MXPA00002351A - Simplified method for biologically cleaning areas of soil contaminated with leftover pollutant mineral oil-based materials - Google Patents

Abstract

The invention relates to a simplified method for biologically cleaning almost any-sized area of soil which is contaminated with mineral oil-based hydrocarbons (MHC), and especially the leftover pollutants associated with mineral oil-based hydrocarbons. According to said method, the contaminated soil is treated with concentrated nutrients to stimulate and help the growth of MHC-consuming micro-organisms so that they can be cultivated and reproduce more quickly. The inventive method is characterised in that it is particularly easy to carry out and in that after a) advance dampening/watering if necessary, b1) the soil being cleaned is broken up to a considerable depth in at least one process, b2) the concentrated nutrients are added in the form of an aqueously dilute emulsion and/or dispersion, said concentrates being sprayed essentially evenly, also in at least one process, and c) the soil is then thoroughly re-watered. Steps b1) and b2) can be carried out once or repeatedly. The following sequences are preferable:(b1)?(b2);(b2)?(b1);(b1)?(b2)?(b1) or (b2)?(b1)?(b2).

Description

SIMPLIFIED METHOD FOR BIOLOGICALLY CLEANING SOIL AREAS CONTAMINATED WITH MATERIAL CONTAMINANT RESIDUES BASED ON MINERAL OIL The careless handling for decades of mineral oils, mineral oil fractions, and products derived in increasing quantities to take advantage of its economic potential has led, worldwide, to significant pollution - according to current knowledge and understanding - that are currently known as polluting waste. An important area of these polluting residues related to hydrocarbon compounds based on mineral oils - hereinafter referred to as "MHC" - encompasses soil surfaces in which for decades, for example, MHCs were stored, pumped, distributed and / or transported. Only by way of example can we mention the deposits in the corresponding tanks for the industrial use of the MHCs and / or the piping systems that were also used for the long-distance transport of MHCs. The understanding of irresponsible management of these products in the past has been increasing for a long time. On the one hand - at least in the most important industrial states of the world - there are much stricter requirements for the uncontaminated handling of this kind of products. On the other hand, there is a greater and broader state of the art both in practice and in the literature to remove contamination, especially polluting waste. Despite this more precise profile of the meaning of the environmental problems to which we focus and despite a substantial increase in safety in the handling of MHCs, there is still an urgent need today for a simple and economical regeneration of large areas of soil especially affected by polluting waste, since a simple transformation of the use of these affected areas through administrative arrangements is not possible. There is also a need for sufficient cleaning of these surfaces / affected by the contaminants to a sufficient depth in the soil in order to allow these surfaces to be used for new purposes. Both in literature and in practice there are numerous proposals to solve the problem raised here. The effectiveness of the cleaning methods used is obviously a decisive factor for the use of the methods in question. However, it is not the only determining factor. In the case of the regeneration of important surface land surfaces, the cost represents at least an equally important factor. The fight against pollution based on hydrocarbon compounds - for example MHC - in the soil and in water through a biological purification is gaining more and more strength. Microorganisms that consume hydrocarbon compounds are, within the framework of this technology, valuable work elements, insofar as their enrichment and / or growth in the place of contamination can be sufficiently stimulated. On this point we can mention the publications in the Chemical Industry /91, 10-12"Hunger auf Erddl" (Hunger for Oil) as well as Erdol und Kohle - Erdgas (Oil and Coal - Gas), 44, April 1991, 197 - 200, Th. Hópner et al., "Die? Lkatastrophe im Persisch-Arabischen Golf "(The oil catastrophe in Persian-Arabian Gulf) as well as the extensive literature / mentioned there. The principle of operation of the biological purification considers t the optimal promotion of the growth of the populations of microorganisms that consume the polluting substances. According to the state of the art data - for example, DE-A-42 18 243 and document PC / EP 92/02146 - there are two important auxiliaries: on the one hand the contribution of elements that favor growth are considered. which, in general terms, are not found in sufficient concentrations in contaminated areas. It is first of all inorganic and / or organic compounds of nitrogen and phosphorus, which are provided as concentrates of nutrients to stimulate and activate the growth of microorganisms that consume