Modification of Textile Mats with Calixarenes – Separation of Uranium from Mine and Seepage Waters

More than 40 years of uranium production in Germany left abandoned equipment and mine wastes, which have to be disposed to avoid the release of contaminants into the biosphere. The separation of uranium(VI) from aqueous solution by calixarenes by means of solvent extraction has been described in literature. Calixarenes are macrocyclic ligands formed by the base inducted condensation reaction of para-substituted phenols and formaldehyde. Substituents at the hydroxyl groups control the selectivity of the ligand for the complexation of uranium(VI) ions.
The present work describes the development of a textile filter material for the separation of uranium(VI) from mine and seepage water using uranophile calixarenes. These ligands are permanently fixed on a textile substrate by a process comparable to a disperse dying procedure. For this purpose the calixarenes are statistically functionalized by spacer groups. The filter materials are especially applicable for the remediation of uranium contaminated waters at low concentration levels.