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Yadav A, Chong S, Riley BJ, McCloy JS, Goel A. Iodine Capture by Ag-Loaded Solid Sorbents Followed by Ag Recycling and Iodine Immobilization: An End-to-End Process. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.2c04357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- Anjali Yadav
- Department of Materials Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Saehwa Chong
- Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Brian J. Riley
- Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - John S. McCloy
- School of Mechanical and Materials Engineering and Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164, United States
| | - Ashutosh Goel
- Department of Materials Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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2
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Asmussen RM, Westesen A, Cordova EA, Fujii Yamagata AL, Schonewill PP, Moore AC, Bourchy A, Saslow SA, Smith GL, Riley BJ, Skeen RS. Iodine Removal from Carbonate-Containing Alkaline Liquids Using Strong Base Resins, Hybrid Resins, and Silver Precipitation. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.2c03527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- R. Matthew Asmussen
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Amy Westesen
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Elsa A. Cordova
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Alessandra Lie Fujii Yamagata
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Philip P. Schonewill
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Aryiana C. Moore
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Agathe Bourchy
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Sarah A. Saslow
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Gary L. Smith
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Brian J. Riley
- Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle BLVD, Richland, Washington 99352, United States
| | - Rodney S. Skeen
- Washington River Protection Solutions, LLC, 2505 Garlick Rd, Richland, Washington 99352, United States
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3
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Efficient removal of iodide/iodate from aqueous solutions by Purolite A530E resin. J Radioanal Nucl Chem 2023. [DOI: 10.1007/s10967-023-08786-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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4
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Suorsa V, Otaki M, Suominen T, Virkanen J, Reijola H, Bes R, Koivula R. Anion exchange on hydrous zirconium oxide materials: application for selective iodate removal. RSC Adv 2023; 13:948-962. [PMID: 36686908 PMCID: PMC9811356 DOI: 10.1039/d2ra06489h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/19/2022] [Indexed: 01/05/2023] Open
Abstract
The radioactive 129I is a top-priority radionuclide due to its the long half-life (1.57 × 107 years) and high mobility. Because of the planned and accidental releases to the environment, specific separation technologies are required to limit the potential radiation dose to human beings. Zirconium oxides are known for their adsorption capability and selectivity to oxyanions and here the applicability to selective IO3 - removal has been investigated regarding the uptake mechanism, regeneration and competition caused by other anions, like environmentally relevant SO4 2-. Granular aggregates of hydrous zirconium oxides with and without Sb doping showed high potential for the selective IO3 - removal in the presence of competing anions, like the forementioned SO4 2- (apparent capacity between 0.1-0.4 meq g-1 depending on SO4 2- concentration). The main uptake mechanism was found to be outer-sphere complexation (ion-exchange) to the protonated hydroxyl groups of hydrous zirconium oxides, but also minor mechanisms were identified including inner-sphere complexation and reduction to I-. The materials were observed to be easily and successively regenerated using dilute acid. Hydrous zirconium oxides showed high potential for IO3 - removal from waste solutions regarding technical (high selectivity and apparent capacity) and ecological/economic (feasible regeneration) aspects.