hydrocarbon compounds. On the other hand, according to the state of the art it is frequent, especially to accelerate the biological decomposition in the initial phase - to apply on the contaminated areas, at weekly intervals, for example, prepared concentrates of suitable microorganisms that consume hydrocarbons. According to the given situation, especially the specific history of the areas that require cleaning, it can however be eventually considered that said inoculations with concentrates of microorganisms are useless. In general terms this is always the case when the natural process of biological decomposition has already led to the formation of sufficient concentrations of microorganism strains; As for this aspect, see, for example, the second source of the literature mentioned above. The teaching in accordance with the present invention is based on the fact that, especially in areas containing polluting residues, the process of natural decomposition, possible in principle by purification under soil conditions, climate, etc. it is not carried out or it is practically not carried out. The teaching of the present invention is also based on the purpose that, also and especially in real conditions, the cleaning of the soil can be carried out by means of purification to substantial depths of the affected soil layers, without employing costly measures or requiring of an important workforce, such as, for example, the removal of affected areas and their treatment in a silo under optimal climatic conditions. Before proceeding with the measures in accordance with the teachings of the present invention to solve this problem, we will mention a peculiarity that is directly related to the understanding of the teaching of the present invention and the use of the measures in accordance with the present invention: Soil samples taken at increasingly greater depths and separately from these polluting residues often show a contaminant profile that is clearly characteristic of the polluted area in question. In the upper layers of the terrain zones there is an enrichment of long and / or cyclic hydrocarbon compounds of high molecular weights that are characterized by being particularly difficult to decompose. Therefore, it is concluded -according to the granular structure of the affected area- that eventually quite deep areas present a load of contaminants. Also in the area of the groundwater level can be observed significant concentrations of unwanted pollutants. The hydrocarbon compounds are evidently from their molecular structure and their molecular size also able for a long time to move in the structure of the soil. They swim in a certain way on the surface of the ground water and with the passage of the years they are fixed on the surface of the particles of ground, if they are not dragged by the ground water. It is interesting to finally observe that the subsequent interpretation of the insufficient cleaning of these terrestrial surfaces affected by the pollutants is the following: the structure of the hydrocarbons causes a major impediment to the decomposition of the comparatively large hydrocarbon molecules on the surface of the affected area which prevents the strains of microorganisms that consume hydrocarbons from accumulating naturally, even when they have comparatively large amounts of oxygen from the air to promote bacterial growth. This affectation is reinforced, in general terms, due to the lack of essential nutrients, especially P and N. The components of hydrocarbons that migrate relatively easily are washed in these depths of the soil, where a lower supply of oxygen is observed as well as eventually a lack of components of essential nutrients. From this basic knowledge, teaching in accordance with the present invention proposes for the first time a particularly simple and economical renewal procedure suitable also for large surfaces to remove MHC contaminants, where contaminated land surfaces of any size can be cleaned. . OBJECT OF THE INVENTION The object of the present invention is therefore a procedure for simplifying the biological cleaning of land surfaces of virtually any size that are contaminated with hydrocarbons based on mineral oils (MHC), and correspondingly polluting residues, by means of the treatment with nutrient concentrates to stimulate and help the growth of microorganisms that consume MHC. The process according to the present invention is characterized in that (a) after a possible pre-wetting / irrigation (bl) inat least one process step is broken to a considerable depth in the soil to be cleaned, (b2) and also in at least one process step the concentrate of nutritive substances is applied in the form of a diluted aqueous emulsion and / or dispersion and especially said concentrates are sprayed in an essentially regular manner and (c) the soil is then intensively rehumidified. In a preferred embodiment, the repetition of at least process steps (a), (b2) and (c) at significant time intervals is considered in accordance with the present invention.

