Experiments Supporting the Design and Operation of Ad Hoc Sand/Clay Beds to Filter Contaminated Waters during Recovery – 21206
Citation:
Hepler, K., N. Kivenas, AND M. Kaminski. Experiments Supporting the Design and Operation of Ad Hoc Sand/Clay Beds to Filter Contaminated Waters during Recovery – 21206. In Proceedings, WM2021, Cincinnati, OH, March 08 - 12, 2021. WM Symposia, Inc., TEMPE, AZ, 21206, (2021).
Impact/Purpose:
Radioactive contaminants may be removed from contaminated waters using beds of sand and clay as part of recovery operations after a radiological contamination event. Fluid flow through mixtures of sand, silt, clay, and/or gravel have been studied extensively; however, these studies typically sought to mimic the packing and structure of soils, which may differ from rapidly assembled sand/clay beds for recovery operations. In this work, we measured the flow rate of sand/clay columns as a function of saturation time, composition, and the presence of filter material at the bottom of the column. The majority of tests performed at saturation without filter material yielded flow rates 50% - 75% of that predicted by Darcy’s law. Adding filter material to the bottom of columns resulted in greatly reduced flow rates, but also led to a wider variance in results relative to the predicted flow rates. Accounting for the reduced porosity when the sand and clay are well mixed improves the predicted flow rates for most columns without filter material. These results imply beds can run 1.5 – 2 times longer than originally predicted before contaminant breakthrough, but also that twice the amount of materials will be required to process contaminated waters at the original flow rates.
Description:
In this work, we measured the flow rate of sand/clay columns as a function of saturation time, composition, and the presence of filter material at the bottom of the column.
