USE OF AT LEAST ONE EPOXIDIZED VEGETABLE OIL OR ONE OF ITS DERIVATIVES IN POLLUTED SOILS

Abstract

The present invention relates to the use of at least one epoxidized vegetable oil and/or of at least one of its derivatives as a carbon source in polluted soils, in particular for improving the bioremediation of polluted soils.

The invention also relates to a method for bioremediation of polluted soil(s), comprising at least a step of injecting an organic or hydro-organic composition comprising at least one epoxidized vegetable oil and/or at least one of its derivatives into a polluted soil.

Claims

1. The use of at least one epoxidized vegetable oil and/or of at least one of its derivatives in polluted soils, as a carbon source for microorganisms.

2. The use as claimed in claim 1, for the bioremediation of said polluted soils.

3. The use as claimed in claim 1 as a carbon source for accelerating bioremediation in polluted soils.

4. The use as claimed in claim 1, wherein the epoxidized vegetable oil and/or one of its derivatives is or are a carbon source for microorganisms.

5. The use as claimed in claim , wherein the polluted soils comprise(s) one or more organic polluting substances.

6. The use as claimed in claim 5, wherein the organic polluting substance(s) is or are chosen from the group consisting of hexane, octane, benzene, toluene, ethylbenzene, xylene, polycyclic aromatic hydrocarbons (PAHs) polychlorinated biphenyls (PCBs), chlorinated solvents, and mixtures thereof.

7. The use as claimed in claim 5, wherein the soils are permeable to very permeable.

8. The use as claimed in claim 5, wherein the epoxidized vegetable oil is chosen from the group consisting of liquid triglycerides of unsaturated C6-C30fatty acids which have undergone an epoxidation reaction.

9. The use as claimed in claim 5, wherein the epoxidized vegetable oil comprises a number of epoxide groups ranging from 1 to 9.

10. The use as claimed in claim 5, wherein the epoxidized vegetable oil is chosen from the group consisting of epoxidized soybean oil, epoxidized palm oil, epoxidized rapeseed oil, epoxidized linseed oil, epoxidized sunflower oil, epoxidized peanut oil, epoxidized camphor oil, epoxidized castor oil, and mixtures thereof.

11. The use as claimed in claim 5, wherein the epoxidized vegetable oil derivative(s) is or are chosen from the group consisting of esters of an epoxidized vegetable oil.

12. The use as claimed in claim 11, wherein the epoxidized vegetable oil derivative is an epoxidized soybean oil ester.

13. A method for bioremediation of polluted soils, comprising at least a step of injecting an organic or hydro-organic composition comprising at least one epoxidized vegetable oil and/or one of its derivatives as defined in claim 1 into at least one area of a polluted soil or near such an area.

14. The method for bioremediation as claimed in claim 13, wherein the epoxidized vegetable oil and/or one of its derivatives is in a content ranging from 1% to 100% by weight relative to the total weight of the composition.

15. The method as claimed in claim 13, wherein the composition also comprises one or more other nutrients.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0051] The polluted soil(s) that can be treated by the present invention comprise(s) one or more organic polluting substances.

[0052] Preferably, the polluted soil(s) that can be treated by the present invention comprise(s) one or more organic polluting substance(s) chosen from the group consisting of hydrocarbons, in particular linear C.sub.6-C.sub.30 hydrocarbons, cyclic hydrocarbons, polycyclic hydrocarbons, solvents, in particular halogenated solvents, or mixtures thereof, and in particular chlorinated solvents, or mixtures thereof.

[0053] More preferentially, the polluted soil(s) that can be treated by the present invention comprise(s) one or more organic polluting substance(s) chosen from the group consisting of hexane, octane, benzene, toluene, ethylbenzene, xylene, polycyclic aromatic hydrocarbons (PAHs) such as anthracene, naphthalene, pyrene, tetracene, coronene, benzopyrene, chrysene, phenanthrene, polychlorinated biphenyls (PCBs), chlorinated solvents, such as for example tetrachloroethylene and trichloroethylene, and mixtures thereof.

[0054] Even more preferentially, the polluted soil(s) that can be treated by the present invention comprise(s) one or more organic polluting substance(s) chosen from the group consisting of hydrocarbons, preferably hexane, octane, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), halogenated solvents, in particular chlorinated solvents, and mixtures thereof.

[0055] Even more preferably, the polluted soil(s) that can be treated by the present invention comprise(s) one or more organic polluting substance(s) chosen from halogenated solvents, in particular chlorinated solvents, and mixtures thereof.

[0056] The epoxidized vegetable oils and/or their epoxidized vegetable oil derivatives that can be used in the context of the present invention are effective for all ranges of soil permeability, and more particularly for permeable to very permeable soils.

