Apparatus for treatment of soils contaminated with organic pollutants

• US 5,205,927 A
• Filed: 08/01/1990
• Issued: 04/27/1993
• Est. Priority Date: 09/25/1987
• Status: Expired due to Fees

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Wickramanayake, Godage B.
• Primary Examiner(s): WYSE, THOMAS G
• Application Number:
  US07/561,474
• Time in Patent Office: 1,000 Days
• Field of Search: 210/747, 210/760, 210/170, 210/192, 210/198.1, 210/206, 210/221.2, 134/31, 134/42, 55/95, 55/244-255, 422/29, 422/186.07-186.12
• US Class Current: 210/170.07
• CPC Class Codes: B09C 1/08 chemically
• CPC Class Codes: B09C 2101/00 In situ
• CPC Class Codes: C02F 1/78 with ozone C02F1/4672 takes precedence
• CPC Class Codes: C02F 2209/06 pH

Abstract

An apparatus for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil in a manner adapted to decompose the organic compounds; one embodiment of the apparatus comprises a means to supply ozone as a gas-ozone mixture, a stability means to treat ozone obtained from the supply and distribution means to apply the stabilized gas-ozone to soil. The soil may be treated in situ or may be removed for treatment and refilled.

Claims

1. An apparatus for treating soil contaminated with organic compounds comprising:

a. an ozone generator adapted to receive an oxygen containing gas from a gas supply means, that generates ozone from oxygen in the gas to produce a gas-ozone mixture;

b. ozone stabilizing means, containing an acid, connected to the ozone generator by a first pipe for receiving the gas-ozone mixture from the ozone generator, that stabilizes the gas-ozone mixture by contacting the mixture with the acid to produce a stabilized gas-ozone mixture, wherein the acid has a pH of about (1) or less; and

c. gas-ozone mixture distribution means, connected to the ozone stabilizing means by a second pipe for receiving the stabilized gas-ozone mixture, that distributes the mixture to the soil as a gas.

2. The apparatus of claim 1 further comprising gas supply means connected to the ozone generator by a third pipe for supplying a gas containing oxygen to the ozone generator.

3. The apparatus of claim 2 further comprising gas conditioning means adapted to purify and/or pressurize the gas, disposed between the gas supply means and ozone generator, wherein the third pipe connects the gas supply means to the gas conditioning means for supplying a gas containing oxygen thereto, and a fourth pipe connects the gas conditioning means to the ozone generator for supplying a conditioned gas containing oxygen thereto.

4. The apparatus of claim 1 wherein the gas-ozone mixture distribution means further comprises injection wells for treating the soil in situ and fifth piping for distributing the gas-ozone mixture to the wells.

5. The apparatus of claim 4 further comprising:

d. ozone neutralizing means adapted to receive the gas-ozone mixture that has passed through the soil and neutralize the residual ozone in the mixture, wherein the ozone neutralizing means is a spread blanket wetted with Na₂ S₂ O₃ solution over an ozonation zone.

6. The apparatus of claim 1 wherein the gas-ozone mixture distribution means further comprises one or more chambers for treating the soil and sixth piping for distributing the gas-ozone mixture to the chamber(s).

7. The apparatus of claim 6 further comprising:

d. ozone neutralizing means adapted to receive the gas-ozone mixture that has passed through the soil and neutralize the residual ozone in the mixture, wherein a seventh pipe connects an outlet of each chamber to the ozone neutralizer means and neutralized gas is discharged to atmosphere from the ozone neutralizer means.

8. The apparatus of claim 1, wherein the ozone stabilizing means comprises a container with acid, and the gas-ozone mixture from the first pipe is bubbled through the acid to contact and stabilize the gas-ozone mixture, and the stabilized gas-ozone mixture flows to the distribution means by the second pipe.

9. The apparatus of claim 1, wherein the ozone stabilizing means comprises a spray system for contacting the gas-ozone mixture from the first pipe and the stabilized gas-ozone mixture flows to the distribution means by the second pipe.

10. The apparatus of claim 1, wherein the acid is a strong inorganic acid.

11. The apparatus of claim 10, wherein the acid is selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid and mixtures thereof.