Browsing by Subject "Aluminum silicate"

Now showing 1 - 3 of 3

Open Access
Radiochemical study of Co2+ sorption on chlorite and kaolinite
(Akademiai Kiado Rt., 1999) Shahwan, T.; Erten, H. N.
In this work, the sorption behavior of Co(II) ions on natural chlorite and kaolinite as a function of time, concentration and temperature was studied. 60Co radiotracer method and the batch technique were used. The kinetic results indicated that about one day of contact time was enough to achieve equilibrium. The sorption process was described by Freundlich type isotherms. Sorption of Co(II) ions on both clays was found to be endothermic with ΔH(o) (kJ/mol) and ΔS(o) (kJ/mol·K) being 33 and 0.14 for kaolinite and 17 and 0.102 for chlorite, respectively. The magnitudes of the corresponding ΔG(o) values suggest that sorption occur mainly via an ion exchange mechanism on both clays.
Open Access
Temperature effects in barium sorption on natural kaolinite and chlorite-illite clays
(Akademiai Kiado Rt., 2004) Shahwan, T.; Erten, H. N.
The sorption of Ba2+ ion on natural kaolinite and chlorite-illite clays was investigated at different initial concentrations and temperatures using the radiotracer method. The sorption data were well described by Freundlich and Dubinin-Radushkevich isotherms. Ba2+ sorption on both clays showed an exothermic behavior with ΔH° (kJ/mol) values being -7 and -5 for sorption on kaolinite and chlorite illite mixed clay, respectively. The ΔG° values indicate that the sorption was spontaneous with sorption energies corresponding to ion-exchange type sorption. X-ray diffraction studies showed that no significant change in the matrix of the clays occurred upon Ba2+ sorption.
Open Access
Thermodynamic parameters of Cs+ sorption on natural clays
(Akademiai Kiado Rt., 2002) Shahwan, T.; Erten, H. N.
The sorption behavior of Cs+ on kaolinite, chlorite-illite, and bentonite clays as a function of time, cation concentration, and temperature was studied using the radiotracer method. Sorption data were well represented by Freundlich and Dubinin-Radushkevich type isotherms. Bentonite was found to have the highest sorption capacity and the highest exchange affinity to Cs+. In all three cases Cs+ sorption was found to be exothermic with ΔH° (kJ/mol) -13, -8, -19 and ΔS° (J/mol·K) -15, 31, and -3 for kaolinite, chlorite-illite, and bentonite, respectively. Negative ΔG° values were obtained in all cases, indicating the spontaneity of sorption. The magnitudes of ΔG° suggest that ion exchange is the primary sorption mechanism.