ISSN:
1572-8757
Keywords:
copper
;
ca-koalinite
;
adsorption
;
desorption
;
thermodynamics
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Physics
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract The temperature effect on Cu adsorption and desorption on kaolinite has been investigated at four temperatures (8°C, 25°C, 30°C and 40°C). The clay sample was saturated with Ca. Copper was sorbed from solutions containing eleven Cu concentrations between 0.0010 and 0.0211 M, equilibrated for 2 days. Cu adsorption decreased, but desorption increased with increasing temperature, indicating that adsorption is an exothermic process while desorption is endothermic. These conclusions are confirmed by the values of ΔH 0 estimated for adsorption and desorption. The initial copper concentration is a significant factor influencing mainly the adsorption process, which is spontaneous (ΔG 0 〈 0) only for low initial Cu concentrations. The desorption process is spontaneous for all Cu concentrations. ΔS 0 values have also been calculated. Experimental adsorption data were successfully fitted to the Freundlich isotherm and to the Gouy-Chapman model in order to express the process quantitatively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1026513032260
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