MODIFIED DIFFUSION TECHNIQUE FOR STUDYING NONLINEAR AND KINETIC SORPTION AND DESORPTION PROCESSES

Citation
G. Kirchner et al., MODIFIED DIFFUSION TECHNIQUE FOR STUDYING NONLINEAR AND KINETIC SORPTION AND DESORPTION PROCESSES, Radiochimica Acta, 74, 1996, pp. 189-192
Citations number
19
Categorie Soggetti
Nuclear Sciences & Tecnology","Chemistry Inorganic & Nuclear
Journal title
ISSN journal
00338230
Volume
74
Year of publication
1996
Pages
189 - 192
Database
ISI
SICI code
0033-8230(1996)74:<189:MDTFSN>2.0.ZU;2-2
Abstract
A new method is presented to interpret data on diffusion-sorption proc esses obtained from through-diffusion experiments. Both sorption and d esorption are modeled as kinetically controlled processes by incorpora ting nonlinear isotherms. The diffusion-sorption equation was solved n umerically and the resulting algorithm was integrated into a nonlinear regression code to test various models. The through-diffusion techniq ue was modified such as to obtain sorption and desorption data from a single experiment. Data are presented for the diffusion of cesium thro ugh a Eutric Cambisol soil pellet. Various sorption models were tested . The best fit to the experimental data was obtained assuming first-or der kinetics with a Freundlich isotherm. Desorption shows a marked hys teresis.