Removal of uranium from aqueous solution by phosphate functionalized superparamagnetic polymer microspheres Fe.sub.3O.sub.4/P

A new phosphate functionalized superparamagnetic polymer sorbent Fe.sub.3O.sub.4/P(GMA-AA-MMA)-PO.sub.4 was developed by functionalizing Fe.sub.3O.sub.4/P(GMA-AA-MMA) prepared by soap free emulsion polymerization with o-phosphoethanolamine. The adsorption process was spontaneous and endothermic in nature and kinetically followed pseudo second-order model. The maximum monolayer adsorption capacity obtained from the Langmuir model was 274.7 mg g.sup.-1 at 298 K. Fe.sub.3O.sub.4/P(GMA-AA-MMA)-PO.sub.4 could selectively adsorb U(VI) in aqueous solution containing co-existing ions and the selectivity of Fe.sub.3O.sub.4/P(GMA-AA-MMA)-PO.sub.4 could reach up to 77 % at pH 4.5. Furthermore, the novel magnetic sorbent could also be easily separated and recovered from aqueous solutions by an external magnetic field.