HR: 1330h
AN: H22A-0906    [PDF]
TI: One-Dimensional Solute Transport in Variably Saturated Soil Using a Geocentrifuge Apparatus
AU: * Mattson, E D
EM: matted@inel.gov
AF: Idaho National Engineering and Environmental Laboratory, Geosciences Research Department PO BOX 1625, Idaho Falls, ID 83415-2107 United States
AU: Baker, K E
EM: bakeke@inel.gov
AF: Idaho National Engineering and Environmental Laboratory, Geosciences Research Department PO BOX 1625, Idaho Falls, ID 83415-2107 United States
AU: Palmer, C D
EM: palmcd@inel.gov
AF: Idaho National Engineering and Environmental Laboratory, Geosciences Research Department PO BOX 1625, Idaho Falls, ID 83415-2107 United States
AU: Smith, R W
EM: smithbob@uidaho.edu
AF: University of Idaho, 1776 Science Center Dr., Idaho Falls, ID 83402 United States
AU: Simunek, J
EM: jsimunek@ussl.ars.usda.gov
AF: Dept. of Environ. Sci., University of Riverside, Riverside, CA 92507 United States
AB: Solute transport data in variably saturated porous media have been difficult to obtain due to long experimental times required to conduct such experiments. Larger length scales of tens of cm require months of experimental time. These long experimental times increase the likelihood of undesirable secondary effects, such as biofouling and instrumentation failure compromising the experimental results. The geocentrifuge offers a potential experimental technique to shorten experimental time scales and thereby overcome these limitations. One-dimensional solute transport experiments (10-cm diameter by 30-cm in length) were conducted using the INEEL 2-m geocentrifuge. Potassium bromide was used as a tracer through Ottawa quartz sand to develop geocentrifuge experimental methodologies and to test a modified numerical tool to design and analyze the results from these experiments. Breakthrough curves were determined through in-flight monitoring of the electrical conductivity of the outflow at 10- and 20-``g''s. Solute transport velocity is proportional to the applied centrifugal acceleration. Breakthrough curves presented in this paper were obtained in less than 2 hours. The time it took to obtain these experimental results is inversely proportional to the applied centrifugal acceleration and is a fraction of the time that it would have taken in using traditional laboratory methods. A modified version of HYDRUS-1D was used to evaluate the solute breakthrough curves. The success of these geocentrifuge experiments suggests that the geocentrifuge technique is a practical and faster experimental methodology to complete tracer experiments in variable saturated media.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2003 Fall Meeting