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

Abstract

The efficiency of the removal of Cs-137 radionuclides with porous and non-porous resorcinol–formaldehyde resins from alkaline solutions simulating the composition of real liquid radioactive waste (LRW) streams has been evaluated. Resins were synthesized through the polycondensation of resorcinol and formaldehyde in an alkaline medium at a molar ratio of 1.8/2.2 and a temperature of 210 °C. The Cs-137 distribution coefficients on RFRs in alkaline solutions simulating LRW were above 103 mL/g under static sorption conditions. In a model solution with pH 11, the full dynamic sorption capacity of non-porous RFR was 0.178 mmol/g. The values of the full dynamic sorption capacities of porous RFRs were 0.274 and 1.035 mmol/g for resins obtained with calcium carbonate and toluene as templates, respectively. When the sizes of RFR beads increased two-fold, the volume until 5% cesium breakthrough decreased by 20–40%. The most pronounced beneficial effect of the RFR’s porosity was observed at flow rates from 25 to 50 BV/h. It was shown that the negative effect of metal cations on Cs-137 uptake increases in the following order: Na+ < Mg2+ < Ca2+ < K+. The number of bed volumes of LRW-simulating solution decontaminated with RFRs until 5% cesium breakthrough was above 450; that is higher than the value of known commercially available analogs. The latter shows that the developed RFRs are promising for application in technological schemes of alkaline LRW processing.

The influence of sodium alginate on the structural and adsorption properties of resorcinol‐formaldehyde resins and their porous carbon derivatives

“…[1,2] The porous RFRs are widely used as ion exchange resins and as a source for the preparation of carbon materials with controlled porosity. [3][4][5][6][7] Such materials are promising and have proven to be very effective in the synthesis of carbon adsorbents, electrode materials for energy sources and supercapacitors, and mesoporous carbon membranes for hydrogen storage. [8][9][10][11] The possibility of obtaining RFR aerogels and low-density porous carbon on this basis has generated particular interest.…”

“…Resorcinol‐formaldehyde resins (RFRs) have been used as glues and adhesives in various industrial fields for several decades [1,2] . The porous RFRs are widely used as ion exchange resins and as a source for the preparation of carbon materials with controlled porosity [3–7] . Such materials are promising and have proven to be very effective in the synthesis of carbon adsorbents, electrode materials for energy sources and supercapacitors, and mesoporous carbon membranes for hydrogen storage [8–11] .…”

Study on Natural Diatomite as an Adsorbent for Uranyl (VI) ions, Using Spectrophotometric Method

“…Consequently, public anxiety over the safe disposal of nuclear waste exists [4]. Many methods, such as chemical precipitation [5], ion exchange [6], membrane separation [7], extraction [8] and adsorption [9,10], have been investigated for extracting and preconcentrating radionuclides from contaminated wastewater [4]. Compared to other methods, adsorption technology is repeatedly used to remove radionuclides from aqueous solutions because of its high efficacy, low cost and ease of use.…”