Highly efficient removal of uranium(VI) from aqueous solution using poly(cyclotriphosphazene-co-polyethyleneimine) microspheres

Poly(cyclotriphosphazene-co-polyethyleneimine) microspheres with the solid structure were synthesized by precipitation polymerization method for the separation of highly toxic uranium(VI). The structure and morphology of the prepared microspheres were analyzed via FTIR, SEM–EDS, TEM and BET. The optimal adsorption conditions were also investigated, and the maximum adsorption capacity was 274.2 mg g−1. The experimental results showed that the adsorption kinetics conformed to the pseudo-second-order kinetics and was in good agreement with the Langmuir adsorption isotherm model. Removal of uranium(VI) ions was achieved by the complexation between the amino groups on the adsorbent and uranyl ions.