Encapsulation of iodine-loaded adsorbents in blended Portland cement and geopolymer wasteforms

Research output: Contribution to journalArticlepeer-review

Electronic versions

DOI

  • Marco Simoni
    a Department of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, U
  • Sarah Kearney
    a Department of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, U
  • Thomas Robshaw
    Nuclear Engineering Group, School of Chemical and Process Engineering, University of Leeds, Woodhouse, Leeds LS2 9JT, United Kingdom
  • Joshua Turner
    National Nuclear Laboratory Ltd., Warrington Road, Birchwood Park, Warrington WA3 6AE, UK
  • Kyle O'Donoghue
    a Department of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, U
  • Daniel Geddes
    a Department of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, U
  • Clint Sharrad
    Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
  • Mark Ogden
  • Brant Walkley
    a Department of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, U
Capture of radioiodine by solid adsorbents and subsequent cementation is a promising solution to achieve “Near Zero” emissions from nuclear fuel cycles. We investigate cementation of iodine-loaded silica adsorbents in blast furnace slag blended Portland cement (BFS:PC) and metakaolin-based geopolymers, and subsequent leaching in deionised water. Adsorbent encapsulation retarded BFS:PC hydration, but not geopolymer reaction. Phase assemblage was unaffected by adsorbent encapsulation for both BFS:PC and geopolymers, which comprised calcium aluminosilicate hydrate and potassium aluminosilicate hydrate gels, respectively. Adsorbents were encapsulated intact within BFS:PC, whereas adsorbents dissolved in the high pH of fresh geopolymers. BFS:PC exhibited low leaching stability and an alteration layer, however minimal iodine leaching occurred due to intact absorbents. Geopolymers showed high leaching stability, however adsorbent degradation resulted in significant iodine leaching. This evidences potential for cementation of radioiodine-loaded adsorbents under mild conditions, and highlights the importance of synergy when designing adsorbents and wasteforms for radioiodine abatement.
Original languageEnglish
Pages (from-to)107480
Number of pages12
JournalCement and Concrete Research
Volume179
Early online date26 Mar 2024
DOIs
Publication statusPublished - 1 May 2024
View graph of relations