Thesis
An evaluation of an ion-exchange method for the removal of technetium-99 from groundwater
Washington State University
Master of Science (MS), Washington State University
2007
Handle:
https://hdl.handle.net/2376/107308
Abstract
This thesis presents and interprets the results of a treatability test for removing technetium-99 (99Tc) from groundwater extracted by the pump-and-treat system at the 200-ZP-1 Operable Unit (OU) at the Hanford Site in Benton County, Washington. The primary risk driving contaminants within the OU included carbon tetrachloride and 99Tc that resulted from disposal activities associated with nuclear fuel processing. Ten extraction wells and five injection wells removed carbon tetrachloride from the groundwater. Groundwater from two of extraction wells began to show increasing concentrations of 99Tc shortly after they were put online in 2005. A treatability test was conducted to evaluate the efficiency of ion exchange at removing 99Tc from groundwater. The test involved the installation of Purolite® A-530E ion exchange resin columns on the discharge lines of two of the extraction wells. Groundwater samples were collected from sampling ports twice a week and analyzed for 99Tc and selected anions. Test results showed that the ion exchange resin was effective at removing 99Tc from groundwater to below detection limits even in the presence of competing anions (e.g., nitrate and sulfate) at concentrations 5 to 6 orders of magnitude higher than 99Tc. Sampling results showed that nitrate and sulfate concentrations in the influent and the effluent remained nominally equal and static over the course of the sampling efforts indicating that competition between nitrate and sulfate for ion exchange sites was very low compared to that of 99Tc. Overall, the Purolite® A-530E ion exchange resin is an effective remedial method for 99Tc removal in groundwater.
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Details
- Title
- An evaluation of an ion-exchange method for the removal of technetium-99 from groundwater
- Creators
- Wanda Sue Elliott
- Contributors
- Mark E. Byrnes (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525378301842
- Language
- English
- Resource Type
- Thesis