The preferred time intervals are here within a range of about 1 to 6 months. For the purposes of the present invention, at least 1 to 3 repetitions are considered. In further preferred embodiments, it is convenient, in accordance with the present invention, to apply additional concentrates of microorganisms on the surface of the soil, which can decompose the MHC compounds. Here the use of concentrates of corresponding microorganisms of natural origin can be an especially important modality. Especially for the removal, also of the comparatively deep soil layers, of the MHCs that are there, the teachings in accordance with the present invention present a special modality, either by forced penetration of air into these deep soil formations. and / or the application of oxygen chemically bound and released into the soil. Next we will present details of this. DETAILS OF THE TEACHING OF THE PRESENT INVENTION The definition presented before the process steps provided in accordance with the present invention makes it understandable that here - for the first time according to the knowledge of the applicant - a technically simple application for the removal of MHC is proposed. through depuration, where surfaces of virtually any size can be cleaned and practically to any extent of MHC contaminants according to quantity and age, under working conditions and acceptable cost. Here is a detailed description of the process: The area to be cleaned must be sufficiently wetted or irrigated. This step of previous process may require a natural rain process or simple methods of artificial irrigation. The surface of the soil usually compressed for decades due to a mechanical load must be broken sufficiently deep. The breakage of this land surface is preferably carried out to a depth of at least 15 cm, however corresponding depths within a range greater than or equal to about 30 cm are preferred. This is immediately understandable: agricultural apparatuses such as, for example, harrows, especially however the use of plows allow easy technological compliance of this condition in accordance with the present invention to modify the terrestrial surface to be cleaned. A deeper breakdown of the earth's surface may be preferred, and in this case depths of up to 50 to 80 cm or even greater can be achieved. We currently have the technology of excavators that allow in a technically easy way the fulfillment of these conditions. The mechanical breakage presented of the land surface leads in several ways to the optimization of the biological cleaning results in accordance with the present invention. The broken soil material allows a greater penetration of air, the existing penetration channels of rainwater in these surface areas of the earth are destroyed, so that a regular wetting of this layer of soil can be obtained. At the same time, it is the layer of the area to be cleaned where the relatively large size MHC components are more difficult to decompose. Through the restructuring presented, a new initial situation is obtained for the following biological purification. / The teaching according to the present invention proposes, in at least one process step, the introduction into the surface areas of the ground of concentrate of nutritive substances useful for biological cleaning. This concentrate of nutritional substances is used in particular in the form of solutions, emulsions and / or diluted aqueous dispersions, whereby a convenient application by spraying can be employed. In a subsequent step of the process according to the present invention, intensive humidification is carried out. In this way the concentrate of nutrients sprayed is distributed regularly in the area of the broken earth, and on the other hand the possibility arises that parts of the concentrate of nutritious substances penetrate in a deeper way towards the area of the earth not affected by the mechanical preparation. The sequence shown here of process steps shows especially that the combination of the process steps (bl) and (b2) in the mode can be used one and several times. Especially important combinations of these process steps of (bl) and (b2) are characterized by one of the following sequences: (bl) = >; (b2), that is, in this case, the land surface to be cleaned is first broken and then the nutrient concentrate is applied. But you can also proceed as follows: (b2) = > (bl) that is, the concentrate of nutrients is first applied to the surface to be cleaned and then the mechanical treatment of the surface of the soil is applied. In further important embodiments, the process step (bl) and / or the process step (b2) can be carried out several times, preferably twice. In this way possible and optionally preferred process combinations are obtained for the use of these steps (bl) and (b2) in the direction of the sequences (bl) = > (b2) = > (bl) or (b2) = > (bl) = > (b2) The irrigation steps of (a) and (c) may be applied one and / or several times in accordance with the teachings of the present invention. Process step (a) can be omitted as already explained in the case of a soil already humidified by rain. In the same way, subsequent irrigation can be eliminated when the application process of the combination of nutrients according to (b2) is carried out immediately before or during a rain phase. Even though the details of the multi-stage work form according to the present invention in each specific case are determined by the specific constitution of the soil and / or the magnitude of the contamination by MHC, we can nevertheless mention the following generalities: repetition, once or several times, of at least the application of concentrate of nutrients for biological cleaning under adequate humidity conditions of the soil to be treated and especially also the subsequent washing in one or several stages in accordance with the process measures (c ) are convenient and preferred. The time between the individual steps of the repeated application of nutrients depends on the given conditions. In general terms we are talking about at least about 1 to 2 weeks, so processes with longer time intervals, for example within a range of 1 to 6 months, are especially suitable. The number of repetitions of the cleaning measure according to the present invention