Premium
THE ADSORPTION OF CATIONS FROM solUTION BY ALLOPHANE IN RELATION TO THEIR EFFECTIVE SIZE
Author(s) -
BIRRELL K. S.
Publication year - 1961
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1961.tb00920.x
Subject(s) - allophane , adsorption , chemistry , salt (chemistry) , inorganic chemistry , monolayer , leaching (pedology) , soil water , geology , biochemistry , soil science
Summary The amounts of cation physically adsorbed from neutral‐salt solutions by allophane and co‐precipitated silica‐alumina mixtures are dependent upon the effective radius of the cation. For non‐hydrated cations, the B.E.T. theory indicates that about the same area of surface is covered by a monolayer of cations, the sizes of which may vary considerably. The results for hydrated cations are consistent with the idea of effective size as a factor in the mechanism of adsorption if the hydration numbers of Glueckauf are regarded as relevant to the process. When using leaching methods which allow the retention of most of the physically adsorbed cation (as is the case when alcohols are used to remove excess salt), cation‐exchange‐capacity values are in inverse order to the effective radii of the cations. This will apply to silica‐alumina catalysts as well as to soils containing allophane.