Removal of radioactive cesium from solutions by zinc ferrocyanide

Adsorption of 134Cs from aqueous solution by zinc ferrocyanide, and the effect of experimental conditions on the adsorption were investigated. Preliminary results showed that zinc ferrocyanide was very efficient as an absorbent. Over 98% of 134Cs could be removed by zinc ferrocyanide of 0.33 g·L−1 from 134Cs solution (Co) of 3.2∼160.0 kBq·L−1, with adsorption capacities (Q) of 9.6∼463.0 kBq·g−1. The adsorption equilibrium time was within one hour and the suitable pH ranged 1∼10. No significant differences on 134Cs adsorption were obsrved at 0∼50°C, or in solutions containing Ca2+, Fe3+, Mg2+, HCO3−, CO32- Cl− and SO42-, even though they are 1000 times higher than the anions or cations in groundwater. However, the adsorption rates decreased when solutions contained K+ or Na+. The adsorption process could be described by Freundlich and Langmuir adsorption equations.