Boron adsorption and silicon release by the clay minerals kaolinite, montmorillonite, and illite

Conference · · Soil Sci. Soc. Am. J.; (United States)

OSTI ID:6622239

Goldberg, S; Glaubig, R A

Boron adsorption behavior on the clay minerals kaolinite, montmorillonite, and illite was investigated. Adsorption increased at low pH, exhibited a peak in the pH range 8 to 10, and decreased at high pH. It was assumed that B adsorbs by means of a ligand exchange mechanism with aluminol groups at the edges of the clay particles. The constant capacitance model was able to describe B adsorption on kaolinites over the entire pH range studied (3-12), using only one adjustable parameter: the boron surface complexation constant. The model was able to fit B adsorption on montmorillonites and illites using three adjustable parameters; however, the chemical significance of some of the surface complexation constants in uncertain. Silicon release to solution increased in the order: kaolinite << illite < montmorillonite and exhibited a minimum in the pH range 8 to 9. Boron adsorption on kaolinites was reduced only slightly in the presence of added silicate despite considerable silicate adsorption. Boron adsorption on montmorillonites was unaffected by the presence of added silicate. It is suggested that B and silicate adsorb on specific sites and that little anion competition occurs.

• Research Organization: Dept. of Agriculture, Riverside, CA
• OSTI ID: 6622239
• Report Number(s): CONF-8611156-
• Conference Information: Journal Name: Soil Sci. Soc. Am. J.; (United States) Journal Volume: 50:6
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ADSORPTION
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
ANIONS
BORON
CHARGED PARTICLES
CHEMISTRY
CLAYS
ELEMENTS
ILLITE
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
KAOLINITE
MATERIALS
MATHEMATICAL MODELS
MINERALS
MONTMORILLONITE
OXYGEN COMPOUNDS
PH VALUE
SEMIMETALS
SILICATE MINERALS
SILICATES
SILICON
SILICON COMPOUNDS
SOIL CHEMISTRY
SOILS
SORPTION