Treatment of radioactive waste using some phosphate compounds

The immobilization and solidification of the hazardous liquid radioactive waste has drawn countless efforts by many researchers in order to ensure public and environmental safety. The aim of this work was to develop some phosphate based ion exchange materials (Hydroxyapatite) that can sequester these cations from aqueous environments and keep them safely stored over long time periods. Hydroxyapatite was synthesized from two low cost sources (eggshell and fishbone), and surface has been modified by gamma induced copolymerization with Acrylic acid and Acrylonitrile. The composite material was characterized by X-Ray diffraction (XRD), X Ray fluorescence (XRF), Fourier Transform Infra Red (FT-IR) analysis, Surface area, and Scanning Electron Microscope (SEM). The prepared materials were used for removal of Co²⁺, Sr²⁺, and Eu³⁺ metal ions from aqueous media through batch technique as a function of solution ph, temperature, shaking time, initial concentration, temperature, and existence of interfering ions. Langmuir, Freundlich, Dubinin-radushkevich (D-R), and Temkin sorption models have been applied, and the experimental data showed good fitting to Freundlich isotherm for both Co²⁺ and Sr²⁺ while for Eu³⁺ the Langmuir and D-R isotherms were the applicable models. The kinetic data of the investigated metal ions was better described by pseudo-second order equation. The prepared sorbents were easily regenerated by using mineral acids