Product for PFAS adsorption
A product for adsorbing one or more PFAS from a liquid is disclosed. The product may comprise attapulgite that has been surface functionalized with (a) a quaternary amine surface coating solution that comprises a mono-quaternary amine compound or a di-quaternary amine compound and (b) a mercapto surface coating solution that comprises a surface coating agent that includes one or more mercapto groups that chemically bond to the attapulgite surface. When the quaternary amine surface coating solution includes the mono-quaternary amine compound, the product is free of di-quaternary amines. When the quaternary amine surface coating solution includes the di-quaternary amine compound, the product is free of mono-quaternary amines. Also disclosed is a method of producing the product and a method of adsorbing a PFAS in a liquid using the product.
1. A product for adsorbing at least one PFAS in a liquid, the product comprising attapulgite that has been surface functionalized with: (a) a quaternary amine surface coating solution that includes a mono-quaternary amine compound or a di-quaternary amine compound, the mono-quaternary amine compound comprising one or more mono-quaternary amines that attach to the attapulgite surface, the di-quaternary amine compound comprising one or more di-quaternary amines that attach to the attapulgite surface, and (b) a surface coating agent that includes one or more mercapto groups that chemically bond to the attapulgite surface,
wherein when the quaternary amine surface coating solution includes one or more mono-quaternary amine compounds, the product or the attapulgite is free of di-quaternary amines,
wherein when the quaternary amine surface coating solution includes one or more di-quaternary amine compounds, the product or the attapulgite is free of mono-quaternary amines,
wherein the product or the attapulgite has a surface area in the range of 45-160 m 2 /g as measured using the BET method,
wherein the product or the attapulgite has a particle size distribution having a d 50 of 6-30 microns, and
wherein the product comprises:
85-94 wt. % of the attapulgite;
2.5-15 wt. % of the (i) mono-quaternary amine(s) or (ii) di-quaternary amine(s); and
1-8 wt. % of the surface coating agent.
2. The product of claim 1 , wherein the surface coating agent is mercapto silane.
3. The product of claim 1 , wherein the product is in powder form and/or free of extrusion.
4. The product of claim 1 , wherein the product has a PFAS removal efficiency for the at least one PFAS of 70-100%, in 12-25 hours in the liquid at a loading of 0.5-2 g of the product per liter of the liquid.
5. The product of claim 1 , wherein the product is free of oleyl amine and octyl amine.
6. The product of claim 1 , wherein the product or the attapulgite is free of residual acid.
7. The product of claim 1 , wherein:
the surface area is in a range of 50-100 m 2 /g; and
the d 50 is in a range of 10-25 microns.
8. The product of claim 1 , wherein the d 50 is in a range of 12-23 microns.
9. The product of claim 1 , wherein the product has a PFAS removal efficiency for the at least one PFAS of 90-100%, in 12-25 hours in the liquid at a loading of 0.5-2 g of the product per liter of the liquid.
10. A method of producing a product for adsorbing at least one PFAS from a liquid, the method comprising:
selecting an attapulgite as feed material, wherein prior to surface treatment, the attapulgite selected as the feed material contains 7-16 wt. % moisture when measured at a temperature of 104° C.;
surface treating the attapulgite with a quaternary amine surface coating solution, the quaternary amine surface coating solution including (i) a mono-quaternary amine compound, the mono-quaternary amine compound comprising one or more mono-quaternary amines that attach to the surface of the attapulgite, or (ii) a di-quaternary amine compound, the di-quaternary amine compound comprising one or more di-quaternary amines that attach to the surface of the attapulgite; and
surface treating the attapulgite with a mercapto surface coating solution, the mercapto surface coating solution including a surface coating agent that includes one or more mercapto groups that chemically bond to the surface of the attapulgite,
wherein the product produced or surface treated attapulgite has a surface area in the range of 45-160 m 2 /g as measured using the BET method,
wherein when the quaternary amine surface coating solution includes the mono-quaternary amine compound, the product or surface treated attapulgite is free of di-quaternary amines,
wherein when the quaternary amine surface coating solution includes the di-quaternary amine compound, the product or surface treated attapulgite is free of mono-quaternary amines.
11. The method of claim 10 ,
wherein the weight percentage of components of the product includes:
85-94 wt. % attapulgite;
2.5-15 wt. % of (i) one or more mono-quaternary amines or (ii) one or more di-quaternary amines; and
1-8 wt. % surface coating agent that includes the one or more mercapto groups,
wherein the product is free of oleyl amine and octyl amine.
12. The method of claim 10 ,
Wherein the quaternary amine surface coating solution further includes water,
wherein the mercapto surface coating solution further includes a solvent,
wherein the surface coating agent comprises mercapto silane.