[0057] Preferably, the epoxidized vegetable oil and/or its derivatives has (have) a viscosity ranging from 4 mPa.Math.s to 700 mPa.Math.s, in particular ranging from 25 mPa.Math.s to 650 mPa.Math.s, measured at a temperature of 25° C., as measured for example using an Ostwald viscometer.

[0058] The epoxidized vegetable oil(s) used according to the invention is or are in particular liquid triglycerides of unsaturated C.sub.6-C.sub.30, preferably C.sub.10-C.sub.24, in particular C.sub.12-C.sub.22, fatty acids which have undergone an epoxidation reaction, that is to say which comprise at least one epoxide function.

[0059] Thus, the epoxidized vegetable oils according to the invention are preferably prepared from: [0060] vegetable oil extracted from an oleaginous plant, [0061] an esterification reaction between one or more unsaturated C.sub.6-C.sub.30, preferably C.sub.10-C.sub.24, in particular C.sub.14-C.sub.22, carboxylic fatty acids and glycerol in order to obtain triglycerides of unsaturated fatty acids, [0062] an epoxidation reaction of the triglycerides of unsaturated fatty acids previously obtained in the presence of an organic peracid, formed with aqueous hydrogen peroxide, and for example performic acid or peracetic acid, and where appropriate an acid catalyst such as sulfuric or phosphoric acid.

[0063] The term “unsaturated fatty acids” means that the fatty chain comprises at least one unsaturation, preferably in the form of a double bond, which can be involved in an epoxidation reaction as indicated above.

[0064] The epoxidized vegetable oil(s) used according to the invention comprise(s) in its structure or their structure at least one epoxide group.

[0065] In other words, the vegetable oils according to the invention are in particular liquid triglycerides of unsaturated C.sub.6-C.sub.30, preferably C.sub.14-C.sub.22, in particular C.sub.12-C.sub.22, fatty acids which comprise in their structure at least one epoxide group.

[0066] For the purposes of the present invention, the term “liquid” is understood to mean that the vegetable oil is liquid at a temperature of 25° C. and at atmospheric pressure (760 mmHg, i.e. 1013.25 hPa).

[0067] Preferably, the epoxidized vegetable oil(s) according to the invention comprise(s) a number of epoxide groups ranging from 1 to 9, preferably ranging from 1 to 6, more preferably ranging from 2 to 6.

[0068] Preferentially, the epoxidized vegetable oil used according to the invention is chosen from the group consisting of epoxidized soybean oil, epoxidized palm oil, epoxidized rapeseed oil, epoxidized linseed oil, epoxidized sunflower oil, epoxidized peanut oil, epoxidized camphor oil, epoxidized castor oil, and mixtures thereof.

[0069] More preferentially, the epoxidized vegetable oil used according to the invention is epoxidized soybean oil, in particular the epoxidized soybean oil sold under the trade name Vikoflex® 7177 (obtained in the presence of formic acid) and Vikoflex® 7170 (obtained in the presence of acetic acid) by the company Arkema.

[0070] For the purposes of the present invention, the term “an epoxidized vegetable oil derivative” is understood to mean a compound which has been synthesized from a vegetable oil as described above. In other words, an epoxidized vegetable oil derivative corresponds to a vegetable oil which has been chemically modified, or else a compound obtained after opening one or more epoxy rings (i.e. epoxide group) of said epoxidized vegetable oil.

[0071] Preferably, the present invention relates to the use of at least one epoxidized vegetable oil and/or at least one epoxidized vegetable oil ester (transesterification of vegetable oil).

[0072] Preferably, the epoxidized vegetable oil ester used in the context of the present invention is more particularly chosen from the group consisting of methyl esters of an epoxidized vegetable oil.

[0073] More preferentially, the epoxidized vegetable oil ester used according to the invention is a methyl ester of epoxidized soybean oil, in particular that sold under the trade name Vikoflex® 7010 by the company Arkema.

[0074] Preferably, the present invention relates to the use of at least one epoxidized vegetable oil and/or of at least one ester of an epoxidized vegetable oil as a carbon source in polluted soils.

[0075] More preferentially, the invention relates to the use of an epoxidized soybean oil and/or of an epoxidized soybean oil ester as a carbon source in polluted soils.

[0076] More preferentially, the epoxidized soybean oil and/or the epoxidized soybean oil ester is used for improving the bioremediation of polluted soils, in particular for accelerating the bioremediation of soils.

[0077] Advantageously, the invention relates to the use of an epoxidized soybean oil as a carbon source in polluted soils.

[0078] Alternatively, the invention also relates to the use of an ester of an epoxidized soybean oil as a carbon source in polluted soils.

[0079] In particular, the methyl ester of an epoxidized soybean oil is used as a carbon source in polluted soils.

