Sustainable System and Method for Removing and Concentrating Per- and Polyfluoroalkyl Substances (PFAS) from Water

Abstract

A sustainable system for removing and concentrating per- and polyfluoroalkyl substances (PFAS) from water. The system includes an anion exchange vessel having a selected anion exchange resin therein configured to remove PFAS from the water. A line coupled to the vessel introduces a flow of water contaminated with PFAS such that the PFAS bind to the selected anion exchange resin and are thereby removed from the water. A regenerant solution line is coupled to the anion exchange vessel to introduce an optimized regenerant solution to the anion exchange vessel to remove the PFAS from the anion exchange resin, thereby regenerating the anion exchange resin and generating a spent regenerate solution comprised of the removed PFAS and the optimized regenerant solution. A separation and recovery subsystem recovers the optimized regenerant solution for reuse and separates and concentrates the removed PFAS.

1 . A system for reducing an amount of a toxic spent regenerant solution produced by a system which removes per- and polyfluoroalkyl substances (PFAS) from contaminated water, the system comprising:
 a concentration subsystem configured to separate and concentrate the PFAS in the contaminated water to produce the toxic spent regenerant solution; and   a separation and recovery subsystem configured to receive the toxic spent regenerant solution, the separation and recovery subsystem including at least one of a distillation subsystem, an evaporation subsystem, or a membrane separation subsystem, at least one of the distillation subsystem, the evaporation subsystem, or the membrane separation subsystem configured to concentrate the PFAS, water, and salt in the toxic spent regenerant solution to reduce the amount of toxic spent regenerant solution.   
     
     
         2 . The system of  claim 1  in which the concentration subsystem includes an anion exchange vessel including an anion exchange resin therein configured to receive a flow of the contaminated water such that the PFAS in the contaminated water bind to the anion exchange resin to remove PFAS from the contaminated water and configured to receive a regenerant solution comprising a mixture of a salt, a solvent and water to regenerate the anion exchange resin and produce the toxic spent regenerant solution. 
     
     
         3 . A method for reducing an amount of a toxic spent regenerant solution produced by a method which removes per- and polyfluoroalkyl substances (PFAS) from contaminated water, the method comprising:
 separating and concentrating the PFAS in the contaminated water to produce the toxic spent regenerant solution; and   subjecting the toxic spent regenerant solution to a separation and recovery process including at least one of a distillation process, an evaporation process, or a membrane separation process, at least one of the distillation process, the evaporation process, or the membrane separation process configured to concentrate the PFAS, water, and salt in the toxic spent regenerant solution to reduce the amount of toxic spent regenerant solution.   
     
     
         4 . The method of  claim 3  in which the separating and concentrating the PFAS includes introducing a regenerant solution comprising a mixture of a salt, a solvent, and water to an anion exchange resin to remove the PFAS from the anion exchange resin to regenerate the anion exchange resin and generate the toxic spent regenerant solution.