RU2317162C1 - Preparation for microbiological treatment of oil slimes and ground polluted by petroleum products - Google Patents

Abstract

FIELD: oil pollution elimination.

SUBSTANCE: invention relates to microbiological cleaning of land in case of pollution with spilt crude oil and petroleum products, including oil slimes. Preparation contains sorbent "Ekolan", mineral fertilizers, water, and oil oxidizing microorganisms: strain Rhodococcus erythropolis BKM Ac-2271 D and/or Rhodococcus erythropolis BKM As-2017 D in concentration not less than 109 colonies per 1 g preparation.

EFFECT: enabled inexpensive high-efficiency microbiological in situ treatment of oil slimes and oil-polluted grounds.

2 cl, 4 dwg, 7 ex

Description

The invention relates to microbiological treatment of land during the spill of oil and oil products, including oil sludge.

Oil pollution and environmental oil products is an urgent environmental problem in the modern world. The production, transportation, processing and storage of hydrocarbons inevitably entails the leakage of significant amounts of toxic pollutant into the environment and its accumulation. The solution to this problem involves the use of the metabolic potential of oil-oxidizing microorganisms. Immobilization as a way of qualitative and quantitative modification of the properties of a biological agent is widely used in practice. Immobilized cells of oil-oxidizing microorganisms are more stable, have increased survival under adverse conditions, exhibit greater metabolic activity when proper conditions are created. In particular, the use of an adsorbent - a carrier of cells of oil-oxidizing microorganisms in the composition of the preparations used in purification, can increase the efficiency and expand the scope of the microbiological method for eliminating hydrocarbon contaminants. The combination of sorption and microbiological purification methods, based on the selection of the carrier - sorbent, as well as the immobilization conditions of cells of microorganisms - oil destructors, is the basis of the drug developed in the framework of this invention.

Known sorbent for the purification of natural water and soil from oil pollution "Moskat" (patent RU 2143947, IPC B09C 1/10), containing aluminosilicate carrier - heat-treated perlite or vermiculite, a microorganism Rhodococcus sp. 30, as well as ammonium nitrate and superphosphate.

Known biological product "Avalon" for cleaning environmental objects from oil and oil products (patent RU 2181701, IPC B09C 1/10). The biological product contains a porous carrier - foamed metaphosphates of variable composition and strains of oil-oxidizing microorganisms immobilized in the pores of the carrier and selected according to the type of contamination.

The disadvantage of the two aforementioned biological products is the use of an inorganic cell carrier, the chemical composition of which determines the impossibility of biological decomposition when cleaning oil pollution objects. The carrier introduced into the soil or soil thus becomes a source of secondary pollution.

More promising are the preparations, which include carriers based on natural organic materials.

Known biological product for purifying water, soil from oil and oil products "Lessorb - bio" (patent RU 2193533, IPC B09C 1/10), including aerobic oil-oxidizing bacteria, water and an organic substrate, which is used as a sorbent "Lessorb", which is a product processing plant material, such as peat.

The disadvantage of this biological product is the unprofitability of its production in regions remote from the locations of peat deposits, a natural source of raw materials for the production of cell carriers.

The closest to the claimed technical essence and the achieved effect is a biological product for purifying water and soil from oil and oil products (patent RU 2191753, IPC B09C 1/10), including aerobic oil-oxidizing bacteria, thiourea, sucrose and an organic substrate - the sorbent "Fezhel", which is a cellulosic carrier coated with a layer of sorbent substance.

The use of the prototype in situ is limited to the purification of oil-contaminated water and soil. To clean oil-contaminated soil, processing is carried out using expensive bioflotation in the reactor. In addition, the prototype is not used to clean oil sludge, i.e. its use is limited.

The objective of the present invention is to develop a cheap drug that provides highly effective microbiological treatment of oil sludge and oil-contaminated soil in situ.

The problem is solved using a bacterial preparation, including a cell carrier, cells of oil-oxidizing microorganisms and mineral fertilizer, and the sorbent "Ekolan" (TU 2164-001-55959238-01), which is a product of heat treatment of wood sawdust, is used as a cell carrier, in the following ratio components, wt.%:

sorbent "Ekolan" - 97-90%;

mineral fertilizers - 0.2-1.6%;

water is the rest.

oil-oxidizing microorganisms - not less than 10 ⁹ cells / g of the drug.

