Immobilization of cesium in alkaline activated fly ash matrix

Borosilicate and aluminosilicate pollucite nanocrystals for the storage of radionuclides

“…The specific conditioning of this element should optimize the global management of the package of high-level waste. Current Portland cement-based technologies for the concentration and immobilization of 135 Cs and 137 Cs are mainly used for low-level wastes, but often present unsatisfactory leaching behaviour [1], albeit several additives have been proposed to improve their leaching behaviour [2][3][4]. The borosilicate glass is the most common industrial solution used for the immobilization of high-level waste [5,6].…”

Geopolymerisation kinetics. 3. Effects of Cs and Sr salts

“…One such application is the immobilisation of caesium and/or strontium, active isotopes of which are problematic species present in many radioactive and nuclear waste streams. Initial work over a decade ago showed some potentially promising results (Davidovits and Comrie, 1988;Khalil and Merz, 1994), and research since that time has resulted in the development of geopolymer formulations with enhanced performance in caesium and strontium immobilisation (Bao et al, 2005;Fernández-Jiménez et al, 2005;Perera et al, 2006;Vance et al, 2006;Berger et al, 2007). The physicochemical and structural roles played by Cs + and Sr 2+ within the geopolymer binder structure were also recently studied in detail by Blackford et al (2007).…”

Mechanisms of Heavy Metal Immobilisation using Geopolymerisation Techniques – A review

“…In contrast, the predominance of chemical immobilisation was proven by Fernandez-Jimenez et al (2005), in which As was supposed to be chemically bound rather than physically encapsulated. To be more specific, As was found to be associated with amorphous Fe-rich regions within fly ash based geopolymers through EDX data.…”