Sorption of homologues of radionuclides by synthetic ion exchanger

Present work describes sorption of homologues of radionuclides (UO22+, Th4+, Eu3+, Sm2+, Ru3+ and Fe3+) on synthesized ion exchangers (analogues of nepheline, marialite and natrolite). The study was investigated by batch technique and three different series of experiments were carried out on different ion exchangers at various parameters such as effect of time (3–24 h), pH (1–9), sorbent concentration (2–10 g/L), metal ion concentration (0.05–0.001 M), temperature (30–50 °C) and effect of competing ions (Na+, K+, Mg2+ and Ca2+). Time of equilibration was found to be 7 h which indicates fast kinetics between the sorbent and sorbate. Sorption was observed to be pH dependent. Sorption was enhanced by increasing the sorbent dose and reduced by increasing metal ion concentration. Thermodynamic study indicates the spontaneous, entropy favorable and endothermic nature of sorption process. Sorption was found to be affected in the presence of competing cations and was observed that it reduced with increase in the concentration of competing cations in the suspension which may be probably due to the competition between these ions and desired metal ion for the sorption. Desorption study showed that organic leachants have greater desorption capacity than water.

Effect of competing cations on the sorption of UO22+ ions by nepheline analogue showed that sorption of uranyl ions was found to be reduced strongly by the presence of divalent cations (Mg2+ and Ca2+) than that of monovalent cations (Na+ and K+).Figure optionsDownload as PowerPoint slideResearch highlights
► Synthesis of analogues of nepheline, marialite and natrolite.
► Sorption of homologues of radionuclides as UO22+, Th4+, Eu3+, Sm2+, Ru3+ and Fe3+.
► Sorption was observed to be pH dependent.
► Thermodynamic study showed endothermic, spontaneous and entropy favorable sorption.