FR2930732A1 - COMPOSITION AND METHOD FOR THE DESTRUCTION OF ORGANOPHOSPHORUS AND / OR ORGANOSOUFRES POLLUTANTS - Google Patents

Abstract

The invention relates to a decontaminating composition comprising: (i) perpropionic acid, (ii) dipicolinic acid, (iii) a salt of hydroxyethyldiethylphosphonic acid, (iv) a surface-active agent, and (v) an alkalinizing agent. The decontaminating compositions that are the subject of the invention have a high stability and high effectiveness, enabling a rapid destruction of the toxic organophosphorus or organosulphur agents.

Description

COMPOSITION AND METHOD FOR THE DESTRUCTION OF ORGANOPHOSPHORUS AND / OR ORGANOSOUFTED POLLUTANTS

The invention relates to the decontamination of toxic agents and / or pollutants organophosphorus or organosoufrés, particularly in the field of chemical warfare agents or in the field of agriculture, for example for the decontamination of insecticides. It relates in particular to a novel decontamination composition comprising two specific stabilizing agents, as well as to a method for destroying these organophosphorus and / or organosulfur pollutants.

In the field of chemical warfare agents, there are currently many organophosphorus esters derived from phosphoric and phosphonic acids, such as Tabun, Sarin or Soman. These compounds exhibit significant neurotoxicity because of their phosphorylating power with respect to cholinesterase whose inhibition leads to death by accumulation of acetylcholine in the body.

In addition, there are also organosulfur toxic products such as industrial sulphides or warfare agents of the family of vesicants, such as yperite.

In the agricultural field, there are toxic organophosphorus compounds, such as organophosphates, amidophosphates, organoamidophosphates, phosphorothionates, phosphonothionates and phosphonoamidothionates used as insecticides and pesticides, as well as organosulfur compounds of the RS-R 'type, R and R 'represent in particular hydrocarbon radicals and halogenated hydrocarbon radicals.

Of the most well-known organophosphorus compounds, compounds such as O, O-diethyl-op-nitrophenyl phosphate (Paraoxon), O, O-diethyl-op-nitrophenyl phosphonothioate (Parathion) and O, O-diethyl-O- (2-Isopropyl-4-methyl-6-pyrimidyl) -phosphorothioate (Diazinon) play an important role in agriculture as insecticides or as pesticides.

In addition, toxic organosulfur compounds, such as 2,2'-dichloro-diethyl sulphide or 2-phenyl-2-chlorodiethyl sulphide are also very aggressive chemical agents and their stability allows them to persist on a ground contaminated for several years, without experiencing a significant decrease in toxicity.

The existence of large stocks of the products listed above is a problem. Their disposal involves the use of decontaminant compositions to be applied to the products themselves or to the contaminated material or persons. The decontaminant compositions may be used in substitution or in combination with physical processes for the displacement of toxicants.

It is therefore important to have, especially in the case of intentional or accidental use of such compounds, a decontaminant composition capable of degrading the toxic products themselves and of decontaminating quickly and efficiently the materials contaminated with toxic agents.

The most effective compositions currently available are solutions of sodium hydroxide in an aqueous medium or in methylglycol (1,2-propanediol) in the presence of amine, or calcium hypochlorite; however, such solutions are corrosive with respect to fragile materials and in particular alloys of light metals.

It is well known that nucleophilic compounds are effective products for removing toxic agents of the organophosphorus and organosulfur series. Thus, the hydroxyl anion in a strongly basic medium is able to neutralize these toxic agents. However, the efficiency obtained is accompanied by a strong aggressiveness vis-à-vis the materials to be decontaminated.

Another way is to use in peroxygenic compounds, such as hydrogen peroxide, tert-butyl hydroperoxide, perborates and peracids, in a relatively basic or even neutral medium, because of their properties which are both nucleophilic and oxidising.

The different peroxygen compounds are most often used in solutions containing quaternary ammonium surfactants, improving the contact between the peroxygen reagent and the toxic agent during decontamination.

