ABSTRACT
Biosorption is a simple and economical method utilized to remove hazardous elements from a waste solution. In this study, a low-cost agricultural waste, Salvadora Persica, was modified with iron oxyhydroxide and evaluated as an economic biosorbent to remove cesium and europium radionuclides from their aqueous solutions. The modified biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), elemental analysis as well as thermogravmetirc analysis (TGA). The sorption of 134Cs and 152+154Eu radioisotopes was investigated singly in a batch mode as a function of the solution pH, contact time, and the initial concentrations of the studied ions. The kinetic of the removal process was examined and it was found that the reaction obeys a pseudo-first-order model and the intraparticle diffusion is not the sole mechanism dominating the reaction. Temkin and Sips isotherm models provide the best fit for the equilibrium data. In addition, the sorption of cesium and europium ions was a spontaneous and endothermic process as inferred from thermodynamic studies. The reusability for the sorption of cesium and europium ions reveals the feasibility and efficacy of the modified biosorbent.
