CZ126393A3 - Method of removing polychlorinated substances, particularly pcb from solid carriers - Google Patents

Abstract

A method of removing polychlorinated substances, particularly PCB from solid carriers like earth, soils, sediments and sludge by sequential stimulation of anaerobic reductive dehalogenation and subsequent aerobic mineralisation of occurring intermediate products, during which, in the first stage multiplication and the activity of soil bacteria is stimulated by inoculation into the contaminated material in a max. 5% aqueous solution of activators of biological activity, containing ammonium sulphate and a synthetic surfactant, in the second phase is performed by reductive dechlorination, during which an aqueous solution or organic waste containing activated charcoal or carbon black is added to the reaction mass, and in the third phase there is aerobic biodegradation, realised by wetting the reaction mass with water saturated with hydrogen peroxide and containing cosubstrate, preferably saccharides, supplemented by biogenic elements and possible other nutrients.

Description

Process for removing polychlorinated substances from solid carriers.

Field of the Invention

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The invention relates to a process for the removal of polychlorinated substances, in particular PCBs from solid supports such as soils, soils, sediments and sludges, by sequential stimulation of anaerobic reductive deha.logena.ee and subsequent aerobic mineralization of the resulting intermediates.

BACKGROUND OF THE INVENTION

It is well known that polychlorinated substances such as chlorodibenzofurans, chlorodibenzodioxins, polychlorinated biphenyls (PCBs) and the like are considered priority toxic pollutants in the environment. Until recently, they have been used on a mass scale, especially PCBs, for their unique physico-chemical parameters in a number of industrial applications. Due to their diverse environmental fate, they have penetrated soils and soils, groundwater and river sediments. A frequent source of high soil contamination. there are accidents, but also permanent leaks of PCB-based heat transfer media. Characteristic of these contamination is the considerable vastness and depth of the soils affected, which can be expressed in thousands of cubic meters of matter to be treated. The process of dehalogenated PCBs and their gradual mineralization (conversion to carbon dioxide, water and inorganic chloride ion) is therefore a very difficult and economically demanding process. A number of methods for destroying a PCB molecule are described in the literature, but are generally not suitable for large-scale applications.

For large-scale deployment it seems a straightforward way of overflowing solid substance or sludges containing toxic organic substances in special furnaces, where the high temperature regime (1200-1600 ° C) is adhered to, long planting times

...- ..i: ... · .....; .- ι ·.!. ί. · exhaust gases under conditions, these high temperatures (3 - 2 s) and excess oxygen (3 - 2) .. Requirements for permissible concentration of some toxic substances in flue gas are considerably striklei (Standard. Disposal,

Handbook of

Η. M.Freeman,

Kazardous Waste

T r eatchange t and

Ed. McSraw-Hill, New York 1-989) and the views of researchers are not entirely consistent about the potential for even more toxic chlorofibibododioxins and furans to air. Moreover, such a completely safe device is not currently available.

The chemical destruction method of PCB appears to be excellent, using the reaction of polyethylene glycol and potassium hydroxide with these components, which rapidly degrades organically bound chlorine to potassium chloride, and releases the biphenyl molecule from the mixture easily (Bru.ne.lle DJ, Singleton DA: Chernosphere 1 2.1 83, (3,983).

j> c j ř / / 7 ť e V V V V i

The modification of this method is d..r§> Cs. patent applications PV 889-92 (Hetflejš J., Kastanek F., Svoboda P, Sabata S .: A method of chemical destruction of polychlorinated biphenyls) successfully used for destruction of PCBs in organic liquids. The chemical reaction using alkaline hydroxides and polyethylene glycol is tolerant to oxygen, water and other organic contaminants such as petroleum products and may therefore be. suitable for applications on. in šitu. decontamination of soils, soils, sediments or various aquifer sludges containing PCBs. However, the disadvantage of this method in truly vast field conditions is the large consumption of relatively expensive chemical, which cannot be regenerated, the need to operate at higher temperatures (around 100 ° C), while transporting waste materials to the incineration plant.

