Removal of iodine from organic media using diethylene triamine-grafted vinylbenzyl chloride-divinylbenzene resin

Abstract

Iodine released from different industrial activities and nuclear fuel reprocessing poses significant health and environmental risks due to its long half-life and high volatility, demanding efficient materials for its removal. In the current study, vinylbenzyl chloride-divinylbenzene-based resin is synthesized and functionalized with diethylene triamine for the removal of iodine from organic media. The synthesis success of the resin beads is confirmed using FTIR, CHNS, and TGA analyses, which revealed the presence of a characteristic N–H band, an increase in nitrogen content, and enhanced thermal stability of the aminated resin. In batch experiments, the aminated resin demonstrated an improved iodine removal efficiency (almost complete removal) compared to the vinylbenzyl chloride-divinyl-based pristine resin (10%), for an initial iodine concentration of 200 mg L⁻¹ in n-hexane at an equilibrium time of 7 h. The adsorption efficiency of the aminated resin is found to be dependent on both the contact time and the initial iodine concentration. The adsorption process follows the pseudo-second-order kinetic model. The Langmuir isotherm model provided the best fit for explaining the adsorption mechanism of iodine on aminated resin. The maximum adsorption capacity of the aminated resin is found to be 54.64 mg g⁻¹. The nearly complete removal of ¹²⁹I is highly promising for reducing nuclear-industry waste challenges and significantly reducing waste volume.