As an oil-oxidizing microorganism, the preparation contains Rhodococcus erythropolis BKM Ac-2271 or / and Rhodococcus erythropolis BKM Ac-2017 microorganisms selected according to the conditions of its use, deposited in the All-Russian collection of microorganisms. The nonpathogenicity of the strains was proved in an acute experiment on white mice. These microorganisms are highly active destructors of various petroleum products in a wide temperature range. They are capable of degradation of heavy oil products included in oil sludge, inaccessible to most oil-oxidizing microorganisms. The number of viable microorganisms is sufficient for the effective use of the drug. A distinctive feature of the prototype is the use of the sorbent "Ekolan". All used oil-oxidizing microorganisms have the ability to adhere to the sorbent "Ekolan". The effectiveness of the drug is due to the strains included in its composition and the use of a new carrier - the Ekolan sorbent, taken in the indicated ratio. To provide microorganisms with nutrients in the initial stages of purification with the claimed preparation, mineral fertilizers were used (ammophos or diammofoska or nitrophoska or nitroammofoska). All of these fertilizers can be used by microorganisms included in the biological product to build up biomass. Biological product consumption - not less than 1 kg per ton of cleaned soil. For purification, biological preparations with microorganisms Rhodococcus erythropolis BKM Ac-2271 or Rhodococcus erythropolis BKM Ac-2017, or taken in a ratio of 1: 1, respectively, can be used as a biological product.

Figure 1 shows the decrease in the concentration of petroleum products in oil-contaminated soil during microbiological treatment using a preparation based on the strain Rhodococcus erythropolis BKM Ac-2271. Figure 2 is a decrease in the concentration of oil products in oil-contaminated soil during microbiological treatment using a preparation based on two strains - Rhodococcus erythropolis BKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017, containing 0.2 wt.% Of mineral fertilizers. Figure 3 shows the decrease in the concentration of oil products in oil-contaminated soil during microbiological treatment using a preparation based on two strains - Rhodococcus erythropolis BKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017, containing 1.6 wt.% Mineral fertilizers. Figure 4 shows a decrease in the concentration of oil products in oil sludge with soil as a result of treatment with a preparation based on two strains - Rhodococcus erythropolis BKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017, containing 0.2 wt.% Of mineral fertilizers.

Example 1. Getting the drug. The biomass of cells of each microorganism - Rhodococcus erythropolis BKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017 was grown separately by deep cultivation in a liquid mineral medium with diesel fuel while monitoring and observing the optimal cultivation parameters. Ammophos mineral fertilizer in a concentration of 0.2% was added to 5 l of a suspension of cells of oil-oxidizing microorganisms concentrated up to 10 g / l asb and mixed with 1 kg of dry sorbent "Ekolan". In addition, trivalent 12-aqueous aluminum chloride was added at a concentration of 0.6327 g / liter to ensure adhesion of a larger number of cells on the support.

Or, in relative units of measurement (wt.%), The initial components were taken in the following ratio:

sorbent "Ekolan" - 97%;

Ammophos mineral fertilizer - 0.2%;

trivalent aluminum chloride 12-water - 0.013%;

water is the rest.

After one hour of immobilization, each mixture was discarded on a sieve (metal mesh with a hole diameter of 1 mm). Wet sorbents were placed in a thin layer on a plastic film and dried under normal conditions to an air-dry state. The resulting dry preparations contain more than 10 ⁹ cells / g of oil-oxidizing microorganisms and are ready for use for cleaning soils contaminated with oil products and oil sludge.

Example 2. Getting the drug. The oil-oxidizing microorganisms of each strain were grown as described in Example 1. Then, ammophos fertilizer at a concentration of 1.6% was added to a suspension of cells concentrated to 10 g / l ASV to provide microorganisms with nutrients in the initial stages of purification, as well as trivalent aluminum chloride 12-water at a concentration of 1.23 g / l to ensure adhesion of more cells on the carrier. The concentrated suspension was mixed with the Ekolan sorbent in a ratio of 5: 1 by weight, mixed, incubated for 1 h and discarded on a sieve with a hole diameter of 1 mm.

Or, in relative units of measurement (wt.%), The initial components were taken in the ratio:

sorbent "Ekolan" - 90%;

Ammophos mineral fertilizer - 1.6%;

trivalent aluminum chloride 12-water - 0.025%;

water is the rest.

Wet sorbents were dried to a moisture content of less than 10% and used to clean oil sludges and soils contaminated with oil products.

Example 3. In 1 ton of oil-contaminated soil placed on a concrete surface with a layer of 0.3 m, 1 kg of the preparation prepared in Example 1 was added. Rhodococcus erythropolis BKM Ac-2271 was used as an oil-oxidizing microorganism. They were mixed, the soil was moistened up to 60% of the maximum moisture capacity, ammophos was added in an amount of 500 g. The cleaned soil was regularly (1 time in 2 weeks) mixed, the moisture and concentration of nutrients were measured and maintained at the initial level. The concentration of residual oil products was measured after one and a half and three months of the experiment. The test results are shown in figure 1. For 3 months of the experiment, the concentration of petroleum products during the treatment with the drug decreased from 23.7 to 4.71 g / kg, the degree of purification was 80.1%.

