RU2571180C2 - Method for purification of marine and brackish water ecosystems from oil and oil products under high latitude conditions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to biotechnology. Claimed is method for purification of brackish water and marine objects and ecosystems from oil and oil products. Contact of oil hydrocarbons to be decomposed with biopreparation, consisting of mixture of oil-oxidising strains of cultures Pseudomonas azotoformans VKM B-2762D, Microbacterium species VKM B-2615D, Rhodococcus erythropolis VKM Ac-2613D, taken in ratio 1:1:1 is realised. Titre of cells in final preparation constitutes not lower than 10¹⁰ cells per 1 g.

EFFECT: invention makes it possible to realise purification of brackish water and marine objects from oil pollutions in the range of temperatures from 0 to 25°C, including purification of water body surface from floating oil, ice and ice slurry from oil, water column from dissolved hydrocarbons, bottom sediments and coastal zone of water objects from precipitated oil.

5 cl, 5 dwg, 8 tbl, 5 ex

Description

The invention relates to biotechnology, methods for cleaning oil-contaminated water ecosystems and can be used to eliminate the effects of oil spills at sea, cleaning oil pollution of brackish water objects in a wide temperature range (from 0 to 25 ° C), including in ice conditions, namely cleaning the surface of ice, ice sludge, water from floating oil, water column from dissolved hydrocarbons, bottom sediments and the coastal zone of water bodies from precipitated oil.

Known hydrophobic organomineral oil biosorbent on the sorbent "SORBONAFT" (RF patent No. 2318736). The biosorbent includes oil-oxidizing microorganisms, namely the biomass of the bacterial strain Rhodococcus erythropolis NK-16 or Arthrobacter sp.HK-15 or the yeast Candida lipolytica KBP-3308 or Candida guilliermondii KBP-3175, or Pichia guilliermondii or immobilized in a hydrophobic sorbent of oil based on peat by fouling of the sorbent by bacteria and / or fungi. The disadvantage of the invention is the need for cleaning the sorbed mass after the completion of oil sorption, as well as reducing the effective biodegradation of oil in the thickness of the sorbent at a temperature below 15 ° C.

Known integrated biosorbent for cleaning water from oil and oil products, including as a carrier a hydrophobic oil sorbent based on peat and oil-oxidizing microorganisms immobilized on a carrier in an effective amount (RF patent No. 2422587). Immobilization on a carrier of microorganisms is carried out by an adsorption method to obtain individual sorbents: bacterial with a culture of Rhodococcus eqvi P-72-00, yeast with a culture of Rhodotorula glutinis 2-4 M and fungal with a mycelium fungus Trichoderma lignorum F-98, while the complex biosorbent for cleaning contains the composition of individual sorbents, in the following ratio of components, wt. %: bacterial with a culture of Rhodococcus eqvi P-72-00 45-55; yeast with a culture of Rhodotorula glutinis 2-4 M 45-55, or bacterial with a culture of Rhodococcus eqvi P-72-00 45-55; fungal with mycelial fungus Trichoderma lignorum F-98 45-55, or bacterial with a culture of Rhodococcus eqvi P-72-00 40-50; yeast with a culture of Rhodotorula glutinis 2-4 M 20-35; mushroom with mycelial fungus Trichoderma lignorum F-98 25-35. Biosorbent is used in conjunction with a concentrated culture of microalgae Chlorella vulgaris Beijer with a ratio of components by dry matter, wt. %: biosorbent 90-97, microalgae biomass Chlorella vulgaris Beijer 3-10. The advantage of the proposed biosorbent is that it effectively simultaneously sorbs and decomposes oil in the water column and in the mass of the sorbent, namely, when oil contaminates the water substrate to 15 g / l and more than 50% of the mass of the sorbent with an initial weight ratio of 1: 1 oil and biosorbent, as well as the destruction of toxic diesel oil products at a concentration of about 40% or 7 g / l, gasoline and kerosene fractions in the mass of contaminated sludge collector water at an initial weight ratio of oil products and biosorbent of 1: 2. The efficiency of cleaning the substrates from oil is achieved through the use of bacterial, yeast, and fungal consortium strains immobilized on a hydrophobic sorbent in the presence of green microalgae of the genus Chlorella and consists in reducing the oil content in the sorbent by 60-89% over 60 days. The disadvantage of this method is the need to clean the spent sorbent from the water surface after oil sorption, poor efficiency at low (less than 15-20 ° C) medium temperature, as well as the complexity and inconvenience of use, since it is necessary to prepare specific types of sorbents depending on the application.

