LAYERED DOUBLE HYDROXIDE OF Zn AND AI MODIFIED BY [Fe(CN)]-ANIONS FOR THE SELECTIVE REMOVAL OF Cs FROM MODEL SOLUTIONS OF LIQUID RADIOACTIVE WASTE

Layered double hydroxides (LDH) have proven themselves as highly effective sorbents of heavy metals and radionuclides. In particular, modification of LDH with ferrocyanide ions is proposed for extraction of cesium-137. However, sorption-selective characteristics of modified LDH under conditions of extraction of cesium radionuclides from model and real solutions of liquid radioactive waste (LRW) remain unexplored to date. In this work, Zn-Al-LDH was obtained by direct coprecipitation with subsequent in situ intercalation of ferrocyanide anions into the interlayer space to achieve selectivity to cesium. In this work, adsorption kinetics was studied with obtaining the corresponding isotherms, the theoretical maximum sorption capacity is 201 mg/g, the experimentally obtained value is 197 mg/g. The effect of interfering ions on the adsorption of Cs was also studied and the distribution coefficients were determined: 4838 and 1763 ml/g under conditions of model solutions of low and moderate salinity, respectively, and 3259 ml/g in seawater. The resulting composite material demonstrates high potential for the selective extraction of cesium radionuclides from aqueous solutions of varying mineralization.