Co-irradiation Grafted Synthesis of Amine-based Adsorbent for Removal of Ion- and Colloid-state 110Agm in Radioactive Wastewater

The form of radionuclide 110Agm in the radioactive wastewater generated from the normal operation of nuclear power plants is complex, and it cannot be completely removed by desalting bed. The wastewater containing 110Agm will put pressure on the radioactive purification system and increase the consumption of resin so that lead to the increase of processing costs due to the increased radioactive solid waste. In addition, 110Agm could be discharged into the environment along with the liquid waste, which can accumulate in marine organisms through the food chain, so it is of great significance to study the removal of 110Agm as one of the main radionuclides in radioactive wastewater of nuclear power plants. In this study, a new amine-type material PP-g-GMA@EDA was synthesized by radiation induced simultaneous grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) nonwovens followed by chemical modification with the ethanediamine (EDA), the EDA content on PP-g-GMA@EDA was 1.33 mmol/g, and the chemical structure was confirmed by ATR spectra. And then the PP-g-GMA@EDA was used as adsorbent to removal Ag·Nps and Ag(Ⅰ) in solution. The results show that in Ag·Nps solutions with different pH values, PP-g-GMA@EDA has better removal efficiency than IRN9766, a commercial resin commonly used in nuclear power plants. The adsorption curve under the action of pH of the solution shows typical anion exchange adsorption characteristics. Under the optimal pH=4, the adsorption efficiency of Ag·Nps can reach 100% under its initial concentration at 0.87 mg/g, and the maximum adsorption capacity is 101.44 mg/g. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterization methods confirme the successful adsorption of Ag·Nps on PP-g-GMA@EDA. For the adsorption of Ag(Ⅰ), PP-g-GMA@EDA is more suitable in low and medium acidity, and shows chelating adsorption characteristics and reaches adsorption equilibrium in 420 min. The results of pseudo-first-order dynamics model and pseudo-second-order kinetics model show that the pseudo-second-order dynamics model can effectively simulate the adsorption process of Ag(Ⅰ) on PP-g-GMA@EDA. The results of batch adsorption experiments confirm the applicability of the amine-type adsorbent PP-g-GMA@EDA for multi-form 110Agm decontamination in wastewater, providing an efficient, sustainable and industrially feasible method for the removal of 110Agm from radioactive wastewater.