Adsorption Behavior of Trace Beryllium (II) onto Metal Oxide Nanoparticles Dispersed in Water
- Shoichi Katsuta
- Naoki Kanaya
- Kotaro Bessho
- Hideaki Monjushiro
Radioactive trace 7Be produced in cooling water systems for high-energy accelerators is known to be captured by metal-oxide colloidal nanoparticles generated through corrosion of metal components in water. This study is aimed at investigating the adsorption behavior of trace Be2+ onto various oxide nanoparticles (Al2O3, SiO2, TiO2, Fe2O3, CoO, and CuO) dispersed in water at 25 °C in order to clarify the tendency and features of the interaction of Be2+ with metal oxides. From pH dependence of the distribution ratio of Be2+ between the nanoparticle phase and the aqueous solution phase, the surface complexation constants (βs,n) have been determined for the reaction of Be2+ with the hydroxyl groups on the oxide surface (>S−OH), i.e., Be2+ + n >S−OH ⇄ (>S−O)nBe(2−n)+ + n H+. The n values are generally 1 and 2 and the sequences of the βs,n values are Fe2O3 > TiO2 » Al2O3 > SiO2 for βs,1 and Fe2O3 > TiO2 > SiO2 > Al2O3 >> CoO » CuO for βs,2. The dependences of the the βs,n values on the kind of oxide are explained based on the electronegativity of the metal (or Si) composing the oxide.
- Albert JohnEditorial Assistant