The closest to the essence of the proposed is a bioremediation method for accelerated biological decomposition of oil hydrocarbons in the polar regions covered with sea ice, and a mixture of bacteria and enzymes as a means for implementing the method (Patent RU No. 2426698). A method for the biological decomposition of oil hydrocarbons in polar regions covered with sea ice involves contacting the oil hydrocarbons to be decomposed with an inoculum. Moreover, the inoculum contains a mixture of bacteria adapted to cold, consisting of at least the following strains: Rhodococcus GH-1 (DSM 18943, DSMZ 12/22/2006), Dietzia GH-2 (DSM 18944, DSMZ 12/22/2006), Shewanella GH-4 ( DSM 18946, DSMZ 12/22/2006), Marinobacter GH-9 (DSM 18951, DSMZ 12/22/2006), Pseudomonas GH-10 (DSM 18952, DSMZ 12/22/2006), Oleispira GH-11 (DSM 18953, DSMZ 12/22/2006) as well as nutrients and at least one environmentally friendly carrier on which at least the indicated bacterial strains intended for use are immobilized. The invention improves the efficiency of decomposition of oil hydrocarbons in the polar regions covered with sea ice. In the proposed bioremediation method, a mixture of several autochthonous bacterial strains adapted to cold is used. At the same time, the bacterial strains used adapted for cold vary in their temperature and salinity regions so that the bioremediation method is effective at all temperatures occurring in natural conditions. But all strains of bacteria in the mixture are united by the fact that they also still exhibit activity (decomposition or the formation of emulsifiers) at -3 ° C. The oil hydrocarbons to be decomposed are contacted with the inoculum in liquid form by pouring or spraying on sea ice and / or adding or pumping water under sea ice into a column of water. Carriers for microorganisms can be used in the form of: inorganic nutrients surrounded by a shell of fatty acid, balls of aramid polymer and activated carbon with a membrane shell, proteins forming fibers, fish meal surrounded by polysorbate 80, or sawdust. The disadvantage of this method is the high degree of dispersion of active biomass in the medium, as well as the limitation of the space of active destruction of oil pollution by the direct accumulation zone of autochthonous oil-oxidizing bacteria on the carrier, as well as the slow utilizability in the aqueous medium of the carrier.

The objective of the invention is to develop a method for efficient cleaning of oil and oil products from the surface of water, ice, ice sludge, water column, bottom sediments and the coastal zone of marine and brackish-water ecosystems in the temperature range from 0 to 25 ° C for industrial use, taking into account the characteristics of contaminated objects .

The technical result consists in optimizing the biodegradation of oil, including in aqueous media, at low, including ice, and normal temperatures through the use of a complex of natural psychrophilic oil-oxidizing microorganisms that produce biosurfactants that reduce the viscosity of oil and contribute to enhanced oil sorption in partially hydrophobic peat sorbent used as a carrier for oil-oxidizing microorganisms and their producers (biosurfactants), in which a buoyancy period is set, and ayuschiysya after the oil degradation process to safe for living organisms simple substances, thereby still not necessary to carry out cleaning and subsequent disposal and oil sorbent after processing oil-contaminated object.