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Affiliation(s)
- Valtteri Suorsa
- Radiochemistry Unit, Department of Chemistry, University of HelsinkiA.I. Virtasen aukio 100014 HelsinkiFinland
| | - Miho Otaki
- Radiochemistry Unit, Department of Chemistry, University of HelsinkiA.I. Virtasen aukio 100014 HelsinkiFinland
| | - Topi Suominen
- Radiochemistry Unit, Department of Chemistry, University of HelsinkiA.I. Virtasen aukio 100014 HelsinkiFinland
| | - Juhani Virkanen
- Department of Geosciences and Geography, University of HelsinkiGustaf Hällströmin katu 200014 HelsinkiFinland
| | - Hanna Reijola
- Department of Geosciences and Geography, University of HelsinkiGustaf Hällströmin katu 200014 HelsinkiFinland
| | - René Bes
- Department of Physics, University of HelsinkiPO Box 64FI-00014 HelsinkiFinland,Helsinki Institute of PhysicsPO Box 64FI-00014 HelsinkiFinland
| | - Risto Koivula
- Radiochemistry Unit, Department of Chemistry, University of HelsinkiA.I. Virtasen aukio 100014 HelsinkiFinland
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5
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Robshaw TJ, Turner J, Tuck O, Pyke C, Kearney S, Simoni M, Sharrad CA, Walkley B, Ogden MD. Functionality screening to help design effective materials for radioiodine abatement. Front Chem 2022; 10:997147. [PMID: 36329859 PMCID: PMC9623042 DOI: 10.3389/fchem.2022.997147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
This paper is part of a growing body of research work looking at the synthesis of an optimal adsorbent for the capture and containment of aqueous radioiodine from nuclear fuel reprocessing waste. 32 metalated commercial ion exchange resins were subjected to a two-tier screening assessment for their capabilities in the uptake of iodide from aqueous solutions. The first stage determined that there was appreciable iodide capacity across the adsorbent range (12–220 mg·g−1). Candidates with loading capacities above 40 mg·g−1 were progressed to the second stage of testing, which was a fractional factorial experimental approach. The different adsorbents were treated as discrete variables and concentrations of iodide, co-contaminants and protons (pH) as continuous variables. This gave rise to a range of extreme conditions, which were representative of the industrial challenges of radioiodine abatement. Results were fitted to linear regression models, both for the whole dataset (R2 = 59%) and for individual materials (R2 = 18–82%). The overall model determined that iodide concentration, nitrate concentration, pH and interactions between these factors had significant influences on the uptake. From these results, the top six materials were selected for project progression, with others discounted due to either poor uptake or noticeable iodide salt precipitation behaviour. These candidates exhibited reasonable iodide uptake in most experimental conditions (average of >20 mg·g−1 hydrated mass), comparing favourably with literature values for metallated adsorbents. Ag-loaded Purolite S914 (thiourea functionality) was the overall best-performing material, although some salt precipitation was observed in basic conditions. Matrix effects not withstanding it is recommended that metalated thiourea, bispicolylamine, and aminomethylphosphonic acid functionalized silicas warrant further exploration.
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Affiliation(s)
- Thomas J. Robshaw
- Department of Chemical and Biological Engineering, the University of Sheffield, Sheffield, United Kingdom
- Faculty of Life Sciences, University of Bradford, Bradford, United Kingdom
| | - Joshua Turner
- National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, United Kingdom
| | - Olivia Tuck
- National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, United Kingdom
| | - Caroline Pyke
- National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, United Kingdom
| | - Sarah Kearney
- Department of Chemical and Biological Engineering, the University of Sheffield, Sheffield, United Kingdom
| | - Marco Simoni
- Department of Chemical and Biological Engineering, the University of Sheffield, Sheffield, United Kingdom
| | - Clint A. Sharrad
- Department of Chemical Engineering and Analytical Science, the University of Manchester, Manchester, United Kingdom
| | - Brant Walkley
- Department of Chemical and Biological Engineering, the University of Sheffield, Sheffield, United Kingdom
| | - Mark D. Ogden
- Department of Chemical and Biological Engineering, the University of Sheffield, Sheffield, United Kingdom
- *Correspondence: Mark D. Ogden,
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6
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Shen Z, Wiechert AI, Choi S, Tavlarides LL, Tsouris C, Yiacoumi S. Silver Sulfide and Silver Sulfate as Aging Byproducts and Adsorbents for Gaseous Iodine Capture in Spent Nuclear Fuel Reprocessing. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c02024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ziheng Shen
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 200 Bobby Dodd Way, Atlanta, Georgia 30332-0373, United States
| | - Alexander I. Wiechert
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 200 Bobby Dodd Way, Atlanta, Georgia 30332-0373, United States
| | - Seungrag Choi
- Department of Biomedical and Chemical Engineering, Syracuse University, 130 Sims Dr, Syracuse, New York 13244, United States
| | - Lawrence L. Tavlarides
- Department of Biomedical and Chemical Engineering, Syracuse University, 130 Sims Dr, Syracuse, New York 13244, United States
| | - Costas Tsouris