depends on the specific conditions. The regular review of the content of contaminants in the vertical layers of the contaminated soil zone provides here information as to the need for a repetition of the measurement in accordance with the present invention and also as to the magnitude of said repetition. In general it has been shown that a 1 to 3 times repetition of these measurements is sufficient to clean deep areas, as no barrier layers are found on the inside of the soil. The growth of strains of suitable microorganisms that consume MHC under aerobic conditions also depends, as is known, on the available oxygen. Here additional measures may be required, especially in deep areas, when on the one hand there are significant MHC contamination and on the other hand when these contaminations can not be tolerated by MHC. The teaching of the present invention can employ a large number of currently known technical measures to assist in these special cases. For example, the measure of introducing necessary oxygen in a chemically bound form and especially in the form of hydrogen peroxide to the working area that requires it is an appropriate measure. In the industry you can get commercial products for these purposes which are available, especially the product sold under the trade name "RENATox" of the company Degussa. It is also possible to forcefully introduce oxygen from the air to the areas in question, especially by creating deep suction wells from which the gas phase is pumped and therefore an air flow is introduced into the soil formation adjacent. We refer as an example to the publication of the Ministry of Research and Technology, Fórderkennzeichen 1460505, "Technologieregister zur Sanierung von Altlasten" (Technological register for the cleaning of polluting waste), B Bóhnke and K. Póppinghaus, December 1990, and especially on pages 31 and 32. On this aspect we can mention what following: The teaching in accordance with the present invention does not necessarily focus on the removal of bound contaminant residues based on MHC at any depth of the formation of the soil in question. The invention focuses primarily on the cleaning of the area of the floor necessary for life, such as, for example, the area necessary for the growth of plants, the construction of buildings and the like. In this area, which is relatively shallow, teaching is applied in accordance with the present invention and its primary objective is the effective and economical cleaning of the soil in this area. Regarding this aspect, we mention an additional possibility in which the elements according to the present invention are supported by a suitable (intermediate) care of the surface of the area to be cleaned. For example, in accordance with the present invention, it may be convenient to plant on the loose surface of the area to be treated plants with deep roots, and as a typical example we can mention the cultivation of sunflowers. At the same time or instead of this example, seeds of plants that accumulate N, such as, for example, alfalfa, clover, or radish, can be planted on the surface. Basically any representative of the legume class is suitable for this purpose. The following embodiments deal with the nutritive substances or mixtures of nutritional substances which can be used according to the present invention for the cultivation of strains of microorganisms that consume MHC. Basically, the general expertise available today, such as those found, for example, in the introduction to DE-A-42 18 243 and in the literature described there, is applied here. The technical disclosure of this document DE-A-42 18 243 for obtaining nutritive substances or mixtures of suitable and especially preferred nutrients is also expressly included in the present invention by reference. Accordingly, only extracts of said disclosure will be mentioned below in an express manner.

Firstly, the circumstances known in the specialized field in the sense that the nutritive substances can consist of both synthetic and / or natural conventional fertilizers, and especially those based on at least mainly hydrophilic components, are also valid in the teaching according to the present invention. . Mixtures of valuable substances with at least a part of hydrophobic components, and especially corresponding compounds of P and / or N, can, however, be especially advantageous in the field of application in question. In this way, corresponding phosphorus (P) and nitrogen (N) compounds can have parts of hydrophobic molecules in such a way that these molecules accumulate in the terrestrial areas loaded with MHC. The advantage of such an interaction between contamination in the soil and the nutritive substance or the mixing of nutrients for the promotion of the proper growth of bacteria is immediately evident: the growth of the necessary bacteria and consequently the decomposition of contaminants based on MHC are optimally promoted in this way. In general terms, a washing of these hydrophobic parts of the nutrient mixture downwards in the groundwater is not carried out, while the components of inorganic and / or organic fertilizers of natural and / or synthetic origin eventually used or Co-workers are easily subjected to a process of washing of this kind in principle unwanted. In a manner known per se, these nutrient concentrates containing valuable hydrophobic substances are used together with emulsification and / or suspension aids, where, however, at least partially, this function can also correspond to one or more components as substances nutritious Suitable additional components with an emulsifying and / or suspending effect are the known crosslinking aids based on alkyl oligoglucosides, of which more precise details can be obtained in the disclosure appearing in the aforementioned document DE-A-42 18 243. Preferred nutrient concentrates according to the present invention contain the water-soluble and / or oil-soluble compounds of P and / or N mixed with other water-soluble and / or oil-soluble organic mixing components, to which they correspond at least partially a character of nutritive substance for the growth of microorganisms that consume hydrocarbon compounds. Water-based preparations can be especially suitable, which contain a phosphoric acid