RU2355488C1 - Biological method of cleaning oil contaminated soil - Google Patents

Abstract

FIELD: biotechnology.

SUBSTANCE: present invention pertains to biotechnology, particularly to cleaning oil contaminated soil. The method involves treatment of contaminated soil with Melaphen, in amounts of 1*10^-8-1*10^-4 g/kg of soil, which stimulates metabolism of microorganisms, soil moistening and tillage. Treatment is done once in every 10-14 days.

EFFECT: 30% increase in efficiency of cleaning in a wide range of oil contaminants.

18 cl, 7 tbl

Description

The invention relates to biotechnology, in particular to the cleaning of the soil from oil pollution.

The problem of cleaning soils from oil pollution is relevant - the effect of these pollution on the soil is manifested in a change in its physical, physico-chemical and chemical properties, in the inhibition of the intensity of biological processes. Oil pollution differs from other anthropogenic influences in that it gives not a constant but a “volley” load on the medium, causing a quick response.

The essence of the restoration of contaminated ecosystems is the maximum mobilization of the ecosystem’s internal resources to restore their original functions. Purification - reclamation of oil-contaminated lands is an acceleration of the self-purification process, in which all the natural reserves of the ecosystem are used: climatic, landscape-geochemical and microbiological.

The problem of protecting the environment from pollution by oil and oil products, as well as their disposal, is becoming increasingly acute due to the limited capabilities and sometimes environmental unsafe use of mechanical, physical and chemical cleaning methods for these purposes. In this regard, the possibility of using microorganisms capable of growing and exhibiting active biochemical activity in an environment with a high content of oil pollution capable of biodegradation of these substances is relevant.

The natural processes of restoration of natural systems after oil pollution are very time-consuming, and the main agents of their self-cleaning are natural destructors - hydrocarbon-oxidizing microorganisms.

There are derived strains of microorganisms that can, in a short time, almost completely utilize tens of tons of petroleum hydrocarbons, transforming them, in particular, into organic matter of their own biomass, carbon dioxide and environmentally friendly products.

For example, it is known (RU 2292326 C2, 2007.01.27) to clean soil contaminated with oil and oil products while restoring its physicochemical properties and natural biocenosis by applying a biological preparation based on microbial fertilizer (processing waste from poultry farms) and based on microorganisms into the soil - destructors (bacteria of the genus Bacillus).

The disadvantage of this method is the difficulty in maintaining and cultivating a pure culture of microorganisms, which is associated with high capital and operating costs.

Therefore, it is advisable to use drugs not based on pure cultures of microorganisms, but on the basis of biologically active substances - growth stimulants obtained both from living cells and chemically synthesized.

Known (RU 2005109528 A, 2006.10.10) is a method for cleaning the soil and soil from oil pollution, including introducing into the soil a nutritional supplement that stimulates the growth of oil-oxidizing microorganisms contained in it, using molasses to a final sugar concentration of 3-10 g / kg of soil , which may additionally contain potassium, and / or nitrogen, and / or phosphorus, taken in quantities of 0.112 g / kg of soil of each; Surfactants in the concentration range of 10-40 mg / kg of soil. After the addition of the additive, the temperature and water conditions of the soil are maintained to ensure the vital function of microorganisms to a residual hydrocarbon fraction of 30-40%.

The disadvantage of this method is the use of growth stimulants in high concentrations, which makes the cleaning process quite expensive.

Currently, for the cleaning of soils from oil pollution, the method we have chosen for the prototype is widely used, using the bioagent "Fyre-Zyme" (FZ), developed by the American corporation Ecology Technologies International, Inc. - environmentally friendly, non-toxic, fast-acting, efficient, economical and an easy-to-use substance for cleaning water and soil from chemical and petrochemical contaminants [http://www.itstoyou.com/internationalenzymes/fyre-zyme/index.html].

