Activity of nanostructured C@ETS-10 sorbent for capture of volatile radioactive iodine from gas stream

• Synthesis of active C@ETS-10 sorbent by wet-impregnation technique.
• Continuous sorption experiments were conducted for capture of volatile iodine.
• Sorbent was analyzed before and after adsorption experiments.
• Elemental iodine (I2) on sorbent was confirmed by SEM–EDS spectra.
• C@ETS-10 was found to be effective sorbent for capture of iodine on specific surface area.

ETS-10 supported hollow carbon nanostructured polyhedron adsorbent, C@ETS-10, was synthesized by wet impregnation method to evaluate removal of iodine from off-gas stream from a used nuclear fuel reprocessing operation. The characteristics of the adsorbent were investigated by various techniques such as transmission electron microscopy (TEM), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), powder X-ray diffraction (P-XRD) and thermogravimetric analysis (TGA), revealing uniform hollow carbon nanostructured polyhedrons with particle size 10–30 nm supported onto ETS-10. The total BET surface area of 10 wt% C@ETS-10 adsorbent was 149 m2 g−1. The performance of C@ETS-10 nanostructured adsorbent for capture of volatile iodine from gas stream was determined as a function of parameters such as the carbon loading, operating temperatures and empty bed contact time (EBCT). Observed sorption capacity of adsorbent was 28.9 mg g−1 of volatile iodine at 20 °C without any chemical reaction with sorbent. The maximum dynamic capacity of a column of 10 wt% C@ETS-10 was calculated to be 40 mg g−1. The nanostructured adsorbent has potential to capture environmental impact of radionuclide off-gas emission from nuclear industry.