High effectiveness of pure polydopamine in extraction of uranium and plutonium from groundwater and seawater.

Sorption properties of polydopamine (PDA) for uranium and plutonium from an aqueous environment are reported at three different pH values (2, 4 and 6.5-7). In addition to deionized (DI) water, artificial groundwater (GW) and seawater (SW) were used with U uptake close to 100% in each case. PDA polymer has been identified as a material with extremely high sorption capacity ∼500 mg g of the polymer at pH 6.5 and high selectivity for uranium. Similar high sorption properties are revealed for plutonium uptake. PDA-uranyl and PDA-plutonium interactions responsible for the observed adsorption processes have been addressed with a set of experimental techniques including FTIR spectroscopy, electron microscopy and cyclic voltammetry.