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 200 Bobby Dodd Way, Atlanta, Georgia 30332-0373, United States
- Manufacturing Science Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, Tennessee 37830, United States
| | - Sotira Yiacoumi
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 200 Bobby Dodd Way, Atlanta, Georgia 30332-0373, United States
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7
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Fujii Yamagata A, Saslow SA, Neeway JJ, Varga T, Reno LR, Zhu Z, Rod KA, Johnson BR, Silverstein JA, Westsik JH, Smith GL, Asmussen RM. The behavior of iodine in stabilized granular activated carbon and silver mordenite in cementitious waste forms. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 244-245:106824. [PMID: 35121278 DOI: 10.1016/j.jenvrad.2022.106824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/12/2022] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Both granular activated carbon (GAC) and silver mordenite (AgM) are utilized for the removal of contaminants and radionuclides (e.g., radioiodine) from off-gas streams in nuclear fuel reprocessing and high temperature immobilization of nuclear waste. Following their service lifetimes, the GAC and AgM contain an inventory of contaminants and radionuclides and require stabilization in a matrix for disposal. GAC and AgM are referred to as solid secondary waste (SSW) materials. Cementitious waste forms can be used as the stabilization matrix for SSW, however, for successful stabilization, the inclusion of GAC and AgM should not negatively impact the physical behavior of the cementitious waste form or increase release of the contaminants/radionuclides compared to the baseline case without stabilization. The present work focuses on evaluation of cement formulations, with and without slag, for the stabilization of iodine-loaded GAC or AgM. The results showed that both a slag-containing and slag-free formulations were able to stabilize GAC and AgM, up to 30 vol%, without deleterious impacts on the bulk physical properties of the encapsulating matrix. When monolithic samples of the GAC or AgM containing cement formulations were subjected to leach tests, it was observed that iodide leached from the SSW) had limited sorption to either of the cement matrices. Nonetheless, the iodine can interact with the SSW materials themselves. Specifically, iodine retention within monolithic samples containing the iodine-loaded GAC or AgM was improved for AgM containing waste forms while no improvement was observed for the GAC containing waste forms. The improvement for the AgM containing waste forms was likely due to an enrichment of Ag at the interface between the AgM particles and the cement matrix that can impede iodine migration out from the waste form. The results are significant in highlighting the potential for long-term retention of iodine in specific cementitious waste forms.
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Affiliation(s)
| | - Sarah A Saslow
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - James J Neeway
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Tamas Varga
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Loren R Reno
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Zihua Zhu
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Kenton A Rod
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | | | - Joshua A Silverstein
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Joseph H Westsik
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Gary L Smith
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - R Matthew Asmussen
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA.
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8
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Robshaw TJ, Turner J, Kearney S, Walkley B, Sharrad CA, Ogden MD. Capture of aqueous radioiodine species by metallated adsorbents from wastestreams of the nuclear power industry: a review. SN APPLIED SCIENCES 2021. [DOI: 10.1007/s42452-021-04818-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Abstract
Abstract
Iodine-129 poses a significant challenge in the drive towards lowering radionuclide emissions from used nuclear fuel recycling operations. Various techniques are employed for capture of gaseous iodine species, but it is also present, mainly as iodide anions, in problematic residual aqueous wastestreams, which have stimulated research interest in technologies for adsorption and retention of the radioiodine. This removal effort requires specialised adsorbents, which use soft metals to create selectivity in the challenging chemical conditions. A review of the literature, at laboratory scale, reveals a number of organic, inorganic and hybrid adsorbent matrices have been investigated for this purpose. They are functionalised principally by Ag metal, but also Bi, Cu and Pb, using numerous synthetic strategies. The iodide capacity of the adsorbents varies from 13 to 430 mg g−1, with ion-exchange resins and titanates displaying the highest maximum uptakes. Kinetics of adsorption are often slow, requiring several days to reach equilibrium, although some ligated metal ion and metal nanoparticle systems can equilibrate in < 1 h. Ag-loaded materials generally exhibit superior selectivity for iodide verses other common anions, but more consideration is required of how these materials would function successfully in industrial operation; specifically their performance in dynamic column experiments and stability of the bound radioiodine in the conversion to final wasteform and subsequent geological storage.
