Efficient radionuclide capture using thermally processed materials

Generating electricity using fission nuclear reactors is a potential method to reduce carbon dioxide emissions. Additionally, nuclear reactors are regarded as reliable production systems. However, apart from the high costs associated with building and maintaining nuclear power plants, the treatment of liquid radioactive waste poses a significant challenge. There is extensive research on the concentration of radionuclides, such as unstable isotopes of copper, lead, nickel, strontium, cesium, etc. from liquid phases onto solid matrices. While commercial ion-exchange resins are commonly used as solid matrices, any material that can bind these isotopes—which are primarily found in ionic form in liquid waste—can be utilized. Materials with notable sorption properties often include those that have been subjected to thermal treatment. For instance, the heat treatment of materials high in carbon can produce either ash or biochar, depending on the conditions of the process. Biochar, in particular, is known for its large specific surface area, which is essential for their effectiveness as sorbents. In addition to the transformation of organic matter due to high temperatures, the thermal treatment of inorganic materials also enhances their sorption properties. Research has shown that changes in structure positively impact the sorption capacity of minerals like bentonite, as well as waste inorganic materials such as red mud. This paper summarizes previous research on the sorption performance of thermally treated materials that can be used in the treatment of liquid radioactive waste.