The peroxides currently proposed in the decontamination of contaminated materials by different families of toxic agents, including Paraoxon; and the sulfur-containing compounds are in the form of aqueous solutions of linear long-chain peracids with a pH of between 6 and 8 or aqueous solutions based on industrial peracids, such as magnesium monoperoxyphthalate or phthalimidoperhexanoic acid, these peracids being, in both cases, associated with surfactants, in particular of the quaternary ammonium salt type.

However, the first peracids are rarely commercially available at an industrial level and have poor stability and solubility, and the second peracids, although commercially available, are in solid form at room temperature, have poor stability at high temperature and are not easy to handle for their implementation.

Aqueous compositions based on C2-C4 percarboxylic acid and dipicolinic acid have been described in international application WO 01/30452 as a decontamination agent. However, such compositions have stability problems and use anhydrous percarboxylic acids obtained by an expensive azeotropic distillation process.

An aqueous composition comprising a peroxidic peracidic agent as a decontaminating agent is described in patent application EP 0894512. Nevertheless, this type of composition has a relatively low decontaminant effect. There remains therefore a real need for new decontaminant compositions of greater stability than those mentioned above, and of high efficiency, allowing rapid destruction of organophosphorus or organosulfur toxic agents.

The applicant has developed a composition for solving the above problems, and in particular has developed a composition having excellent stability and excellent efficiency, leading to rapid destruction of toxic agents.

The present invention therefore firstly relates to a decontaminating composition comprising: (i) perpropionic acid, (ii) dipicolinic acid, (iii) hydroxyethylidene diphosphonic acid (HEDP or its salts) (iv) a surfactant, and (v) an alkalinizing agent.

Surprisingly, it has been found that the composition as defined above is stable enough to obtain a prolonged effectiveness in decontamination.

Surprisingly, it has also been found that the composition according to the invention comprising perpropionic acid has a higher decontamination efficiency than compositions comprising peracetic acid. (examples 2 and 3)

Preferably, the salt of hydroxyethylidene diphosphonic acid is sodium hydroxyethylidene diphosphonate (HEDP).

For the purposes of the present invention, the term "decontaminating composition" means a composition that can be used for the decontamination of materials soiled with organophosphorus and / or organosulfur compounds and for the degradation of the toxic products themselves.

Advantageously, the perpropionic acid used is in the form of an aqueous solution, in particular as it was obtained by reaction of an aqueous solution of hydrogen peroxide with propionic acid, in the presence of a catalyst, such as sulfuric acid or boric acid. Such a preparation method is for example described in the French patent application FR2462425. In contrast to the anhydrous solutions of perpropionic acid described in the French patent applications FR2464947 and FR2519634, the aqueous solutions are obtained with a simple process, not implementing an azeotropic distillation step with toxic or flammable organic solvents such as 1,2-dichloroethane or cyclohexane.

Thus, the perpropionic acid used is in the form of an aqueous solution comprising: perpropionic acid as product, propionic acid as reagent unreacted, hydrogen peroxide as reagent having unreacted, sulfuric acid or boric acid as catalyst.

The decontaminant composition defined above may therefore comprise, in addition to the compounds (i) to (v): - propionic acid, - hydrogen peroxide, and - sulfuric acid, and / or boric acid.

Such compositions are liquids soluble in water, which allows an easy implementation of the decontaminant composition object of the invention.

In a particular embodiment of the invention, the composition defined above is in the form of an aqueous solution. Thus, the subject of the invention is also an aqueous solution comprising a decontaminating composition as defined above.

