KR-102963526-B1 - Modified clay adsorbent and PFAS adsorption method using the same

Abstract

A method for adsorbing PFAS compounds from a contaminated environment may include the step of mixing a modified clay adsorbent with the environment. The modified clay may include clay intercalated with a mixture of a single-quaternary amine compound and a di-quaternary amine compound.

Inventors

• 도노반, 미카엘

Assignees

• 스페셜티 미네랄스 (미시간) 인코포레이티드

Dates

Publication Date

20260513

Application Date

20200522

Priority Date

20190522

Claims (20)

1. As a modified clay adsorbent for adsorbing PFAS compounds from a contaminated environment, It comprises clay intercalated with one or more di-quaternary amine compounds and one or more single-quaternary amine compounds, and A modified clay adsorbent in which one or more of the above-mentioned double-quaternary amine compounds are present in a molar ratio of 25 mol% to 95 mol% based on the total molar of the quaternary amine compounds present in the modified clay adsorbent.
2. The clay of claim 1 is a modified clay adsorbent in which one or more double-quaternary amine compounds and one or more single-quaternary amine compounds are inserted with a total cation exchange capacity of at least 50% of the clay.
3. As a modified clay adsorbent for adsorbing PFAS compounds from a contaminated environment, A first modified clay comprising clay having one or more single-quaternary amine compounds inserted therein; and A second modified clay comprising clay having one or more double-quaternary amine compounds inserted therein, and A modified clay adsorbent in which the second modified clay is present in the modified clay adsorbent in an amount such that one or more double-quaternary amine compounds are present in an amount of 25 mol% to 95 mol% based on the total mole of quaternary amine compounds present in the modified clay adsorbent.
4. In paragraph 3, the first modified clay and the second modified clay are each a modified clay adsorbent in which one or more single-quaternary amine compounds and double-quaternary amine compounds are inserted with a cation exchange capacity of at least 50% of each of the first or second modified clays.
5. In any one of claims 1 to 4, the one or more double-quaternary amine compounds are a modified clay adsorbent having 18 or more carbons.
6. In claim 5, the one or more double-quaternary amine compounds are one or more of dequalinium chloride and compounds of formula I, and A modified clay adsorbent, wherein, in the above formula, X is chloride, R1 is an aliphatic radical having 1 to 13 carbons, R2 , R3 , R4 , R5 , R6 , and R7 are independently selected from aliphatic radicals and aromatic radicals, and at least one of R2 , R3 , R4 , R5 , R6 , and R7 is an aliphatic radical or aromatic radical having 8 or more carbons.
7. In claim 6, the modified clay adsorbent, wherein the compound of formula I is pentamethylpropylene diammonium hydrochloride.
8. A modified clay adsorbent according to any one of claims 1 to 4, wherein the one or more double-quaternary amine compounds are present in an amount of 25 mol% to 50 mol% based on the total molar of the quaternary amine compounds in the modified clay adsorbent.
9. A modified clay adsorbent according to any one of claims 1 to 4, wherein the clay is one or more of atapulgite, bentonite, montmorillonite, nontronite, beidellite, volkonscoite, hectorite, saponite, soconite, sobockite, stevensite, swinfordite, vermiculite, palygorskite, calonite, and sepiolite.
10. In any one of claims 1 to 4, the modified clay adsorbent is a modified clay adsorbent present in the mat.
11. A modified clay adsorbent according to any one of claims 1 to 4, wherein the single-quaternary amine compound is one or more of dimethyl di(C14 to C18 alkyl) ammonium chloride.
12. A kit comprising a modified clay adsorbent of any one of claims 1 to 4 and instructions for adding said clay adsorbent to a contaminated environment for the adsorption of PFAS compounds.
13. As a kit, As a modified clay adsorbent of claim 3, the first and second modified clays exist as individual components, the modified clay adsorbent, and A kit comprising instructions for individually adding the first modified clay and the second modified clay to the contaminated environment to form the modified clay adsorbent in an amount such that the one or more double-quaternary amine compounds are present in an amount of 25 mol% to 95 mol% based on the total molar of the quaternary amine added to the contaminated environment.
14. A kit according to claim 13, wherein the first and second modified clays are added in an amount such that the one or more double-quaternary amine compounds are present in an amount of 25 mol% to 50 mol% based on the total molar of the quaternary amine compounds added to the contaminated environment.
15. A kit according to claim 13 or 14, wherein the first and second modified clays are substantially added simultaneously.
16. A kit according to claim 13 or 14, wherein the first and second modified clays are added sequentially.
17. As a method for adsorbing PFAS compounds from a contaminated environment, The method comprises the step of mixing a modified clay adsorbent with the contaminated environment, wherein the modified clay adsorbent comprises clay having one or more double-quaternary amine compounds inserted therein, and the double-quaternary amine compounds are diqualinium chloride and/or a compound of Formula I. A method wherein, in the above formula, X is a chloride, R1 is an aliphatic radical having 1 to 13 carbons, R2 , R3 , R4 , R5 , R6 , and R7 are independently selected from aliphatic radicals and aromatic radicals, and at least one of R2 , R3 , R4 , R5 , R6 , and R7 is an aliphatic radical or an aromatic radical having 8 or more carbons.
18. In claim 17, the method wherein the modified clay adsorbent is modified with a compound of formula (I).
19. In paragraph 18, the method wherein the compound of formula I is pentamethylpropylene diammonium hydrochloride.
20. A method according to any one of claims 17 to 19, wherein the modified clay adsorbent is bentonite modified with diqualinium chloride.