The action of the drug is based on the selective activating effect of carefully selected fermented enzymes and nutrients on oil and a number of other bacteria in the soil, starting the process of their extremely rapid reproduction and, as a result, the rapid biodegradation of pollutants. FZ is a product formed from the fermentation of carefully selected sugars, amino acids, extracellular enzymes and bioemulsifiers. The basis of the drug is made up of enzymes - amylase, catalase, protease, lyase. In addition to enzymes, the composition of the FZ preparation includes simple and complex sugars, protein, amino acids, which serve to nourish and stimulate the vital activity of bacteria, as well as a small amount of biodegradable surfactants, which provide better penetration of the drug into the soil and mobilization of oil products. The product is supplied as a dark brown liquid concentrate.

According to the instructions for the FZ preparation, contaminated soil with a low level of oil pollution (0-20000 mg / kg) is irrigated with a 5% FZ solution in an amount of 3.5 ml per 100 g of soil, and at high concentrations of oil pollution (20000-100000 mg / kg) irrigate with 5% FZ in an amount of 5 ml per 100 g of soil, and mix thoroughly to evenly distribute the drug. The frequency of administration of the drug is about 10 days.

The disadvantage of this method is the high cost of this drug, which has to be made in significant quantities, in addition, it should be noted that after applying this drug and moistening the soil, “vitrification” occurs - hardening and drying of the lumps of soil. Aeration of such soils is difficult, soil respiration is reduced, and additional loosening of soil samples is required.

The objective of this invention is the creation of a new method of cleaning soils from oil pollution, expanding the range of known methods of biological treatment of soils from oil pollution, using domestic inexpensive, non-toxic, effective, environmentally friendly drug Melafen, acting in extremely low concentrations, not inferior, and in some cases superior in terms of the effectiveness of soil cleaning from oil pollution, modern expensive imported drugs, and allowing you to effectively clean the soil s from oil pollution in a wide range - with an initial concentration of oil pollution up to 100,000 mg / kg.

The technical result of the invention is to stimulate the drug Melafen vital activity contained in the soil of microorganisms-destructors included in the composition of oil compounds and thereby accelerate the destruction of oil pollution.

The technical result is achieved by the claimed method of biological cleaning of soils from oil pollution, including periodic treatment of contaminated soil with a drug that stimulates the metabolism of microorganisms, moistening the soil, loosening and mixing, where Melafen is used as such a preparation in an amount of 1 * 10 ^-8 -1 * 10 ^{- 4} g / kg of soil, which is applied to the soil being cleaned at intervals of about once every 10-14 days.

The drug Melafen is a melamine salt of bis (oxymethyl) phosphinic acid of the formula I:

Melafen is proposed as a highly effective synthetic plant growth and development regulator (RU 2158735, C1, 2000.11.10).

Melafen does not have toxic, mutagenic, DNA-damaging, genotoxic effects in a wide range of studied concentrations from 0.46 · 10 ^-9 M to 0.46 · 10 ^-3 M (A.B. Margulis, O.N. Ilyinskaya; Genotoxic effects of growth regulator of plants - Melafen / Collection of materials of the All-Russian seminar-meeting “State of research and prospects for the application of the new generation plant growth regulator“ Melafen ”in agriculture and biotechnology”, Kazan, publishing house “School” - 2006 - P.150). It was established that the drug belongs to class IV - slightly hazardous substances with weakly expressed cumulation. The oral LD ₅₀ is 6500 mg / kg for rats and 2000 mg / kg for mice. The drug does not have irritating and sensitizing effects, acute inhalation toxicity, teratogenic and embryotoxic effects (M.Ya. Tremasov, A.I. Sergeychev, E.I. Semenov; Pharmacological and toxicological characteristics of the drug "Melafen" / Collection of materials of the All-Russian seminar - meeting “State of Research and Prospects for the Use of the New Generation Plant Growth Regulator Melafen in Agriculture and Biotechnology”, Kazan, “School” Publishing House - 2006 - P.143).

It has been established that Melafen is a promising drug for use in biotechnological processes (RU 2174555 C1, 2001.10.10).

