Cs⁺ decontamination properties of mordenites and composite materials synthesized from coal fly ash and rice husk ash

Abstract

Mordenites were synthesized using the natural resource such as coal fly ash and rice husk ash. The Cs + adsorption rate (100 ppm Cs + , 100 mL) in seawater for the prepared mordenite (1.0 g) was 83.2%. The Cs + adsorption rate for these mordenites almost depended on the calculated Cs + exchangeable value (mmol) using the cation exchange capacity (CEC) values. Composite powder materials consisting of mordenite and nanosized magnetite (Fe 3 O 4 ) (10, 20, 30 wt%) were also synthesized from coal fly ash and rice husk ash. The total Cs + decontamination rates using the magnetic collection after the Cs + adsorption in water and seawater were ca. 90% and ca. 70% for the examined 20 wt% magnetite-containing composite material, respectively. Although the elution ratio of the Cs + ion was ca. 8% from all of the adsorbed Cs + by the dissolution test in slowly shaken deionized water for 14 days in the case of the Cs + adsorbed composite material (20wt% magnetite), the Cs + ion did not elute when the sample was heated at 1000°C and higher temperature due to the Cs + containment in the glassy phase.

Optimization of the Solidification Method of High-Level Waste for Increasing the Thermal Stability of the Magnesium Potassium Phosphate Compound

“…Natural zeolites (NZ) contain clinoptilolite with a unique structure, which provides a high cation exchange ability of these sorbents and selectivity for cesium release [15][16][17][18]. Synthetic zeolite-mordenite Na 8 Al 8 Si 40 O 96 × 24H 2 O (MOR) has 12-ring cavities with a diameter of 6.5 Å or more in its structure, thus it is easy to place Cs + ions with a radius of 3.40 Å in these cavities [19][20][21].…”