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Title: Mechanism of iodine release from iodoapatite in aqueous solution

Abstract

Safe disposal of nuclear waste is essential to ensure the sustainability of nuclear energy. This is especially true for the volatile radionuclide iodine-129 due to its long half-life (15.7 Ma) and high mobility in most disposal environments. The dissolution behaviour of lead vanadium iodoapatite (Pb 5(VO 4) 3I) synthesized to evaluate its possible use for immobilizing iodine-129 was investigated to understand the mechanism by which iodide is released. Experiments using a semi-dynamic method were carried out in cap-sealed Teflon vessels at a constant temperature 90 ± 0.5 °C with a fixed sample surface area-to-solution volume ratio of 16 m -1. The leachates were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and the leached surfaces were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR). The results show that lead and vanadium dissolved congruently at a constant rate, while the iodine was initially released at a significantly higher rate than suggested by its stoichiometry with respect to lead and vanadium. The iodine-to-lead molar ratio in the solution gradually decreased over time, but iodine release remained superstoichiometric. The results suggest the release of iodide occurs by an ion-exchange process that is faster than the dissolution rate ofmore » the Pb–V–O framework. Analysis of the leached samples shows that the spectroscopic signature of OH groups in the leached samples is consistent with an ion exchange mechanism.« less

Authors:
ORCiD logo [1];  [2];  [2];  [3];  [4]; ORCiD logo [4]; ORCiD logo [1]
  1. Department of Geology and Geophysics, Louisiana State University, Baton Rouge, USA
  2. Department of Chemical Engineering, Louisiana State University, Baton Rouge, USA
  3. Nuclear Engineering, Argonne National Lab, Lemont, USA
  4. Department of Mechanical and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, USA
Publication Date:
Research Org.:
Louisiana State Univ., Baton Rouge, LA (United States); Rensselaer Polytechnic Inst., Troy, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1417677
Alternate Identifier(s):
OSTI ID: 1600980
Grant/Contract Number:  
SC0016584
Resource Type:
Published Article
Journal Name:
RSC Advances
Additional Journal Information:
Journal Name: RSC Advances Journal Volume: 8 Journal Issue: 8; Journal ID: ISSN 2046-2069
Publisher:
Royal Society of Chemistry
Country of Publication:
United Kingdom
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Zhang, Z., Heath, A., Valsaraj, K. T., Ebert, W. L., Yao, T., Lian, J., and Wang, J. Mechanism of iodine release from iodoapatite in aqueous solution. United Kingdom: N. p., 2018. Web. doi:10.1039/C7RA11049A.
Zhang, Z., Heath, A., Valsaraj, K. T., Ebert, W. L., Yao, T., Lian, J., & Wang, J. Mechanism of iodine release from iodoapatite in aqueous solution. United Kingdom. doi:10.1039/C7RA11049A.
Zhang, Z., Heath, A., Valsaraj, K. T., Ebert, W. L., Yao, T., Lian, J., and Wang, J. Mon . "Mechanism of iodine release from iodoapatite in aqueous solution". United Kingdom. doi:10.1039/C7RA11049A.
@article{osti_1417677,
title = {Mechanism of iodine release from iodoapatite in aqueous solution},
author = {Zhang, Z. and Heath, A. and Valsaraj, K. T. and Ebert, W. L. and Yao, T. and Lian, J. and Wang, J.},
abstractNote = {Safe disposal of nuclear waste is essential to ensure the sustainability of nuclear energy. This is especially true for the volatile radionuclide iodine-129 due to its long half-life (15.7 Ma) and high mobility in most disposal environments. The dissolution behaviour of lead vanadium iodoapatite (Pb5(VO4)3I) synthesized to evaluate its possible use for immobilizing iodine-129 was investigated to understand the mechanism by which iodide is released. Experiments using a semi-dynamic method were carried out in cap-sealed Teflon vessels at a constant temperature 90 ± 0.5 °C with a fixed sample surface area-to-solution volume ratio of 16 m-1. The leachates were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and the leached surfaces were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR). The results show that lead and vanadium dissolved congruently at a constant rate, while the iodine was initially released at a significantly higher rate than suggested by its stoichiometry with respect to lead and vanadium. The iodine-to-lead molar ratio in the solution gradually decreased over time, but iodine release remained superstoichiometric. The results suggest the release of iodide occurs by an ion-exchange process that is faster than the dissolution rate of the Pb–V–O framework. Analysis of the leached samples shows that the spectroscopic signature of OH groups in the leached samples is consistent with an ion exchange mechanism.},
doi = {10.1039/C7RA11049A},
journal = {RSC Advances},
number = 8,
volume = 8,
place = {United Kingdom},
year = {2018},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
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DOI: 10.1039/C7RA11049A