Determination of the influence of Melafen on the process of cleaning soils from oil pollution is carried out in laboratory conditions on the soils of Western Siberia and the Republic of Tatarstan. As a control, oil refining is used in vivo (without the introduction of drugs) and with the introduction of the FZ preparation.

Soil samples are taken in bags made of polyethylene according to GOST 17.4.4.02. Soil samples are selected taking into account sufficient distance from settlements and industries. The soil is stored according to the rules for storing soil samples for analytical and microbiological analyzes.

Determine the natural moisture of the soil to find the required amount of the drug, which is applied to the soil samples.

Soil samples are dried at room temperature to an air-dry state. A dried soil sample weighing 100 g is transferred to a 250 g plastic container. The background oil content in the initial soil samples is determined.

Then add the appropriate amount of oil to obtain the specified concentration of oil pollution. For each type of soil a series of oil contaminants with different oil concentrations is prepared. To study the degradation of oil pollution of soils in Western Siberia, West Siberian oil is used as a pollutant (from the West Noyabrsk field of TsDNG-5, BPS, 1232 well); and to study the degradation of oil pollution of soils of the Republic of Tatarstan - Tatarstan oil (from the Romashkinskoye field).

To study the dynamics of the biological purification of soils from oil in the presence of FZ and Melafen preparations, soil samples are prepared in the same way, then the appropriate amount of solutions of the preparations is added.

Determination of the concentration of oil pollution in soil samples is carried out in accordance with PNA F 16.1: 2.2.22-98 "Methodology for measuring the mass fraction of oil products and bottom sediments by IR spectrometry".

In addition to laboratory tests, pilot industrial tests are conducted on soils in the territory of the Vyngapurovskoye oil field TPDN Zapolyarnefte OAO Sibneft-Noyabrskneftegaz (Noyabrsk).

The invention is illustrated by the following examples of specific performance.

Example 1

The study of the destruction of oil pollution with a concentration of 20 g / kg in the soils of Western Siberia in vivo

A 100 g soil sample of Western Siberia is transferred to a 250 g plastic container. The background oil content of the original soil sample is determined. Then the soil is moistened, loosened and incubated until the natural soil microflora is activated.

Add 2 g of oil; West Siberian oil is used as pollutant.

Sampling to determine the concentration of oil in the sample is carried out with an interval of 10 days. Moisturize and loosen the sample, stirring. The results are shown in column 3 of table 1.

Example 2

The study of the destruction of oil pollution with a concentration of 20 g / kg in soil samples of Western Siberia using the drug Melafen

A 100 g soil sample of Western Siberia is transferred to a 250 g plastic container. The background oil content of the original soil sample is determined. Then the soil is moistened, loosened and incubated until the natural soil microflora is activated.

Add 2 g of oil; West Siberian oil is used as pollutant.

A soil sample is treated by irrigation with 2 ml of a solution of Melafen at a concentration of 1 * 10 ^-6 (1 * 10 ^-4 ; 1 * 10 ^-2 ) g / l, so that its amount in soils is

1 * 10 ^-8 (1 * 10 ^-6 ; 1 * 10 ^-4 ) g / kg, respectively. At the same time, soil moisture, which is about 50%, is taken into account. At intervals of 10 days, a sample is taken to determine the change in the concentration of oil in the sample. Moisturize and loosen the sample, mix and re-treat with Melafen at the appropriate concentration.

The results of the influence of the drug Melafen in the amount of 1 * 10 ^-8 ; 1 * 10 ^-6 ; 1 * 10 ^-4 g / kg are given in columns 4, 5, 6 of table 1, respectively.