The advantage of using natural psychrophilic oil-oxidizing microorganisms that produce biosurfactants, both individually and on a natural sorbent, is that accelerated destruction of oil occurs in any natural (natural) temperature range. When using a carrier (sorbent), the presence of biosurfactants produced by microorganisms inside biosorbents provides accelerated sorption of oil in the thickness of the sorbent at a time when the sorbent is still “afloat”. Depending on the conditions of use (surface of water, ice, water column, sediment, contaminated land and coastal zones of marine or brackish-water ecosystems), at the stage of biosorbent production, an appropriate consortium is selected for inoculation of the sorbent.

To clean marine and brackish water objects, the Soilin-S biological product is used, which, depending on the composition of the pollution, may include one strain or a consortium of psychrophilic halotolerant strains selected from a number of microorganisms:

- Pseudomonas azotoformans KM-161 CA (deposited in the All-Russian Collection of Microorganisms of the Institute of Biochemistry and Physiology of Microorganisms, number VKM В-2762D), can effectively oxidize oil hydrocarbons at low ambient temperatures (the temperature range for the oxidation of hydrocarbons is from 1 to 20 degrees Celsius) , has a high oil-oxidizing activity against naphthenic hydrocarbons, aromatic compounds of oil, is able to effectively reduce the concentration of hydrocarbons dissolved in water. Synthesizes a natural biosurfactant of the viscosine lipopeptide group in response to the presence of oil in the medium, thereby contributing to a decrease in its viscosity;

- strain Microbacterium species KM-251CO (deposited in the All-Russian collection of microorganisms of the Institute of Biochemistry and Physiology of Microorganisms, number VKM Ac-2615D), oxidizes paraffinic, resinous, heterocyclic and polyaromatic compounds of oil at low ambient temperature (from 2-4 degrees Celsius) to conditions of increased salinity of the medium, synthesizes trigazolipids in response to the presence of n-alkanes in the medium, contributing to a decrease in the viscosity of oil;

- strain Rhodococcus erythropolis KM-102CA.2 (deposited in the All-Russian collection of microorganisms of the Institute of Biochemistry and Physiology of Microorganisms, number VKM Ac-2613D), which, with water salinity up to 15-27 g / l in the temperature range from 2 to 25 ° C, destroys PAHs , paraffinic, heterocyclic oil compounds and reduces the concentration of hydrocarbons dissolved in water, synthesizes natural biosurfactants of the trigazolipid group of glycolipids in response to the presence of n-alkanes in the medium, contributing to a decrease in oil viscosity.

In the composition of the complex biological product Soilin-S, the ratio of any of the strains is equal to 1: 1 or 1: 1: 1, or 1: 1: 1: 1. The titer of cells in the finished product based on one or two or three or four of the above strains is not less than 10 ¹⁰ cells per 1 g.

Depending on the conditions of use, biological products are used separately or on a carrier in the form of a biosorbent containing a partially hydrophobic carrier with a given buoyancy period with strains immobilized in it. Separately, the use of biological products is optimal for purification of oil and dissolved hydrocarbons from small enclosed water bodies, and on a sorbent to remove oil pollution from the surface of ice, soil of the coastal zone, clean ice ice, to remove floating oil from the surface of water bodies, to purify the water column from dissolved hydrocarbons and ensuring the destruction of hydrocarbons in the mass of bottom sediments.

A peat sorbent with a predetermined buoyancy period from one to 48 hours is used as a carrier. A ready-made peat sorbent is used, the preparation technology of which is based on the reagentless hydrophobization of high peat by selective removal of hydrophilic groups of organic molecules and supramolecular associates resulting from pyrolysis (Tekhnosorb LLC, Kirovo-Chepetsk). Owing to a predetermined temperature and pyrolysis time, the sorbent acquires partial hydrophobicity and the ability to stay on the surface of a water body, which is necessary for effective cleaning of oil floating on the surface of a water body (specified buoyancy period from 1 hour to 2 days). Our use of peat sorbent was due to its ability to collapse in the natural environment to prohuminic components that are safe for the natural environment and are included in the further normal circulation of ecosystem substances.

