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Biocolloid and solute tracer transport in gravel aquifers - a groundwater protection perspective
Auteur(s)
Kennedy, Keith
Schurch, Marc
Editeur(s)
Seiler, Klaus-Peter
Wohnlich, Stefan
Maison d'édition
: A a Balkema Publishers
Date de parution
2001
De la page
125
A la page
128
Résumé
Migration conditions in a gravel aquifer of the upper Rhone River valley were studied using particle and solutes as contaminant surrogates. Transport rates were 130 to 480 m/d over distances to 22 in, up to 40 times faster than predicted using conventional flow/effective porosity parameters. In one well, a 1-m vertical pathway heterogeneity dominated the 12-m aquifer saturated thickness. Biocolloids were consistently detected earlier than solutes due in part to their significantly lower detection limits and possibly to preferential particle advection. Biocolloid detection occurred 3- to 7-times earlier than time to solute breakthrough peaks, those values commonly relied on when calculating reference velocity parameters. Relative colloid recovery was typically 1.5 to 4 percent and in one case was 72 % of the solute illustrating relatively low biocolloid attenuation in river gravel macropores. Transport direction was up to 90 degrees off those determined from head-derived measurements. Results suggest that reliable groundwater protection strategy in heterogeneous gravel aquifers may improve when field-verified with migration characterization using multiple tracer types.
Nom de l'événement
31st International-Association-of-Hydrogeologists Congress
Lieu
Munich, Germany
Identifiants
Type de publication
conference paper