Highly efficient capture of TcO 4 /ReO 4 by imidazolium ionic liquid supported silica materials prepared by radiation induced RAFT-mediated graft polymerization technology

Technetium (99Tc) is a main long-lived radionuclide of nuclear waste, which poses a great threat to the environment and human health. The reasonable disposal of 99 Tc is vital important. In this paper, a series of novel materials (SMILRm, m = 0, 1/500, 1/200, m is the molar ratio of IL to RAFT reagent) was synthesized by radiation-induced grafting combined with reversible addition-fragmentation chain transfer (RAFT) polymerization. The adsorption performance of SMILRm to 99 Tc were investigated. The graft polymerization process is controlled by the RAFT reagent, resulting in a restricted dispersion of SMILRm molecular weight. With the increase of RAFT reagent content, the grafting yield (GY) decreased. The addition of RAFT reagent increases the specific surface area of the adsorbent, accelerates the adsorption rate, increases the adsorption capacity, but reduces the adsorption selectivity. Especially, the adsorption of SMILR0 was a single step adsorption and obeyed Langmuir adsorption model, while SMILRm (1/500, 1/200) showed a stepwise adsorption isotherm model. SMILRm exhibited excellent recyclability and could efficiently capture ReO 4 from a simulated Beishan groundwater in dynamic experiments. Finally, XPS and FT-IR analysis confirmed that the adsorption was an ion exchange mechanism. The results showed that SMILRm are suitable for the effective removal of ReO 4 /TcO 4 from radioactive wastewater with complex composition.