The biosorbent is in contact with the pollution medium. On a surface filled with oil (ice, soil, water), the biosorbent is sprayed in one of two known ways - in dry form from a knapsack spray or in a directed stream of water from a motor pump. After contact of oil with a biosorbent containing psychrophilic oil-oxidizing microorganisms and biosurfactants, the process of oil sorption immediately begins, a biodegradation process takes place in the thickness of the sorbent, which continues until hydrocarbons are completely destroyed in the thickness of the sorbent at the bottom of the reservoir. Sorbed oil loses its ability to adhere to solid objects, which is important to reduce the risk of oil pollution getting onto the skin of aquatic inhabitants and birds, both on the water surface and on the coastal territory of contaminated objects. After spraying the biosorbent in the aquatic environment, part of the microorganisms enter the aqueous phase and help to reduce the mass fraction of hydrocarbons dissolved in the water, and after lowering the biosorbent to the bottom of the reservoir, the process of their multiplication continues, leading to the oxidation of oil in the mass of bottom sediments, which makes it possible to use it for cleaning bottom sediments from oil that had previously entered them. At the end of the process of oil destruction, the mass of oil-oxidizing microorganisms is reduced to background values, and the sorbent is destroyed to simple compounds.

Thus, the task of cleaning closed small bodies of water from oil and oil pollution is solved using biologics and biologics on a carrier, partially hydrophobic biosorbent with a predetermined buoyancy period, where a time factor is used to improve the efficiency of purification of aqueous media from floating oil depending on the temperature, and sorption of oil in the thickness of the biosorbent contributes to lowering the viscosity of oil natural biosurfactants released by microorganisms in biological products, which, in their essay ed, provide biodegradation of oil in the temperature range from 0 to 25 ° C both in the thickness of the sorbent and outside it. After oil sorption, the biosorbent does not need to be cleaned, it is deposited on the bottom of the reservoir, where the process of biodegradation of hydrocarbons is completed and the sorbent itself is destroyed to compounds that are safe for the natural environment.

Examples of the method

Example 1. The manufacture of biological products and biosorbents

At the stage of manufacturing biosorbents, biopreparations using liquid nutrient media are prepared separately by the deep fermentation method.

For strains of the Soilin-S preparation, a nutrient medium per 1000 ml of water is used - peptone 5 g, NaNO ₃ - 2.0 g; KH ₂ PO ₄ - 1.0 g; KCl - 0.5 g; MgSO ₄ × 5H ₂ O - 0.5 g; sucrose - 15.0; alkanes or diesel fuel - 10 g. For strains of the drug Soilin-P, 1000 ml of water are taken, g, NaNO ₃ - 3.0; KH ₂ PO ₄ - 1.0; KCl - 0.5; MgSO ₄ 5H ₂ O - 0.5; FeSO ₄ - 0.01; NaCl - 1.5; enzymatic peptone - 20.0; yeast extract (yeast autolysate) - 1.0; alkanes (or diesel) - 10.0. Each strain is produced separately and, depending on the required volume, there can be one, two or three stages of biomass production. The first stage is the production of the biomass of the strain from the test tube by seeding with a microbiological loop in flasks with a sterile medium, cultivation on a shaker at 15-25 ° C, 180-220 rpm, 3-5 days. The second - inoculum from flasks infect mini-fermenters (volume 100 l) with ready-made sterile nutrient medium - 3 days. The third - from mini-fermenters infect industrial fermenters with a volume of up to 60 m ³ with a ready-made sterile nutrient medium - 3 days. To prepare preparations without a carrier, after the production of a liquid form, separately grown strains are dried in the spray drying mode at a temperature of no more than 70 ° C, the finished mass is precipitated on diammoniphosphate and Packed in plastic bags of 1-10 kg. The titer of cells in dry preparations is 1-5 billion / cell per 1 g. The moisture content of the finished dried preparation should not exceed 20%. In this form, the preparations, provided there is no direct sunlight, can be stored at a temperature of 4-30 ° C while maintaining their properties for at least 3 years. Before using the biological products for their intended purpose, depending on the conditions of their use, equal amounts of dry biomass of individual strains are mixed and the amount of finished preparations necessary for the volume of the cleaned object is dissolved in water at the rate of 1 kg of dry biomass per 100 l of water. In the form of a solution, the preparations are introduced into a contaminated reservoir at the rate of 1 kg of dry biomass to remove 100 m ^{3 of} water from dissolved hydrocarbons.

