Adsorption et désorption de la pyrazone par quelques colloïdes organiques et minréaux |
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| Authors: | P. FUSI S. CECCONI M. franci C. VAZZANA |
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| Affiliation: | Istituto di Chimica Agraria e Forestale dell' Universitàdi Firenze. Centro di Studio per i Colloidi del Suolo del C.N.R.—Firenze, Italia |
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| Abstract: | Adsorption and desorption of pyrazone by some organic and mineral colloids The adsorption and desorption of pyrazone on organic and mineral colloids and on ion-exchanging resins saturated with H+, Na+, K+, Ca++ and Mg++ ions was studied. The following order of adsorption was found for H-adsorbants: H-Amberlite> Dowex-H > H-humus > Al,H-montmorillonite> Al,H-illite> Al,H-kaolinite. This adsorption, which seems to be due to physical links and not to protonation mechanisms, is greater than that found with the -K, -Na, -Ca, and -Mg systems. With Ca- systems the same order of adsorption was obtained: Dowex-Ca>Ca-montmorillonile>Ca-illite> Ca-kaolinite. In contrast to what we found with Dowex resin, with montmorillonlte and illite the saturating cation seemed to affect adsorption of pyrazone; indeed we obtained the following order: Ca++> Mg++> K+> Na+. For all the systems we examined desorption of the adsorbed pyrazone was complete. |
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