Removal of Radiocesium from Aqueous Media with Zinc–Aluminum Layered Double Hydroxide Intercalated with Copper(II) Hexacyanoferrate

Abstract

Sorption of radiocesium from aqueous media with zinc–aluminum layered double hydroxide intercalated with copper(II) hexacyanoferrate (Zn/Al-CuFeCN) was studied. The highest ¹³⁷Cs distribution coefficients (790–850 cm³ g^–1) on this sorbent are reached at initial pH in the range 5.0–9.0 (pH after sorption 6.8–7.3). The limiting value of the Cs⁺ adsorption onto Zn/Al-CuFeCN, calculated from the Langmuir equation, is 64.1 mg g^–1. At a concentration of up to 100 mg dm^–3, Na⁺ ions do not noticeably affect the Cs⁺ sorption onto Zn/Al-CuFeCN, whereas the K⁺ and Ca²⁺ ions slightly (by 5–10%) decrease the degree of the Cs⁺ removal. The sorbent shows high selectivity (99.8%) in decontamination of natural water.