In the manufacture of a biosorbent for given conditions, the biomass of microorganisms at the end of any of the fermentation stages required by product volume is infected by spraying a pre-prepared sorbent with a predetermined buoyancy period at the rate of 10 l of biomass with a cell titer of 10 billion / ml per 1 m ^{3 of} sorbent and dried flow of warm (not higher than 40 ° C) air to an air-dry state. The titer of living cells in dry biosorbent is at least 100 million cells per 1 g.

The use of biosorbents is carried out in solving the following problems of cleaning oil from ecosystems: cleaning the surface of water and / or cleaning the surface of ice, and / or cleaning water when ice is formed, and / or cleaning the coastal zone of contaminated objects, and / or cleaning bottom sediments.

Example 2. The oil intensity of biosorbents and the influence of biological products on the rate of sorption

The sorbent can be applied to the water surface in two ways: in dry form with a small (up to 100 m ² ) spill area using a knapsack spray and in a water stream using fire equipment with a significant area of oil pollution. The consumption of biosorbent depends on the area and thickness of the oil film on the surface. The oil capacity of the biosorbent is 400-700%, the consumption of the sorbent depends on the viscosity of the oil (table. 1):

The conglomerate formation time is from 1 minute to 10 minutes, the buoyancy period is set depending on temperature conditions from 1 hour to 2 days.

The time of oil sorption depending on the temperature of the environment when using biosorbents with the Soilin-S preparation for brackish water systems with a salinity of 17-25% is 5-7 times shorter than for sorbents without drugs. The viscosity of oil when it comes to biological products decreases at a temperature of 5-10 ° C from 150 to 30-50 cSt.

Example 3. Evaluation of the rate of purification of aqueous media at different ambient temperatures in the presence of Soilin-S biological product and biosorbents inoculated with them.

Laboratory tests were carried out (Table 2) of several modifications of the developed biosorbent, characterized by a buoyancy period (1 hour, 12 hours, 24 hours, 48 hours). As a control option, a sorbent without microbial mass was considered. Zero control was the option without the use of sorbents and microorganisms. The rate of oil decomposition was also tested in versions without sorbent in individual preparations. The experiment was carried out at temperatures of 10, 5, 0 degrees Celsius. The biosorbent with the Soilin-S complex was tested with water taken from a field test site in the Dry Sea region (a lagoon near the White Sea). The tested biologics included all recommended strains.

Thus, 15 options were tested in the experiment, each of them at three types of temperatures. In total, the experiment was conducted according to 45 options, differing in the temperature of the medium and the type of purification activation agent (table 3). In the experiment, the sorption rate of oil in variants with sorbents (sec), the time of sinking of the sorbent in variants with sorbents (hours), the dynamics of hydrocarbons dissolved in water in all variants (mg / dm ³ ), the rate of oil destruction in the mass of the recessed sorbent and in the mass were estimated oil in versions without sorbent (mg / kg).

Significant absorption of dissolved hydrocarbons by sterile sorbents (option 0-15) does not occur (Fig. 1 sorbent without microorganisms), while biosorbents enriched with microbial associations (options 16-27) show a high rate of release of dissolved hydrocarbons into the substrate, and subsequent destruction of oil in the sorbent and in water (tables 4, 5). Variants with the use of microbial mass without sorbents differed in the highest degree of destruction of dissolved hydrocarbons (variants 40-42). In this case, the initial concentration of dissolved hydrocarbons is significantly high, which is due to the strongest surface-active effect exerted on the oil substrate by biosurfactants of the preparations. In seawater, this effect is enhanced (options 40-42), which indicates a greater degree of interaction of sea water and biosurfactants. In part, this may also be due to the initially more alkaline reaction of the medium in seawater in comparison with the distillate. This should be borne in mind and taken into account when carrying out work on cleaning shallow and stagnant water bodies from oil, where the most optimal option is a simple treatment with biological products.

