# Features of Uranium Recovery from Complex Aqueous Solutions Using Composite Sorbents Based on Se-Derivatives of Amidoximes

## TL;DR

This paper evaluates new composite materials for efficiently recovering uranium from complex water sources, showing high performance and reusability.

## Contribution

The study introduces Se-derivative amidoxime-based composite sorbents with high uranium recovery efficiency and reusability in complex aqueous solutions.

## Key findings

- Composite sorbents achieved 80–98% uranium recovery from real water samples.
- Materials maintained high efficiency even in the presence of competing ions like EDTA and oxalate.
- Desorption efficiency exceeded 95% using NaHCO3/NH4NO3, with no loss in performance over multiple cycles.

## Abstract

The article presents a comprehensive comparative performance evaluation and validation of composite adsorbents based on the Se-derivative of 4-amino-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide for U (VI) recovery from complex multicomponent aqueous media. Our results indicate the composite materials to be comparable to, and in some cases to surpass, existing adsorbents in recovery efficiency. Under static sorption conditions for trace U (VI) from real multicomponent solutions (tap, river, and sea water), the sorption efficiency reached 80–98%, while the distribution coefficients ranged from 104 to 106 cm3 g−1. The sorption-selectivity properties of the materials were evaluated in the presence of competing ions (EDTA and oxalate ions), which possess a high chelating capacity and a strong tendency to form complexes with uranium. The dependence of sorption efficiency on the concentration of these ions and the solution pH was investigated. The possibility of reusing the materials over multiple sorption-desorption cycles was assessed. An optimal regenerating eluent agent was identified (NaHCO3/NH4NO3), providing a desorption efficiency of >95% without degrading the material’s sorption properties over repeated cycles. Using a combination of physicochemical methods, including sorption techniques, the mechanism of uranium sorption and its dependence on the material structure were determined. The efficiency of uranium recovery from multicomponent natural waters was also investigated under dynamic conditions over repeated sorption-desorption cycles. The results demonstrate through comparative analysis that the developed composites exhibit a high sorption capacity and possess a high practical potential for the concentration and recovery of uranium from high-salinity solutions with complex composition.