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RECORD NUMBER: 278 OF 285

OLS Field Name OLS Field Data
Main Title Transport of macromolecules and humate colloids through a sand and a clay amended sand laboratory column /
Author West, Candida Cook.
CORP Author Robert S. Kerr Environmental Research Lab., Ada, OK.
Publisher Robert S. Kerr Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency,
Year Published 1990
Report Number EPA/600/2-90/020
Stock Number PB90-219205
Subjects Colloids--Mathematical models. ; Organic water pollutants--Mathematical models.
Additional Subjects Columns(Process engineering) ; Water pollution ; Water chemistry ; Colloids ; Sands ; Clays ; Solubility ; Experimental design ; Column packings ; Colloid chemistry ; Aquifers ; Molecules ; Sorption ; Particle size distribution ; Polymers ; Materials tests ; Environmental transport ; Land pollution ; Subsurface environments
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB90-219205 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 01/01/1988
Collation vii, 42 pages : illustrations ; 28 cm
Abstract
Evaluating contaminant fate in any environment necessitates determining the compartments into which the contaminant will distribute. In saturated subsurface environments the partitioning of a contaminant between the mobile aqueous phase and the immobile aquifer solid matrix is often the controlling distribution. The association of a contaminant with immobile solids results in a reduction in the dissolved mobile concentration of the contaminant, sometimes by orders of magnitude. However, it has been suggested that mobile entities such as suspended organic and inorganic colloids and macromolecules may increase the 'apparent' solubility of some contaminants. If this is the case, then predictions of contaminant transport based upon a two-phase system may seriously underestimate observed aqueous phase concentratations of contaminant in laboratory and field studies. The influence of these entities would need to be addressed by modeling systems as three phases consisting of immobile sorbed, dissolved and mobile sorbed phases. There is a good deal of research activity in the areas of colloid origination, chemistry, stability and mobility. Recently, colloidal entities such as macromolecules and viruses have been observed to be capable of eluting prior to conservative solutes in column and field studies. The intent of the study was to observe the transport of colloid-sized entities and to examine the validity of two proposed mechanisms by which the phenomenon may occur in the subsurface.
Notes
"April 1990." "EPA/600/2-90/020." PB90-219205. Includes bibliographical references (pages 40-42). Microfiche.