The same technique can be useful when cleaning water from barns and sludge collectors from dissolved hydrocarbons, as well as after purifying water from dissolved hydrocarbons in fire maps of drilling sites.

In case of massive oil spills, the nature and speed of the release and subsequent decomposition of hydrocarbons will be different, but the overall picture will remain. In natural reservoirs, especially flow type, the removal and dispersion of dissolved oil products is much faster, while the microbial destruction of oil in the thickness of the sorbent or on the surface of the water without a sorbent will determine the intensity of their decrease in water concentration.

The study of the decomposition rate of oil directly in experimental versions is especially important, since this is the main aspect for the feasibility of developing and further using the technology.

For the experiment, equal concentrations of oil in the options were used. This allows us to evaluate more realistically the behavior of oil pollution depending on the processing method than if we reduced the oil mass to equal values depending on its concentration only in the sorbed mass. The assessment is based on the total mass of pollution per unit volume of material. In our experiment for 1 g of sorbent we used 5 g of oil (the average value of the sorbing ability of the tested sorbents).

In sterile variants (zero control, sorbents without microorganisms), the destruction of the oil mass should not occur, we can only talk about the processes of physical purification of the medium - leaching of dissolved compounds, as well as the release of volatile components from the oil mass. But the latter will be of little importance due to the low temperature of the environment.

The results of evaluating the rate of oil destruction in the experimental variants are presented in table 5 and in FIG. 2-4. The first thing that attracts attention is that the water temperature determines the rate of the physical cleansing of water substrates from oil, but it is very small in sterile environments (zero control) and sorbents without microbial mass. The rate of oil absorption by sorbents without microorganisms and their drowning directly affects the intensity of physical purification of substrates: the lower the absorption rate, the lower the intensity of physical purification of aqueous media from hydrocarbons.

The conducted tests allowed us to draw the following conclusions to substantiate the elements of the developed technology in specific application conditions:

1. The rate of drowning of biosorbents affects the depth of the primary destruction of oil and the longer the sorbent is on the surface of the water, the more significant is the decomposition of oil;

2. The rate of sorbent drowning affects the rate of formation and subsequent decomposition of dissolved hydrocarbons - the higher the rate of oil adsorption into the sorbent mass and subsequent drowning, the faster the absorption of the oil component dissolved in water;

3. In the temperature range from 0 to 10 ° C, the rate of oil decomposition increases;

4. The destruction of the oil mass in a non-flowing medium without the use of sorbents is higher than with their use.

5. The decomposition of oil when using biosorbents in the marine environment occurs on the first day by an average of 55-60% at a temperature of 0 degrees, 60-70% at a temperature of up to 5 degrees, and 70-75% at a temperature of up to 10 degrees. After drowning within 40 days from the adsorption of the oil mass, the cleaning of sorbents from oil can occur under water by 90-95%;

6. The oxidation of oil by microbial mass in a non-flow system allows to reduce the concentration of hydrocarbons in the medium to 96-99% for 1.5 months.

Example 4. Evaluation of the effectiveness of water purification and bottom sediments from oil in the field experience.

A test of biosorbents was carried out for a brackish water reservoir in the summer. Used biosorbents with a buoyancy period of 1 hour. In experimental plots with a depth of up to 1.5 m, rigidly installed cages were placed in which the oil was poured with a layer of 1 cm. Then the cages were treated with biosorbents with the corresponding biological products - Soilin-S preparation was used for the brackish-water object.