The compositions which are the subject of the invention comprise an alkalinizing agent. Preferably, the basifying agent is chosen from sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate or hydrogencarbonate, potassium carbonate or hydrogencarbonate, sodium phosphate, and sodium hydroxide. sodium, potassium phosphate, ammonium phosphate, sodium silicates, potassium silicates, ammonium silicates, sodium borates, potassium borates, ammonium borates, and mixtures thereof. The alkalinizing agent (s) make it possible to adjust the pH of the compositions which are the subject of the invention. Advantageously, the compositions which are the subject of the invention have a pH greater than 7, preferably between 8 and 12, in particular between 8.5 and 9.5. The compositions according to the invention may be buffered at a pH of between 7 and 10. When the composition which is the subject of the invention is a basic composition, dipicolinic acid, perpropionic acid and HEDP may be in the form of their corresponding salts. The compositions which are the subject of the invention may further comprise an alkaline buffer. For the purposes of the present invention, the term "alkaline buffer" means both a single type of alkaline buffer and a mixture of alkaline buffers. The compositions according to the invention comprise an alkaline buffer such as an alkali metal carbonate or an alkali silicate, in particular potassium or sodium carbonate.

For the purposes of the present invention, the term "surfactant" is intended to mean an anionic, cationic, nonionic or amphoteric surfactant used in a proportion of 0 to 25%, preferably 5 to 20% by weight, relative to the total weight of the composition. As the cationic surfactant, mention may be made of those of the quaternary ammonium type, and for example cetyl trimethyl ammonium bromide, cetyl trimethyl ammonium chloride, cetyldimethyl 2-hydroxyethyl ammonium bromide, cetyl methyl bromide, and the like. bis (2-hydroxyethyl) ammonium - benzyltrimethylammonium bromide, and - cetyl diaza-1,4-bicyclo [2.2.2] octylammonium bromide.

These surfactants are known and, for the most part, commercially available. They can be prepared by the methods described by C. A. Bunton et al., J. Am. Chem. Soc., 95, 2912 (1973) and by L. Horner et al., Phosphorus and Sulfur, 11, 399 (1981). As optional nonionic surfactant, mention may be made, for example, of: - alcohols alkoxylated fatty compounds of the formula: R - [(CH 2) 20] n - [CH 2 CH (CH 3) O] nH wherein is alkyl or alkenyl having 8 to 22 carbon atoms, preferably 12 to 14 carbon atoms; n and m, independently, represent an integer from 0 to 50, the sum of which n + m> 1; alkylpolyglucosides of formula R "'- [glucose] n- in which R"' is C8-C16 alkyl and n is an integer of 1 to 3; reduced sugar esters, polyol esters and their ethoxylated derivatives, such as, for example, sorbitan monostearate, glycerol or ethylene glycol, or ethoxylated ethoxylated sorbitan monostearate; the ethoxylated alkylamides of formula:

Wherein R is as defined above and r and s are integers from 0 to 15, the sum of which r + s> I; alkylpyrrolidones, the alkyl group of which is C6-C20; and their mixtures.

Preferably, the perpropionic acid is present in said aqueous solution at a concentration of, for example, 0.05 to 4.5 mol / L.

In a preferred embodiment, the composition which is the subject of the invention comprises, by weight relative to the total weight of the composition: 4 to 16% of perpropionic acid, 30 to 0.1 to 2% of dipicolinic acid, 0.5 to 5% of sodium hydroxyethyldiethylphosphonate, 5 to 20% of surfactant, RCN0 (CH2CH2O) sH2 to 20% of basifying agent, and 5 to 15% of alkaline buffer.

The solutions that are the subject of the invention may also comprise at least one constituent chosen from a hydrotrope agent, such as urea, sodium cumene sulphonate, a viscosing agent such as xanthan gum, modified corn starch, hydroxyethylcellulose, or an antifoaming agent.

The compositions may be in the form of powder, liquid, gel or suspension.

The compositions according to the invention are preferably used in aqueous solution at a concentration of 0.5 to 40% by weight of perpropionic acid relative to the total weight of the solution. They can also be used in the form of emulsions or microemulsions after dispersion in a water-immiscible organic solvent such as, for example, aliphatic or aromatic hydrocarbons, optionally chlorinated hydrocarbons, for example toluene, xylene, sodium hydroxide and the like. methylene chloride and tetrachlorethylene.