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Works referenced in this record:

Bulk Iodoapatite Ceramic Densified by Spark Plasma Sintering with Exceptional Thermal Stability
journal, July 2014

  • Yao, Tiankai; Lu, Fengyuan; Sun, Hongtao
  • Journal of the American Ceramic Society, Vol. 97, Issue 8
  • DOI: 10.1111/jace.13101

Experimental study of igneous and sedimentary apatite dissolution
journal, August 2003


Impact of leach on lead vanado-iodoapatite [Pb5(VO4)3I]: An infrared and Raman spectroscopic study
journal, February 2007

  • Zhang, Ming; Maddrell, E. R.; Abraitis, P. K.
  • Materials Science and Engineering: B, Vol. 137, Issue 1-3
  • DOI: 10.1016/j.mseb.2006.11.003

Elaboration of an iodine-bearing apatite Iodine diffusion into a Pb3(VO4)2 matrix
journal, February 1997


Rapid synthesis of Pb5(VO4)3I, for the immobilisation of iodine radioisotopes, by microwave dielectric heating
journal, July 2011


Wet chemical synthesis of apatite-based waste forms – A novel room temperature method for the immobilization of radioactive iodine
journal, January 2017

  • Cao, Charles; Chong, Saehwa; Thirion, Lynn
  • Journal of Materials Chemistry A, Vol. 5, Issue 27
  • DOI: 10.1039/C7TA00230K

Iodine solubility in a low-activity waste borosilicate glass at 1000°C
journal, September 2014


Synthesis of lead vanadate iodoapatite utilizing dry mechanochemical process
journal, November 2014


Materials and processes for the effective capture and immobilization of radioiodine: A review
journal, March 2016


Ion exchange equilibria in zeolite minerals
journal, September 1996


An evaluation of cement-based waste forms using the results of approximately two years of dynamic leaching
journal, January 1987

  • Côtê, Pierre L.; Constable, Thomas W.; Moreira, Alan
  • Nuclear and Chemical Waste Management, Vol. 7, Issue 2
  • DOI: 10.1016/0191-815X(87)90007-6

MCC-1: A Standard Leach Test for Nuclear Waste Forms
journal, February 1982

  • Strachan, D. M.; Turcotte, R. P.; Barnes, B. O.
  • Nuclear Technology, Vol. 56, Issue 2
  • DOI: 10.13182/NT82-A32859

Spark plasma sintering of iodine-bearing apatite
journal, May 2010


Tailoring the radiation tolerance of vanadate–phosphate fluorapatites by chemical composition control
journal, January 2013

  • Lu, Fengyuan; Dong, Zhili; Zhang, Jiaming
  • RSC Advances, Vol. 3, Issue 35
  • DOI: 10.1039/c3ra42246a

New conditionings for separated long-lived radionuclides
journal, September 2002


Durability testing of an iodate-substituted hydroxyapatite designed for the conditioning of 129 I
journal, February 2017


Kinetics and mechanism of natural fluorapatite dissolution at 25°C and pH from 3 to 12
journal, December 2007

  • Chaïrat, Claire; Schott, Jacques; Oelkers, Eric H.
  • Geochimica et Cosmochimica Acta, Vol. 71, Issue 24
  • DOI: 10.1016/j.gca.2007.08.031

Iodine valence and local environments in borosilicate waste glasses using X-ray absorption spectroscopy
journal, January 2015


Incorporation of iodates into hydroxyapatites: a new approach for the confinement of radioactive iodine
journal, January 2011

  • Campayo, Lionel; Grandjean, Agnès; Coulon, Antoine
  • Journal of Materials Chemistry, Vol. 21, Issue 44
  • DOI: 10.1039/c1jm14157k

Metal ion exchange by natural and modified zeolites
journal, June 1997


Materials Science of High-Level Nuclear Waste Immobilization
journal, January 2009

  • Weber, William J.; Navrotsky, Alexandra; Stefanovsky, Sergey
  • MRS Bulletin, Vol. 34, Issue 1
  • DOI: 10.1557/mrs2009.12

Some properties of a lead vanado-iodoapatite Pb10(VO4)6I2
journal, April 2001


French Studies on the Development of Potential Conditioning Matrices for Iodine 129
journal, January 2015

  • Campayo, Lionel; Audubert, Fabienne; Lartigue, Jean-Eric
  • MRS Proceedings, Vol. 1744
  • DOI: 10.1557/opl.2015.309

The dissolution kinetics and apparent solubility of natural apatite in closed reactors at temperatures from 5 to 50 °C and pH from 1 to 6
journal, October 2007


The dissolution of apatite in the presence of aqueous metal cations at pH 2–7
journal, October 1998


Anion-Exchange Properties of Hydrotalcite-Like Compounds
journal, January 1983