The Removal of Pu(IV) from Aqueous Solution Using 2,3‐Dihydroxyterephthalamide‐Functionalized PEI with Polymer Filtration

Abstract Polymer filtration (PF) uses a size‐exclusion ultrafiltration membrane to retain higher molecular weight species while allowing the passage of smaller species through the membrane. Metal‐ion separations from aqueous streams are accomplished with PF by using water‐soluble chelating‐polymers (WSCP), which are appropriately sized polymers that have covalently attached metal‐binding ligands. In this study, a new WSCP was prepared by modifying polyethylenimine (PEI) through an amide linkage to attach 2,3‐dihydroxyterephthalamide (TAM) groups that have high binding constants for high valent metal cations. The TAM ligand contains a dimethylethylenediamine side chain that was found to maintain polymer solubility throughout the working pH and ionic strength ranges studied. The new WSCP (designated PDT) showed selectivity for Pu(IV) over Am(III). For example, at pH 4.5, the distribution coefficient (D) was 1.6 × 103 for Am(III) (14% bound) and 1.3 × 106 for Pu(IV) (99.3% bound). The Pu(IV) D increased as a...