Lead Investigator: John McCloy (Lead, Washington State University)

Project Objectives:

• Demonstrate proof of principal removal of Tc (or proxy Re), Hg, and/or I (in various forms) from caustic waste using Fe-S magnetic particles.
• Demonstrate one or more possible waste form paths for immobilization of the radionuclide/contaminant-laden Fe-S particles.
• Assess overall disposal benefits of the addition of this process and propose flow sheet changes necessary to incorporate the process.

Significance/Impact:
Volatile contaminants, including radionuclides ⁹⁹Tcand ¹²⁹Iand hazardous elements like Hg, are problematic components for remediation in various DOE-EM cleanup sites. These can be present both in radioactive tank waste as well as in soil and groundwater. While technologies do exist to treat groundwater and soil, novel methods may enable improved separation, especially from tank waste, that would allow waste forms with lower concentrations of these compounds, which generally drive the long-term dose (e.g., Tc, I) or heavy metal leaching performance (Hg). Additionally, commercially baselined sorbents for off-gas systems (such as modified graphite for Hg capture) frequently become unavailable from manufacturers (Fountain et al., 2022), and new materialshave to be qualified. Using a magnetic sorbent could allow the removal of contaminants in a flowing stream of liquid, and the removed contaminants could then be sequestered in a purpose-designed waste form; alternatively, they could be added back into a specific existing waste form (e.g., cementitious material or recycled into the glass feed).

Public Benefits:
The technology being developed as part of this CRESP project provides a foundation for targeted contaminant removal from water and wastewater streams with wide applicability beyond DOE.​ The research also provides a potential path for lower-cost immobilization for low activity and related waste streams outside of DOE. 

References: (* indicates CRESP publication)

Asmussen, M., Levitskaia, T., Bottenus, C., and Fountain, M.S. (2020) Iodine Speciation Basis and Gap Analysis for Hanford Tank Farm Inventory and during Processing. PNNL-30105, Pacific Northwest National Laboratory.

Bannochie, C.J., Fellinger, T.L., Garcia-Strickland, P., Shah, H.B., Jain, V., and Wilmarth, W.R. (2018) Mercury in aqueous tank waste at the Savannah River Site: Facts, forms, and impacts. Separation Science and Technology, 53, 1935-1947.

Cordova, E.A., Garayburu-Caruso, V., Pearce, C.I., Cantrell, K.J., Morad, J.W., Gillispie, E.C., Riley, B.J., Colon, F.C., Levitskaia, T.G., Saslow, S.A., Qafoku, O., Resch, C.T., Rigali, M.J., Szecsody, J.E., Heald, S.M., Balasubramanian, M., Meyers, P., and Freedman, V.L. (2020) Hybrid Sorbents for 129I Capture from Contaminated Groundwater. ACS Applied Materials & Interfaces, 12, 26113-26126.

Darab, J.G., Amonette, A.B., Burke, D.S.D., Orr, R.D., Ponder, S.M., Schrick, B., Mallouk, T.E., Lukens, W.W., Caulder, D.L., and Shuh, D.K. (2007) Removal of Pertechnetate from Simulated Nuclear Waste Streams Using Supported Zero-valent Iron. Chemistry of Materials, 19, 5703-5713.

Fountain, M.S., Asmussen, M., Riley, B.J., Chong, S., Choi, S., and Matyáš, J. (2022) Roadmap to Iodine and Mercury Abatement Materials Selection in Nuclear Waste Processing Off-Gas Streams.  Pacific Northwest National Laboratory.

Gong, Y., Huang, Y., Wang, M., Liu, F., and Zhang, T. (2019) Application of Iron-Based Materials for Remediation of Mercury in Water and Soil. Bull. Environ. Contam. Toxicol., 102, 721-729.

Icenhower, J.P., Qafoku, N.P., Zachara, J.M., and Martin, W.J. (2010) The biogeochemistry of technetium: A review of the behavior of an artificial element in the natural environment. American Journal of Science, 310, 721-752.

Lere-Adams, A.J., Dixon Wilkins, M.C., Bollinger, D., Stariha, S., Farzana, R., Dayal, P., Gregg, D.J., Chong, S., Riley, B.J., Heiden, Z.M., and McCloy, J.S. (2024) Glass-bonded ceramic waste forms for immobilization of radioiodine from caustic scrubber wastes. Journal of Nuclear Materials, 591, 154938.

Moore, J., Nienhuis, E., Ahmadzadeh, M., and McCloy, J. (2019) Synthesis of greigite (Fe3S4) particles via a hydrothermal method. AIP Advances, 9, 035012.

Moore, R.C., Pearce, C.I., Morad, J.W., Chatterjee, S., Levitskaia, T.G., Asmussen, R.M., Lawter, A.R., Neeway, J.J., Qafoku, N.P., Rigali, M.J., Saslow, S.A., Szecsody, J.E., Thallapally, P.K., Wang, G., and Freedman, V.L. (2020) Iodine immobilization by materials through sorption and redox-driven processes: A literature review. Science of The Total Environment, 716, 132820.

Riley, B.J., Vienna, J.D., Strachan, D.M., McCloy, J.S., and Jerden Jr, J.L. (2016) Materials and processes for the effective capture and immobilization of radioiodine: A review. Journal of Nuclear Materials, 470, 307-326.

Wang, J., Feng, X., Anderson, C.W.N., Xing, Y., and Shang, L. (2012) Remediation of mercury contaminated sites – A review. Journal of Hazardous Materials, 221-222, 1-18.

Watson, J.H.P., and Ellwood, D.C. (2003) The removal of the pertechnetate ion and actinides from radioactive waste streams at Hanford, Washington, USA and Sellafield, Cumbria, UK: the role of iron-sulfide-containing adsorbent materials. Nuclear Engineering and Design, 226, 375-385.

Xiong, Z., He, F., Zhao, D., and Barnett, M.O. (2009) Immobilization of mercury in sediment using stabilized iron sulfide nanoparticles. Water Research, 43, 5171-5179.

Yadav, A., Chong, S., Riley, B.J., McCloy, J.S., and Goel, A. (2023) Iodine Capture by Ag-Loaded Solid Sorbents Followed by Ag Recycling and Iodine Immobilization: An End-to-End Process. Industrial & Engineering Chemistry Research, 62, 3635-3646.

Yang, Y., Chen, T., Sumona, M., Sen Gupta, B., Sun, Y., Hu, Z., and Zhan, X. (2017) Utilization of iron sulfides for wastewater treatment: a critical review. Rev. Environ. Sci. Bio/Technol., 16, 289-308.