TY - JOUR
T1 - Titanosilicates
T2 - Giant exchange capacity and selectivity for Sr and Ba
AU - Noh, Young Dong
AU - Komarneni, Sridhar
AU - MacKenzie, Kenneth J.D.
PY - 2012/7/19
Y1 - 2012/7/19
N2 - Two different microporous Na-titanosilicates with high cation exchange capacities were synthesized and characterized by X-ray diffraction, scanning electron microscopy (SEM) and solid-state 29Si and 27Al magic-angle spinning nuclear magnetic resonance (MASNMR) spectroscopy. The ion exchange properties of Na-ETS-4 (ETS = Engelhard TitanoSilicate) and Na-titanosilicate were investigated for Sr 2+ and Ba 2+ using isotherms and Kielland plots in order to check the potential for the decontamination of 90Sr and 133Ba from nuclear waste solutions. Na-ETS-4 and Na-titanosilicate show high affinity for Sr 2+ to high equivalent fraction of Sr 2+ on solid phase. In case of Ba 2+ the selectivity coefficient of both titanosilicate exchangers rapidly decreased due to the steric hindrance at exchange sites at X Ba > ∼0.5. However, Na-ETS-4 was still selective for Ba 2+ even after the above rapid decrease in selectivity, unlike Na-titanosilicate. Therefore, Na-ETS-4 is one of the best candidates for the removal of both Sr 2+ and Ba 2+ from nuclear waste solutions.
AB - Two different microporous Na-titanosilicates with high cation exchange capacities were synthesized and characterized by X-ray diffraction, scanning electron microscopy (SEM) and solid-state 29Si and 27Al magic-angle spinning nuclear magnetic resonance (MASNMR) spectroscopy. The ion exchange properties of Na-ETS-4 (ETS = Engelhard TitanoSilicate) and Na-titanosilicate were investigated for Sr 2+ and Ba 2+ using isotherms and Kielland plots in order to check the potential for the decontamination of 90Sr and 133Ba from nuclear waste solutions. Na-ETS-4 and Na-titanosilicate show high affinity for Sr 2+ to high equivalent fraction of Sr 2+ on solid phase. In case of Ba 2+ the selectivity coefficient of both titanosilicate exchangers rapidly decreased due to the steric hindrance at exchange sites at X Ba > ∼0.5. However, Na-ETS-4 was still selective for Ba 2+ even after the above rapid decrease in selectivity, unlike Na-titanosilicate. Therefore, Na-ETS-4 is one of the best candidates for the removal of both Sr 2+ and Ba 2+ from nuclear waste solutions.
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U2 - 10.1016/j.seppur.2012.05.013
DO - 10.1016/j.seppur.2012.05.013
M3 - Article
AN - SCOPUS:84861769200
SN - 1383-5866
VL - 95
SP - 222
EP - 226
JO - Separation and Purification Technology
JF - Separation and Purification Technology
ER -