Method for recovering fluorinated alkanoic acids from waste waters
Assignee3M Innovative Properties Company
InventorsBernd Felix, Reinhard Sulzbach, Stephan Führer, Thomas Kaiser, Hagen Kniep, Armin Budesheim
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Abstract
Fluorinated emulsifier acids can be isolated from wastewater by firstly removing fine solids and/or material which can be converted into fine solids from the wastewater, preferably by precipitation, subsequently bringing the wastewater into contact with an anion-exchange resin and eluting the adsorbed emulsifier acids from the latter.
Claims16
A process for the recovery of fluorinated emulsifier acids from wastewater, which comprises firstly removing interfering constituents which are selected from fine solids and material which can be converted into fine solids from the wastewater, and subsequently binding the fluorinated emulsifier acids on an anion-exchange resin and eluting the fluorinated emulsifier acids from the latter.
A process for the recovery of fluorinated emulsifier acids from wastewater which comprises providing wastewater from the polymerization of fluorinated monomers comprising fine solids and/or material which can be converted into fine solids and oxalic acid, treating the wastewater with an aluminum salt solution while mixing intensively, subsequently adjusting the pH to a value in the range from 6 to 7.5 by means of milk of lime, filtering off the precipitate which forms and, after adjusting the pH of the solution to a value below 7 using sulfuric acid, and passing the solution over an ion exchanger.
A process for the recovery of fluorinated emulsifier acids from wastewater, which comprises providing wastewater from the polymerization of fluorinated monomers comprising interfering constituents selected from the group consisting of fine solids and material which can be converted into fine solids, removing the interfering constituents from the wastewater, and subsequently binding the fluorinated emulsifier acids on an anion-exchange resin.
Dependencies are inferred from the claim text.