摘要 |
The oxine ligands 5-chloro-8-hydroxyquiniline and 5-sulfoxyl-8-hydroxyquinoline are covalently bound, using, for example, the Mannich reaction, to a silica gel polyamine composite made from a silanized amorphous silica xerogel and polyallylamine. The resulting modified composites, termed CB-1 (X═Cl) and SB-1 (X═SO3H), respectively, show a clear selectivity for trivalent over divalent ions and selectivity for gallium over aluminum. The compounds of the invention can be applied for the sequestration of metals, such as heavy metals, from contaminated mine tailing leachates.
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