Highly efficient removal of Cs(I) using the magnetically separable potassium ferrocyanide: Mechanism, economic analysis, and impact insights

Abstract

Cs nuclides, originating from nuclear weapon tests or compromised nuclear power plants are highly mobile and easily migrate among environmental media, eventually bio-accumulating in the human body and causing serious disease. Reliable and highly efficient removal of Cs(I) ions from radioactive wastewater is of great importance. Herein, a novel magnetic potassium ferrocyanide nanocomposite, viz. K4Fe(CN)6@Fe3O4, was rationally designed for Cs(I) removal. Through a well-controlled in-situ growth method, potassium ferrocyanide [K4Fe(CN)6, KFC] nanocrystals were in-situ grown onto the surface of Fe3O4 nanospheres forming KFC@Fe3O4 nanocomposite. The Cs(I) removal rate of KFC@Fe3O4 can reach over 95% within a relatively short time. Even in the presence of considerable amounts of Na+, Ca2+ and NH4+ ions, KFC@Fe3O4 maintained a considerably high removal rate. KFC@Fe3O4 yielded a relatively lager saturation magnetization value, enabling its rapid separation from the reaction system by introducing an external magnetic field. Notably the embedded potassium in KFC@Fe3O4 plays a vital role in Cs(I) exchange process. The experimental results underscore the superior performance of KFC@Fe3O4 as a potential Cs(I) adsorbent in wastewater. The implications of this study reach extend beyond mere technological advancements, highlighting that the application of this novel methodology for nuclear wastewater treatment requires the engagement of a broad spectrum of potential users. Overall, this study elucidated the mechanism of Cs(I) removal by KFC@Fe3O4, ad developed an eco-friendly and cost-effective strategy for radioactive wastewater purification, while deliberating on the advantages and potential challenges of scaling up the material and process for future application.