Towards the Extraction of Radioactive Cesium-137 from Water via Graphene/CNT and Nanostructured Prussian Blue Hybrid Nanocomposites: A Review

Cesium is a radioactive fission product generated in nuclear power plants and is disposed of as liquid waste. The recent catastrophe at the Fukushima Daiichi nuclear plant in Japan has increased the (137)Cs and (134)Cs concentrations in air, soil and water to lethal levels. (137)Cs has a half-life of 30.4 years, while the half-life of (134)Cs is around two years, therefore the formers’ detrimental effects linger for a longer period. In addition, cesium is easily transported through water bodies making water contamination an urgent issue to address. Presently, efficient water remediation methods towards the extraction of (137)Cs are being studied. Prussian blue (PB) and its analogs have shown very high efficiencies in the capture of (137)Cs(+) ions. In addition, combining them with magnetic nanoparticles such as Fe(3)O(4) allows their recovery via magnetic extraction once exhausted. Graphene and carbon nanotubes (CNT) are the new generation carbon allotropes that possess high specific surface areas. Moreover, the possibility to functionalize them with organic or inorganic materials opens new avenues in water treatment. The combination of PB-CNT/Graphene has shown enhanced (137)Cs(+) extraction and their possible applications as membranes can be envisaged. This review will survey these nanocomposites, their efficiency in (137)Cs(+) extraction, their possible toxicity, and prospects in large-scale water remediation and succinctly survey other new developments in (137)Cs(+) extraction.