Ammonium Binding Resins: Polymer-tethered Tetraphenylborate

A novel approach to the problem of removing (organo)ammonium ions from industrial effluent and agricultural wastewater streams is proposed. Capitalizing on the insolubility of (organo)ammonium tetraphenylborate in water, we have designed, synthesized, and tested a polymer-tethered system that eliminates the ammonium ion from aqueous solution. Furthermore, the binding can be controllably reversed, thereby regenerating the material by deprotonating the ammonium ion in strong base, without significantly reducing the binding properties of the matrix. This work thus presents the synthesis and characterization of a polymeric system bearing anionic tetraphenylborate groups that reversibly sequester (organo)ammonium cations.