Very promising method for large-scale use. Due to the possibility of working at ambient temperatures and with low investment and relatively low operating costs, the biodegradation method appeared, which is proving to be very good, for example, even during and after soil gradation. oil rites (Musil Ρ., Marek M. Dernnerová K, Kaštánek F.: Biodegradation of Petroleum Hydrocarbons on Location After Departure of the Soviet Army. Symp.Soil Oecontamination Using Biologiea 1. Processes, K. arisruhe / O, Dec. 1.9 9 2, p.231). However, there are considerable problems with xenobiotic polychlorinated compounds. Leaving aside the problematic field use of genetically engineered microorganisms, it is rather obvious that microorganisms they would use. PCBs as the only growth substrate will not be isolated and probably do not exist in nature. There is some hope in the naturally occurring organism with high degradation potential, the white rod-shaped fungus. Phanerochaete chrysosporittm (Bumpus J.A., Tien M., Wright D., Aust S.D .: Science 228, 1434 (1985)). Its activity is attributed to the production of lignolytic enzyme oxidase, which catalyses the decomposition of the chemical structure of some complicated xenobxtic components. However, the efficacy of biodegradation is highly dependent on the concentration of oxygen, and nutrients (the microorganism exposes the enzyme under very specific conditions at a limit nitrogen concentration), which is very difficult to implement under in situ conditions. It is necessary to use controlled ferrnentors, where the reaction takes place, in suspension at relatively low soil retainers. However, it remains problematic. in this case, the question of the possible spread of this woodcut fungus into the surroundings, with the potential danger to the surrounding vegetation.

However, the possibility of activating local soil cultures of microorganisms and exploiting the synergistic effect remains possible. k. destruction of complex xeriobiotic, biodegradation to date, stubbornly defying components. The return to this method is motivated by the effort to use the principle of the so-called cometabolism: soil bacteria use another non-toxic substance, which is added to the substrate, as a carbon source. An example is the biodegradation of PC8 by bacteria using biphenyl as a carbon source to produce chlorinated benzoic acid derivatives (Hernandez BS, Arensdorf, JJ, rocht DD: Int.Symp.Soil Oecontamination Using Biological Processes, Karlsruhe / D.Oc. 42.9.

Focht D.D., Brummer W. (19S5)). The method of recovery from the

Appl.Environ.Microbiol. Thus, a genetic fund for degrading PCB is present which contains at least two groups of soil bacteria, in this case: chlorobenzoates. In general, PCBs and utilizers can be used as a carbon source to metabolize various substances that the microbial consortium will utilize by a synergistic effect in the corrietabolization process.

Research has concluded that the extent of the possibility of degradation of xenobiotic components by natural soil aerobic highly chlorinated PCB hope for microbial agents, providing anaerobic microorganisms is limited, if not completely, paralyzed, and that greater degradation of chlorinated organic processes. Studies on anaerobic biodeyradiation have focused on so-called reductive dehalogenation; in the gradual degradation of halogen atoms under reductive anaerobic conditions, but when. the intrinsic mechanism of the methane formation process is suppressed (Zitomer O.H., Speece R.E .: Environ. Sci.Technol 27,227 (1993)). These reductions are. biologically catalysed by a consortium of soil bacteria in the absence of oxygen. The main benefit in the fact that less j s o. k t e rn r e cl. k t i v η 1 bacteria reductive dehalogen.ee is Halogenated biphenyls that

d. e h a. 1 ogenations are. less toxic and. accessible to other conditions. Thus, it is possible to biodegrade a number of xenobiotic substances and components (insecticides, chlorinated benzenes, tetrachlorethylene, carbon tetrachloride, hexa-, penta-, tetra-, tri- PCBs, dioxins, etc.). DDT, which is completely inert to the aerobic process, can be partially dechlorinated as a first stage of mineralization under anaerobic conditions in a high layer of thick suspension in the presence of an indigenous consortium of soil bacteria (Hill DW, McCarty PL: J.Water Pollut. Control. Eed. 39, 1259 (1967)]. Similarly, highly chlorinated biphenyls are extremely resistant to conventional aerobic transformation but are accessible to anaerobic reductive decnlorination. Studies carried out in the USA with contaminated river sediments demonstrate that in or e o d e g r d a c i, n y n i i z a,. and the process environment, the concentration of penta-, tetra-, and tri-chlorobiphenyls is greatly reduced, except for di- and monochloride. results (Brown JF et al .: Science 236,709 (1987). Results are reported to confirm that reductive dechlorination of 2, 3,4,5,6, pentachlorobiphenyl releases organic chlorine as a chloride ion, along with the proton from the present The aqueous phase (Nies L., Voge.l TM: Appl. Environ.Microbiol. 57,277 1 (1991). These less chlorinated PCBs (generally less toxic) are then more readily biodegradable under aerobic conditions. The process of reductive dehalogenation is not yet theoretically explained and is most likely to occur by the aforementioned cometabolization mechanism (Shelton DR, Tiedje JM: Appl. Environ. Microbiol. 48,846 (1984), but there is also the possibility that the dehalogenation partially contributes to microorganisms usable energy (Dalting J., Tiedje JM: Arch Microbiol., 149, 102 (1987) With regard to the categorization of bacteria that cause reductive dechlorination in an arierobic or microaerobic environment, They are both strictly anaerobic (Methanosorcina) and facultative anaerobic (Citrobac.ter) bacteria. (Mohn W. W., Tiedje J.