The change in the parameters of water pollution and bottom sediments in the experimental freshwater reservoir is estimated in Table 6. Immediately after the start of the experiment, the level of hydrocarbons dissolved in water in the water inside the cages increased from 5 to 10 times from the initial values. However, after a day, the indicators changed and began to decline. Contamination of bottom sediments occurred to a small extent. As in water, the destruction of residual pollution was completed on the third day of the experiment.

Assessment of the structure of n-alkanes in samples of bottom sediments showed (Fig. 5) that, over 2 months of experience, there was a significant change in the composition of this fraction in samples of bottom sediments and a decrease in the total mass fraction of n-alkanes.

The experience with sea water was laid in the inland pond near the White Sea - in a shallow lagoon. For the experiment, cages with a diameter of 3 meters were made to limit the spread of the oil mass on the surface. The area of each cage was 7 m ² , 7 liters of oil were poured into each of them. The film layer on the surface of the water inside the cages was 1 cm. Water temperature 5-10 ° C.

Here we were able to visually and dynamically track the external parameters of the technology for cleaning the surface of the water with the help of sorbents quickly enough (within a few hours). First of all, attention was drawn to the fact that immediately after pollution in all cages, as well as outside them, stable rainbow films formed. After treating the water-contaminated surface of water with biosorbents, the iridescent films began to “tear” and disappeared after 3 hours. Re-sampling of water and bottom sediments was carried out 4 days after the experiment. The results are presented in table 7. As can be seen from the data presented, contamination with dissolved hydrocarbons was noted in water immediately after laying the experiment, the concentration in the water inside the cages increased by an average of 10 times. However, after 4 days, the parameters returned to normal. After 4 days, the level of contamination of bottom sediments also decreased to the initial values and did not exceed the background values.

The difference between this experimental site was not only increased salinity of the water (up to 15 g / l), but primarily a significantly lower water temperature, but this did not affect the rate of water purification from oil.

An analysis of the structure of the alkane fraction in the samples of bottom sediments of the brackish-water reservoir showed that after 2 months of experiment the total concentration of n-alkanes decreased by 9.5 times, while the structure of this fraction underwent significant changes, which were characterized by a sharp decrease in the composition of the fraction of hydrocarbon concentration with chain length C17-C21 and C23-C33 (Fig. 5).

Before and after the experiment, an assessment was made of the state of biota in the experimental reservoirs. In the species composition of the freshwater object before the experiment (in May), one month after the tests (in July) and 3 months (in September), small-worm worms - oligochaetes dominated. Their share in the sample was 75.3% in May. In July, during the period of mass development of insect larvae with an aquatic stage of development, the proportion of oligochaetes decreased to 54.5%, and in August, after the emergence of insects, the proportion of oligochaetes again returned to the state at the beginning of the growing season and amounted to 19.1%.

The total number of invertebrates in the lake at the end of the previous vegetation season before laying the experiment (6378 ind./m ² ) was comparable with that for the beginning of the vegetation season just before the experiment - 6360 ind./m ² . The dynamics of the abundance and species composition of invertebrates in the benthos of the lake during the growing season was typical of a small reservoir of northern latitudes. The effect of hydrocarbon introduction on a freshwater body of water was not noted in the composition and quantity of aquatic invertebrates. Similar results were obtained when assessing the ecological state of a brackish-water object on the coast of the White Sea: the dynamics of the abundance and species composition of invertebrates in the benthos of a shallow lagoon during the growing season was typical of a water body of northern latitudes, influenced by tidal phenomena. The effect of the introduction of hydrocarbons on the brackish water body was not noted in the composition and quantity of water invertebrates. This, in turn, indicates the absence of the negative impact of the spent biosorbent with oil deposited on the bottom of the reservoirs and its safety for the ecological state of the reservoirs in the process of ongoing biodegradation of oil in the thickness of the biosorbents.

Thus, the technical result of effective cleaning of the water surface, water column and bottom sediments from oil was obtained using partially hydrophobic biosorbents with a complex of oil-oxidizing cultures of psychrophilic microorganisms.

Example 5. Cleaning the surface of ice and ice sludge from oil on the example of an oil-contaminated area.