Article highlights
Metallated adsorbents for the capture and retention of radioiodine in the nuclear industry are assessed.
The strengths and weaknesses of organic, inorganic and hybrid support matrices and loading mechanisms are discussed.
Pathways for progression of this technology are proposed.
Graphic abstract
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9
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Abstract
AbstractAg–bentonite was prepared by ion exchange process to sorb iodide and chloride ions in batch experiments. The modified bentonite was examined with XRF and XRD. 75% of the cation exchange capacity was exchanged by silver ions. It was found that the sorption of chloride ions is an exothermic precipitation process because the solubility decreases with increasing temperature. In the case of iodide sorption, the dissolution of AgI was observed under high concentration of non-radioactive iodide ions, which is well known in analytical chemistry. The phenomenon occurs not only in the bulk aqueous phase but also in the interlayer space of montmorillonite.
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10
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Inglezakis VJ, Satayeva A, Yagofarova A, Tauanov Z, Meiramkulova K, Farrando-Pérez J, Bear JC. Surface Interactions and Mechanisms Study on the Removal of Iodide from Water by Use of Natural Zeolite-Based Silver Nanocomposites. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1156. [PMID: 32545557 PMCID: PMC7353426 DOI: 10.3390/nano10061156] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 12/01/2022]
Abstract
In this work a natural zeolite was modified with silver following two different methods to derive Ag2O and Ag0 nanocomposites. The materials were fully characterized and the results showed that both materials were decorated with nanoparticles of size of 5-25 nm. The natural and modified zeolites were used for the removal of iodide from aqueous solutions of initial concentration of 30-1400 ppm. Natural zeolite showed no affinity for iodide while silver forms were very efficient reaching a capacity of up to 132 mg/g. Post-adsorption characterizations showed that AgI was formed on the surface of the modified zeolites and the amount of iodide removed was higher than expected based on the silver content. A combination of experimental data and characterizations indicate that the excess iodide is most probably related to negatively charged AgI colloids and Ag-I complexes forming in the solution as well as on the surface of the modified zeolites.
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Affiliation(s)
- Vassilis J. Inglezakis
- Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur Sultan 010000, Kazakhstan; (A.S.); (A.Y.)
- Environment & Resource Efficiency Cluster (EREC), Nazarbayev University, Nur Sultan 010000, Kazakhstan
| | - Aliya Satayeva
- Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur Sultan 010000, Kazakhstan; (A.S.); (A.Y.)
- Environment & Resource Efficiency Cluster (EREC), Nazarbayev University, Nur Sultan 010000, Kazakhstan
| | - Almira Yagofarova
- Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur Sultan 010000, Kazakhstan; (A.S.); (A.Y.)
- Environment & Resource Efficiency Cluster (EREC), Nazarbayev University, Nur Sultan 010000, Kazakhstan
| | - Zhandos Tauanov
- Faculty of Chemistry and Chemical Technology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan;
| | - Kulyash Meiramkulova
- Department of Environmental Engineering & Management, L.N.Gumilyov Eurasian National University, Nur Sultan 010000, Kazakhstan;
| | - Judit Farrando-Pérez
- Laboratorio de Materiales Avanzados, Departamento de Química Inorgánica-Instituto Universitario de Materiales, Universidad de Alicante, 03690 Alicante, Spain;
| | - Joseph C. Bear
- School of Life Science, Pharmacy & Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK;
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11
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Moore RC, Pearce CI, Morad JW, Chatterjee S, Levitskaia TG, Asmussen RM, Lawter AR, Neeway JJ, Qafoku NP, Rigali MJ, Saslow SA, Szecsody JE, Thallapally PK, Wang G, Freedman VL. Iodine immobilization by materials through sorption and redox-driven processes: A literature review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 716:132820. [PMID: 31982189 DOI: 10.1016/j.scitotenv.2019.06.166] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 06/10/2023]
Abstract
Radioiodine-129 (129I) in the subsurface is mobile and limited information is available on treatment technologies. Scientific literature was reviewed to compile information on materials that could potentially be used to immobilize 129I through sorption and redox-driven processes, with an emphasis on ex-situ processes. Candidate materials to immobilize 129I include iron minerals, sulfur-based materials, silver-based materials, bismuth-based materials, ion exchange resins, activated carbon, modified clays, and tailored materials (metal organic frameworks (MOFS), layered double hydroxides (LDHs) and aerogels). Where available, compiled information includes material performance in terms of (i) capacity for 129I uptake; (ii) long-term performance (i.e., solubility of a precipitated phase); (iii) technology maturity; (iv) cost; (v) available quantity; (vi) environmental impact; (vii) ability to emplace the technology for in situ use at the field-scale; and (viii) ex situ treatment (for media extracted from the subsurface or secondary waste streams). Because it can be difficult to compare materials due to differences in experimental conditions applied in the literature, materials will be selected for subsequent standardized batch loading tests.