Table 1 The main experimental stages and results of biological treatment of oil-contaminated soil in the West Siberian region (oil concentration in the soil is 20 g / kg) The time from the start of the experiment, days Contents of biological soil treatment The concentration of oil in the soil, g / kg In the counter. samples In experimental samples with the content of the drug "Melafen", concentration, g / kg 10 ^-8 10 ^-6 10 ^-4 one 2 3 four 5 6 0 Moistening, loosening and incubation of soil samples, to activate the natural soil microflora - - - - 7 Preparation of model soil samples: oil application, treatment with Melafen twenty twenty twenty twenty 17 Sample selection 9.40 3.96 3.20 3.93 eighteen Moistening, loosening - - - - 22 Moistening, loosening - - - - 27 Sample selection 3.53 3.73 4.14 4.03 28 Mixing, treatment with Melafen - - - - 33 Moistening, loosening - - - - 37 Sample selection 1.25 0.53 0.63 0.63

Figure 1 shows the kinetics of the destruction of oil pollution in soil samples of the West Siberian region at an initial oil concentration of 20 g / kg

Within 10 days after the introduction of oil (taking into account the adaptation period), a sharp decrease in the oil content is observed in all samples. This is due to the mobilization of the native oil-oxidizing soil microflora from an inactive state during storage of the soil. The introduction of oil into the soil is considered as the supply of a nutrient medium (substrate) for oil-oxidizing microorganisms that use it for the purpose of constructive and energy metabolism, as a result of which the concentration of oil pollution decreases.

Under the influence of the drug Melafen, the oil content in the soil within 10 days after contamination decreases three times faster than in unprocessed soil. This suggests that the drug Melafen has a stimulating effect on the natural microflora in the indicated concentrations and accelerates the process of biodegradation of oil in the soil.

From 10 to 20 days, a further decrease in the oil content in the soil is observed, and in the control this process is more intensive than in the experiment, and on the 20th day this indicator in the control reaches the level of experimental samples. After 20 days, the concentration of oil in the soil practically does not change and amounts to from 3.5 to 4.1 g / kg in the control sample and in all experimental samples. According to the results of the observations, it can be assumed that the drug Melafen was completely utilized by soil microorganisms within 10 days.

Further, experimental soil samples are additionally treated with new portions of the drug Melafen. A further decrease in the concentration of oil in the soil is noted, and a decrease in the concentration of oil in the experimental samples was more than 2 times more effective than in the control.

Thus, the drug Melafen has a stimulating effect on soil microorganisms, although the stimulating effect is less pronounced than in the first 10 days. This may be due to the achievement of the “threshold” of biodegradation of oil under the experimental conditions, which corresponded to the oil content in soil samples of 0.9-1.3 g / kg.

The effectiveness of oil biodegradation in the soils of the West Siberian region is presented in table 2.

table 2 The effectiveness of oil biodegradation in soils of the West Siberian region Dose of oil, g / kg The concentration of the drug, g / kg The effectiveness of biodegradation of oil in the soil,% 10 days 20 days 30 days twenty 0 53.0 82.5 93.8 10 ^-8 80.2 81.5 97.4 10 ^-6 84.0 79.5 96.9 10 ⁴ 80,4 80.0 96.9

Example 3

The study of degradation of oil pollution concentration of 40 g / kg in soil samples of the Republic of Tatarstan in vivo

Example 3 is carried out analogously to example 1, but the soil of the Republic of Tatarstan is used as soil samples and 4 g of Tatarstan oil is added as pollutant. The results are presented in column 3 of table 3.

Table 3 The main experimental stages and results of biological treatment of oil-contaminated soil of the Republic of Tatarstan (oil concentration in the soil 40 g / kg) The time from the start of the experiment, days Contents of biological soil treatment The concentration of oil in the soil, g / kg In the counter. samples In experimental samples with the content of the drug "Melafen", in the amount of, g / kg 10 ^-8 10 ^-6 10 ^-4 one 2 3 four 5 6 one Preparation of model soil samples: oil pollution, treatment with Melafen 40 40 40 40 2 Moistening, loosening - - - - 3 Moistening, loosening - - - - 6 Sample selection 4.95 6.91 6.1 3.41 8 Moistening, loosening - - - - 10 Moistening, loosening - - - - 12 Sample selection 6.81 8.24 9.01 8.09 fifteen Mixing, treatment with Melafen - - - - eighteen Moistening, loosening - - - twenty Moistening, loosening - - - - 22 Sample selection 4.78 3.34 3.83 4.08

Example 4

The study of the destruction of oil pollution of a concentration of 40 g / kg in soil samples of the Republic of Tatarstan using the drug Melafen

Example 4 is carried out analogously to example 2, but the soil of the Republic of Tatarstan is used as soil samples and 4 g of Tatarstan oil is added as pollutant. The results are presented in columns 4, 5, 6 of table 3 for Melafen in the amount of 1 * 10 ^-8 ; 1 * 10 ^-6 ; 1 * 10 ^-4 g / kg, respectively.

