MANGANESE-MEDIATED REDOX PROCESSES FOR ENVIRONMENTAL CONTAMINANT REMEDIATION

• US 20100215437A1
• Filed: 02/24/2010
• Published: 08/26/2010
• Est. Priority Date: 02/24/2009
• Status: Active Grant

• Current Assignee: Geo-Cleanse International Incorporated
• Original Assignee: Geo-Cleanse International Incorporated
• Inventors: BRYANT, James Daniel
• Granted Patent: US 8,556,537 B2
• Time in Patent Office: Days
• US Class Current: 405/128.500
• CPC Class Codes: B09C 1/002 involving in-situ ground water treatment
• CPC Class Codes: B09C 1/08 chemically
• CPC Class Codes: C02F 1/66 by neutralisation; pH adjustment for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58
• CPC Class Codes: C02F 1/722 Oxidation by peroxides
• CPC Class Codes: C02F 1/725 by catalytic oxidation
• CPC Class Codes: C02F 2101/306 Pesticides
• CPC Class Codes: C02F 2101/36 containing halogen
• CPC Class Codes: C02F 2101/363 PCB's; PCP's
• CPC Class Codes: C02F 2103/06 Contaminated groundwater or leachate

Abstract

Methods and compositions for the remediation of environmental contaminants using redox reactions are described. The redox reactions include manganese compounds and peroxide generating compounds. The methods and compositions are also useful for the remediation of highly oxidized environmental contaminants.

Claims

1. A process for remediation of a site having one or more soil contaminants, one or more groundwater contaminants, or a combination thereof, the process comprising the steps of contacting the site with (a) Mn(IV) or a compound capable of generating Mn(IV);

(b) a buffered aqueous solution having a pH in the range from about 6 to about 10; and

(c) a peroxide or a compound capable of forming a peroxide.

2. The process of claim 1 wherein the pH is in the range from about 6.5 to about 8.

3. The process of claim 1 wherein the buffered aqueous solution further comprises one or more compounds capable of forming a ligand with manganese.

4. The process of claim 1 wherein the buffered aqueous solution comprises one or more phosphate salts.

5. The process of claim 1 wherein the compound capable of generating Mn(IV) comprises a permanganate compound.

6. The process of claim 1 wherein the Mn(IV) is in the form of a MnO₂ precipitate.

7. The process of claim 1 wherein the peroxide or the compound capable of forming the peroxide comprises hydrogen peroxide.

8. The process of claim 1 wherein the peroxide or the compound capable of forming the peroxide comprises calcium peroxide, magnesium peroxide, sodium percarbonate, or a combination thereof.

9. The process of claim 1 wherein the contaminants comprise a compound capable of reacting with a reducing agent but not an oxidizing agent.

10. The process of claim 1 wherein the contaminants comprise a highly oxidized carbon compound.

11. The process of claim 1 wherein the contaminants comprise a compound capable of reacting with a reductive radical compound.

12. The process of claim 11 wherein the reductive radical compound is superoxide.

13. The process of claim 1 wherein the contaminants comprise one or more chloromethanes, nitroaromatics, or a combination thereof

14. The process of claim 1 wherein the contaminants comprise one or more components selected from the group consisting of carbon tetrachloride, chloroform, methylene chloride, acetone, freons, nitrobenzenes, hexavalent chromium, and cyanide.

15. The process of claim 1 wherein the contaminants comprise a compound oxidizable by the compound capable of generating Mn(IV).

16. The process of claim 1 wherein the contaminants comprise one or more components selected from the group consisting of tetrachloroethene, trichloroethene, dichloroethylene, vinyl chloride, ethylene dibromide, polychlorinated biphenyls, and naphthalene.

17. The process of claim 1 wherein the contaminants comprise one or more compounds selected from the group consisting of benzene, toluene, xylene, ethylbenzene, chlorobenzene, naphthalene, trinitrotoluene, benzo(a)pyrene, anilines, chlorophenols, methyl tert-butyl ether, tert-butyl alcohol, alkenes, alkanes, perchloroethylene, trichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, carbon disulfide, quinones, hydroquinones, formate, and organic acids.

18. The process of claim 1 wherein the contaminants comprise a pesticide.

19. The process of claim 1 wherein steps (b) and (c) are performed contemporaneously or simultaneously.

20. A process for remediation of a site having one or more soil contaminants, one or more groundwater contaminants, or a combination thereof, the process comprising the steps of contacting the site with (a) Mn(IV) or a compound capable of generating Mn(IV);

(b) one or more compounds capable of forming a ligand with a manganese ion; and

(c) a peroxide or a compound capable of forming a peroxide.

21. The process of claim 20 wherein the one or more compounds capable of forming a ligand with the manganese ion are included in a buffered aqueous solution having a pH in the range from about 6 to about 10.

22. The process of claim 21 wherein the pH is in the range from about 6.5 to about 8.

23. A process for site remediation, where the site includes oxidizable and reducible contaminants, the process comprising the step of performing a manganese redox cycle at the site, where the manganese redox cycle is capable of both oxidizing and reducing one or more of the contaminants.

24. The process of claim 23 wherein the manganese redox cycle is performed by (a) contacting the site with a permanganate compound, (b) contacting the site with a buffer, and (c) contacting the site with a peroxide or a compound capable of forming a peroxide.

25. The process of claim 24 wherein the buffer comprises a phosphate salt.

26. A kit comprising a permanganate, a phosphate buffer, and a peroxide or a compound capable of forming a peroxide, and a set of instructions for using the kit for remediation of a site having one or more soil contaminants, one or more groundwater contaminants, or a combination thereof.

27. The kit of claim 26 wherein the phosphate buffer and the peroxide or the compound capable of forming a peroxide are included in a ratio in the range from about 1:

1 to about 10;

1.

28. The kit of claim 26 wherein the phosphate buffer and the peroxide or the compound capable of forming a peroxide are premixed at a ratio in the range from about 1:

1 to about 10;

1.