They can be used manually or mechanically by spraying, whitewashing, spraying, soaking, impregnating or any other operation permitting the contact of said compositions with contaminated material or persons.

The present invention also relates to a process for decontaminating toxic agents and / or organophosphorus or organosulfur pollutants, comprising contacting said toxic agent and / or pollutant with a composition as defined above.

Said toxic agent and / or organophosphorus or organosulfur pollutant, may be for example in the military field, an organophosphorus or organosulfur warfare agent or in the field of agriculture an organophosphorus or organosulfur phytosanitary agent, in particular an insecticide, or an industrial pollutant.

The present invention also relates to a method for decontaminating materials contaminated with organophosphorus and / or organosulfur compounds, comprising the application to the soiled material of the composition as defined above, by spraying, spraying or simple washing or that said soiled material is soaked in a tank containing the composition as defined above.

Due to the pH of the compositions which are the subject of the invention, when soiled materials are decontaminated, these can be chosen as well from cured vehicles covered with polyurethane paints, uncured vehicles (glycerophthalic paints, high porosity surfaces, presence elastomers) as well as delicate equipment (vehicle interiors, radios, electronic equipment).

Because of their low aggressiveness, these compositions are also useful for the decontamination of people by contact with the skin.

The molar ratio of perpropionic acid to pollutant is generally 5 to 10 for organophosphorus pollutants (phosphate hydrolysis) or 3 to 5 for organosulfur pollutants (oxidation to sulfone). The invention also relates to a process for obtaining a decontaminant composition according to the invention. This process comprises the following successive steps: a) obtaining a composition comprising perpropionic acid, dipicolinic acid and hydroxyethylidene diphosphonic acid, b) dissolving the composition obtained in step a) in an aqueous composition comprising a surfactant consisting of an amine oxide, and an alkalizing agent.

In another embodiment of the invention, a process for obtaining a decontaminant composition comprises the following successive steps: a) obtaining a composition comprising perpropionic acid and dipicolinic acid b) dissolving the composition obtained in step a) in an aqueous composition comprising a surfactant, an alkalinizing agent, and a salt and hydroxyethylidene diphosphonic acid, and preferably sodium hydroxyethylidene diphosphonate.

By way of example, the hydroxyethylidene diphosphonic acid of the composition which is the subject of the invention may consist of the product sold by the company Solutia under the trade name DEQUEST 2010, and the sodium hydroxyethylidene diphosphonate may consist of the product marketed by the SOLUTIA company under the trade name DEQUEST 2016.

The following examples illustrate the present invention without, however, limiting its scope. In these examples, the percentages are by weight unless otherwise indicated.

EXAMPLE 1 The perpropionic acid solution is prepared by mixing: 1000 g of propionic acid, 500 g of 70% hydrogen peroxide, 25 g of sulfuric acid, 7.5 g of dipicolinic acid and 15 g of hydoxyethylidene diphosphonic acid ( DEQUEST 2010). The mixture is stirred for 12 hours at room temperature to obtain the equilibrium concentrations. The solution thus prepared contains:% weight Perpropionic acid 38.2 ** Hydrogen peroxide 8.3 * Propionic acid 33.8 Water 17.2 Sulfuric acid 1.0 Dipicolinic acid 0.5 Hydroxyethylidene acid 1.0 diphosphonic * Water oxygenated is determined by cerium (IV) sulphate. ** The total active oxygen is determined by iodometry. Perpropionic acid is determined by the difference between total active oxygen and hydrogen peroxide. 370 g of the previously prepared solution are then mixed with: - 70 g of Barquat MS 100 (from LONZA), - 100 g of GLUCOPON, - 90 g of potassium hydroxide, - 190 g of potassium carbonate, and - 900 g of water, for decontamination application

