Enhancing the Sr uptake on resorcinol–formaldehyde polycondensates by modifying the structure and shape

Resorcinol–formaldehyde polycondensates—the well-established Cs-selective agents, along with their crown ether (18-crown-6) composite discs, were synthesized, characterized (FT-IR, SEM–EDS, surface area, porosity) and applied for strontium uptake from aqueous solutions. Effects of crown ether amounts, Sr in feed, pH, equilibration time, temperature, competing ions, on the sorption, along with re-usability of synthesized sorbents, were evaluated. The fate of Sr was followed by EDXRF spectrometry on both solution and solid phases. Solution pH (3–12) and temperature (upto 100 °C) had negligible impact on the holding capacities. Sorption capacity was enhanced by ~ 33% upon modification, and followed pseudo-second order kinetics.