TREATMENT OF AQUEOUS COMPOSITION WITH METAL COMPONENT

1 . A method of treating feed water, the method comprising:

adding a metal component comprising a metal to the feed water, wherein the feed water comprises a fluoroalkyl compound, wherein the metal component comprises an ion of the metal, a solid or dissolved compound of the metal, an elemental form of the metal, or a combination thereof, wherein the addition of the metal component to the feed water forms a solid;

removing the solid from the metal component-treated feed water, to form a clarified aqueous composition and to form an aqueous concentrate having a higher concentration of the solid than the clarified aqueous composition, wherein the aqueous concentrate comprises the metal component added to the feed water, and wherein the clarified aqueous composition has a lower concentration of the fluoroalkyl compound as compared to the feed water; and

reusing at least some of the metal component in the aqueous concentrate as 1 wt % to 100 wt % of the metal component that is added to the feed water.

2 . The method of claim 1 , wherein the metal is Mg, Al, Fe, Zn, Cu, Cd, Cr, Hg, Ni, V, Ce, or a combination thereof.

3 . The method of claim 1 , wherein the metal is Mg.

4 . The method of claim 1 , wherein the fluoroalkyl compound is a perfluoroalkyl or polyfluoroalkyl substance (PFAS), perfluoroalkyl substance, a polyfluoroalkyl substance, a perfluoroalkyl acid (PFAA), or a combination thereof.

5 . The method of claim 1 , wherein the metal component comprises an ion of the metal and/or a hydroxide salt of the metal.

6 . The method of claim 1 , wherein adding the metal component to the feed water comprises adding to the feed water a salt of the metal of the metal component.

7 . The method of claim 1 , further comprising acidifying the aqueous concentrate to bring a pH of the aqueous concentrate to a pH of 0.5 to 5 sufficient to at least partially dissolve one or more salts comprising the metal of the metal component added to the feed water, and reusing at least some of the metal of the metal component in the acidified aqueous concentrate as 1 wt % to 100 wt % of the metal component that is added to the feed water.

8 . The method of claim 7 , further comprising purging one or more acidification contaminants from the acidified aqueous concentrate.

9 . The method of claim 7 , wherein the acidified aqueous concentrate comprises a metal component-treated fluoroalkyl compound formed by addition of the metal component to the feed water, wherein the method further comprises destroying the fluoroalkyl compound in the acidified aqueous concentrate.

10 . The method of claim 7 , wherein the contacting of the feed water and the metal component forms a metal component-treated fluoroalkyl compound, further comprising performing a secondary separation to separate a residual solution from the aqueous concentrate after the acidifying to concentrate the metal component-treated fluoroalkyl compound in the aqueous concentrate and to form the residual solution separated therefrom.

11 . The method of claim 10 , wherein a ratio of a volume of the aqueous concentrate having the residual solution removed therefrom to a volume of the acidified aqueous concentrate prior to removal of the residual solution therefrom is 1:100,000 to 1:1.

12 . The method of claim 10 , wherein a ratio of a volume of the acidified aqueous concentrate having the residual solution removed therefrom to a volume of the feed water is 1:1,000,000 to 1:1.

13 . The method of claim 1 , wherein the method is free of treating the feed water or clarified aqueous composition with a galvanic cell.

14 . The method of claim 1 , further comprising treating the clarified aqueous composition with a galvanic cell, to form product water.

15 . The method of claim 14 , wherein the galvanic cell comprises:

an anode comprising Mg, Al, Fe, Zn, Cu, Cd, Cr, Hg, Ni, V, Ce, or a combination thereof; and

a cathode having a different composition than the anode, wherein the cathode comprises Al, Zn, Fe, Cd, Ni, Sn, Pb, Cu, Ag, Co, Mn, Pd, Ag, carbon, or a combination thereof.

16 . The method of claim 15 , wherein:

the anode comprises Al; and

the cathode comprises Cu.

17 . The method of claim 1 , further comprising purging one or more acidification contaminants from a recycle stream comprising the metal component from the aqueous concentrate prior to or during combining the recycle stream and the feed water.

18 . The method of claim 1 , further comprising pretreating the feed water prior to and/or during addition of the metal component to the feed water, wherein the pretreatment comprises adjusting pH of the feed water, adding one or more additives to the feed water, filtering the feed water, allowing sediment to settle from the feed water, removing nitrogen from the feed water, removing phosphorus from the feed water, treating the feed water with a pretreatment galvanic cell, or a combination thereof.

19 . A method of treating feed water, the method comprising:

performing a treatment comprising adding a metal component comprising a metal to feed water comprising a fluoroalkyl compound to form a solid comprising a metal component-treated fluoroalkyl compound, wherein the metal component is an ion of the metal, a solid or dissolved compound of the metal, an elemental form of the metal, or a combination thereof;

removing the solid from the feed water to form a clarified aqueous composition having a lower concentration of the fluoroalkyl compound than the feed water and to form an aqueous concentrate having a higher concentration of the solid than the clarified aqueous composition;

acidifying the aqueous concentrate;

performing a secondary separation to separate a residual solution from the aqueous concentrate after the acidification and to concentrate the metal component-treated fluoroalkyl compound in the aqueous concentrate; and

adding the metal component from the residual solution to the feed water prior to or during the treatment.

20 . A method of treating feed water, the method comprising:

performing a treatment comprising adding a metal component comprising a metal to feed water comprising a fluoroalkyl compound to form a solid comprising a metal component-treated fluoroalkyl compound, wherein the metal component comprises an ion of the metal, a solid or dissolved compound of the metal, an elemental form of the metal, or a combination thereof;

removing the solid from the feed water to form a clarified aqueous composition having a lower concentration of the fluoroalkyl compound than the feed water and to form an aqueous concentrate having a higher concentration of the solid than the clarified aqueous composition;

acidifying the aqueous concentrate;

performing a secondary separation to separate a residual solution from the aqueous concentrate after the acidification and to concentrate the metal component-treated fluoroalkyl compound in the aqueous concentrate;

purging one or more acidification contaminants from the residual solution; and

adding the metal component from the residual solution to the feed water prior to or during the treatment.