Figure 2 shows the kinetics of biodegradation of oil pollution in soil samples of the Republic of Tatarstan with an initial oil concentration of 40 g / kg in the soil. In the course of experimental studies, it was shown that after the introduction of oil at a concentration of 40 g / kg in laboratory soil samples for 7 days, a sharp decrease in the content of oil products was observed in both experimental and control samples, the most significant decrease in the concentration of oil products was observed for experimental samples. From 7 days to 16 days, a slight increase in the concentration of oil products in all soil samples was recorded.

After 16 days, a further decrease in the concentration of oil products is observed, and the efficiency of oil-oxidizing microorganisms in the control and experimental samples is almost the same and amounts to 88 91% (table 4).

Table 4 The effectiveness of oil biodegradation in the soils of the Republic of Tatarstan at an initial oil concentration of 40 g / kg Dose of oil, g / kg The amount of the drug, g / kg The effectiveness of biodegradation of oil in the soil,% 7 days 16 days 23 days 40 -(the control)- 87.6 82.9 88.0 10 ^-8 91.5 79.7 89.8 10 ^-6 84.7 77.5 90,4 10 ^-4 82.7 79,4 91.6

When oil is added to the soil at a concentration of 40 g of oil per 1 kg of soil, the following results are obtained: the reduction in oil content in the first 7 days in the control sample is 87.6%, and in the experimental samples 82-91%. Further, the decrease in the content is insignificant and amounts to 88% in the control and 89.8-91.6% in the experiment. A significant residual content of oil products in soil samples indicates the inaccessibility of oil products and the accumulation of metabolic products. Melafen does not provide effective removal of the substrate in this case, however, the degree of removal in the experimental samples is higher than in the control.

Similarly, experiments are conducted to study the biodegradation of oil pollution in the range of 20-100 g / kg in soils of the West Siberian region in the presence of FZ preparations (5 ml of a 5% preparation per 100 g of soil) and Melafen (2 ml of a preparation of concentrations 10 ^-4 and 10 ^-6 g / l per 100 g of soil).

In figures 3-6 presents graphs of the kinetics of the destruction of oil pollution in vivo (figure 3) and with the introduction of drugs: FZ (figure 4) and Melafen in the amount of 10 ^-6 g / kg of soil (figure 5) and in the amount of 10 ^{- 8} g / kg of soil (Fig.6).

The nature of the curves in all the studied samples is almost the same. Within 14 days after the introduction of oil (taking into account the adaptation period), a sharp decrease in the oil content is observed in all samples. As noted above, the indigenous oil-oxidizing soil microflora is activated when oil is introduced, which is a substrate for it, used in metabolic processes, as a result of which the concentration of oil pollution decreases.

In samples with natural degradation conditions and using FZ, an increase in hydrocarbon content (HC) is observed from 14 to 28 days; this is due to the fact that in the first 10-20 days the utilization of the limiting and unsaturated linear HC occurs, and the residual concentrations of aromatic fractions adversely affect the vital activity of microorganisms. Further, the destruction curves go to a linear section.

The curves of the kinetics of the destruction of oil pollution using Melafen have a similar character - the course of the curves is smooth, without sharp peaks. For samples with an initial oil concentration of 100, 80 and 60 g / kg using the drug Melafen in an amount of 10 ^-6 g / kg, a slight increase in the content of oil products is observed during the period from 50 to 60 days. The introduction of an additional dose of the drug at this stage leads to a further gradual decrease in the concentration of oil pollution. A similar situation occurs in samples with an initial oil concentration of 100, 80, 60 g / kg using the drug Melafen in an amount of 10 ^-8 g / kg during the period from 20 to 35 days. Thus, the drug Melafen has a stimulating effect on soil microorganisms, although the stimulating effect is less pronounced than in the first 14 days, which may be associated with the achievement of the “threshold” of oil biodegradation.

