Nanocomposite Polymer Fibers for Selective Removal of Cesium Radionuclides from High Salt Solutions

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Cs radionuclides are the main component of liquid radioactive waste formed owing to the operation of nuclear facilities. Due to their long half-life (~ 30 years), and high chemical activity, and radioactivity as a gamma-ray emitter, cesium radionuclides pose a considerable threat to human health. Therefore, the treatment of liquid radioactive waste to a safe level is a crucial key to the sustainable development of nuclear energy. Among the handling methods developed for the removal of
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Cs from contaminated waters, selective adsorption is the simplest and most economical one. Transition metal ferrocyanide nanoparticles (FC NPs) are highly selective to cesium ions; however, they have not found wide practical applications as adsorbents due to low hydromechanical stability. In the last decade, a variety of techniques have been developed for the synthesis of composite adsorbents by incorporating the FC NPs into the appropriate solid supporting matrix to improve their hydromechanical strength and adsorption characteristics. We fabricated nanocomposite adsorbent for cesium ions by direct formation of potassium copper ferrocyanide NPs on the polyacrylonitrile fibers. The scanning electron microscope data revealed the rounded FC NPs (40–60 nm), uniformly distributed within the fibers' volume. The synthesized composite fibers demonstrated rapid adsorption, high adsorption capacity, good chemical stability over a wide pH range, and a high cesium removal efficiency from a multi-component model solution with a high salt content (~70 g/l). The synthesized composite fibers can be recommended for the decontamination of seawater and low-level LRW with high salt content. The great advantage of synthesized composite fibers is their simplicity of manufacture, low cost due to the use of inexpensive commercially available polyacrylonitrile fibers, fast adsorption, high adsorption capacity, and high selectivity to cesium ions.