Effect of solution chemistry on clay colloid release from an iron oxide-coated aquifer sand

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00058a025· OSTI ID:6906962

Ryan, J N ^[1]; Gschwend, P M ^[2]

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1. Univ. of Colorado, Boulder, CO (United States)
2. Massachusetts Inst. of Technology, Cambridge, MA (United States)

This research compared the influence of (1) dissolution of iron oxides and (2) alteration of electrostatic interactions on the mobilization of colloids in a clay- and iron oxide-coated sand obtained from an Atlantic Coastal Plain aquifer in which colloids have been found suspended only in anoxic groundwater. The sediment was flushed with solutions of varying ionic strength, pH, and reductant and surfactant concentrations, and the steady-state rates of clay colloid release and iron oxyhydroxide dissolution were measured. The clay release rates were directly related to the calculated detachment energies and unrelated to rates of iron(III) oxide dissolution, indicating that electrostatic interactions dominated the binding of colloids to grain coatings. Mobilization of colloids by iron(III) oxide dissolution through reductive dissolution was limited by high ionic strength. Flushing of the sediment by a natural groundwater with high dissolved organic carbon concentration released clay without rapidly dissolving iron oxides. 59 refs., 8 figs., 3 tabs.

• DOE Contract Number: FG02-86ER60413; FG02-89ER60846
• OSTI ID: 6906962
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 28:9; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606 -- Other Materials-- Physical Properties-- (1992-)
54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
AQUIFERS
CHALCOGENIDES
CLAYS
COLLOIDS
COMPILED DATA
DATA
DISPERSIONS
DISSOLUTION
ELECTROSTATICS
GOETHITE
GROUND WATER
HYDROGEN COMPOUNDS
INFORMATION
IRON COMPOUNDS
IRON OXIDES
KAOLINITE
MINERALS
MONITORING
NUMERICAL DATA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SAND
SEDIMENTS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WATER