Adsorption of cesium on bound porous materials containing embedded phosphotungstic acid
The adsorption of cesium on mesoporous silica materials containing embedded phosphotungstic acid (PTA) was studied. The materials contained active adsorbent and binders: γ-Al2O3, kaolin, or charcoal. The presence of Keggin units of PTA in the bound materials was confirmed by FT-IR spectroscopy. Among all materials, the formulation with γ-Al2O3 demonstrated the highest porosity and effectiveness in adsorption. Pure PTA/SiO2 contained a significant fraction of small particles between 100 and 300 nm. However, in the alumina-bound material, they were not detected. SEM imaging showed that these particles occupied interparticle space between larger γ-Al2O3 particles. The material was stable up to 540 °C. In most materials, the adsorption of cesium decreased with increase of the binder contents but not proportionally. The adsorption capacity of all materials depended on the concentration of cesium in the solutions. Maximum adsorption was achieved after 1 h. The adsorption of cesium is controlled by intraparticle diffusion while its rate can be described by the pseudo-second-order model.
KeywordsCesium Adsorption Phosphotunstic acid Silica gel γ-Alumina
This research was sponsored by NATO’s Emerging Security Challenges Division in the framework of the Science for Peace and Security Programme (Grant SfP 984639). We thank Prof. F. Hossler for recording SEM images, and Prof. M. Roginskaya for assistance in the manuscript preparation.
- Fujimura, S., Muramatsu, Y., Ohno, T., Saitou, M., Suzuki, Y., Kobayashi, T., Yoshioka, K., Ueda, Y.: Accumulation of 137Cs by rice grown in four types of soil contaminated by the Fukushima Dai-ichi nuclear power plant accident in 2011 and 2012. J. Environ. Radioact. 140, 59–64 (2015)CrossRefGoogle Scholar
- Marosi, L., Platero, E.E., Cifre, J., Arean, C.O.: Thermal dehydration of H3 + xPVxM12–xO40·yH2O Keggin type heteropolyacids; formation, thermal stability and structure of the anhydrous acids H3PM12O40, of the corresponding anhydrides PM12O38.5 and of a novel trihydrate H3PW12O40·3H2O. J. Mater. Chem. 10, 1949–1955 (2000)CrossRefGoogle Scholar
- Moffat, J.B.: Metal–oxygen clusters: the surface and catalytic properties of heteropoly oxometalates. Springer, New York (2001)Google Scholar
- Orth, R.J., Brooks, K.P., Kurath, D.E.: Review and assessment of technologies for the separation of cesium from acidic media. Pacific Northwest Laboratory, Richland (1994)Google Scholar
- Sangvanich, T., Sukwarotwat, V., Wiacek, R.J., Grudzien, R.M., Fryxell, G.E., Shane Addleman, R., Timchalk, C., Yantasee, W.: Selective capture of cesium and thallium from natural waters and simulated wastes with copper ferrocyanide functionalized mesoporous silica. J. Hazard. Mater. 182, 225–231 (2010)CrossRefGoogle Scholar