Microbiol. Rev. 56.48 (1.992)). Cornetabolization of biphenyl also took place in the presence of Acinetobacter, Pseudomonas, Flavobacteria, Clavibacter. It seems that the breathing mechanisms are also closely dependent on the presence of microorganism products. utilizing, for example, yeast extract (Wiegel, J., Zhang, X, Dalton, D .: in ACS - Symposium Series No 422, ACS, New York, 1990). Thus, the dechlorination process is utilized not only by microorganisms that are directly involved in transformation reactions, but also by those that interact with dechlorination bacteria and affect their activity. The sum of various effects of all interacting microorganisms in their synergistic effect will determine the success, mineralization of hazardous components in the environment. Thus, the bacterial consortium utilizes PCBs with constituent substrates (glucose, methanol, acetates, lactates, etc.) (Woods S.L., Benjamin

MM. Εnviron.Sci.T echnol 23.62 (1,989).

presence of NaaSCU. thus preferential

Although most reductive dechlorination mechanisms are biologically catalysed, it appears that the presence of some riebiotic components contributes to the acceleration of the reaction, such as the presence of a sulfur ion, which is also commonly found in a reducing anaerobic environment (Barkash JE »Reinhard M .: Environ Sci.Technol. 23, 1348 (1989)

The result of reductive dechlorination is the removal of chlorine in meta and para positions (Quensen JE et al. I rit. Symp. Soii Decontamination Using Biological Processes, Karlsruhe / D, 0e, 1992, p. 91). removal of chlorine from the ortho position (Commander LCM, et al, Ibid., p. 570), it being known that less chlorinated components are more readily degraded by it. aerobic conditions. Thus, for complete PC8 mineralization, sequential biodegradation is available in the order of anaerobic and subsequent aerobic treatment of substrates. with PCB. In the initial anaerobic stage it may be. reductive dechlorination followed by an aerobic stage which will contribute to the completion of the mineralization process. Such a method was intended to degrade PCBs (Aroclor 1242, USA) in river sediments, with sequential induction of anaerobic and aerobic conditions by primary sulphate R ec 1 a m and others. N - Processes with methanol like; Why. On- Site and. Hydrocarbon R.F., Ed.s./ In field success, the bioremediation of o c r g e n e c o c t e c o s c o s c o c e s o c o c e s phase. K from the adsorbed adsorption. surface in closed containers (Anid. P.J., Vogel T, M for Xenobiotic

Treatrnent. , / Hi.nchee R.R., Olfenbuttel

Butterworth-Heinemann, Boston 1991, p.428).

conditions were not used.

At the same time, it is known that undersurface toxic toxic and non-aqueous phases, eg, PCB components, particulate matter or capillary forces in the the presence of surfactants facilitates the interparticle space of a complicated heterogeneous structure. In environmental terms, biosurfactants, especially lipids, are the most appropriate in:. . ο, ...

ί ~ γ I '- ^ ^α from synthetic pak. nonionic surfactants (alcohols alcohols, sucrose stearate, etc.) (.hosaric N., l ... u 6: Int. Salts Oecontaminaticn. Karlsruhe, Dec.1992, p. 44, Mtinnstermann et al., ibid, p. 414). Based on the above-mentioned findings and the actual experimental activities the present complex method of PCB bid.egrada.ce is based on soils, soils, sediments and sludge.

