Rates of Exchange of Cs + and Sr 2+ for Poorly Crystalline Sodium Titanium Silicate (CST) in Nuclear Waste Systems

Academic Article


  • The compound sodium titanium silicate, popularly known as CST, is highly selective for Cs +. It was synthesized for the purpose of removing 137Cs from basic nuclear waste systems. This compound has a tunnel structure in which the Cs + ion just fits but diffusion through the tunnels is relatively slow. CST loses its ability to sequester Cs + in the strongly basic nuclear waste solutions. However, replacement of titanium with 25 mol% of niobium increases the selectivity to a satisfactory level. It has been found that producing a less crystalline form of Nb-CST greatly improves the rate of Cs + removal. Additionally, the non-niobium CST is selective for strontium both as Sr 2+ and Sr(OH) +. It is suggested that both radioisotopes of cesium and strontium may be efficiently extracted by a combination of a mixture of poorly crystalline CST and Nb-CST. © 2012 Copyright Taylor and Francis Group, LLC.
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    Author List

  • Clearfield A; Medvedev DG; Kerlegon S; Bosser T; Burns JD; Jackson M
  • Start Page

  • 229
  • End Page

  • 243
  • Volume

  • 30
  • Issue

  • 3