ester as an emulsifier and source of P as well as in a desired manner one or more N sources which can be dispersed in water or be soluble in water. It may be advisable to use concentrates of nutritional substances containing from 10 to 40% by weight of phosphoric acid ester with an emulsifying action, from 10 to 40% by weight of N source, and the rest of water. Especially preferred can be concentrates of nutritional substances containing from 20 to 30% by weight phosphoric acid esters with an emulsifying action, from 15 to 30% by weight of N source, and from 0.5 to 5% by weight. of nonionic surfactants and the rest of water. Concentrates of nutritional substances which, as esters of phosphoric acid, contain phospholipids, alkyl phosphates and / or alkyl ether phosphates are suitable representatives within the framework of the present invention. The source of N is, in general terms, in the form of inorganic and / or organic bound nitrogen, and urea can be the preferred N source, especially in amounts of about 10 to 50% by weight, in the mixture of nutritious substances. Preferred nonionic surfactants are the aforementioned alkylglycoside compounds - preferably prepared from straight-chain fatty alcohols containing 8 to 24 carbon atoms and monoglycosides and / or oligoglycosides - plus partial sugar esters of monocarboxylic acids with 8 to 24 carbon atoms, sorbitan esters and / or surfactants of biological origin. Examples are sophorose lipid, trehalose lipid and lipopeptides. With reference to the specific disclosure of DE-A-42 18 243, a summary of further preferred elements of the invention is presented below. The phosphoric acid esters used can acquire special importance, which are chosen according to the present invention in such a way that on the one hand they serve as a source of P and on the other hand they have an emulsifying effect. Preferred phosphoric acid esters are obtained from cultured microorganisms. Among the compounds that can be used, phospholipids are of special importance. Phospholipids are amphiphilic substances that can be obtained from plant or animal cells. The preferred phospholipids are glycerophospholipids, which are also commonly known as lecithin. Known substances which can be used here are the diacyl phospholipids, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylglycerin, phosphatidylglycerinphosphate, diphosphatidylglycerin, N-acylphosphatidylethanolamine and phosphatidinic acid. Preferred are monoacyl phospholipids, lysophosphatidylcholine, 1-isophosphatidylethanolamine, lysophosphatidylinositol, lysophosphatidylserine, lysophosphatidylglycerol, lysophosphatidylglycerophosphate, lysiphosphatidylglycerin, lyso-n-acylphosphatidylethanolamine, and lysophosphatidinic acid. Due to the accessibility, the expert in the field will first use the commercially available phosphatidylglycerides such as lecithin and cephalin of vegetable or animal origin. These preparations are obtained mainly from oils such as, for example, corn oil or cottonseed oil or soybean oil. Within the framework of the present invention, enzymatically hydrolyzed glycerol phospholipids (enzymatically hydrolysed lecithin) which, based on the division of a fatty acid ester, have a hydrophilic character are preferred. Only products that, through enzymatic hydrolysis, have lost their phosphoric acid radical are excepted. In addition to the mentioned phospholipids or instead of said phospholipids, it is also possible to use phosphoric acid partial esters with fatty alcohols and especially straight-chain fatty alcohols as the P source of the nutrient concentrate. For further details see the disclosure of DE-A-42 18 243. As the source of N, the nutrient concentrates contain corresponding compounds in the form of inorganic and / or organic bound nitrogen. Preferred N sources are the sources containing only bound organic nitrogen. Inorganic salts, such as, for example, alkali nitrate or alkali nitrite, or ammonium salts are suitable sources of N. Organic sources of N are, for example, aminocarboxylic acids, for example of the glutamic acid type. Urea has proven to be especially practical for the management and promotion of the growth of microorganisms, since urea has at the same time a conservation effect against unwanted microbial attacks, in such a way that the concentrates of nutritious substances present a greater stability storage. If phospholipids are used as the source of P, then the use of an additional source of N can be avoided, since the class of elements in question contains both P and N. For the components of the mixture to be used optionally with a surfactant action, see the data provided especially for the alkyl glycoside compounds, as well as the special disclosure of DE-A-42 18 243. The surfactant compounds are usually in an amount of 0.5 to 5% by weight in the concentrate of nutrients . In general terms, the amount of surfactant reaches up to 1% by weight to cause the expected stimulation of the growth of the microorganisms and to promote said growth. In this way the surfactants can, based on the alkylglycoside compounds, should be within a range of 0.5 to 1% by weight - in relation to the total mixture - for an effective improvement of the growth of the microorganisms. For additional details, especially in terms of suitable process parameters, see the German literature already mentioned several times. Concentrates of nutrients are usually diluted 10 to 50 times with water, and are applied once or several times in quantities of 5 to 200 mg per g of contaminant on the surface of contaminated soil. EXAMPLES Four test fields of approximately 30 square meters were chosen in which for decades the soil surface was contaminated with fuels. The test fields consisted up to a depth of three meters essentially of medium sand with parts of fine sand that allowed a good penetration. The upper soil layer of 20 cm consisted of humus. The level of the water table with stationary variations was on average 2 meters. Regarding the distribution according to the depth to the groundwater zone, several levels of pollutant concentration can be mentioned, where the areas of greatest contamination were at a depth of 0.8 to 1.5 m. For the cleaning of the soil, the following treatment process was chosen.