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Affiliation(s)
- Robert C Moore
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Carolyn I Pearce
- Pacific Northwest National Laboratory, Richland, WA, United States of America.
| | - Joseph W Morad
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Sayandev Chatterjee
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | | | - Robert M Asmussen
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Amanda R Lawter
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - James J Neeway
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Nikolla P Qafoku
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Mark J Rigali
- Sandia National Laboratories, Albuquerque, NM, United States of America
| | - Sarah A Saslow
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Jim E Szecsody
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | | | - Guohui Wang
- Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Vicky L Freedman
- Pacific Northwest National Laboratory, Richland, WA, United States of America
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12
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Asmussen RM, Matyáš J, Qafoku NP, Kruger AA. Silver-functionalized silica aerogels and their application in the removal of iodine from aqueous environments. JOURNAL OF HAZARDOUS MATERIALS 2019; 379:119364. [PMID: 29753522 DOI: 10.1016/j.jhazmat.2018.04.081] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 04/01/2018] [Accepted: 04/29/2018] [Indexed: 06/08/2023]
Abstract
One of the key challenges for radioactive waste management is the efficient capture and immobilization of radioiodine, because of its radiotoxicity, high mobility in the environment, and long half-life (t1/2 = 1.57 × 107 years). Silver-functionalized silica aerogel (AgAero) represents a strong candidate for safe sequestration of radioiodine from various nuclear waste streams and subsurface environments. Batch sorption experiments up to 10 days long were carried out in oxic and anoxic conditions in both deionized water (DIW) and various Hanford Site Waste Treatment Plant (WTP) off-gas condensate simulants containing from 5 to 10 ppm of iodide (I-) or iodate (IO3-). Also tested was the selectivity of AgAero towards I- in the presence of other halide anions. AgAero exhibited fast and complete removal of I- from DIW, slower but complete removal of I- from WTP off-gas simulants, preferred removal of I- over Br- and Cl-, and it demonstrated ability to remove IO3- through reduction to I-.
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Affiliation(s)
- R Matthew Asmussen
- Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA
| | - Josef Matyáš
- Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA.