EXAMPLE 2 The reactivity as a function of time of the formulation prepared in Example 1 is tested for decontamination on Paraoxon. In a stirred glass reactor, 1.8 g of the formulation prepared in Example 1 are added to 50 mg of Paraoxon. The initial molar ratio decontaminant / toxic is therefore 5.8. T minutes after the addition, a sample is taken and the reaction is stopped by adding an excess of sodium thiosulfate. To the sample is then added 8 ml of water saturated with NaCl, 10 ml of ethyl acetate 50150 hexane and 0.1% of dibutyl sebacate (internal standard). The organic phase is removed and dried over sodium sulphate and the residual Paraoxon is determined by GC. This procedure is repeated after different aging times of the formulation prepared in Example 1. The results are summarized in the following table: T (min) Paraoxon Conversion (%) 88 180 56 240 54 EXAMPLE 3 The perpropionic acid formulation described in Example 1 was compared with a similar formulation based on peracetic acid. The solution of 39% peracetic acid is prepared according to a procedure identical to Example 1, replacing the propionic acid with acetic acid and then added with the same amounts of the other constituents.

The resulting formulation is tested with Paraoxon according to the procedure described in Example 2. The initial decontaminant / toxic molar ratio is 6.8. The results are given in the following table: T (min) Paraoxon conversion (%) 42 180 18 These examples thus show the advantage of the perpropionic acid formulation over the peracetic acid formulation for the decontamination of organophosphorus toxins.

Claims (11)

Claims: 1. A decontaminant composition comprising: (i) perpropionic acid, (ii) dipicolinic acid, (iii) hydroxyethylidene diphosphonic acid or a salt thereof, (iv) a surfactant, and (v) an alkalinizing agent. 2. Composition according to claim 1, characterized in that the salt of hydroxyethylidene diphosphonic acid is sodium hydroxyethylidene diphosphonate 3. Composition according to any one of claims 1 or 2, characterized in that the basifying agent is selected from sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium silicates, sodium hydroxide, potassium silicates, ammonium silicates, sodium borates, potassium borates, ammonium borates, and mixtures thereof. 4. Composition according to any one of the preceding claims, characterized in that it further comprises an alkaline buffer, preferably selected from an alkali carbonate and an alkali silicate. 5. Composition according to any one of the preceding claims, characterized in that it further comprises a nonionic surfactant. 6. Composition according to any one of the preceding claims, characterized in that the perpropionic acid is present at a concentration of 0.05 to 4.5 mol / l. 7. Composition according to any one of the preceding claims, characterized in that it is buffered at a pH of between 7 and 10.30. 8. Composition according to any one of the preceding claims, characterized in that it comprises, by weight relative to the total weight of the composition: - 4 to 16% of perpropionic acid, - 0.1 to 2% of dipicolinic acid; 0.5 to 5% sodium hydroxyethyldiethyl phosphonate; 5 to 20% surfactant; 2 to 20% basifying agent; and 5 to 15% alkaline buffer. 9. A method for decontaminating toxic agents and / or organophosphorus pollutants or organosoufrés, comprising contacting said toxic agent and / or pollutant with a composition as defined in one of the preceding claims. 10. Process for obtaining a decontaminant composition according to any one of claims 1 to 8, characterized in that it comprises the following successive steps: a) obtaining a composition comprising perpropionic acid, dipicolinic acid and hydroxyethylidene diphosphonic acid, b) dissolving the composition obtained in step a) in an aqueous composition comprising an amine oxide surfactant, and an alkalizing agent. 11. Process for obtaining a decontaminant composition according to any one of claims 1 to 8, characterized in that it comprises the following successive steps: a) obtaining a composition comprising perpropionic acid and dipicolinic acid b) dissolving the composition obtained in step a) in an aqueous composition comprising a surfactant, an alkalinizing agent, and a salt and hydroxyethylidene diphosphonic acid, and preferably hydroxyethylidene diphosphonate sodium.