Example 4. In May 2005, 11 tons of oil-contaminated soil from the territory of CJSC KNPZ "KEN" were placed on concrete sites. A preparation was made into the soil, consisting of preparations prepared in Example 1 with oil-oxidizing microorganisms Rhodococcus erythropolis BKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017, taken in a 1: 1 ratio, at the rate of 1 kg / t of soil. They were mixed, the humidity was maintained at the level of 60% of the maximum moisture capacity, and fertilizers from the series - ammophos, nitroammophosk, diammofosk - were calculated at the rate of 100 g / t of contaminated soil. Fertilizer treatments, moistening, and loosening were carried out 3 times a month. A decrease in the concentration of petroleum products in oil-contaminated soil is shown in figure 2. The final concentration of petroleum products did not exceed 2.00 g / kg, while in the untreated section, the concentration remained equal to 37 g / kg. Thus, as a result of processing, the cleaning efficiency for 2.5 months was more than 94%. The effectiveness of the proposed drug in the cleaning of oil-contaminated soil turned out to be no less than that of the prototype and at the same time did not require treatment of the cleaned mass in a flotation unit, which made the bioremediation process cheaper.

Example 5. In September 2005, 14 tons of oil-contaminated soil from the territory of ZAO KNPZ "KEN" were placed on concrete pads. A preparation was introduced into the soil, consisting of preparations prepared in Example 2 with oil oxidizing microorganisms Rhodococcus erythropolis VKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017, taken in a 1: 1 ratio, based on 1 kg / t of soil. They were mixed, the humidity was maintained at the level of 60% of the maximum moisture capacity, during each treatment fertilizer was introduced from the series - ammophos, nitroammophosk, diammofosk - at the rate of 100 g / t of contaminated soil. Fertilizer treatments, moistening, and loosening were carried out 3 times a month. A decrease in the concentration of petroleum products in oil-contaminated soil is shown in figure 3. The final concentration of petroleum products in the soil was 2.97 g / kg. Thus, the cleaning efficiency was 89%.

Example 6. Tests of the drug were carried out from March to September 2005 on the basis of Ecobio LLC. Oil sludge mixed with soil was placed on the concrete site. A preparation consisting of preparations prepared in Example 1 with oil-oxidizing microorganisms Rhodococcus erythropolis BKM Ac-2271 and Rhodococcus erythropolis BKM Ac-2017, taken in a 1: 1 ratio, at a rate of 1 kg / ton of soil, as well as ammophos from calculation of 500 g / t, humidification and mixing were carried out. Ammophosome treatments, wetting and loosening were repeated 3 times a month. Figure 4 shows a decrease in the concentration of petroleum products in the treated soil. As a result of treatment with the drug, the concentration of petroleum products decreased from 318.6 to 47.3 g / kg, which shows the possibility and effectiveness of using the drug to clean oil sludge.

Example 7. In 2 cups per 400 ml, 200 g of a mixture of oil sludge and soil were added, with a petroleum product content of 98 g / kg, 0.2 g of the preparation prepared in Example 1 with an oil-oxidizing microorganism Rhodococcus erythropolis BKM Ac-2271 was added to one. Oil oxidizing microorganisms were not added to the second glass. Water was added to both glasses to 60% of the total moisture capacity and ammophos in an amount of 0.1 g. The soil to be cleaned was regularly mixed, the humidity and concentration of nutrients were measured and maintained at the initial level. After 6 months of purification, the degree of destruction of hydrocarbons at their initial concentration of 98 g / kg was 55%. In a glass, where oil-oxidizing microorganisms did not contribute, the decrease in concentration did not exceed 3%.

The use of the preparation according to the invention allows for low-cost, highly effective microbiological in situ cleaning of oil sludge and oil contaminated soils resulting both from accidental spills and from the production activities of oil producing and oil refining enterprises.

Claims (2)

1. A preparation for microbiological purification of oil sludge and soil contaminated with oil products, including a cell carrier, cells of oil-oxidizing microorganisms and mineral fertilizer, characterized in that the carrier used is the sorbent "Ekolan", which is a product of heat treatment of sawdust, and taken as oil-oxidizing microorganisms Rhodococcus erythropolis VKM Ac-2271 D and / or Rhodococcus erythropolis VKM Ac-2017 D, in the following ratio of components, wt.%: sorbent "Ekolan" 90-97% mineral fertilizers 0.2-1.6% water rest oil-oxidizing microorganisms not less than 10 ⁹ cells / g of the drug 2. The drug according to claim 1, characterized in that the oil-oxidizing microorganisms are taken in a ratio of 1: 1.

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