ИСТИНА

Sorption of 137Cs from aqueous solution onto LDHs of the composition LDH-М2+-М3+-Fe(CN)6 (М2+ = Mg, Cu, Ni, Zn; М3+ = Al, Fe) was studied. The LDH-Мg-М3+-Fe(CN)6 (М3+ = Al, Fe) take up 137Cs from 10–5 mol/l aqueous CsNO3 solutions extremely weakly, whereas the LDH-М2+-М3+-Fe(CN)6 (М2+ = Cu, Ni, Zn; М3+ = Al, Fe) solid phases efficiently take up 137Cs. After 15-min contact of the solid and liquid phases, the apparent distribution coefficient Kd* of 137Cs ranges from ~3∙102 to ~104 ml/g for M2+ = Cu, from ~4∙103 to ~2∙104 ml/g for M2+ = Ni, and from ~5∙103 to ~3∙104 ml/g for M2+ = Zn at V/m = 50 ml/g. As the NaOH concentration in the solution is increased, the sorption performance of the examined LDHs, except LDH-Ni-Al-Fe(CN)6, drastically decreases, which is due to the formation of LDH-M2+-M3+-OH (M2+ = Ni, Zn; М3+ = Al, Fe) having low ability to take up 137Cs.