Field treatment field test 1 test 2 test 3 irrigation pretreatment * irrigation felling vegetation * irrigation concentrated concentrate measurements fertilization fertilization of substances with nutritious nutrients nutrient zine conformity conformity with DE-A- with DE-A- agricultural 4218243 4218243 penetration plow plow plow treatment irrigation irrigation subsequent irrigation repetition of concentrated concentrate fertilization the measure of substances of substances with nutritious nutrients zante fertilization of conformi- de conform- ore after 6 years with DE-A- with DE-A-weeks 4218243 4218243 treatment field test 4 pretreatment no treatment measures of any treatment fertilization penetration no treatment subsequent treatment no treatment repeat measurement no fertilization treatment after 6 weeks A decomposing Natural biological ion was followed up, first, for three years, and due to the insufficiency of soil nutritive substances, as expected, no significant advances were observed (field of evidence 4). At the beginning of the test the following initial loads were observed: Degree of loading field field field test field 1 test 2 test 3 test 4 in mg / kg in mg / kg in mg / kg in mg / kg upper level 2,300 1,300 2,300 800 of the soil, unsaturated zone 3,800 10,200 2,100 4,300 from 0.2 to 0.8 m depth (outside the fluctuation zone of the water table level) unsaturated zone of 3,700 20,000 4,000 10,200 0. 8 to 1.50 m depth (outside the zone of fluctuation of the water table) saturated zone (in 360 2,700 1,800 2,400 the zone of fluctuation of the water table) After a reaction time from April to August, the following reductions of pollutants: Degree of loading field field field test field 1 test 2 test 3 test 4 in mg / kg in mg / kg in mg / kg in mg / kg upper level 11,, 110000 700 2,400 700 of soil reduction of 52% 46% none none taminants unsaturated zone of 1,800 10,200 2,300 no 0.2 to 0.8 m depth (out of 53% none of the water table fluctuation level) unsaturated zone of 2,600 13,800 4,100 10,200 0.8 at 1.50 m depth (out of 30% 31% none none the zone of fluctuation of the water table) saturated zone (within 160 2,100 1,900 2,600 of the zone of fluctuation of the napa 55% 22% none none phreatic) results show that the natural decomposition m Through the use of suitable nutrients - such as for example the mixture of substances described in DE-A-4218243 - it is significantly accelerated. This effect, as expected, is' especially noticeable in the unsaturated zone of the soil, but also in the saturated parts. The felling of the existing vegetation - in this case herbs - does not provide any substantive advantage and is recommended only in impenetrable lands. In addition it is observed that the usual agricultural fertilizers are inadequate to accelerate the decomposition, since the nutritious substances are washed very quickly.