Pod s t a t a v nálezez

SUMMARY OF THE INVENTION A method for removing polychlorinated substances, in particular PC8 from solid carriers such as soils, soils, sediments and sludges, by sequential stimulation of anerobic reductive dehalogenation and subsequent aerobic mineralization of the formed intermediates is that a solid PCB carrier containing at most 800 mg / kg PCB is first contacted by mixing, sprinkling or injecting an aqueous solution of 80 l / m2 / day for a maximum of 20 days. content. a moisture contacting solid PCB of up to 50 ' containing an activating agent with 0.02 to 0.5 ' ammonium sulfate, 0.02 to 13 ' synthetic nonionic surfactant selected from the group of ethoxylated alcohols, ethoxylated fatty acids, ethoxylated alkylphenols; 0.02 to 1% of carbonate, sodium a. A residue containing, singly or in a mixture, quaternary salts, glycolipids, phospholipids, fatty acids and their esters, peptides, dextrins and axites, all in a total quantity of up to 5% based on the total amount of solution; in a second phase, an aqueous solution or organic waste is added to the reaction mass in an amount of up to 20 .mu.m / m2 / day at a layer thickness of up to 1 m for up to 120 days. containing 0.02 to 05% activated carbon or carbon black, 0.02 to 8 g / l sucrose, 0.02. up to 5 g / l of ethyl acetate, 0.02 to 6 g / l of sodium acetate, 0.02 to 10 g of sulphite leachate and a residue containing, individually or in combination, glucose, toluene, methanol, entanol, biphenyl, glycerol, lactic acid acetic, propionic, butyric, butobutyl or benzoic, peptone, vegetable oils, starch and starch-containing wastes, all in a total quantity of up to 12 g / l based on the total amount of aqueous solution or organic waste, and in the third stage is added to the reaction mass in an amount of 2.0 L / m 2 / d.en at a layer thickness of up to 1 m for up to 90 days with an aqueous solution containing. 0.1 to 0.5 g / l of hydrogen peroxide, 0.02 to 2 g / l of carbohydrates such as glucose or sucrose 0.01 to 5 g / l of sulphate liquor; individually or in a mixture of yeast autolysate. yeast extract a. peptone, ammonium sulphate, phosphate and hydro-phosphate of alkali metals and ammonium chloride, alkali metal magnesium sulphate, chloride, calcium, copper sulphate, chloride, ferric, zinc sulphate, manganese sulphate, biotin, m-inositol, Ca-panthotenate, thiamine and pyroxide, all in amounts up to 1g / l based on the total amount of the aqueous solution.

According to another variant of the invention, it comprises organic waste. added in the second phase to the reaction. 0.02 to 0.5% activated carbon; or carbon black, sulfite and sulfate ions in the form of 0.02. up to 1% of sodium and / or calcium sulphide and sodium sulphate and the remainder, whether or not containing mixed or individually sugar beet pulp, straw, tree bark, silage, tussock, distillation residues after distillation of ethanol, alkali metal phosphates and hydrogen phosphates; ammonium urea and Mg, Ca Fe, Zn and ions. br omet hansulphonic acid, all up to 50% by weight of the reaction mass,

In another possible embodiment of the process according to the invention, the polychlorinated substances are removed from the extracted solid support on a decontamination surface in a layer not exceeding 1.5 m for the first two time phases and 0.5 m for the third time phase. is passed through a filter containing! as a fill of activated carbon or via a bioreactor containing a filler of plastics of ceramic materials or lignocellulosic materials with immobilized bacteria are also of the same type found in the tube.

- the principle of activation of biodegradation The activity of spontaneous microorganisms in contaminated material, such as soil, soil, sediments or aquifers, help to introduce suitable activators of biological activity into this contaminated material, using the knowledge that is one of the bases It is an object of the invention that the presence of microscopic particles of a large cross-phase surface inert substance, such as, for example, contributes to increasing the interphase transfer of the immiscible organic liquid into the aqueous phase containing nutrients and microorganisms. activated carbon in the form of a suspension of micron size particles at concentrations in the aqueous phase up to 0.5% by weight This mechanism was previously described as favorable for accelerating the interfacial transfer of oxygen from gas bubbles to the liquid phase (Kaštánek F., Zahradník J,: Chemical Reactors for Gas (Liquid. System, Horwood, Chicheste, 1993), but its action is broader and applicable to the biodegradation method of the present invention. It consists in the mechanism of disruption of the interfacial interface by braun movement of oscillating activated carbon particles and transfer of bacteria and nutrients into intimate contact with immiscible organic toxic liquid. At the same time, the presence of the activated carbon particles acts as a sorbent. nutrients and prevents their rapid elution from treated soils. Activation of the biodegradation activity of bacteria causes it to progressively occur.

multiplying the desired bacterial colonies in the contaminated substrate, which is due to. The process takes place in time-separated sequences, the start and end of which are controlled on the basis of continuous monitoring of PCB content and quality.