| | - Nikolla P Qafoku
- Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA
| | - Albert A Kruger
- U.S. Department of Energy, Office of River Protection, P.O. Box 450, Richland, WA, 99352, USA
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13
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Li D, Kaplan DI, Price KA, Seaman JC, Roberts K, Xu C, Lin P, Xing W, Schwehr K, Santschi PH. Iodine immobilization by silver-impregnated granular activated carbon in cementitious systems. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 208-209:106017. [PMID: 31325735 DOI: 10.1016/j.jenvrad.2019.106017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 06/10/2023]
Abstract
Silver (Ag)-based technologies are amongst the most common approaches to removing radioiodine from aqueous waste streams. As a result, a large worldwide inventory of radioactive AgI waste presently exits, which must be stabilized for final disposition. In this work, the efficacy of silver-impregnated granular activated carbon (Ag-GAC) to remove iodide (I-), iodate (IO3-) and organo-iodine (org-I) from cementitious leachate was examined. In addition, cementitious materials containing I-, IO3-, or org-I loaded Ag-GAC were characterized by iodine K-edge XANES and EXAFS to provide insight into iodine stability and speciation in these waste forms. The Ag-GAC was very effective at removing I- and org-I, but ineffective at removing IO3- from slag-free grout leachate under oxic conditions. I- or org-I removal was due to the formation of insoluble AgI(s) or Ag-org-I(s) on the Ag-GAC. When I--loaded Ag-GAC material was cured with slag-free and slag grouts, I- was released from AgI(s) to form a hydrated I- species. Conversely, when org-I loaded Ag-GAC material was cured in the two grout formulations, no change was observed in the iodine speciation, indicating the org-I species remained bound to the Ag. Because little IO3- was bound to the Ag-GAC, it was not detectable in the grout. Thus, grout formulation and I speciation in the waste stream can significantly influence the effectiveness of the long-term disposal of radioiodine associated with Ag-GAC in grout waste forms.
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Affiliation(s)
- Dien Li
- Savannah River National Laboratory, Aiken, SC, 29808, United States.
| | - Daniel I Kaplan
- Savannah River National Laboratory, Aiken, SC, 29808, United States
| | - Kimberly A Price
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, 29802, United States
| | - John C Seaman
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, 29802, United States
| | - Kimberly Roberts
- Savannah River National Laboratory, Aiken, SC, 29808, United States
| | - Chen Xu
- Department of Marine Science, Texas A & M University at Galveston, Galveston, TX, 77553, United States
| | - Peng Lin
- Department of Marine Science, Texas A & M University at Galveston, Galveston, TX, 77553, United States
| | - Wei Xing
- Department of Marine Science, Texas A & M University at Galveston, Galveston, TX, 77553, United States
| | - Kathleen Schwehr
- Department of Marine Science, Texas A & M University at Galveston, Galveston, TX, 77553, United States
| | - Peter H Santschi
- Department of Marine Science, Texas A & M University at Galveston, Galveston, TX, 77553, United States
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Li D, Kaplan DI, Sams A, Powell BA, Knox AS. Removal capacity and chemical speciation of groundwater iodide (I -) and iodate (IO 3-) sequestered by organoclays and granular activated carbon. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 192:505-512. [PMID: 30114621 DOI: 10.1016/j.jenvrad.2018.08.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/06/2018] [Accepted: 08/08/2018] [Indexed: 06/08/2023]
Abstract
Radioiodine (present mostly as 129I) is difficult to remove from waste streams or contaminated groundwater because it tends to exist as multiple anionic species (i.e., iodide (I-), iodate (IO3-) and organo-iodide) that do not bind to minerals or synthetic materials. In this work, the efficacy of organoclay OCB and OCM, and granular activated carbon (GAC) as sorbents to bind I- and IO3- from artificial groundwater (AGW) was examined. These sorbents were highly effective at removing I- and IO3- from AGW under oxic condition, with the adsorption capacity up to 30 mg I/g sorbent. Based on X-ray spectroscopy measurements, I- was bound to organic ligands in organoclays OCB and OCM, but when GAC was exposed to I- in groundwater, the sequestered I species was molecular I2. For IO3- interacting with organoclay OCB and GAC, the adsorbed I species remained being IO3-, but when organoclay OCM that contains both quaternary amine and sulfur was exposed to IO3-, the sulfur compound would reduce IO3- to I- that was then bound to organic ligands. Thus, the inexpensive and high-capacity organoclays and GAC may provide a practical solution for removing 129I contaminant from environmental systems and liquid nuclear wastes.
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Affiliation(s)
- Dien Li
- Savannah River National Laboratory, Aiken, SC, 29808, USA.
| | | | - Allison Sams
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA
| | - Brian A Powell
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA; Department of Chemistry, Clemson University, Anderson, SC, 29625, USA
| | - Anna S Knox
- Savannah River National Laboratory, Aiken, SC, 29808, USA
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