The effect of amorphization on the Cs ion exchange and retention capacity of zeolite-NaY

Clay mineral weathering and contaminant dynamics in a caustic aqueous system

“…15a). However, unlike the case for Il and Vm, the ED patterns of these particles rapidly disappear under electron beam exposure, suggesting that these zeolites are susceptible to radiation damage (Gu et al, 2000;Wang et al, 2000). EDS data indicate that they comprise dominantly Si, Al (with Si:Al ϳ 1) and Na, in addition to smaller amounts of Sr and Cs (Fig.…”

“…Zeolite properties, such as Cs or Sr retention, may be altered as a result of radiation-induced crystalline-to-amorphous transitions at temperatures in the range of 400 to 900°C (Kosanović et al, 1996(Kosanović et al, , 1998Colantuono et al, 1997;Alberti et al, 2001;Joshi et al, 2002). Thermal treatment and dehydration cause the rearrangement of extra-framework cations and residual water molecules (Gu et al, 2000;Hunger et al, 2000). For example, Gu et al (2000) found that radiationinduced crystalline-to-amorphous transformation of Cs-exchanged zeolite NaY reduced ion exchange capacity over time, but it also enhanced the retention of Cs against desorption by blocking structural channels.…”

“…Thermal treatment and dehydration cause the rearrangement of extra-framework cations and residual water molecules (Gu et al, 2000;Hunger et al, 2000). For example, Gu et al (2000) found that radiationinduced crystalline-to-amorphous transformation of Cs-exchanged zeolite NaY reduced ion exchange capacity over time, but it also enhanced the retention of Cs against desorption by blocking structural channels. Further research is needed to quantify the potential for radionuclide immobilization in the context of high heat and radioactivity common in the impacted environments.…”

Cesium leaching from γ-irradiated CsA and CsX zeolites

“…With 200 and 400 keV electrons, analcime, natrolite and zeolite Y are amorphized at room temperature [11,12]. The effects of gamma irradiation have been compared to those due to a thermal treatment.…”

Static and dynamic properties of amorphous material derived from zeolite ZSM-5

“…ZSM-5 and ferrierite-based materials with low levels of X-ray diffraction (XRD) crystallinity were found to exhibit greater catalytic performance in the isomerization of linear butenes to iso-butenes compared to their crystalline analogs [2,3]. Amorphization caused by high radiation on certain zeolites shows enhancement of retention capacity of exchangeable ions due to the closure of structural channels [4,5]. Hence these can be used as back fill material for nuclear waste disposal [6,7].…”