Selective Separation of Radiocesium from Complex Aqueous Matrices Using Dual Solid-Phase Extraction Systems

The release of radiocesium (r-Cs) into natural aqueous systems is of concern because of its extended solubility as an alkaline metal ion and its facile incorporation into living beings. A technique for the selective separation of Cs from an aqueous matrix using dual solid-phase extraction (SPE) systems in a series is proposed in this paper. The SPEs equipped with chelates (Nobias Chelate-PA1 and Nobias Chelate-PB1), an ion-exchange resin (Nobias Ion SC-1), or macrocycles (MetaSEP AnaLig Cs-01 and MetaSEP AnaLig Cs-02) were evaluated in terms of selectivity and retention/recovery behavior toward Cs and other potentially competing ions (Li, Na, K, Rb, Ba, Ca, Mg, and Sr). The simulated solution of Cs-133, a chemical analog of r-Cs, was used to optimize the separation process. Operating parameters such as pH (3-13), flow rate (0.2-5.0 mL min(-1)), and elution behavior (HCl, 0.1-5.0 mol L-1) were optimized to ensure maximum removal of Cs from the aqueous matrices. The dual SPE system comprised Nobias Chelate-PB1 that minimized the competing impact of ions, while selective Cs retention was attained with MetaSEP AnaLig Cs-02. The proposed process was verified using real r-Cs-contaminated water from Fukushima, Japan, to observe the quantitative separation and preconcentration of r-Cs from the complex matrices. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This paper proposes a technique for selective separation of Cs from water using dual solid-phase extraction systems. Various materials were evaluated for selectivity and retention behavior towards Cs and other competing ions, with operating parameters optimized for maximum Cs removal. The dual SPE system successfully separated and preconcentrated radioactive Cs from complex matrices, as demonstrated with contaminated water samples from Fukushima, Japan.