10.1021/es501782g.s001
Wenming Dong
Wenming
Dong
Jiamin Wan
Jiamin
Wan
Additive
Surface Complexation Modeling of Uranium(VI)
Adsorption onto Quartz-Sand Dominated Sediments
American Chemical Society
2014
reference quartz
unit surface area
Savannah River Site
component additivity
mineral pairs
sediment
goethite
SCM
SedimentsMany aquifers
Additive Surface Complexation Modeling
CA
SRS
USA
surface area abundances
South Carolina
humic acid adsorption method
kaolinite
modeling results
surface complexation modeling
2014-06-17 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Additive_Surface_Complexation_Modeling_of_Uranium_VI_Adsorption_onto_Quartz_Sand_Dominated_Sediments/2282128
Many aquifers contaminated
by U(VI)-containing acidic plumes are
composed predominantly of quartz-sand sediments. The F-Area of the
Savannah River Site (SRS) in South Carolina (USA) is an example. To
predict U(VI) mobility and natural attenuation, we conducted U(VI)
adsorption experiments using the F-Area plume sediments and reference
quartz, goethite, and kaolinite. The sediments are composed of ∼96%
quartz-sand and 3–4% fine fractions of kaolinite and goethite.
We developed a new humic acid adsorption method for determining the
relative surface area abundances of goethite and kaolinite in the
fine fractions. This method is expected to be applicable to many other
binary mineral pairs, and allows successful application of the component
additivity (CA) approach based surface complexation modeling (SCM)
at the SRS F-Area and other similar aquifers. Our experimental results
indicate that quartz has stronger U(VI) adsorption ability per unit
surface area than goethite and kaolinite at pH ≤ 4.0. Our modeling
results indicate that the binary (goethite/kaolinite) CA-SCM under-predicts
U(VI) adsorption to the quartz-sand dominated sediments at pH ≤
4.0. The new ternary (quartz/goethite/kaolinite) CA-SCM provides excellent
predictions. The contributions of quartz-sand, kaolinite, and goethite
to U(VI) adsorption and the potential influences of dissolved Al,
Si, and Fe are also discussed.