Compact Storage of Radioactive Cesium in Compressed Pellets of Zeolite Polymer Composite Fibers

Abstract

To facilitate the safe storage of radioactive Cs, a zeolite–poly(ethersulfone) composite fiber was fabricated to be a compact storage form of radioactive Cs, and an immobilization was investigated with respect to the effects of volume reduction and stability of the fiber’s adsorbent matrix. Using compressed heat treatment at 100–800 °C for a zeolite polymer composite fiber (ZPCF) containing Cs, the fabrication changed its form from a fiber into a pellet, which decreased the matrix volume to be about one-sixth of its original volume. The Cs leakage behavior of the ZPCF matrix was examined in its compact pellet form for non-radioactive Cs and radioactive Cs when different fabrication conditions were carried out in the immobilization. The elution ratio of non-radioactive Cs from the matrix was minimal, at 0.05%, when the ZPCF was compressed with heat treatment at 300 °C. When using radioactive Cs for the compression at below 300 °C, the pellet form also had no elution of the pollutants from the matrix. When the compressed treatment was at 500 °C, the matrix exhibited elution of radioactive Cs to the outside, meaning that the plastic component was burning and decomposed in the pellet. A comparison of ZPCF and natural zeolite indicated that the compressed heating process for ZPCF was useful in a less-volume-immobilized form of the compact adsorbent for radioactive Cs storage.

Rare-Earth Metals-Doped Nickel Aluminate Spinels for Photocatalytic Degradation of Organic Pollutants

“…Furthermore, the bands which occurred at 1639 cm −1 arose from the H-O-H deformation vibrations of water molecules. Since the calcination of the catalysts underwent at 800 °C, and thus water should have been eliminated, we attributed the presence of the adsorbed water molecules to the absorption from the atmosphere during the IR pellets formation [44,45]. Importantly, all samples revealed the bands in the 400-1000 The FTIR spectroscopy analysis allowed us to prove the spinel nickel aluminate structure of the prepared materials and to investigate the presence of the functional groups on the catalysts' surfaces (see Figure 2b).…”

Nylon-6–Mordenite Composite Membranes for Adsorption of Ethylene Gas Released from Chiquita Bananas

“…Thus, those composite membranes have advantageous properties in the process for practical uses with lower volume and easily move the compact forms in the preferred positions. 16,18,19 In addition, porous composite materials have high adsorption capacity and potential for recovery property. In the case of gaseous separation, there were studies on membrane formed adsorbers.…”

“…As mentioned above, mostly the adsorbents had forms of porous powder; but relative to such powder adsorbents, some disadvantages are in handing off and settle in the operation process. Thus, those composite membranes have advantageous properties in the process for practical uses with lower volume and easily move the compact forms in the preferred positions. ,, In addition, porous composite materials have high adsorption capacity and potential for recovery property. In the case of gaseous separation, there were studies on membrane formed adsorbers. ,, For instance, Norwahyu et al fabricated composite membranes containing different loadings of zeolite T into a 6FDA–durene polymer and used them for CO 2 /CH 4 separation .…”