Radioactive decontamination of metal surfaces using peelable films made from chitosan gels and chitosan/magnetite nanoparticle composites

In this work, we explored the feasibility of using peelable films from chitosan gels and chitosan/magnetite nanoparticle (NPs–Fe3O4) composites to deal with radioactive contamination on metallic surfaces. We formulated four chitosan-based gels, one without NPs–Fe3O4 and three with NPs–Fe3O4: one using commercial nanoparticles and the other two synthesized by applying the chemical reduction method at 25 °C and 94 °C. The decontamination capacity of these gels was evaluated on steel stainless and aluminum, clean and corroded, and on weathered iron test pieces. The films of chitosan-based gels were characterized by infrared spectroscopy. The radioactive decontamination process from metal surfaces was most efficient on clean surfaces. The decontamination factors were independent of the presence of NPs–Fe3O4 in the chitosan-based gel applied to the metal surface and depended on the type of radioisotope deposited on the metal. Gels formulated with 2.8% w/v chitosan in 1 M acetic acid with and without NPs–Fe3O4 (333 μg/mL) were applied to a non-compactable waste contaminated with uranium, which obtained removal efficiencies of 85%.