Modeling the fate of aluminum in a watershed system under acidified conditions

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 1987

OSTI ID:5945547

McAvoy, D C

Acid deposition has impacted surface water quality to various degrees in many parts of the world. This study focuses on identifying the major mechanisms contributing to the increase of stream water acidity in an acid-sensitive watershed. Two mathematical models, a chemical equilibrium model and a transport simulation model, have been developed and utilized to gain a better understanding of the fate and transport of aluminum in an acidified watershed system. The chemical equilibrium model determines inorganic monomeric aluminum species by performing thermodynamic equilibrium calculations whereas the simulation model describes aluminum transport within a watershed system by incorporating soil chemistry, stream water chemistry, and hydrologic properties. Precipitation, soil, and stream water data were collected from the acid-sensitive West Wachusett Brook catchment. Organic ligands seem to regulate aluminum levels in the wetland stream whereas aluminum trihydroxide solubility appears to control the mountain stream levels. Furthermore, organic acids in the wetland drastically changes stream water quality by buffering pH changes and chelating aluminum. Soil and stream water data suggest that during intensive storm events the rainwater mostly travels through the upper soil horizons before entering the stream environment. Moreover, these data imply that rainfall volume may be more important than rainfall pH in affecting stream water acidity for this particular watershed. Equilibrium modeling showed the mountain stream to be potentially toxic to fish during moderate-to-intense rainfall events. The wetland stream, on the other hand, being dominated by organo-aluminum complexes revealed minimal toxicological effects.

• Research Organization: Massachusetts Univ., Amherst (USA)
• OSTI ID: 5945547
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ALUMINIUM
ENVIRONMENTAL TRANSPORT
MATHEMATICAL MODELS
SURFACE WATERS
ACIDIFICATION
ACID RAIN
HYDROLOGY
MOUNTAINS
ORGANIC MATTER
PH VALUE
RAIN WATER
SOIL CHEMISTRY
STORMS
VOLUME
WATER CHEMISTRY
WATER QUALITY
WATERSHEDS
WETLANDS
AQUATIC ECOSYSTEMS
ATMOSPHERIC PRECIPITATIONS
CHEMISTRY
DISASTERS
ECOSYSTEMS
ELEMENTS
ENVIRONMENTAL QUALITY
HYDROGEN COMPOUNDS
MASS TRANSFER
METALS
OXYGEN COMPOUNDS
RAIN
WATER
510200* - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)
520200 - Environment
Aquatic- Chemicals Monitoring & Transport- (-1989)