Description

Modified clay adsorbent and PFAS adsorption method using the same Cross-reference of related applications This application claims the benefit of priority of U.S. Provisional Application No. 62/851,431 filed on May 22, 2019, the entire contents of which are incorporated herein by reference. Technology field The present disclosure relates to a method for adsorbing PFAS compounds, in particular to a method for adsorbing PFAS compounds using clay modified with one or more bifunctional quaternary amine compounds. Perfluorocompounds (PFCs) are widely used, which has made them a subject of international concern regarding water pollution. Perfluoroalkyl and polyfluoroalkyl substances (commonly collectively referred to as PFAS) are a group of synthetic compounds that includes PFOA, PFOS, GenX, and numerous other chemicals. PFAS have been manufactured and used in various industries, including the United States, since the 1940s. Perfluorooctanesulfonate (PFOS) is one of the common PFCs and has been used in numerous industries as a surfactant, flame retardant, lubricant, and polymer additive. Perfluorooctanoic acid (PFOA) and PFOS are the most widely manufactured, and these compounds have been extensively studied. PFCs can accumulate in the human body over long periods, and many do not decompose naturally. Exposure to PFAS has been proven harmful to human health. The removal of PFCs from wastewater sources is crucial for preventing pollution of natural waterways. Because PFCs are generally very stable, it is difficult to decompose them in the surrounding environment using some conventional techniques, including biological degradation, oxidation, and reduction. Adsorption has been used as an alternative method to effectively remove PFCs from wastewater, soil, and other pollutants using conventional adsorbents, including activated carbon, resins, and bioadsorbents. There is a need for improved methods to adsorb PFAS compounds from soil, wastewater, and other pollutants. The modified clay adsorbent according to the present disclosure may comprise clay intercalated with one or more di-quaternary amine compounds and one or more single-quaternary amine compounds, and the one or more di-quaternary amine compounds are present in a molar ratio of about 25 mol% to about 95 mol% based on the total molar of quaternary amine compounds present in the modified clay adsorbent. A modified clay adsorbent according to the present disclosure may comprise a first modified clay comprising clay having one or more single-quaternary amine compounds inserted therein; and a second modified clay comprising clay having one or more double-quaternary amine compounds inserted therein. The second modified clay may be present in the modified clay adsorbent in an amount such that one or more double-quaternary amine compounds are present in an amount of about 25 mol% to about 95 mol% based on the total molar of quaternary amine compounds present in the modified clay adsorbent. A method for adsorbing PFAS compounds from a contaminated sample or environment according to the present disclosure comprises the step of mixing a modified clay adsorbent with said sample or environment, wherein the modified clay adsorbent comprises clay having one or more double-quaternary amine compounds inserted therein, and the double-quaternary amine compounds are diqualinium chloride and/or a compound of formula (I): In the above formula, X is chloride, R1 is an aliphatic radical having 1 to 13 carbons, R2 , R3 , R4 , R5 , R6 , and R7 are independently selected from aliphatic radicals and aromatic radicals, and at least one of R2 , R3 , R4 , R5 , R6 , and R7 is an aliphatic radical or an aromatic radical having 8 or more carbons. A method for adsorbing PFAS compounds from a contaminated sample or environment according to the present disclosure comprises the step of mixing a modified clay adsorbent with said sample, wherein the modified clay adsorbent comprises clay having one or more single-quaternary amine compounds and one or more double-quaternary amine compounds inserted therein, and the one or more double-quaternary amine compounds are present in an amount of about 25 mol% to about 95 mol% based on the total molar ratio of the quaternary amine compounds in the modified clay adsorbent. A method for adsorbing PFAS compounds from a contaminated sample or environment comprises the step of mixing a modified clay adsorbent with said sample or environment, wherein the modified clay adsorbent comprises a first modified clay comprising clay with one or more single-quaternary amine compounds inserted therein and a second modified clay comprising clay with one or more double-quaternary amine compounds inserted therein, and the ratio of the amount of the first modified clay to the amount of the second modified clay is selected such that the one or more double-quaternary amine compounds are present in an amount of about 25 mol% to about 95 mol% based on the total molar ratio of the q