Nanocomposites and nanomaterials

Nanocomposite adsorbent based on natural zeolite for selective removal of 137Cs from high salt solutions 
Bondar Yu.V., Kuzenko S.V., Olkhovyk Yu.O.
State Institution “The Institute of Environmental Geochemistry of National Academy of Sciences of Ukraine”, 34a Palladin ave., Kyiv 03142, Ukraine. 
E-mail: juliavad_peremoga@ukr.net

The development of effective adsorbents for the selective removal of radionuclides from contaminated waters is a topical issue to reduce the amount of hazardous liquid radioactive waste and ensure radiation safety.		
Synthesis of composite adsorbents based on natural zeolites with a sorption-active inorganic phase incorporated into their porous structure is considered a promising approach to the manufacture of low-cost adsorbents with high selectivity.		
This study concerns the synthesis of a novel nanocomposite adsorbent based on clinoptilolite tuff of the Sokyrnytsia deposit (Ukraine) for selective removal of 137Cs radionuclides. The composite adsorbent was fabricated by a two-stage synthesis: preliminary chemical treatment of the clinoptilolite tuff (CLT) grains with subsequent in situ formation of potassium copper ferrocyanide (KCuFC) nanoparticles within the CLT pores (Fig.1).
The efficiency of the synthesized adsorbent in selective removing cesium ions was evaluated under various experimental conditions. Unlike natural CLT samples, the composite ones (CLT-KCuFC) have been found to exhibit fast adsorption rate, high adsorption capacity over a wide pH range, and unique selectivity to Cs ions in model high salt solutions with sodium and potassium ions, as well as enhanced fixation of adsorbed cesium ions (Fig. 2). The synthesized adsorbent has a lot of advantages, such as its simplicity and low-cost fabrication process, chemical resistance, radiation and thermal stability, high selectivity to Cs ions in high salt solutions (for example, sea water).