Claims (18)

1. CLAIMS A procedure for the simplified biological cleaning of land surfaces of almost any magnitude, contaminated by hydrocarbon residues based on mineral oils (MHC), by means of the treatment with concentrations of nutritive substances to stimulate and help the growth of microorganisms that consume MHC, characterized because (a) after a previous humidification / irrigation if necessary (bl) in at least one process step the soil to be cleaned is broken to a considerable depth, (b2) and on the other hand in at least one process step the The concentrate of nutritional substances is applied in an emulsion and / or dilute aqueous dispersion and sprayed in an essentially regular manner and (c) is finally intensively rehumidified. A method according to claim 1, characterized in that the combination of the process steps (bl) and (b2) are carried out in the form of one of the following sequences: (bl) = > (b2); (b2) = > (bl); (bl) = > (b2) = > (bl) or (b2) = > (bl) = > (b2) A method according to claims 1 and 2, characterized in that in the process step (s) (bl), the breaking of the floor surface is carried out to a depth of at least 15 cm, preferably at a depth equal to or greater than 30 cm, and it may be preferred to reach depths of up to 50 to 80 cm. 4. A method according to claims 1 to 3, characterized in that the irrigation process steps of (a) and (c) can be carried out in one and / or several steps, so that the process step (a) It can be removed in the case of a wet floor due to rain. 5. A process according to claims 1 to 4, characterized in that the irrigation in one and / or several stages in accordance with process step (c) is so intensive that at least the penetration of the nutrient mixture is ensured in the area of loose soil (bl), preferably parts of the nutrient mixture also penetrate the deep parts of the soil. 6. A method according to claims 1 to 5, characterized in that at least the process steps (a), (b2) and (c) are repeated at greater intervals, so that the preferred time intervals are within a range of 1 to 6 months and the repetition can conveniently be performed 1 to 3 times. A process according to claims 1 to 6, characterized in that the components of nutritive substances used and especially the corresponding compounds of phosphorus (P) and nitrogen (N) have hydrophobic molecule parts, in such a way that these molecules can accumulate in zones of soil loaded with MHC. A process according to claims 1 to 7, characterized in that the nutrient concentrates used in process step (b2) contain emulsification and / or suspension aids where at least a part of this function can also correspond to one or various components having the character of nutritive substances, but it is also preferred that at least partially corresponding additional components are contained in the nutrient concentrate. A process according to claims 1 to 8, characterized in that the alkyl oligoglycosides are used in the concentrate of nutritional substances as emulsification and crosslinking aids. . A process according to claims 1 to 9, characterized in that the concentrates of nutrients that are used contain phosphorus (P) and nitrogen (N) compounds soluble in water and / or oil in mixture with water-soluble organic mixing components. and / or additional oil soluble, to which correspond at least partially a character of nutritive substances for the growth of microorganisms that consume hydrocarbon compounds, so water-based compositions containing a phosphoric acid ester as an emulsifier and source of P as well as optionally one or more N sources soluble in water or that can be dispersed in water are preferred. . A process according to claims 1 to 10, characterized in that the concentrates of nutritive substances used contain from 10 to 40% by weight of phosphoric acid ester with an emulsifying action, from 10 to 40% by weight of N source and rest of water. . A process according to claims 1 to 11, characterized in that the concentrates of nutritive substances used contain from 10 to 30% by weight of esters of phosphoric acid with an emulsifying action, from 15 to 30% by weight of N source, and 0.5 to 5% by weight of nonionic surfactant compounds and the rest of water. A process according to claims 1 to 12, characterized in that the concentrates of nutritional substances that are used contain as phosphoric acid esters phospholipids, alkyl phosphates and / or alkyl ether phosphate. . A process according to claims 1 to 13, characterized in that the nutrient concentrate which is the source of N is in the form of inorganic nitrogen and / or bound organic, where urea may be preferred as a source of N, especially in amounts from about 10 to 50% by weight in the nutrient mixture. . A process according to claims 1 to 14, characterized in that concentrates of nutritional substances containing, as nonionic surfactants, alkyl glycoside compounds, prepared from fatty alcohols of preferably straight chain with 8 to 24 carbon atoms can be used. carbon and monoglycoside and / or oligoglycosides, sugar partial esters of monocarboxylic acids with 8 to 24 carbon atoms, sorbitan ester and / or surfactants of biological origin such as, for example, sophorose lipid, trehalose lipid and lipopeptides. . A process according to claims 1 to 15, characterized in that the nutrient concentrates are diluted with water up to 10 to 50 times and are applied once or several times in amounts of 5 mg to 200 mg per gram of contaminant on the surface of the contaminated soil. 17. A process according to claims 1 to 16, characterized in that additional concentrates of microorganisms are applied on the surface of the soil, which can decompose the hydrocarbon compounds and those of natural origin are preferred. 18. A method according to claims 1 to 17, characterized in that a forced introduction of air is also provided in deep soil formations and / or the introduction of oxygen bound and released in the soil.