Nickel-Barium Exchange Selectivity Coefficients for Montmorillonite

1966 ◽  
Vol 30 (6) ◽  
pp. 804-805 ◽  
Author(s):  
G. W. McLean ◽  
P. F. Pratt ◽  
A. L. Page
Keyword(s):  
Selectivity Coefficients ◽  
Exchange Selectivity

Anion recovery from water by cross-linked cationic surfactant nanoparticles across dialysis membranes

2018 ◽  
Vol 5 (6) ◽  
pp. 1350-1360 ◽  
Author(s):  
Ming Chen ◽  
Chad T. Jafvert
Keyword(s):  
Ion Exchange ◽  
Cationic Surfactant ◽  
Selectivity Coefficients ◽  
Dialysis Membranes ◽  
Exchange Selectivity

Ion exchange selectivity coefficients for a new cross-linked micellar nanoparticle are reported and are used to predict specific ion recovery (e.g., phosphate) across dialysis membranes.

Na/Ca selectivity coefficients of montmorillonite in perchlorate solution at different temperatures

2012 ◽  
Vol 1475 ◽  
Author(s):  
Aku Itälä ◽  
Arto Muurinen
Keyword(s):  
Cation Exchange ◽  
Spent Nuclear Fuel ◽  
Spent Fuel ◽  
Selectivity Coefficients ◽  
Crystalline Bedrock ◽  
Bentonite Buffer ◽  
Different Temperatures ◽  
C 50 ◽  
Exchange Selectivity

ABSTRACTThe Finnish spent nuclear fuel disposal is based on the Swedish KBS-3 concept in crystalline bedrock. The concept aims at long-term isolation and containment of spent fuel in copper canisters surrounded by bentonite buffer which mostly consists of montmorillonite. For the long-term modelling of the chemical processes in the buffer, the cation-exchange selectivity coefficients have to be known at different temperatures. In this work, the cation-exchange selectivity coefficients and cation-exchange isotherms were determined in batch experiments for montmorillonite at three different temperatures (25 °C, 50 °C and 75 °C). Five different ratios of NaClO4/Ca(ClO4)2 were used in the experimental solutions. After equilibration the solution and montmorillonite were separated and the solution analysed to get the desired exchange parameters. The experiments were modelled with a computational model capable of taking into account the physicochemical processes that take place in the experiment.

Exchange selectivity of lanthanide ions in montmorillonite

Clay Minerals ◽  
1992 ◽  
Vol 27 (1) ◽  
pp. 81-89 ◽  
Author(s):  
J. Maza-Rodriguez ◽  
P. Olivera-Pastor ◽  
S. Bruque ◽  
A. Jimenez-Lopez
Keyword(s):  
Ionic Strength ◽  
External Solution ◽  
Specific Adsorption ◽  
Lanthanide Ions ◽  
Exchange System ◽  
Selectivity Coefficients ◽  
Heavier Lanthanides ◽  
Relative Affinity ◽  
High Concentrations ◽  
Exchange Selectivity

AbstractThe exchange of Ca2+ and Na+ by tanthanide ions (Ln3+ = Pr3+, Gd3+, Er3+) in montmorillonite was investigated at two different ionic strengths (0·01 and 0·1 mol/kg). Preferential sorption of Ln3+ was observed and variable selectivity coefficients were found depending upon the lanthanide concentration in the solid, and ionic strength. The highest exchange extent of Ln3+ always occurred for the system Na+/Ln3+, but the exchange selectivities of Ln3+ were generally higher in the exchange system Ca2+/Ln3+. Although the relative affinity of montmorillonite for the three lanthanide ions was similar, distinctive behaviour between Pr3+ and the heavier lanthanides, Gd3+ and Er3+, was noted. The study of Ln3+ adsorption in trace amounts showed specific adsorption of lanthanides at high concentrations of Na+ in the external solution and that the exchange stoichiometries in the interlayer regions were 3 : 1 at equilibrium pH = 4.

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