A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization
by FTIR and elementary analysis, the new resin has been investigated in liquid–solid extraction of europium(III). The results
indicated that phosphonic resin could adsorb Eu(III) ion effectively from aqueous solution. The adsorption was strongly dependent
on pH of the medium with enhanced adsorption as the pH value of 6.5. The influence of other analytical parameters including
contact time, amount of resin, metal ion concentration, and ionic strength were investigated. The maximum uptake capacity
of Eu(III) ions was 122.6 mg/g grafted resin at ambient temperature, at an initial pH value of 6.50. The overall adsorption
process was best described by pseudo first-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had
a better fit with the experimental data. Furthermore, Eu(III) could be eluted by using 1.0 mol/L H2SO4 solution and the grafted resin could be regenerated and reused.