U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings
of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993,
Water-Resources Investigations Report 94-4015
Evaluation of Geochemical Indicators of Metal Adsorption in
a Sand and Gravel Aquifer, Cape Cod, Massachusetts
Christopher C. Fuller (U.S. Geological Survey, Menlo Park, Calif.),
Jennifer A. Coston (U.S. Geological Survey, Menlo Park, Calif.), James A.
Davis (U.S. Geological Survey, Menlo Park, Calif.), and Eleanor Dixon (U.S.
Geological Survey, Menlo Park, Calif.)
The geochemical properties of an aquifer sand that control
metal-ion adsorption were investigated to determine their
potential use as indicators of the spatial variability of metal
adsorption in the aquifer. Over the length of a 4.5-meter
long core, lead (Pb) and zinc (Zn) adsorption varied by a factor
of two and four, respectively. Pb2+ and Zn2+
are adsorbed primarily by iron and aluminum oxide coatings on
quartz-grain surfaces. Upon normalization to surface area, both
Pb2+ and Zn2+ adsorption were significantly correlated
with the amount of iron and aluminum dissolved from the aquifer
material by partial chemical extraction. The use of partial
chemical extraction combined with surface-area measurement as
a potential indicator of metal adsorption in other aquifers needs
to be tested.