Method and apparatus for soil decontamination

• US 4,978,508 A
• Filed: 09/01/1988
• Issued: 12/18/1990
• Est. Priority Date: 09/01/1988
• Status: Expired due to Fees

• Current Assignee: Pacific Resource Recovery Corporation
• Original Assignee: Pacific Resource Recovery Corporation
• Inventors: Hansen, Andrew H., Walker, William C., Walker, Richard K., Braly, Sam
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Hsing, Ben C.
• Application Number:
  US07/239,278
• Time in Patent Office: 838 Days
• Field of Search: 204/158.2, 204/158.21, 204/157.15, 422/186.08, 422/186.1, 422/186.11, 422/186.14, 422/186.3
• US Class Current: 422/186.08
• CPC Class Codes: B01F 25/4316 the baffles being flat pieces of material, e.g. intermeshing, fixed to the wall or fixed on a central rod
• CPC Class Codes: B01F 25/431971 Mounted on the wall
• CPC Class Codes: B01J 19/123 Ultraviolet light
• CPC Class Codes: B09C 1/00 Reclamation of contaminated soil
• CPC Class Codes: B09C 1/02 Extraction using liquids, e.g. washing, leaching , flotation
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 2103/06 Contaminated groundwater or leachate

Abstract

A method and apparatus for decontaminating soil which has been contaminated with hazardous hydrocarbons. The apparatus includes a blending or scrubbing unit for mixing the contaminated soil with water and a suitable surfactant to form a slurry; screening apparatus operably interconnected with the blending unit for removing from the slurry particles larger than a predetermined size to form a small particle slurry; a reactor unit operably interconnected with the screening apparatus for reacting the slurry with ozone to form an ozone enriched slurry; an ultraviolet radiation generator for irradiating the ozone enriched slurry with ultraviolet radiation; a static mixer operably interconnected with the reactor unit for mixing a floculating material with the slurry to form a floculated slurry; and a belt-forming press for receiving the floculated material from the static mixer and for forming the floculated slurry into contamination free blocks.

Claims

1. An apparatus for decontaminating soil which is contaminated with hazardous hydrocarbons, comprising:

(a) blending means for mixing the contaminated soil with water and a surfactant to form a slurry;

(b) first screening means operably interconnected with said blending means for removing from said slurry particles larger than a first predetermined size to form a small particle slurry;

(c) reactor means operably interconnected with said screening means for reacting said small particle slurry with ozone, said reactor means comprising;

(i) enclosure means for receiving said small particle slurry from said first screening means;

(ii) recirculating pump means for continuously recirculating said small particle slurry through said enclosure means; and

(iii) ozone generating means operably associated with said recirculating pump means for injecting ozone into said small particle slurry to form an ozone enriched slurry;

(d) illuminating means operably associated with said reactor means for illuminating said ozone enriched slurry with ultraviolet light;

(e) second screening means operably connected with said reactor means for removing particles larger than a second predetermined size from said ozone enriched slurry to form a fine particle slurry;

(f) mixer means operably interconnected with said second screening means for mixing floculating material with said fine particle slurry to form a floculated slurry;

(g) forming means for forming said floculated slurry into discrete segments.

2. An apparatus for decontaminating soil as defined in claim 1 in which said enclosure means comprises a tank having an inlet and an outlet, and in which said recirculating pump means comprises a pump having a spray generating outlet, said pump being adapted to continuously pump said small particle slurry from said outlet of said tank to said inlet of said tank for introduction of said small particle slurry into said tank in the form of a spray.

3. An apparatus as defined in claim 2 in which said illuminating means comprises a source of ultraviolet radiation adapted to continuously direct ultraviolet radiation toward said spray being introduced into said tank.

4. An apparatus for decontaminating soil which is contaminated with hazardous hydrocarbons, comprising:

(a) blending means for mixing the contaminated soil with a mixture of water, sodium hydroxide, sodium laural sulphate and hydrogen peroxide to form a slurry;

(b) a first vibratory screen apparatus operably interconnected with said blending means for removing from said slurry particles larger than about 1/8th inch in diameter to form a small particle slurry;

(c) reactor means, including recirculating pump means and ozone generating means, operably interconnected with said screening means for continuously reacting said small particle slurry with ozone to form an ozone enriched, small particle slurry;

(d) illuminating means operably associated with said reactor means for continuously illuminating said ozone enriched, small particle slurry with ultraviolet light;

(e) a second vibratory screen apparatus operably connected with said reactor means for removing particles larger than about 80 mesh from said small particle slurry to form a fine particle slurry;

(f) mixer means operably interconnected with said second screening means for mixing lime and an anionic polymer material with said fine particle slurry to form a floculated slurry; and

(g) forming means for forming said floculating slurry into brickettes.