To compare the effectiveness of the preparations FZ and Melafen, Figs. 7-11 show the curves of the kinetics of the destruction of oil pollution by pollutant concentrations.

The background content of oil pollution is presented in Fig.12.

The analysis of the curves in Fig. 7 with an initial oil concentration of 100 g / kg shows that the maximum decrease in HC content occurs in the first 12 days for all samples. Then there are 2 sharp spasmodic increases in oil pollution under natural degradation (control) - from 12 to 22 days - by 27% and from 40 to 54 days by 26%. The degree of purification in vivo is 57%.

The effectiveness of the drug Melafen in the amount of 10 ^-6 and 10 ^-8 g / kg is 69 and 58%, respectively, according to this indicator, Melafen exceeds the prototype.

The nature of the curves characterizing the effect of the drug Melafen for both concentrations is similar. In the period from 18 to 77 days for a sample with Melafen in an amount of 10 ^-8 g / kg, an increase in the content of oil contaminants occurs, and the additional introduction of the drug is insignificant, but improves efficiency.

The effectiveness of the FZ preparation is 56%, the nature of the curve is smooth, without peaks, the maximum degree of purification is achieved on the 104th day of the experiment and is 69%.

An analysis of the curves presented in Fig. 8 with an initial oil concentration of 80 g / kg shows that the maximum reduction in pollution occurs on the 15th day of the experiment in samples of natural purification and with the use of the drug Melafen in an amount of 10 ^-8 g / kg. Then in both samples there is a sharp increase in the content of oil pollution to a concentration of 35 g / kg. The degree of purification in vivo and with the use of the drug Melafen in the amount of 10 ^-8 g / kg for the samples of this series are the same and make up 63%.

Curves of samples using FZ and Melafen in the amount of 10 ^-6 g / kg go the same from 1 to 14 days, then in samples with Melafen in the amount of 10 ^-6 g / kg there is a decrease in the concentration of oil pollution, and in samples with FZ the nature of the curve becomes wavy (this is due to the "glazing" of the samples under the influence of the drug FZ). The degree of purification in samples with FZ is 59%, and with Melafen in the amount of 10 ^-6 g / kg - 62%.

The analysis of the curves in Fig. 9 with an initial oil concentration of 60 g / kg shows a similar character of the curves in the samples with Melafen in the amount of 10 ^-6 and 10 ^-8 g / kg with a slight increase in the content of oil pollution in the period from 25 to 40 days and a further decrease their content is up to 18 g / kg (in samples with Melafen in an amount of 10 ^-6 g / kg). The curve for the sample with Melafen in the amount of 10 ^-6 g / kg has a wave-like character. The effectiveness of the drug Melafen in this experiment is 60% for both concentrations.

The destruction curve under self-cleaning conditions is similar for samples with Slach. = 100, 80 g / kg. The degree of effectiveness is 64.62%, respectively.

The curve of destruction using FZ is similar for the sample with Slach. = 80 g / kg, efficiency - 44%.

The curves of destruction of oil pollution with an initial oil concentration of 40 g / kg for samples using preparations of FZ and Melafen (in the amount of 10 ^-6 and 10 ^-8 g / kg), presented in figure 10, are of a similar nature. The maximum degree of purification of these samples is: 57, 61 and 54%, respectively.

The destruction curve under self-cleaning conditions is similar for samples with Slach. = 60 g / kg. The degree of effectiveness is 57%.

In the period from 1 to 13 days in all samples of the series with Sach. = 20 g / kg (11) there is a decrease in the content of oil pollution. The maximum is observed in the sample with Melafen in the amount of 10 ^-8 g / kg on day 35 and is 74%. The degrees of effectiveness are: FZ - 54%, Melafen in the amount of 10 ^-6 g / kg - 57%, Melafen in the amount of 10 ^-8 g / kg - 60%.