[0080] Again alternatively, the invention also relates to the use of an epoxidized soybean oil and of an ester of an epoxidized soybean oil as a carbon source in polluted soils.

[0081] Advantageously, the epoxidized vegetable oil and/or one of its derivatives can be used as a carbon source in polluted soils in combination with one or more other nutrients.

[0082] Preferably, these nutrients are chosen from the group consisting of sugars or vegetable oils free of epoxide groups.

[0083] The invention also relates to a method for bioremediation of polluted soils, comprising at least a step of injecting an organic or hydro-organic composition comprising at least one epoxidized vegetable oil and/or one of its derivatives as defined above into at least one area of a polluted soil, as defined above, or near such an area.

[0084] As indicated above, the soil contains one or more organic substances as defined above.

[0085] Preferably, the epoxidized vegetable oil and/or one of its derivatives is in a content ranging from 1% to 100% by weight, preferably ranging from 5% to 100% by weight, preferably ranging from 10% to 100% by weight, preferably ranging from 20% to 100% by weight relative to the total weight of the composition.

[0086] The composition can also comprise one or more nutrients such as sugars or vegetable oils free of epoxide groups.

[0087] The method according to the invention makes it possible in particular to activate, stimulate or even improve the bioremediation of organic substances by means of the microorganisms, in particular bacteria, mentioned above.

[0088] Preferably, the composition comprises at least one epoxidized vegetable oil and/or at least one ester of an epoxidized vegetable oil.

[0089] The following examples serve to illustrate the invention without, however, exhibiting a limiting nature.

EXAMPLE

[0090] In the following example, the diffusion in sand between an epoxidized soybean oil, a methyl ester of an epoxidized soybean oil and a pure soybean oil, i.e. a vegetable oil not modified by epoxidation, was compared.

I. Protocol

1. Preparation of Emulsions

[0091] Emulsions comprising 30 g of tap water, 70 g of organic compound (soybean oil, commercial products Vikoflex® 7177 and Vikoflex® 7170) and 0.1 g of a dye (Solvent Violet 59, C162025, CAS 6408-72-6) were prepared by rapid stirring for a period of 15 minutes in a closed container using a magnetic stirrer bar.

[0092] The dye used is organic in nature and is only soluble in the organic phase of the emulsions prepared.

[0093] The dye is used to visualize the progress of the organic phase. A verification by total carbon analysis confirmed that very little (content less than 0.6 mg.I.sup.−1) carbon is found in the colorless phase, and the colored phase corresponds to the organic phase.

[0094] 2. Preparation of the Chromatography Column

[0095] A chromatography column (diameter 3 cm), with sintered glass disk and stopcock was filled (stopcock closed) with 10 cm of soil from Saint-Auban (Durance valley, France) sieved to a grain size of less than 1600 μm.

[0096] The column was filled with water to the upper level of the soil.

[0097] The stirring of the emulsion was then stopped and the emulsion was added to the chromatography column until a level of 5 cm above the soil was reached.

[0098] The chromatography column was then pressurized with a constant air flow, regulated by a Brooks R2 15C flowmeter.

[0099] A timer was started at the moment the stopcock was opened so as to measure the time for the emulsion to percolate through the soil.

[0100] A colorless phase was first collected and then the timer was stopped when a colored drop dripped from the sintered glass.

II. Results

[0101] The results are collated in table 1 below:

TABLE-US-00001 TABLE 1 Sand Emulsion Emulsion percolation Oils tested weight (g) weight (g) time 1: Vikoflex ® 7177 68.9 24.3 31 min 1: Vikoflex ® 7177 66.4 23.4 29 min 1: Vikoflex ® 7177 66.9 22.9 34 min 1: Vikoflex ® 7177 65 19.9 29 min 1: Vikoflex ® 7177 66.9 20 32 min 2: Vikoflex ® 7170 67.5 21.8 47 min 2: Vikoflex ® 7170 67.9 21.7 47 min 2: Vikoflex ® 7170 67 23 46 min 2: Vikoflex ® 7170 68.7 24 51 min 3: Non-epoxidized 66.1 21.4 4 min 30 sec soybean oil 3: Non-epoxidized 66 22.5 4 min 30 sec soybean oil 3: Non-epoxidized 66.3 22 4 min 20 sec soybean oil 3: Non-epoxidized 66.15 22.4 5 min 20 sec soybean oil

[0102] The results show that the epoxidized soybean oil sold under the name Vikoflex® 7177 and the epoxidized soybean oil sold under the name Vikoflex® 7170 diffuse more slowly than pure soybean oil in permeable soils.

[0103] Consequently, the epoxidized soybean oil sold under the name Vikoflex® 7177 and the epoxidized soybean oil sold under the name Vikoflex® 7170 are more biologically available as a carbon source for bacteria than an identical vegetable oil free of epoxide group.