In-situ subsurface decontamination of sodic soil, clay and ground water

• US 10,369,604 B2
• Filed: 07/23/2018
• Issued: 08/06/2019
• Est. Priority Date: 05/11/2011
• Status: Active Grant

• Current Assignee: William L. Lundy
• Original Assignee: William L. Lundy
• Inventors: Lundy, William L.
• Primary Examiner(s): Stelling, Lucas A
• Application Number:
  US16/042,653
• Publication Number:
  US 20180339326A1
• Time in Patent Office: 379 Days
• CPC Class Codes: B09C 1/002 involving in-situ ground water treatment
• CPC Class Codes: B09C 1/08 chemically
• CPC Class Codes: B09C 2101/00 In situ
• 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 1/683 by addition of complex-forming compounds
• CPC Class Codes: C02F 1/70 by reduction C02F1/4676 takes precedence
• CPC Class Codes: C02F 1/722 Oxidation by peroxides
• CPC Class Codes: C02F 1/725 by catalytic oxidation
• CPC Class Codes: C02F 2101/36 containing halogen
• CPC Class Codes: C02F 2103/06 Contaminated groundwater or leachate
• CPC Class Codes: C02F 2305/023 Reactive oxygen species, singlet oxygen, OH radical
• CPC Class Codes: C02F 2305/026 Fenton's reagent
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage

Abstract

A method of decontaminating soil and ground water containing organic contaminants and metal compounds. It comprises the steps of first treating such soils and ground water with an effective amount an aqueous solution containing a peroxide and a water soluble chelating agent for a time sufficient to have the water soluble chelating agent chelate at least one of the metals of the metal compounds present in the soil and ground water. Next, the chelated metals are brought into contact with the peroxide to catalytically convert the peroxide to an oxidizing agent and hydroxyl ion. The hydroxyl ion converts the halogenated organic compound into environmentally safe, non-toxic compounds. Gases that are produced from this reaction, and from the oxidation of organic compounds, are used to diffuse solution into the soil to chelate calcium and magnesium, thereby causing the sodium to be dislodged from the soil and reduce sodicity in the soil.

Claims

1. A method of decontaminating soil and/or ground water containing halogenated organic contaminants and a metal compound, the method comprising:

(a) treating the soil and/or ground water with an effective amount of an alkaline aqueous solution having a pH of 7 to 10 and comprising an alkaline buffering agent, a peroxide, and a chelating agent, for a time sufficient to have the chelating agent chelate the metal of the metal compound present in the soil and/or ground water;

(b) reacting the chelated metal with the peroxide to catalytically convert the peroxide to oxidizing agents and reducing agents, the reducing agent comprising hydroxide ions, and the oxidizing agents comprising hydroxyl radials;

(c) contacting the halogenated organic contaminants in the soil and/or ground water with the hydroxide ions to convert and reduce the halogenated organic contaminants through reduction reaction to environmentally safe, non-toxic compounds, wherein the reduction reaction is nucleophilic substitution; and

(d) penetrating the soil and/or ground water with carbon dioxide to diffuse the alkaline aqueous solution into the soil and/or ground water and generate additional reaction.

2. The method of claim 1, wherein the concentration of peroxide is about 0.6 to about 4.5 Moles/Liter.

3. The method of claim 1, wherein the concentration of chelating agents is about 0.03 to about 1.5 Moles/Liter.

4. The method of claim 1, wherein the buffering agent comprises di-ammonium and the concentration of di-ammonium phosphate is about 0.5 to about 2.0 lbs/gallon.

5. The method of claim 1, wherein the temperature of the soil and/or ground water rises no more than 10.0 degrees F.

6. The method of claim 1, wherein treating the soil and/or ground water with the effective amount of the alkaline aqueous solution comprises:

spraying or injecting the alkaline aqueous solution over or into the soil and/or ground water to be treated, and

injecting the solution into areas exhibiting higher concentrations of contaminants.

7. The method of claim 6, wherein the alkaline aqueous solution is sprayed onto a floor and walls of an excavated area, in the amount of 0.25-2.0 gal/sq. ft.

8. The method of claim 6, wherein the alkaline aqueous solution is injected at a rate of 3-10 gallons per minute.

9. The method of claim 1, wherein treating the soil and/or ground water with the effective amount of the alkaline aqueous solution comprises injecting the alkaline aqueous solution into the soil and/or ground water at a rate of 3-10 gallons per minute.

10. The method of claim 1, wherein treating the soil and/or ground water with the effective amount of the alkaline aqueous solution comprises:

spraying or injecting the alkaline aqueous solution over or into the surface to be treated;

determining areas not yet reached by the reagent; and

spraying or injecting the solution into the areas not yet reached by the reagent.

11. The method of claim 10, wherein determining the areas not yet reached by the reagent comprises:

observing the evolution of gases at the surface; and

identifying the areas not yet reached by the reagent as those areas known to be contaminated but did not evolve gases at the surface.