The destruction curve under self-cleaning conditions is smooth, without peaks, the efficiency is 56%.

The data obtained as a result of the experiment are presented in table 5.

The maximum decrease in HC content occurs in samples using the Melafen preparation in an amount of 10 ^-6 g / kg, the average value of efficiency (for all studied concentrations of contaminants) is 69.27%. For samples of the series with the use of the drug FZ - 58.71%, with the use of the drug Melafen in an amount of 10 ^-8 g / kg - 56.57%.

For the drug Melafen in an amount of 10 ^-6 g / kg, the best indicator of effectiveness - 78% - is achieved in conditions of severe soil contamination with Sachn. = 100 g / kg.

For the drug Melafen in an amount of 10 ^-8 g / kg, the highest efficiency indicator - 68% - was found in samples with contamination. = 20 g / kg.

By the time during which 50% efficiency is achieved in all soil samples, the drug Melafen “leads” in the amount of 10 ^-6 g / kg, the time of 50% destruction is 10-12 days. The FZ preparation overcomes the 50% efficiency threshold on the 13th day of the experiment in samples with contamination of 20, 80 and 100 g / kg, and on the 40th day in samples with contamination of 60 and 80 g / kg, and Melafen in the amount of 10 ^-8 g / kg - on 14 days for samples of 60, 80 and 100 g / kg and on day 30 for samples of 20 and 40 g / kg.

Thus, the use of drugs for biodegradation of oil pollution in comparison with the natural conditions of soil cleaning increases the cleaning efficiency - the difference reaches an average of 28% - and reduces the time for cleaning oil-contaminated soils. The most effective results were obtained in the presence of Melafen in the amount of 1 * 10 ^-6 g / kg of soil.

Table 5 Biological treatment of soils from oil pollution in vivo and in the presence of Fyre-Zyme preparations, Melafen In vivo biodegradation Biodegradation in the presence of the drug "Fyre-Zyme" Biodegradation in the presence of Melafen in an amount of 10 ^-6 g / kg Biodegradation in the presence of Melafen in an amount of 10 ^-8 g / kg From the beginning, mg / kg Con. Mg / kg The degree of purification,% From the beginning, mg / kg Con. Mg / kg The degree of purification,% From the beginning, mg / kg Con. Mg / kg The degree of purification,% From the beginning, mg / kg Con. Mg / kg The degree of purification,% 100,000 35816 64.18 100,000 40656 59.34 100,000 22320 77.68 100,000 50160 49.84 80,000 30360 62.05 80,000 34848 56.44 80,000 25116 68.61 80,000 37840 52.70 60,000 25920 56.80 60,000 28152 53.08 60,000 19228 67.95 60,000 25704 57.16 40,000 15840 60.40 40,000 15180 62.05 40,000 13800 65.50 40,000 17760 55.60 20000 6804 65.98 20000 7470 62.65 20000 6682 66.59 20000 6494.4 67.53 1645 (background) 312 81.03 1645 338 79.45 1645 200,2 87.83 1645 825 49.85

Example 5

Pilot tests of biodegradation of oil-contaminated soils of the West Siberian region using the drug Melafen

As the object of study, the soils of 3 studied areas are selected:

1 site - control, not contaminated with oil site;

Section 2 - an oil-contaminated area for studying the destruction of oil pollution in vivo;

3 site - an oil-contaminated site for the study of the destruction of oil pollution using the drug Melafen in an amount of 10 ^-6 g / kg.

The studied areas loosen, moisturize. Section number 3 is irrigated with a solution of Melafen to a concentration of 10 ^-6 g / kg (1 m ² of soil is treated with 0.05 * 10 ^-4 g of Melafen, dissolved in 4.95 l of water). Every 14 days, loosening, moistening (for section 3 also the introduction of the drug Melafen) and stirring is repeated. Samples are taken to study the dynamics of the biodegradation of oil.

