Record Details
Biological remediation strategy for immobilizing Ag-110m and Cs-134 in soils
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Biological remediation strategy for immobilizing Ag-110m and Cs-134 in soils |
| Names |
Whitlow, Jesse Lynn
(creator) Higley, Kathryn (advisor) |
| Date Issued | 2014-06-06 (iso8601) |
| Note | Graduation date: 2015 |
| Abstract | After contamination of soil in Japan due to the Fukushima Daiichi accident, there has been an increased interest in remediation of radiologically contaminated land. This study investigated the efficacy of a new biological remediation technology developed by Earthfort, an Oregon based company to hold radionuclides at the soil surface. Cesium-134 and Ag-110m were used to represent potential environmentally relevant fission products in this study due to their availability for production in the OSU TRIGA Reactor and their relevance to the Fukushima Daiichi accident. The experiment was conducted using bare and vegetated soil columns. Three groups each had 30 soil columns containing approximately 500g of soil. The plant groups consisted of soybeans, radishes and a bare soil column without plants. In each group, 12 columns had Ag-110m added topically, before germination, 12 had Cs-134 added and 6 control columns had no contaminated spike added. Half of those columns received a treatment of Earthfort's inoculant. Due to the varied growth rate of the plants, the periods of time during which the inoculant was applied varied as necessary. The group with soybean columns was allowed two months to grow and the other two groups were allowed one month. Columns contaminated with Ag-110m were each contaminated with 11.0 μCi (4.07E5 Bq) and those contaminated with Cs-134 received 5.2 μCi (1.92E5 Bq). All columns were watered daily with 75ml of water to simulate rainfall. In the treatment groups, 30 ml of inoculant was added per column weekly. After the experiment, the columns were segmented and the Ag-110m and Cs-134 contents were measured. Five minute counts were taken using a High Purity Germanium (HPGe) detector. Statistical analysis was performed using R version 3.0.1®. Two approached were used. The data was fit to a multiple linear regression model and interactions were analyzed. Second, a simple comparison of the means of the normalized activity was performed segment by segment. Both methods yielded the same result. The inoculant has a small, but statistically significant effect in facilitating migration of the contaminants. The inoculated columns showed increased radionuclide transport compared with non-inoculated columns. |
| Genre | Thesis/Dissertation |
| Topic | Biological Remediation |
| Identifier | http://hdl.handle.net/1957/50465 |
