Method for removing perfluorinated alkanoic acids
Assignee3M Innovative Properties Company
InventorsTilman C. Zipplies, Klaus Hintzer, Helmut Traunspurger, Karl D. Weilandt
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Abstract
Provided are methods for removing a perfluorinated alkanoic acid from solutions containing the perfluorinated alkanoic acid and a fluorinated alkoxy acid. These methods include contacting the first solution with an anion-exchange resin to produce a second solution and a resultant anion-exchange resin having perfluorinated alkanoic acid adsorbed thereto, wherein the perfluorinated alkanoic acid is present in the first solution at a first concentration and is present in the second solution at a second concentration which is lower than the first concentration, and separating the second solution from the resultant anion-exchange resin.
Claims15
A method for preferentially removing a perfluorinated alkanoic acid from a first solution containing the perfluorinated alkanoic acid and a first fluorinated alkoxy acid, the method comprising
- pre-loading an anion-exchange resin with a second fluorinated alkoxy acid, which may be the same or different than the first fluorinated alkoxy acid, to form a pre-loaded anion-exchange resin,
- contacting the first solution with the pre-loaded anion-exchange resin and preferentially removing the fluorinated alkanoic acid relative to the first fluorinated alkoxy acid to produce a second solution and a resultant anion-exchange resin having the perfluorinated alkanoic acid adsorbed thereto, wherein the perfluorinated alkanoic acid is present in the first solution at a first concentration and is present in the second solution at a second concentration which is lower than the first concentration, and
- separating the second solution from the resultant anion-exchange resin.
Dependencies are inferred from the claim text.