The main stages of the experiment and the research results are presented in table 6, and the effectiveness of biodegradation of oil pollution of soils in vivo and in the presence of the drug "Melafen" in table 7.

Table 6 Pilot trials of biodegradation of oil-contaminated soils of the West Siberian region using the drug Melafen in an amount of 10 ^-6 g / kg The time from the start of the experiment, days Contents of biological soil treatment The concentration of oil pollution, mg / kg 1 plot 2 plot 3 plot one 2 3 four 5 0 Loosening, application of the drug Melafen in 3 plots 1645 94640 94640 10 The introduction of the drug Melafen and loosening in 3 sites - - - fifteen Sampling, Loosening 1545.6 43296 35,481.6 twenty The introduction of the drug Melafen and loosening in 3 sites - - - 29th Sampling, Loosening 1500 45264 32716.8 thirty The introduction of the drug Melafen and loosening in 3 sites - - - 40 The introduction of the drug Melafen and loosening in 3 sites - - - 43 Sampling, Loosening 1950 36720 20974.8 51 The introduction of the drug Melafen and loosening in 3 sites - - - 57 Sampling, Loosening 1748.4 40,075.2 18216 61 The introduction of the drug Melafen and loosening in 3 sites - - - 71 Sampling, loosening Application of the drug Melafen and loosening at 3 sites 1560 41472 14168 Table 7 The effectiveness of biodegradation of oil pollution of soils in vivo and in the presence of the drug "Melafen" in the amount of 10 ^-6 g / kg during pilot testing Time, day In vivo biodegradation Biodegradation with the use of the drug Melafen D _beg. mg / kg D _con. mg / kg The degree of purification,% D _beg. mg / kg D _con. mg / kg The degree of purification,% fifteen 94640 43,296.0 54.25 94640 35,481.6 62.51 29th 45,264.0 52.17 32716.8 65,43 43 36720.0 61,20 20974.8 77.84 57 40,075.2 57.66 18216.0 80.75 71 41472.0 56.18 14168.0 85.03

On Fig shows the kinetics of the destruction of oil pollution during pilot trials.

The results obtained, presented in Fig.13 and in table 7, correlate with the data obtained in laboratory studies. The initial content of oil pollution in the 2nd and 3rd sections was 94.64 g / kg. In the period from 1 to 20 days, a decrease in the content of oil pollution is observed, and in section 3 this is more pronounced, which is explained by the mobilization of natural oil-oxidizing soil microflora as a result of the stimulating effect of the drug Melafen.

From 30 to 71 days in section 2, the content of oil pollution remains almost constant and averages 40 g / kg. In section 3, during this period, a further decrease in the concentration of oil pollution to 14.17 g / kg is observed.

The average value of the degree of cleaning efficiency in vivo for the entire period of the experiment was 56.65%; the use of Melafen increases this indicator to 76.36%.

The data obtained confirm the biostamulating effect of the drug Melafen on the process of destruction of oil pollution in soils.

Thus, a new method of biological treatment of soils from oil pollution using a domestic inexpensive, non-toxic, effective, environmentally friendly drug Melafen, acting in extremely low concentrations, is proposed.

The advantages of the proposed method:

- the effectiveness of cleaning soils from oil pollution in a wide range of pollution;

- environmental safety - the use of non-toxic drug Melafen in extremely low concentrations (10 ^-8 -10 ^-4 g / kg of soil), which are completely utilized in the natural environment;

- the stimulating effect of the drug on higher plants contributes to the phytomelioration of disturbed lands as the final stage of soil rehabilitation from oil pollution;

- simplicity of the process and equipment maintenance;

- minimization of operating costs.

Claims (1)

The method of biological cleaning of soils from oil pollution, including periodic treatment of contaminated soil with a drug that stimulates the metabolism of microorganisms, moistening the soil, loosening, characterized in that Melafen is used as a stimulating drug in an amount of 1 · 10 ^-8 -1 · 10 ^-4 g / kg of soil, which is applied to the cleaned soil with a frequency of once every 10-14 days.

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