchanger. Ion exchange equilibrium was studied using thermodynamic and kinetic models. The results showed a high selectivity towards cationic species of antimony (III), molybdenum (VI), lead (II) and arsenium (III). Waste waters and sediments from tailing ponds samples were analysed.

scholarly journals Transition states and entangled mass action law

2021 ◽  
Vol 22 ◽  
pp. 103922
Author(s):  
A.N. Gorban
Keyword(s):  
Transition States ◽  
Mass Action ◽  
Mass Action Law
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