For the tests, a wetland area contaminated as a result of an accidental oil spill was selected, which is localized in the winter by clay mud. In the spring, after snow melted, a pond formed inside the dump, on the surface of which there was ice contaminated with oil, floating oil and ice sludge. The temperature of the water under the ice at the start of the test was 1-2 ° C. A layer of oil on the surface of ice and water is from 0.5 to 2 cm. Before the experiment, water and bottom soil samples were taken to determine the concentration of pollutants. The level of dissolved hydrocarbons in the water of the site was 18-20 mg / dm ³ , the concentration of chlorides was up to 7500 mg / dm ³ . Contamination of the bottom soil at different points of the site ranged from 80,000 to 460,000 mg / kg. The surface of the contaminated area was treated with a biosorbent inoculated with Soilin-S biological product with a buoyancy period of 48 hours. The area under cultivation is 2 hectares, the mass used for processing dry biosorbent is 100 kg. The treatment was carried out by mixing the finished sorbent with water in a receiving tank, where water from the same reservoir and sorbent were dosed, the suspensions were sprayed from the motor pump with a directed stream to the contaminated fragments of the site. In this case, the sorbent was mixed with oil on the ice surface and its adsorption into the sorbent mass. Sludge of ice, contaminated with oil, was impregnated with a floating sorbent, sorption of oil mass in the thickness of the sorbent took place in open areas of water. Half an hour after the treatment, almost all surface oil was absorbed into the mass of the introduced biosorbent. After 2 days, the sorbent settled to the bottom, and the ice and water on the site visually cleared of oil. At the same time, iridescent films also ceased to be fixed on the surface of the water. During the summer period, we regularly monitored the state of water and bottom soil of the experimental site. The measurement results are shown in Table 8. The water temperature of the site did not rise to more than 10 ° C during the summer season at the bottom of the reservoir until the end of summer, ice was faxed in places. The depth of the reservoir ranged from 1 to 2 m.

At the beginning of the observation period after treatment, with an increase in air temperature, an increase in the concentration of hydrocarbons dissolved in water was observed, which could be associated with a high concentration of oil in the mass of bottom sediments and the release of hydrocarbons into the water body. For 2 months from the start of the experiment, the level of hydrocarbons dissolved in water in the water of the site decreased 100 times, the bottom sediments were cleaned of oil by 90%.

Thus, the technical result of effective cleaning of oil from the ice surface, ice sludge, water and the mass of bottom sediments using biosorbents with a complex of salt-tolerant psychrophilic microorganisms as part of the Soilin-S complex biological product in the temperature range from 0 to 10 ° C in industrial conditions.

Claims (5)

1. The method of purification from oil and oil products of brackish-water and marine objects and ecosystems, comprising contacting the decomposable hydrocarbons with strains of oil-oxidizing microorganisms, characterized in that they use a biological product consisting of a mixture of oil-oxidizing strains of cultures of Pseudomonas azotoformans VKM B-2762D, Microbacterium species -2615D, Rhodococcus erythropolis VKM Ac-2613D, taken in the ratio 1: 1: 1, with a titer of cells in the finished preparation of at least 10 ¹⁰ cells per 1 g 2. The method according to p. 1, characterized in that for the purification of oil from water objects using a biological product immobilized on a partially hydrophobic carrier - peat sorbent. 3. The method according to p. 2, characterized in that for the cleaning of oil from the surface of ice and ice sludge at a temperature of from 0 to 10 ° C at water bodies use a biological product immobilized on a partially hydrophobic peat sorbent with a buoyancy period of 48 hours 4. The method according to p. 2, characterized in that for the purification of oil from the coastal zone of water bodies use a biological product immobilized on a partially hydrophobic peat sorbent with a buoyancy period of 1 hour 5. The method according to p. 2, characterized in that for the purification of oil from the bottom sediments of water bodies using a biological product immobilized on a partially hydrophobic peat sorbent with a buoyancy period of 12-24 hours

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