RU2113095C1 - Method for biological recultivation of soil contaminated with oil and deposit water - Google Patents

Abstract

FIELD: environmental control, in particular, oil industry and agriculture. SUBSTANCE: method involves staged cultivation of soil for 3 years; during the first year, soil is cultivated by ripping for 22-25 cm depth with following chiseling; during the second year, carrying out phytoreclamative practice such as planting of bushes and semishrubs; during the third year, planting bushes and semishrubs and seeding grasses. At the first year, sorbents are applied to soil surface prior to ripping. Upon sorbent application and ripping, soil washing is carried out by sprinkling with following plowing for 25-27 cm depth. Such method allows full sandy soil cleaning cycle to be conducted, blown sands to be strengthened and forest pastures to be restored on these sands by selecting most favorable combination of agricultural technical and phytoreclamative practice. EFFECT: increased efficiency in environmental control and improved quality of soil. 3 cl, 1 tbl

Description

 The invention relates to the protection of the environment, in particular to the biological reclamation of sandy lands contaminated with oil in conjunction with produced water in desert and semi-desert zones as a result of accidental release from wells or as a result of leaks from an oil pipeline or sump. It can be used in the oil industry and agriculture.

 A known method of biological reclamation of land RD 39-30-925-83. Ministry of the oil industry. VNIISPTneft. Guidelines for the biological reclamation of lands disturbed during the collection, preparation and transportation of oil, 1984. It is approved by order of the Ministry of the Oil Industry of 17.11.83 N 616 for a period of validity from 01.01.84 to 01.01.89. The method includes chemical soil reclamation, agrotechnical instructions for preserving moisture in the soil, applying organic and mineral fertilizers, sowing perennial grasses with seed rates.

 However, this method does not give positive results on sandy lands. In addition, the method does not have a clear, consistent technology for performing work in time, depending on the seasons, on the degree of contamination. As a result, the known method does not solve the problems of restoration of forest reclamation pastures contaminated with oil in conjunction with the formation waters of the sandy lands of deserts and semi-deserts.

 A known method of fixing movable sand (ed. St. N 279224), including applying to the surface of the site as a binder, certain doses of nerosine, followed by sowing the seeds of psammophytes. However, the high cost of nerosine, the use of aviation for its application, as well as the ability to harden at low temperatures create inconvenience in its use.

 A known method of fixing sand (ed. St. N 417102), including applying to the surface of the site as a binder of certain doses of cheaper Arlan oil, followed by sowing plant seeds.

 However, the use of aviation for applying oil makes the method of high cost.

 In addition, this method does not give positive results in oil fields, where there is a problem of cleaning sandy lands that excessive pollution of other oils, which negatively affects the growth of plants.

 The technical task of the invention is a more effective and accelerated biological degradation of hydrocarbons and the desalinization of contaminated lands with the displacement of excess salts from the root layer of the soil; consolidation of mobile sand in the oil fields.

 The technical problem is solved due to the fact that in the method of biological reclamation of sandy soil contaminated with oil together with produced water, including tillage, reclamation is carried out in stages for 3 years, and in the first year, the soil is cultivated by loosening to a depth of 22 - 25 cm s with subsequent chiseling, in the second year they carry out a phyto-reclamation event in the form of planting shrubs and shrubs, and in the third year they also plant shrubs, shrubs and sow grass, in the first year before loosening iem performed applying to the surface of the earth sorbent after application of sorbents and loosening carried sprinkling washing and plowing to a depth of 25 - 27 cm.

 After the first year of biological reclamation as a result of agrotechnical measures, the processes of physicochemical degradation of hydrocarbons in soil and soil are intensified and the most low molecular weight components — volatile and gaseous compounds — are removed from oil. Residual oil structures undergo biochemical oxidation. In addition, there is an intensive desalinization of land and liberation from water-soluble salts along the entire soil profile with the formation of slightly saline (residually saline) land differences. The salt concentration feeds 7 - 8 times in the upper horizon (0 - 50 cm) and 3 - 5 times in the lower horizon (50 - 100, 100 - 150 cm), the sodium content in the absorbing complex decreases to 15 - 18%.

 In the second year of biological reclamation, high zone temperatures and agrotechnical measures for planting shrubs and shrubs lead to biochemical transformations of methanonaphthenic and aromatic hydrocarbons and the accumulation of the naphthenoaromatic fraction in the residual oil, which serves as a food source for microorganisms. The root systems of shrubs contribute to the improvement of the agrophysical properties of sandy lands and the intensification of the process of biodegradation of hydrocarbons. The surge in microbiological activity of soil by the end of the second year is noticeably falling, the number of groups of microorganisms is approaching background values, with the exception of actinomycetes.

 Residual salt concentrations do not prevent the beginning of the fixation of mobile sands by salt tolerant plants. As a result of agrotechnical and phyto-reclamation measures, a geochemical situation is created in which the residual salts are displaced from the root layer, the sodium content decreases to 5 - 7%.

 After the third year of biological reclamation, polycyclic aromatic hydrocarbons resistant to microbiological processes are destroyed. The content of 3,4-benzpyrene in the biomass of herbs does not exceed the MPC. Almost complete displacement of sodium from the root layer is carried out. Microbiological processes are normalized and the natural reaction of soil solutions is restored over the entire root habitat profile of sandy lands. From a geobotanical point of view, the formation of grass stands and the growth of valuable fodder plants occur normally. The moving sands of the centers of deflation are sufficiently fixed by salt tolerant plants - phytomeliorants.

