Naslov
Removal of Heavy Metal Ions from Solutions by Means of Zeolites. I. Thermodynamics of the Exchange Processes between Cadmium Ions from Solution and Sodium Ions from Zeolite A
(Removal of Heavy Metal Ions from Solutions by Means of Zeolites. I. Thermodynamics of The Exchange Processes between Cadmium Ions from Solution and Sodium Ions from Zeolite A)

Autori
Biškup, Biserka ; Subotić, Boris

Izvornik
Separation science and technology (0149-6395) 33 (1998), 4; 449-466

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
cadmium ions; exchange equilibrium; ion exchange; sodium ions; thermodynamic data; zeolite A

Sažetak
Relationships between corrected selectivity coefficient, KC, and fraction of the exchanged cadmium ions in zeolite A, fCd, Z, were determined from the data obtained by measuring the concentrations of sodium and cadmium ions in both the solid and the liquid phase at equilibrium of the exchange processes between cadmium ions from solution and sodium ions from zeolite A at different total ion concentrations and different temperatures. Thermodynamic equilibrium constants, Ka , calculated from the corresponding Kielland� s plots (KC vs. fCd, Z plots) were used for the calculation of the appropriate values of standard free energy, DGo , standard enthalpy, DHo and standard entropy, DSo. Influence of the degree of exchange on the activity coefficients of sodium and cadmium ions in zeolite is also considered.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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