Methods and systems of PFAS destruction using UV irradiation at 222 nanometers
AssigneeClaros Technologies Inc.
InventorsAndrew Thomas Healy, Evan Anthony Leslie, Zekun Liu, Terrance P. Smith, Joseph Reuel Levine Tirado
Life of this patent
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Abstract
Methods, systems and devices for PFAS destruction including adding a sulfite salt to an aqueous solution containing PFAS and then irradiating the aqueous solution with light at 222 nm. The method may include adding a base to the aqueous solution in an amount sufficient to raise a pH of the aqueous solution including PFAS to about 10 or more. It may also include adding a halide salt such as a bromide salt or an iodine salt, and further adding a carbonate. Greater than 90%, or greater than 99%, of the PFAS in the solution may be destroyed by irradiating the aqueous solution in this way.
Claims20
A method of PFAS destruction comprising:
- a. adding an amount of persulfate and acid or base to an aqueous solution including PFAS to decrease or increase a pH and subjecting the aqueous solution including PFAS to an increased temperature and pressure of at least about 1 bar for a period of time sufficient for thermal oxidation;
- b. after step a, adding a sulfite salt to the aqueous solution including PFAS;
- c. after step a, if the pH of the aqueous solution is less than about 10, adding base to the aqueous solution including PFAS to increase the pH to about 10 or more;
- and
- d. after steps a-c, irradiating the aqueous solution including PFAS with light at 222 nm.
A photoreactor for PFAS destruction comprising:
- a reactor vessel configured to receive an aqueous solution including PFAS;
- a first light source comprising an ultraviolet light source configured to deliver light at about 222 nm to the aqueous solution including PFAS in the reactor vessel;
- a second light source comprising an ultraviolet light source configured to deliver light at about 222 nm to the aqueous solution including PFAS in the reactor vessel.
A system of PFAS destruction comprising:
- a pretreatment reactor comprising:
- a pre-treatment vessel configured to contain an aqueous solution containing PFAS at elevated pressure and comprising a heating element to heat the aqueous solution contained therein;
- and
- sources of persulfate and acid or base configured to deliver persulfate and acid or base to the aqueous solution before or within the pre-treatment vessel;
- a photoreactor downstream of the pretreatment reactor, the photoreactor comprising:
- a reactor vessel configured to receive an aqueous solution;
- a plurality of ultraviolet light sources configured to deliver light at 222 nm to the aqueous solution including PFAS in the reactor vessel;
- and
- a source of a sulfite salt configured to deliver the sulfite salt to the aqueous solution before or within the reactor vessel.
Dependencies are inferred from the claim text.