cesium chromate (Cs2CrO4) is a yellow crystalline solid that is the caesium salt of chromic acid. It is used in a variety of applications, from oil well drilling fluids to atomic clocks and centrifugation fluids.
Unlike other elements in the periodic table, cesium is not stable and is radioactive; hence it must be stored and handled with great care. It can be absorbed by the skin and may cause irritation of the respiratory tract. It is also toxic in high levels and can be corrosive to eyes, skin, and the liver.
The adsorption of Cs from water is very important in wastewater treatment, especially after the Fukushima Daiichi nuclear power plant accident. Various effective adsorbents have been studied and developed for Cs removal from radioactive waste seawater.
In this study, we investigated the adsorption of Cs from DI water and seawater using a combination of base-activated OMs. The Kd values of each adsorbent were almost equal, and the base-activated OM was found to have the higher Cs adsorption capacity.
The surface negative charge induced by the deprotonation of base-activated OMs was a major advantage for Cs adsorption. Mineralogical properties and Cs adsorption results of the different OMs suggest that the surface negative charges of the mineral surface in base-activated OMs could induce a pH-dependent redox reaction to desorb Cs ions from the mineral surface, as shown in the XPS spectra.
