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US-20260124598-A1 - REMOVAL OF PERFLUOROALKYL AND POLYFLUOROALKYL SUBSTANCES FROM WATER USING SIZED-SORBENT MATERIALS

US20260124598A1US 20260124598 A1US20260124598 A1US 20260124598A1US-20260124598-A1

Abstract

Sorbent materials for the removal of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from drinking water and methods of using the same are disclosed. The sorbent materials are sized using a 20 US mesh and a 40 US mesh and provide improvements in PFAS removal and PFAS capacity as compared to larger sized sorbent materials.

Inventors

  • Adam M. Redding
  • Richard A. Mimna

Assignees

  • CALGON CARBON CORPORATION

Dates

Publication Date
20260507
Application Date
20251107

Claims (11)

  1. 1 . A method of removing perfluoroalkyl and polyfluoroalkyl substances (PFAS) from liquid or gas, the method comprising: providing a sorbent material having a particle size between 0.4 mm and 0.85 mm; and contacting the sorbent material with a liquid or gas containing the PFAS.
  2. 2 . The method of claim 1 , wherein the sorbent material comprises one or more of carbonaceous char, activated carbon, reactivated carbon, and carbon black.
  3. 3 . The method of claim 1 , wherein the sorbent material is formed from one or more of bituminous coal, sub-bituminous coal, lignite coal, anthracite coal, wood, wood chips, sawdust, peat, nut shells, pits, coconut shell, babassu nut, macadamia nut, dende nut, peach pit, cherry pit, olive pit, walnut shell, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitches, bagasse, rice hulls, corn husks, wheat hulls and chaff, graphenes, carbon nanotubes, or polymer fibers.
  4. 4 . The method of claim 1 , wherein the sorbent material comprises an iodine number greater than 1000 mg/g.
  5. 5 . The method of claim 1 , wherein the sorbent material comprises an iodine number of at least 1030 mg/g.
  6. 6 . The method of claim 1 , wherein the sorbent material comprises a molasses number of at least 175.
  7. 7 . The method of claim 1 , wherein the sorbent material comprises an apparent density of less than 0.58 g/cc.
  8. 8 . The method of claim 1 , wherein the sorbent material comprises a D50 particle size of 0.6 mm to 0.7 mm.
  9. 9 . The method of claim 1 , wherein the sorbent material is provided as a granular activated carbon, the method further comprising screening the granular activated carbon using a 20 US mesh and a 40 US mesh.
  10. 10 . The method of claim 1 , wherein the PFAS comprise one or more of perfluorobutanoic acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, and perfluorononanoic acid.
  11. 11 . The method of claim 1 , wherein the PFAS comprise one or more of perfluorobutane sulfonate, perfluoropentane acid, perfluorohexane sulfonate, perfluoroheptane sulfonate, and perfluorooctane sulfonate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit of and priority to U.S. Provisional Patent Application No. 63/717,645 titled “REMOVAL OF PERFLUOROALKYL AND POLYFLUOROALKYL SUBSTANCES FROM WATER USING SIZED-SORBENT MATERIALS” filed Nov. 7, 2024, the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of compounds that include perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and compounds produced by the GENX process such as 2,3,3,3,-tetrafluoro-2-(heptafluoropropoxy)propanoate and heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether. Such highly fluorinated compounds enjoyed widespread industrial use for many years, owing to their chemical durability, excellent surfactant properties, and key role as precursors to fluoropolymers including polytetrafluoroethylene. Unfortunately, these same properties render PFAS resistant to degradation in the environment, while simultaneously leading to bioaccumulation when ingested over time. Some recent studies have linked PFAS to various detrimental health effects, most notably elevated levels of cholesterol, but also kidney cancer, testicular cancer, thyroid disease, and pregnancy-induced hypertension. To date, several technologies have been employed to remove PFAS compounds from the environment and from drinking water. PFAS removal has typically been accomplished with granular activated carbon (GAC) in a range of mesh sizes between 8×16 and 12×40 US Mesh. PFAS can also be removed from a reverse osmosis reject waste stream using granular activated carbon. Additionally, anion exchange resins previously used for perchlorate removal have demonstrated success at removing the similarly negatively charged carboxylate and sulfonate PFAS. PFAS removal via GAC appears to be particularly sensitive to hydraulic loading rate (i.e., contact time), which suggests that diffusion rate into the GAC structure is a controlling factor. In other words, when GAC has more contact time with the water to be treated, the PFAS removal typically improves. There is continued need for performance improvements so that the GAC is even more effective at removing PFAS compounds from the environment and from drinking water. SUMMARY In one embodiment, a method of removing perfluoroalkyl and polyfluoroalkyl substances (PFAS) from liquid or gas includes providing a sorbent material having a particle size between 0.4 mm and 0.85 mm; and contacting the sorbent material with a liquid or gas containing the PFAS. In some embodiments, the sorbent material includes one or more of carbonaceous char, activated carbon, reactivated carbon, and carbon black. In some embodiments, the sorbent material is formed from one or more of bituminous coal, sub-bituminous coal, lignite coal, anthracite coal, wood, wood chips, sawdust, peat, nut shells, pits, coconut shell, babassu nut, macadamia nut, dende nut, peach pit, cherry pit, olive pit, walnut shell, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitches, bagasse, rice hulls, corn husks, wheat hulls and chaff, graphenes, carbon nanotubes, or polymer fibers. In some embodiments, the sorbent material includes an iodine number greater than 1000 mg/g. In some embodiments, the sorbent material includes an iodine number of at least 1030 mg/g. In some embodiments, the sorbent material includes a molasses number of at least 175. In some embodiments, the sorbent material includes an apparent density of less than 0.58 g/cc. In some embodiments, the sorbent material includes a D50 particle size of 0.6 mm to 0.7 mm. In some embodiments, the sorbent material is provided as a granular activated carbon, the method further including screening the granular activated carbon using a 20 US mesh and a 40 US mesh. In some embodiments, the PFAS include one or more of perfluorobutanoic acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, and perfluorononanoic acid. In some embodiments, the PFAS include one or more of perfluorobutane sulfonate, perfluoropentane acid, perfluorohexane sulfonate, perfluoroheptane sulfonate, and perfluorooctane sulfonate. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 depicts a diagram of an illustrative method of removing PFAS from a liquid or gas in accordance with an embodiment. FIGS. 2-23 depict graphical representations of the removal of PFAS from water by sized sorbent materials in accordance with an embodiment. DEFINITIONS As used herein, the term “about” when immediately preceding a numerical value means a range of plus or minus 10% of that value, for example, “about 50” means 45 to 55, “about 25,000” means 22,500 to 27,500, etc., unless the context of the disclosure indicates otherwise, or is inconsistent with such an interpretation. As used herein, the term “fresh sorbent media” means a sorbent material that contains sorbent capacity. For example, a fresh sorben