ABSTRACT
Efficient sequestration of radioiodine is one of the challenging tasks in nuclear establishment due to the radio-pharmaceutical applications as well as radiation release into environment point of view. In the present manuscript, an efficient and simple sequestration has been reported by triethylene diamine (TEDA)-functionalized Ag-activated charcoal, and the separation characteristics were compared to the virgin charcoal and Ag-activated charcoal. The kd values at 3 M HNO3 were found to follow the trend TEDA+Ag-activated charcoal > Ag-activated charcoal > charcoal. Pseudo-second-order kinetics was found to be predominating. Chemisorption involving Langmuir isotherm was operative with good sorption capacity (99.4 mg g−1). The sorption processes were found to be endothermic but spontaneous (ΔGTEDA+Ag activated charcoal~ −14.41 kJ mol−1, ΔGAg activated charcoal ~ -14.35 kJ mol−1 and ΔGActivated charcoal ~ -14.34 kJ mol−1). Though functionalization improved the separation efficiency, the radiological robustness was only moderate. Sodium thiosulfate as aqueous complexing agent was utilized for effective back extraction of iodine from loaded sorbents.
Acknowledgments
The author wishes to acknowledge P.K. Mohapatra, Associate Director, RC & I Group and Head, Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai, India. The author wishes to acknowledge Dr M.S. Kulkarni, Head, HPD and Shri R.V. Kolekar, Head, RPS-SF, HPD and Dr Ashok Kumar, Group Leader, HP Unit Isotope wing, HPD.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Author contributions
J Sapkal: Experiments and Data acquisition; Pankaj Sorate: Experiments; Arijit Sengupta: Conceptualization and manuscript writing.