The decontamination process thus proceeds in three stages:

l. The multiplication and activity of soil bacteria responsible for the production of biosurfactants by which the organic phase biod.egraaeci is made available - K. Spraying of soils, soils, sediments, sludge as solid carriers of polychlorinated substances such as PCBs and / or their injection with dilute aqueous O4 solutions and an environmentally safe emulsifier, in the presence of viscosity regulators, such as dextrins, will eventually be xanthates. .

2.Reductive dechlorination, to carry out the first step of degrading the chlorine atoms from the biphenyl molecule under anaerobic conditions in the absence of atmospheric oxygen. The realization of this step is accomplished by mixing, scrubbing or injecting PC8 solid carriers with solutions containing 0.5% powdered activated carbon or micron size (up to 7 microns) cosubstrate containing, individually or in a mixture of glucose, sucrose, methanol, ethanol, toluene, biphenyl , benzoic acid, acetic acid, ethyl acetate, sodium acetate, glycerol, and the like. starch and starch containing wastes, sjfrovatku, fudge, distillation residues, vegetable residues after oil extraction, vegetable oil, sulphite leaches, lactic acid waste, spent grains, silage vegetable residues, sludge after aeration from municipal waste water treatment plants, sugar beet pulp, the solid PCB carrier with these cosubstrates is sprinkled with oxygen-free water to the desired moisture content (by the addition of sodium sulfite in the presence of microbial size activated carbon particles) and contains sulfide (10 mM) and sulfate ions (10 mM), phosphates and acid phosphates (200 mg / liter of solution) and trace. amount (below 20 mg / liter of solution) of Mg ions, and trace amounts of Ca.Fe.Zn (below 10 mg / liter of solution). As a component suppressing methane production and inducing the anaerobic mechanism to be oriented towards the reductive dechlorination process, bromoethanesulfonic acid is present in the solution.

in trace amounts (below 10 rng / liter of solution).

.. Aerobic biodegrad. cidium mono-chlorobiphenyl, effected by scrubbing the solid PCB carrier, or by injecting it with oxygen-saturated water (by bubbling the scrubbing aqueous solution through the air), with the addition of hydrogen peroxide (up to 0, 5% vol.), In the presence of cosubstrate t. Υ., The most saccharide arid, jakozdrojeu ti iiu ···· .- ,. ·. · '. ·? And yeast extract, optionally yeast autolysate or peptone (elf? 0.05 wt%). The solution is supplemented with biogenic elements, possibly with other growth promoting components. The following composition of mineral and support nutrients, based on 10 g of glucose, appears to be the most suitable: g of ammonium sulfate, 0.64 g of ammonium phosphate, 0.29 g of KCl, 0.14 g of CaCl2.2H20.0.73 g Cu.S04.5 H2.0, 4.3 mg FeCl3.6 H2.0, 3 mg ZnSO4.7H2O, 3.5 mg MnSO4.2H2O, 0.01 mg biotin, 10 mg Ca-Pantothenate, 2 mg thiamine , 0.25 g yeast extract.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is in a culture vessel

Example 1

100 g of soil containing 760 micromoles of 2,3,4,6-CB and 12% moisture were shaken with 0.7% w / w of ¹ Novanit MA (which is the name for iso-tridecyl ethoxylate from manufacturer: Chemické závody Nováky, SR) such as surfactan and 1% strength sodium carbonate, 0.3% w / w sulfuric acid. sodium and 0.05% w / w sodium sulfide and under anaerobic conditions at 25 ° C for 6 days. Thereafter, 1.2 g of sulphite liquor and 0.3 g of glucose, powdered activated carbon (up to 7 microns) were added to the vessel in an amount of 0.5 g and a trace element nutrient medium, with an addition of 0/05% to the total weight of the vessel. bromoethanesulfonic acid. The total moisture content was adjusted to 68%, pH 7. After a lag period of 25 days, the course of reductive dehalogenation was evident. The average transformation rate of 2,3,4,6 -CB in this second phase, which lasted 12.0 days, was 4.7 micromoles of PCB per day. The initial dechlorinated product was identified as 2,4,6 -CB, which further degraded to 2,6 -CB. The concentration of 2.6 -CB did not decrease further after 120 days. Therefore, the reaction mode was changed to aerobic by initiating the overflow of the vessel contents above. suspension with air while periodically dosing hydrogen peroxide (0.5% H 2 O 2 ^at 0.02 mL / 10 min). Oo container was. yeast extract (0.05%) was added once and the content of cosubstrate (glucose) was added to an initial concentration of 2% by weight. in relation to the weight of the batch. After an incubation period of 12 days, a decrease in content was noted. 2,6-CB, average speed 16 miles · ··. ' mole / day, for 10 days to the final concentration. 3.6 micromoles of PCB, which no longer changed.