13. The method of claim 10 , wherein the surface treating of the attapulgite with a mercapto surface coating solution is subsequent to the surface treating of the attapulgite with a quaternary amine surface coating solution.
14. The method of claim 13 , wherein the quaternary amine surface coating solution further includes water.
15. The method of claim 10 , wherein the product or surface treated attapulgite has a particle size distribution having a d 50 of 6-30 microns.
16. The method of claim 9 , wherein the product has a PFAS removal efficiency for the at least one PFAS of 70-100%, in 12-25 hours in the liquid at a loading of 0.5-2 g of the product per liter of the liquid.
17. The method of claim 10 , wherein:
the attapulgite selected as the feed material contains 9-14 wt. % moisture; and
the product has a particle size distribution having a d 50 of 10-25 microns.
18. The method of claim 10 , wherein:
the product has a particle size distribution having a d 50 of 12-23 microns; and/or
the product has a PFAS removal efficiency for the at least one PFAS of 95-100%, in 12-25 hours in the liquid at a loading of 0.5-2 g of the product per liter of the liquid.
19. A method for adsorbing at least one PFAS in a liquid, the method comprising:
contacting the liquid with a product comprising attapulgite that has been surface functionalized with (a) a quaternary amine surface coating solution that includes a mono-quaternary amine compound or a di-quaternary amine compound, the mono-quaternary amine compound comprising one or more mono-quaternary amines that attach to the attapulgite surface, the di-quaternary amine compound comprising one or more di-quaternary amines that attach to the attapulgite surface, and (b) a surface coating agent that includes one or more mercapto groups that chemically bond to the attapulgite surface; and
separating the product from the liquid to recover a resultant liquid that has a lower amount of PFAS than the liquid had prior to the mixing,
wherein the weight percentage of the components of the product includes: 85-94 wt. % attapulgite, 2.5-15 wt. % of (i) one or more mono-quaternary amines or (ii) one or more di-quaternary amines, and 1-8 wt. % surface coating agent that includes the one or more mercapto groups,
wherein when the quaternary amine surface coating solution includes one or more mono-quaternary amine compounds, the product or the attapulgite is free of di-quaternary amine compounds,
wherein when the quaternary amine surface coating solution includes one or more di-quaternary amine compounds, the product or the attapulgite is free of mono-quaternary amine compounds,
wherein the product or the attapulgite has a surface area in the range of 45-160 m 2 /g as measured using the BET method,
wherein the removal efficiency of the product for a PFAS is 10-100%, at a loading of 0.5-2 g of the product per liter of the liquid.
20. The method of claim 19 , wherein the liquid includes water, edible oil, wastewater, process water, or combinations thereof.
21. The method of claim 19 , wherein the surface coating agent comprises mercapto silane.
22. The method of claim 19 , wherein when the contacting is for 12-25 hours, the removal efficiency of the product for the PFAS is 70-100%, at the loading of 0.5-2 g of the product per liter of the liquid.
23. The method of claim 19 , wherein when the contacting is for 12-25 hours, the removal efficiency of the product for the PFAS is 80-100%, at the loading of 0.5-2 g of the product per liter of the liquid.
24. The method of claim 19 , wherein when the contacting is for 12-25 hours, the removal efficiency of the product for the PFAS is 95-100% at the loading of 0.5-2 g of the product per liter of the liquid.
25. A product for adsorbing at least one PFAS in a liquid, the product comprising attapulgite that has been surface functionalized with: (a) a quaternary amine surface coating solution that includes a mono-quaternary amine compound or a di-quaternary amine compound, the mono-quaternary amine compound comprising one or more mono-quaternary amines that attach to the attapulgite surface, the di-quaternary amine compound comprising one or more di-quaternary amines that attach to the attapulgite surface, and (b) a surface coating agent that includes one or more mercapto groups that chemically bond to the attapulgite surface,
wherein when the quaternary amine surface coating solution includes one or more mono-quaternary amine compounds, the product is free of di-quaternary amines,
wherein when the quaternary amine surface coating solution includes one or more di-quaternary amine compounds, the product is free of mono-quaternary amines,
wherein the product or the attapulgite has a surface area in the range of 45-160 m 2 /g as measured using the BET method,
wherein the product or the attapulgite has a particle size distribution having a d 50 of 6-30 microns, and
wherein the product or the attapulgite has a porosity of 40-90% and a pore volume of 0.7-1.5 mL/g.
26. The product of claim 25 , wherein the surface coating agent is mercapto silane.
27. The product of claim 25 , wherein the product is free of oleyl amine and octyl amine.
28. The product of claim 25 , wherein the product or the attapulgite is free of residual acid.