Abstract
The experimental sorption isotherms of fluoride were compared for several aluminosilicate
clays. A competitive Langmuir isotherm incorporating pH dependence in fluoride sorption was
used to model the experimental results. Bentonite was determined to be a far superior fluoride
sorbent than kaolinite quantitatively, although results suggest that fluoride sorption by bentonite
may not be achieved through the same sorption mechanism as for kaolinite. Factors found to
influence fluoride sorption include solution pH, clay surface area, aluminium content and the
presence of certain exchangeable cations capable of forming fluoride precipitates. Characterisation
of fluoride sorption behaviour by clay mixtures was achieved through weighted averaging of the
sorption behaviour for the individual clays of the mixture.
clays. A competitive Langmuir isotherm incorporating pH dependence in fluoride sorption was
used to model the experimental results. Bentonite was determined to be a far superior fluoride
sorbent than kaolinite quantitatively, although results suggest that fluoride sorption by bentonite
may not be achieved through the same sorption mechanism as for kaolinite. Factors found to
influence fluoride sorption include solution pH, clay surface area, aluminium content and the
presence of certain exchangeable cations capable of forming fluoride precipitates. Characterisation
of fluoride sorption behaviour by clay mixtures was achieved through weighted averaging of the
sorption behaviour for the individual clays of the mixture.
| Original language | English |
|---|---|
| Journal | Geoderma |
| Volume | 84 |
| Pages (from-to) | 89-180 |
| ISSN | 0016-7061 |
| Publication status | Published - 1998 |
| Externally published | Yes |