Example. 2

On the experimental decontamination impermeable surface was collected soil taken from the surface, contaminated site and consisting of a mixture of loess with humus impurities. The area occupied by the soil was. 4 x 4 meters. This soil was gradually piled up to two different heights:

At a height of 0.9 m the soil was sprayed for 10 days at 10 l / m2 / d.en with 0.3X aqueous ammonium sulfate solution, then 20 days at 5 liters / m2 / d.en aqueous carbon black solution water, containing 0.5a active carbon blacks of up to 7 microns, 10g / l per sacbarose, 200mg / l sodium phosphate, 10mM sodium sulphide and 10g / l methanol. Then the soil was stratified to a height of b = 0.3 m, while the remainder was not distributed. The mixture was sprayed with a solution containing glucose cosubstrate for 30 days. and mineral substances customary for aerobic fermentation: 2 g / l ammonium sulfate, 0.64 g / l acid phosphate. sodium and an additive of 0.2 g / l yeast autolysate.

The aqueous solution was purged with air prior to introduction into the zinc and made up to 0.55% hydrogen peroxide. The intensity, sprinkling was 8 1 / rn ² / day. After 10 days of sprinkling, the soil was mechanically rake to aerate it. The initial PCB content (Delor 106 was 2,500 ppm. After the sprinkling in the second stage1, the PCB content dropped to · 4 8 ρρm.

R e f i s 1 I u t i o t i .1. n o s t

The process according to the invention is suitable for the removal of polychlorinated substances, in particular PCBs from solid or semi-solid carriers such as. soils, sediments, sediments and sludges on a large scale in situ at the minimum energy and labor cost of the additives used.

Claims (2)

PATENTOVÉ NÁRGKtf Process for removing polychlorinated substances, in particular PCBs from solid supports such as soils, soils, sediments and sludges, by sequential stimulation of anerobic reductive dehalogenation and subsequent aerobic mineralization of the formed intermediates, characterized in that the solid PCB carrier containing maximum 800 mg / kg PCB is first contacted by mixing, sprinkling or injecting an aqueous solution of 80 l / m 2 / day at a solid support layer thickness of up to 1 m for a maximum of 20 days at a moisture content of the contacted solid PCB of up to 50% by weight 0.02 to 0.5% ammonium sulfate, 0.02 to 1% wt. synthetic non-ionic surfactant selected from ethoxylated alcohols, ethoxylated fatty acids, ethoxylated alkylphenols, and 0.02 to 1% w-carbonate or carbonate _solution} and then in a second stage, the resulting reaction mass was added an aqueous treatment solution or organic waste in a quantity of up to 20 1 / up to 1 m for up to 120 days containing 0.02 to 0.5% w / w of carbon black or carbon black, 0.02 to 8 g / l of saccharides containing by weight 0.02 to 10 g of sulphite liquor and the remainder of the nutrient medium in a total amount of up to 12 g / l per total amount of aqueous solution or organic waste, and in the third phase added to the reaction mass in an amount of 20 l / m 2 / day at thickness layers to 1 m for up to 90 days, an aqueous solution containing, 0.1 to 0.5 g / l hydrogen peroxide, 0.02 to 2 g / l carbohydrates such as glucose or sucrose, and in an amount of 1 g / l of mineral nutrients. Method according to claim 1, characterized in that the polychlorinated substances are removed from the extractive solid support on a decontamination surface in a layer not exceeding 1.5 m for the first two time phases and 0.5 m for the third time phase, the liquid aqueous extract flowing from the decontamination The surface is passed through a filter containing activated carbon as a filler or through a bioreactor comprising a filler of plastic materials of ceramic materials or 1 ignocellulosic material with immobilized bacteria, which are of the same type found in a solid support.