Speciation of aluminum in acidic freshwaters
The determination of the physical speciation of aluminum in water samples by filtration through polycarbonate membranes proved feasible; control experiments revealed neither contamination nor analyte loss. Treatment of sample filtrates with a fractionally loaded Chelex 100 ion-exchange resin (>75% H/sup +/-form) allows one to distinguish between different forms of aluminum on the basis of their kinetic and thermodynamic properties. Monomeric hydroxo- and fluoroaluminum complexes exchanged readily (>85% after 30 min), as did low molecular weight polynuclear species. Under similar conditions, forms of Al associated with fulvic and humic acids of natural origin exchanged much more slowly (<5% after 30 min, at an Al:dissolved organic carbon atomic ratio of approx. 1:155). Before photooxidation, the filterable aluminum present in natural waters exhibited intermediate behavior (0-50% exchange after 30 min); after UV irradiation the nonexchangeable Al fraction had practically disappeared (90-96% exchange after 30 min), suggesting that the major portion of the nonexchangeable Al initially present was associated with organic matter.
- Research Organization:
- Universite du Quebec, Ste-Foy
- OSTI ID:
- 5439341
- Journal Information:
- Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 55:14; ISSN ANCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ALUMINIUM
CHEMICAL REACTIONS
CHEMISTRY
ELEMENTS
FILTRATION
FRESH WATER
FULVIC ACIDS
HUMIC ACIDS
HYDROGEN COMPOUNDS
ION EXCHANGE
METALS
MOLECULAR WEIGHT
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC MATTER
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
POLLUTION
QUANTITY RATIO
SEPARATION PROCESSES
WATER
WATER CHEMISTRY
WATER POLLUTION