Preparation of mordenite and its composite material with nano-sized magnetite from diatomites for radioactive Cs decontamination

Abstract

Mordenite was artificially synthesized using various diatomites for radioactive Cs decontamination. A high CEC (Cation Exchange Capacity) value was obtained when the diatomite had a high Al/Si elemental ratio. The Cs+ adsorption rate from 100 ppm Cs solution for the synthesized mordenite (1.0 g) was ca. 100% and ca. 83% in 100mL of water and seawater, respectively. The composite powder material consisting of mordenite and nano-sized magnetite was synthesized from a mixed slurry of the diatomite and nano-sized magnetite. Magnetic collection rate for the composite material using a neodymium magnet was larger than 90% for the 20 and 30 wt% magnetite-containing composite materials. The total Cs decontamination rates using magnetic collection after the Cs+ adsorption in water were 92.7% and 97.2% for the 20 and 30 wt% magnetite-containing composite material, respectively.