Synthesis of porous resorcinol-formaldehyde resins and study of their sorption characteristics toward Cs in highly mineralized alkaline media

Abstract

The present work was devoted to study of sorption parameters of resorcinol-formaldehyde resins synthesized through introduction of an inorganic filler (in amounts of 10 and 25 wt.%) with its subsequent leaching. The surface morphology and composition of ion-exchange resins have been investigated by means of the method of scanning electron microscopy. The effect of internal diffusion on the peculiarities of the ion-exchange process has been determined. It has been revealed that the ion-exchangers destruction upon a prolonged contact with highly alkaline solutions is followed by the decrease of internal diffusion coefficients and selectivity toward Cs-137 micro-quantities. The sorption properties of resins under dynamic conditions at high solution feeding rates have been studied. A sample with the highest efficiency of Cs-137 removal from highly mineralized solutions has been identified.

Removal of Cs-137 Radionuclide by Resorcinol–Formaldehyde Ion-Exchange Resins from Solutions Simulating Real Liquid Radioactive Waste

“…The porous morphology of the ion-exchange resins was achieved using CaCO3 or toluene as pore-forming agents, as described in detail in [21,22], respectively. The synthesis conditions are shown in Table 5.…”

“…The final ion-exchange resin marked as "RFR-i" consisted of dark-brown granules of an irregular shape. The porous morphology of the ion-exchange resins was achieved using CaCO 3 or toluene as pore-forming agents, as described in detail in [21,22], respectively. The synthesis conditions are shown in Table 5.…”

“…In our earlier works, we reported the methods to fabricate porous RFR using CaCO 3 powder [21] and toluene [22] as pore-forming templates, which were added to the liquid mixture of oligomers prior to polycondensation. The subsequent removal of templates from the polymer matrix yielded a porous structure, which was beneficial in the increase of the ion-exchange rate [21,22]. The values of the distribution coefficients of Cs-137 in LRW alkaline simulates (NaNO 3 -2.25 mol/L, NaOH-0.75 mol/L) obtained using these materials were above 10 3 mL/g.…”