EVALUATION OF FLOW CHARACTERISTICS OF A SAND COLUMN USING MAGNETIC-RESONANCE-IMAGING

Magnetic resonance imaging (MRI) was used to evaluate a column designe d to conduct contaminant retardation tests on geological materials und er saturated conditions. MRI procedures revealed sediment heterogeneit ies and preferential flow pathways inherent in the sediments as well a s those created in the packing of the column. Sequential MRI images we re also used to estimate tracer flow velocities and to detect density flows driven by density differences of as little as 0.0013 g/ml. Inter pretation of the images emphasized the importance of small changes in hydraulic conductivity and of column orientation in experiments with f luids of different densities. MRI analysis during column flow experime nts holds promise as a measurement technique to estimate retardation f actors for selected solutes.