Title: Method for in situ or ex situ bioremediation of hexavalent chromium contaminated soils and/or groundwater

Abstract

A method of reducing the concentration of Cr(VI) in a liquid aqueous residue comprises the steps of providing anaerobic Cr(VI) reducing bacteria, mixing the liquid aqueous residue with a nutrient medium to form a mixture, and contacting the mixture with the anaerobic Cr(VI) reducing bacteria such that Cr(VI) is reduced to Cr(III). The anaerobic Cr(VI) reducing bacteria appear to be ubiquitous in soil and can be selected by collecting a soil sample, diluting the soil sample with a sterile diluent to form a diluted sample, mixing the diluted sample with an effective amount of a nutrient medium and an effective amount of Cr(VI) to form a mixture, and incubating the mixture in the substantial absence of oxygen such that growth of Cr(VI) sensitive microorganisms is inhibited and growth of the anaerobic Cr(VI) reducing bacteria is stimulated. A method of in situ bioremediation of Cr(VI) contaminated soil and/or groundwater is also disclosed.

Inventors:

Turick, Charles E ^[1]; Apel, William W ^[1]

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1. Idaho Falls, ID

Issue Date:

1997-10-28

Research Org.:

Idaho National Laboratory (INL), Idaho Falls, ID (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

871209

Patent Number(s):

5681739

Application Number:

08/452591

Assignee:

Lockheed Idaho Technologies Company (Idaho Falls, ID)

Patent Classifications (CPCs):

B - PERFORMING OPERATIONS B09 - DISPOSAL OF SOLID WASTE B09C - RECLAMATION OF CONTAMINATED SOIL

C - CHEMISTRY C02 - TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE C02F - TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

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B - PERFORMING OPERATIONS B09 - DISPOSAL OF SOLID WASTE B09C - RECLAMATION OF CONTAMINATED SOIL

B09C1/10 - microbiologically, {biologically} or by using enzymes

C - CHEMISTRY C02 - TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE C02F - TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

C02F3/34 - characterised by the microorganisms used

C - CHEMISTRY C12 - BIOCHEMISTRY C12N - MICROORGANISMS OR ENZYMES

C12N1/00 - Microorganisms, e.g. protozoa

C - CHEMISTRY C12 - BIOCHEMISTRY C12P - FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {

C12P1/00 - Preparation of compounds or compositions, not provided for in groups C12P3/00 - C12P39/00, by using microorganisms or enzymes

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DOE Contract Number:  

AC07-94ID13223; AC07-76ID01570

Resource Type:

Patent

Country of Publication:

United States

Language:

English

Subject:

method; situ; bioremediation; hexavalent; chromium; contaminated; soils; groundwater; reducing; concentration; liquid; aqueous; residue; comprises; steps; providing; anaerobic; bacteria; mixing; nutrient; medium; form; mixture; contacting; reduced; iii; appear; ubiquitous; soil; selected; collecting; sample; diluting; sterile; diluent; diluted; effective; amount; incubating; substantial; absence; oxygen; growth; sensitive; microorganisms; inhibited; stimulated; disclosed; reducing bacteria; nutrient medium; contaminated soils; liquid aqueous; contaminated soil; soil sample; effective amount; situ bioremediation; substantial absence; hexavalent chromium; aqueous residue; /435/