Use of Cage-Functionalized Macrocycles and Fluorinated Alcohols in the Liquid-Liquid Extraction of NaOH and Other Sodium Salts: Strategies Toward Waste-Volume Reduction

Concepts for the selective separation of sodium hydroxide and other sodium salts from alkaline high-level wastes are described together with initial results. Eight extraction mechanisms may be envisaged for transferring NaOH equivalents to an organic solvent by liquid-liquid extraction. Selectivity derives from principles of solvation, host-guest chemistry, and cation exchange. Initial results are presented on the synthesis and properties of new cage-functionalized macrocyclic hosts and fluorinated alcohol cation exchangers. Such compounds show promise toward reducing the overall waste volume by removal of bulk quantities of sodium salts.