Selective removal of cesium from aqueous solutions with nickel (Ⅱ) hexacyanoferrate (Ⅲ) functionalized agricultural residue-walnut shell

摘要

A novel nickel (Ⅱ) hexacyanoferrate (Ⅲ) functionalized agricultural residue-walnut shell (Ni~(Ⅱ)HCF~(Ⅲ)-WS) was developed to selectively remove cesium ion (Cs~+) from aqueous solutions. This paper showed the first integral study on Cs~+ removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2 h. As a special characteristic of Ni~(Ⅱ)HCF~(Ⅲ)-WS, acidic condition was preferred for Cs~+ removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni~(Ⅱ)HCF~(Ⅲ)-WS could selectively remove Cs~+ though the coexisting ions (Na~+ and K~+ in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni~(Ⅱ)HCF~(Ⅲ)-WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni~(Ⅱ)HCF~(Ⅲ)-WS) was reduced after incineration (at 500 ℃ for 2h). Due to its relatively high distribution coefficient and significant volume reduction, Ni~(Ⅱ)HCF~(Ⅲ)-WS is expected to be a promising material for Cs~+ removal in practice.