SYSTEM AND METHOD FOR SEPARATING COMPETING ANIONS FROM PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) IN A FLOW OF WATER
A system for separating competing anions from per- and polyfluoroalkyl substances (PFAS) in a flow of water contaminated with PFAS and elevated levels of competing anions that includes a separation subsystem which receives the flow of water contaminated with PFAS and elevated levels of competing anions and separates competing anions from the PFAS and concentrates the PFAS to produce a treated flow of water having separated competing anions therein and a flow of water having a majority of PFAS therein. At least one anion exchange vessel having an anion exchange resin therein receives the flow of water having a majority of PFAS therein and removes PFAS from the water to produce a flow of treated water having a majority of the PFAS removed. The separation of competing anions by the separation subsystem increases the treatment capacity of the anion exchange resin to remove PFAS from the contaminated water.
1 . A method for separating competing anions from per- and polyfluoroalkyl substances (PFAS) in a flow of water contaminated with PFAS and elevated levels of competing anions, the method comprising:
receiving the flow of water contaminated with PFAS and elevated levels of competing anions;
separating competing anions from the PFAS and concentrating the PFAS to produce a treated flow of water having separated competing anions therein and a flow of water having a majority of the PFAS therein;
receiving the flow of water having a majority of the PFAS therein;
removing PFAS from the flow of water having a majority of the PFAS therein to produce a flow of treated water having a majority of the PFAS removed; and
wherein the separation of competing anions from the PFAS increases a treatment capacity of an anion exchange resin to remove PFAS from the contaminated water.
2 . The method of claim 1 in which the anion exchange resin includes a regenerable anion exchange resin.
3 . The method of claim 1 in which the anion exchange resin includes a single use anion exchange resin.
4 . The method of claim 1 in which the separating includes membrane separation.
5 . The method of claim 4 in which the membrane separation includes nanofiltration.
6 . The method of claim 4 in which the separation includes ultrafiltration.
7 . The method of claim 1 in which the separating includes foam fractionation.
8 . The method of claim 7 including increasing the production of microbubbles and foam.
9 . The method of claim 8 including:
receiving the flow of water contaminated with PFAS and elevated levels of competing anions,
introducing and mixing a gas into a recycled flow of water having separated competing anions therein and generating a two-phase flow of microbubbles and water having separated competing anions therein, and
receiving the two-phase flow in a cylindrical baffle and inducing rotational movement that generates intense mixing and turbulence to maximize formation and distribution of the microbubbles and foam.
10 . The method of claim 9 including separating the two-phase flow of microbubbles and water having separated competing anions therein from the treated flow of water having separated competing anions therein.
11 . The method of claim 7 in which the foam fractionation is configured to produce a concentrated flow of foam that transforms into the flow of water having the majority of the PFAS therein.
12 . The system of claim 7 in which the foam fractionation includes heating the foam to enhance the transformation of the foam into the flow of water having the majority of PFAS therein.
13 . The method of claim 1 in which the competing ions include one or more of: chloride, sulfate, nitrate, bicarbonate, and perchlorate.
14 . The method of claim 1 in which the flow of water contaminated with PFAS and elevated levels of competing anions includes industrial wastewater.
15 . The method of claim 1 in which the flow of water contaminated with PFAS and elevated levels of competing anions includes landfill leachate.
16 . The method of claim 1 in which the flow of water contaminated with PFAS and elevated levels of competing anions includes contaminated groundwater.
17 . The method of claim 1 including adding a supplemental surfactant to increase the productions of microbubbles and foam.
18 . The method of claim 17 in which the supplemental surfactant includes an anionic, cationic, zwitterionic, nonionic, and/or a protein-based surfactant.