Life in the Lab
Laura Zaunbrecher is a Ph.D. student in the lab of W. Crawford Elliott, chair of the department of geosciences. She is participating in the investigation into a type of soil that adsorbs the radioactive isotope cesium-137.
As told to Jeremy Craig
My project investigates how stable cesium is naturally enriched in sediments at the Savannah River Site (SRS), as well as at other contaminated sites across the country. A lot of these places are contaminated mainly by uranium, but at the SRS, radioactive cesium, a fission product of uranium, is the major contaminant. The soil at SRS contains a clay mineral that is able to adsorb and contain the radioactive waste product, radioactive cesium. We're looking at how the soils are adsorbing cesium and preventing the spread of radioactive waste; this is important because cesium can be taken up by biological systems and become part of the food chain.
The particular clay we're studying is called hydroxy interlayered vermiculite. This clay has been concentrating cesium in the soils at SRS while other alkali metals are washed away by weathering. Investigating the behavior of stable cesium in these soils allows us to study the weathering of soils on a time scale that cannot be investigated in the laboratory, as these natural enrichments of cesium occur on a time scale of thousands of years. We can then hypothesize about the long-term behavior of radioactive cesium contamination in the environment.
After graduation, I'd like to continue with remediation work. I want to make a difference in cleaning up the environment to help make our world a better place and a better place for future generations. That's always been my goal since I started my graduate research work, and I hope to find a job that will lead me down that path.