Hydrothermal Technology for Decontamination and Mineralization of Perfluoro- and Polyfluoroalkyl Substance (PFAS) in Wastes, Concentrate Solutions, and Chemical Stockpiles

Patent metadata

Field	Value
Publication number	US-2020155885-A1
Application number	US-201916689426-A
Country	US
Kind code	A1
Filing date	Nov 20, 2019
Priority date	Nov 20, 2018
Publication date	May 21, 2020
Grant date	—

Abstract

Disclosed herein are methods and systems for treating a waste substance containing perfluoro- and polyfluoroalkyl substances (PFAS). The method includes combining the PFAS with a first amendment in a reactor to create a combination, heating and pressurizing the combination to hydrothermal conditions, and holding the combination at hydrothermal conditions for a holding time sufficient to at least partially mineralize the PFAS to create a treated combination.

First claim

We claim:

1 . A method for treating a waste substance containing PFAS, the method comprising:
combining the PFAS with a first amendment in a reactor to create a combination; heating and pressurizing the combination in the reactor to a hydrothermal condition; and holding the combination in the hydrothermal condition for a holding time sufficient to at least partially mineralize the PFAS to create a treated combination.

2 . The method of claim 1 , wherein the hydrothermal condition comprises:
a temperature of about 200° C. to about 700° C.; and a pressure of about 2 MPa to about 50 MPa.

3 . The method of claim 1 , further comprising bringing the combination to a moisture content.

4 . The method of claim 1 , further comprising adjusting the pH of the treated combination.

5 . The method of claim 4 , further comprising reducing the pH of the treated combination.

6 . The method of claim 1 , wherein the amendment is an acid.

7 . The method of claim 6 , wherein the acid is one of HCl, H 2 SO 4 , or HNO 3 .

8 . The method of claim 1 , wherein the amendment is a base.

9 . The method of claim 8 , wherein the base is at least one of NaOH, Ca(OH) 2 , Na 2 CO 3 , KOH, NH 4 OH, Mg(OH) 2 .

10 . The method of claim 3 , wherein the moisture content is at least 75% water.

11 . The method of claim 3 , wherein further comprising combining the PFAS with a solvent.

12 . The method of claim 11 , wherein the solvent is methanol and the moisture content is at least 25% water.

13 . The method of claim 1 , wherein the amendment is an oxidant or a reductant.

14 . The method of claim 1 , wherein the amendment is at least one of K 2 FeO 4 , KMnO 4 , K 2 CrO 4 , NaClO 4 , NaClO 3 , NaClO, H 2 O 2 , NaBH 4 , Na 2 SO 3 , Na 2 S 2 O 3 , Na 2 S 2 O 4 , Na 2 S 2 O 5 , Na 2 S 2 O 5 , Na 2 HSO 5 , KI, FeSO 4 , NaNO 3 , FeCl 3 , NiCl 2 , ZnCl 2 , NaH 2 PO 4 , Na 2 HPO 4 , NaF, D 2 O, octanoic acid, ammonium acetate, ammonium hydroxide, methanol, isopropanol, sulfite, or water.

15 . The method of claim 1 , wherein the waste substance further contains an organic compound.

16 . The method of claim 1 , wherein the method is continuous.

17 . The method of claim 1 , wherein the method is batched.

18 . The method of claim 1 , where in the pressurizing is autogenous.

19 . A system for treating a waste substance containing PFAS substances, the system comprising a vessel adapted to:
combine the PFAS with a first amendment in the vessel to create a combination; heat the combination in the vessel to a temperature of about 200° C. or more; pressurize the combination in the vessel to a pressure of about 2 MPa or more; and hold the combination in a heated and pressurized state for a holding time sufficient to at least partially mineralize the PFAS to create a treated combination.

20 . The system of claim 19 , wherein the amendment is at least one of HCl, H 2 SO 4 , HNO 3 , NaOH, Ca(OH) 2 , KOH, NH 4 OH, Mg(OH) 2 , Na 2 CO 3 , K 2 FeO 4 , KMnO 4 , K 2 CrO 4 , NaClO 4 , NaClO 3 , NaClO, H 2 O 2 , NaBH 4 , Na 2 SO 3 , Na 2 S 2 O 3 , Na 2 S 2 O 4 , Na 2 S 2 O 5 , Na 2 S 2 O 8 , Na 2 HSO 5 , KI, FeSO 4 , NaNO 3 , FeCL 3 , NiC 2 , ZnCl 2 , NaH 2 PO 4 , Na 2 HPO 4 , NaF, D 2 O, octanoic acid, ammonium acetate, ammonium hydroxide, methanol, isopropanol, sulfite, or water.

Assignees

• Colorado School Of Mines

Inventors

• Strathmann Timothy James
• Higgins Christopher P
• Wu Boran
• Hao Shilai

Classifications

• C02F1/025 Primary

  Thermal hydrolysis · CPC title

• A62D2101/22

  containing halogen · CPC title

• C02F1/441

  by reverse osmosis · CPC title

• C02F2101/36

  containing halogen · CPC title

• A62D3/38

  by oxidation; by combustion · CPC title