thumbnail

Speciation and equilibrium relations of soluble aluminum in a headwater stream at base flow and during rain events

Water Resources Research

By:

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time

Abstract

In the Shenandoah National Park, Virginia, the short-term dynamics of soluble aluminum in stream water sampled during rain events differed significantly from stream water sampled during base flow conditions. Three fractions of dissolved aluminum were measured. The inorganic monomeric fraction made up approximately two thirds of the total reactive aluminum at base flow, followed by the acid-soluble and organic monomeric fractions, respectively. Equilibrium modeling showed that hydroxide complexes were the most abundant form of inorganic monomeric aluminum followed by fluoride, free aluminum ion, and sulfate. The activity of inorganic monomeric aluminum at base flow appears to be in equilibrium with an Al(OH)3 phase with solubility intermediate between microcrystalline gibbsite and natural gibbsite. During two rain events, the concentration of all three aluminum fractions increased significantly. The primary cause of the transient increase in the Al(OH)3 saturation index appears to have been the neutralization of excess H+ added by soil water through reaction with stream water HCO3- at a more rapid rate than excess inorganic monomeric aluminum could be removed from solution by hydroxide mineral precipitation. -from Author

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Speciation and equilibrium relations of soluble aluminum in a headwater stream at base flow and during rain events
Series title:
Water Resources Research
Volume
25
Issue:
7
Year Published:
1989
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1653
Last page:
1665
Number of Pages:
13