RU2217246C2 - Method of cleaning and re-cultivation of soils contaminated with oil and petroleum products - Google Patents

Abstract

FIELD: microbiological cleaning and re-cultivation of soils contaminated with oil and petroleum products. SUBSTANCE: proposed includes treatment of soil with compound containing oil-refining bacteria together with biodegradable agents of the following trophic level - earthworms. Process of motion and propagation of bacteria is accelerated due to transfer of microbiological compounds over perimeter and in depth by earthworms, thus facilitating access of oxygen to deep layers of soil contaminated with oil. Proposed method ensures activation of destruction of oil contamination promoting re-cultivation of soils due to forming bio-humus and improving structure of soils. EFFECT: enhanced efficiency. 1 dwg, 2 tbl

Description

 The invention relates to the field of biotechnology, and in particular to methods for cleaning soils from oil pollution.

 In case of emergency oil spills in the soil, biota vital activity is largely suppressed (1,2). Of extreme relevance is the problem of reclamation of oil-contaminated soils (3). However, significant successes in the practice of reclamation of oil-contaminated soils, unfortunately, have not yet been recorded (4). Currently, the use of microorganisms introduced into the soil is considered the most advanced technology for cleaning oil-contaminated soils (4). In this case, microorganisms are able to destroy the upper layer of oil pollution (15-20 cm). Thanks to our joint use of biodestructors of two trophic levels - bacterial preparations and earthworms, lower layers of oil pollution are destroyed (to a depth of 60-70 cm), the quality and quantity of oil destruction have improved from 30 to 50% for the same exposure time, and notable successes in restoration have been achieved .

 Known methods using strains of fungi, actinomycetes, bacteria that can destroy oil and oil products in soils, however, the use of these strains for the purpose of purification does not solve the problem of reclamation and the possibility of transformation is also limited.

 A known strain of Pseudomonas aeruginosa PAO containing plasmids CAM, OST, NAH, SAL, controlling the utilization of hydrocarbons used for microbiological degradation of oil and oil products (5).

 A known Actinomyces flavus actinomycete strain with the ability to absorb oil hydrocarbons (6).

 A known strain of Pseudomonas putida 36 is used to clean water and soil from oil and oil products (7).

 A disadvantage of the known strains and microbiological preparations is the selective effect on certain fractions of petroleum products, they only destroy the upper layers of oil pollution and are not able to process the lower layers, and are also not able to rehabilitate the soil.

 To eliminate these drawbacks, it is proposed to treat the soil with preparations containing oil refining bacteria together with biodestructors of the next trophic level - earthworms. This activates the destruction of oil pollution by microflora, and also contributes to soil remediation and favors the formation of biohumus worms during life activity, which is a highly effective organo-mineral fertilizer and an agent that improves structure (8). Using an electronic spectrophotometer, the oil content was determined before and after processing.

 The drawing shows a diagram of the appearance of caprolites (vermicompost) on the surface, which are an indicator of soil quality.

 Example. A layer of oil-contaminated soil with a thickness of 50 mm is placed in cages measuring 180 mm - 120 mm - 60 mm. The oil content is pre-measured. Putidul bacterial preparation was placed in one series of cages, earthworms in another, and Putidul together with earthworms in the third series of cages. Oil-contaminated soil that was not processed was used as a control. Check the oil content after 24 hours.

 As can be seen from table 1, bacterial preparations did not allow to reduce the oil content by more than 33.9%, earthworms reduced the oil content by 14.3%, and the combined use of bacterial preparations and earthworms allowed to reduce the oil content by more than 51.8 %

 To confirm that bacterial preparations and earthworms, when used together, reduce the toxicity of oil pollution and soil remediation, biotesting of seed germination media was carried out (9).

 Based on the data in Table 2, it can be said that treatment of oil-contaminated soil with bacterial preparations and earthworms together leads to a maximum decrease in the inhibitory effect of pollutants on germination of plant seeds after 40 days.

 For soil treated with earthworms, the number of sprouted seeds increased 2 times, the average root length was 11%. For the soil treated with bacterial preparations, this indicator remained at the same level and amounted to 17%, and the average root length of the germinated seeds was 49.5%. The maximum amount (81.6%) of germinated seeds was found in an extract from the soil, in which there was a joint use of biodestructors. The average root length of the germinated seeds in this case was 88%.

Sources of information
1. Guzev BC, Levin S.V., Seletsky G.I. n. Role of Soil Mncrobiota in the Reclamation of Oil-Contaminated Soils.- M.: Microorganisms and Soil Protection. Ch. 4.- Ed. D.G. Zvyagintseva, 1989, p. 129-150.

 2. Buzmakov S.A., Ladygin I.V. On the influence of oil fields on the flora and fauna of the Kama Urals. - Geoecol. aspects of management, health and recreation. Thes. doc. instead of scientific conf. Perm, May, 1993. Part 1. Perm, pp. 201-205.

 3. Chen S.T. 1992. Understanding the fete of petroleum hydrocarbons in the subsurfase environment. - J. Chem. Educ. 69, 5, 357-361.

 4. Halimov E.M., Levin S.V., Guzev B.C. Ecological and microbiological aspects of the damaging effect of oil on soil properties - News. Mosk. un-that. Ser. 17. Soil science. 1996.2, p. 59-64.

 5. US patent 3813316, cl. 195-28, published. 1974.

 6. Copyright certificate of the USSR 250849, cl. C 12 N 1/20, 1968.

 7. A.S. 1076446 USSR. The strain Pseudomonas Putida 36, used to purify water and soil from oil and oil products / V.N.Dyachenko, L.E. Tolstokorova, T.N. Morozova // Invention .-1984.- 8, - p. 4.

 8. Igonin A. M. How to increase soil fertility tenfold using earthworms. - M: Information and Implementation Center "Marketing", 1995, - p.22-25.

 9. The combined report of the CMEA member countries on the topic of March 7, 2005. Budapest, 1975, p. 2-4.

Claims (1)

The method of cleaning and reclamation of soils contaminated with oil and oil products, characterized in that the soil is treated with preparations containing oil refining bacteria together with biodestructors of the next trophic level - earthworms.

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