Radiochemical studies on separation of some elements using advanced materials

Grapheme oxide (G O) was synthesized via modified Hummers' method, Manganese dioxide decorated grapheme oxide (G O-MnO₂) was prepared via fixation of MnO₂ on the surface of graphene oxide (G O) and was explored as an adsorbent material for simultaneous removal of europium, cerium and neodymium ions from aqueous solutions. G O, Mn O₂ and G O-Mn O₂ composite were characterized by different techniques such as Fourier transform infrared spectrum (F T-IR), scanning electron microscopy (S E M), Thermal analysis (T G A), X-ray diffraction (XRD), (B E T) surface area measurements and Raman spectroscopy. Experimental studies were conducted to evaluate and optimize the various sorption conditions and modeling the equilibrium sorption data using different models with determining the sorption kinetics and isotherms parameters. Sorption isotherm models applied to the system revealed that Langmuir model controlled the sorption process. Thermodynamic parameters such as ΔG° , ΔH° and ΔS° were calculated. ΔG° values indicated that the sorption of Eu(III), Ce(III) and Nd(III) ions was spontaneous in nature. The endothermic nature of the sorption process was suggested from the positive values of ΔH° . Desorption of Eu(III), Ce(III) and Nd(III) ions from loaded samples was studied using different eluents and maximum recovery was obtained using EDTA and AlCl₃ solutions. More importantly, both Al Cl₃ and EDTA were individually applied as eluents in chromatographic separation of Eu(III) from Ce(III) in G O-Mn O₂ composite packed column. The chromatographic separation in binary system of Eu(III) and Ce(III) from G O–Mn O₂ composite packed column was carried out by EDTA and Al Cl₃ as an eluents. The data suggest the possible use of synthesized adsorbents for the sorption of these cations from their aqueous solutions.