 This method is illustrated by a flow chart explaining the invention, made in the form of a table. In contaminated oil fields, the mobile sands that are formed are mainly represented by deflation foci (in the wells, sections within 1 hectare, through oil pipelines within 2 to 3 hectares), in which mainly the removal of soil destruction products by the wind takes place. Deflation foci can be located in desertification foci (areas up to 100 hectares, within which both removal and deposition of re-cultivated soil material are observed) of various ecological and morphological areas on the sandy lands of pastures belonging to different forest reclamation categories and types.

 The classification of the All-Russian Research Institute of Agroforestry includes 3 areas, 4 categories, 4 types.

 According to the ecological and morphological characteristics of sandy lands, the following areas are distinguished: 1 - destructive, which is located in the windward eastern part of the desertification zone and occupies up to 30% of the total area; 2 - destructive-accumulative, located in the middle part of the outbreak and occupies up to 55% of its area; 3 - accumulative, formed in the western part of the outbreak upon falling asleep with sand on a natural grass stand on zonal full-profile soil.

 Depending on the state of the soil and vegetation cover, four forest reclamation categories of pastures are distinguished: I - desertified areas with small and medium-sized sands and highly dispersed soils; II - pastures on medium-bore soils; III - pastures on soils pliable deflation; IV - pastures on soils resistant to deflation.

 Within the range of forest reclamation categories, forest reclamation types of pastures are distinguished, differing in the availability of created afforestation and perennial phreatophyte plants with physiologically accessible moisture, which is determined by the presence of additional sources of moisture: available, limited accessible groundwater, redistributed atmospheric precipitation.

Forest reclamation type “a” includes territories with fresh (mineralization less than 1 ha / l) groundwater, occurring at a depth of not more than 3–4 m (sand and pebble deposits, single-phase coarse-grained sands), 6–8 m (single-phase and layered fine-grained dust sands), 8 - 12 m (medium and fine grained with sandy loam and loam interlayers), 12 - 14 m (sandy loam and loam), if there are no screen horizons (solonetzic, saline, etc.) in the aeration zone. )
Land reclamation type “b” includes territories with limited accessible groundwater with a salinity of more than 1 g / l. The longevity and taxation indices of plantations decrease here as the salinity of groundwater increases, since their growth is accompanied by salinization of the rhizosphere.

 The forest reclamation type “c” includes gentle slopes, valleys, hollows and other areas where additional wetting is possible due to surface runoff in areas with no less than 80 days of snow cover. Under these conditions, the productivity and longevity of phytocenoses depend on the amount of redistributed precipitation.

 The forest reclamation type “g” includes all other varieties of pastures in territories that do not have additional sources of moisture. In these areas, with an average annual rainfall of less than 300 - 500 mm, deciduous tree plantations quickly thin out and often die at the age of 7 - 12 years. The same thing happens with shrub plantings with an average annual rainfall of less than 200 - 250 mm.

 The method is as follows.

 After an accidental release from wells or as a result of a leak from an oil sump, the boundaries of sandy soil pollution with oil together with produced water are established, and depending on this, a certain technological sequence of operations, type and sequence of agricultural and phyto-receptions are taken at certain stages of biological restoration of sandy lands.

1. If oil pollution, together with formation water of sandy lands to a weak degree, is 3 l / m ² , in the first year loosening to a depth of 22 - 25 cm is carried out, loosening to a depth of at least 22 cm and more than 25 cm will not optimally form a descending water salt a stream that removes readily soluble salts from the root layer and provides for the process of weathering of oil, evaporation, partial destruction of light fractions, photooxidation of oil components on the earth's surface, the development of oil-oxidizing microorganisms, chiseling is carried out after loosening After chiseling, loosening to a depth of less than 22 cm and more than 25 cm will not optimally provide an improvement in the water-air regime, restoration of microbiological communities and partially soil animals; after chiseling, loosening is carried out to a depth of 22 - 25 cm.

 In the second year of biological reclamation of sandy lands in destructive areas, planting is carried out with standard seedlings of shrubs and shrubs in early spring in March - April, in the autumn in November and early spring of next year, seedlings that are not planted are planted. Sand reinforcing plantations, which form the anti-erosion basis of the territory, are laid, oriented perpendicular to the direction of erosion winds, the row spacing is 6-8, m, the distance between seedlings is 1.5 m.

 In destructive-accumulative areas, taking into account the forest reclamation categories and types of pastures, bushes are planted by planting seedlings and cuttings seedlings in early spring in March - April, in the autumn in November and early spring of the next year, plants that have not taken root are planted. Plantations are laid in rows oriented perpendicular to the direction of erosion-hazardous winds. The row spacing is 4 - 6 m, the distance between plants in the row 1 - 1.5 m.

 In accumulative areas, taking into account the forest improvement categories and types of pastures, planting is carried out by cuttings seedlings taking into account deep planting in early spring in March - April, in the autumn in November and early spring of next year, plants that have not taken root are planted. Plantations are laid in rows oriented perpendicular to the direction of erosion-hazardous winds. The row spacing is 4–6 m, the distance between plants in the row is 1–1.5 m. Sand stabilization is usually achieved if at the end of the first vegetation of the shrub at least 1 thousand / ha of live bushes.

 In the third calendar year of the biological reclamation of sandy lands in early spring in March-April in all ecological and morphological areas, unplanted shrubs and semi-shrubs are planted with allowance for various forest reclamation categories and types of pastures. In parallel with the addition of shrubs and shrubs in their row-spacings, valuable forage grasses are sown for the formation of productive forest pastures, for example, Siberian wheatgrass, common thistle, gray wheatgrass, melilot, and others. In the rows of shrubs, the soil is prepared by plowing tapes 3 m wide to a depth of 27 - 30 cm and disking. Pure forage grasses should be alternated. Seeds are sown with grain seeders. The depth of seed placement is 1 - 2 cm, the sowing rate of cereals is 15 - 20 kg / ha, of barley 8 - 10 kg / ha, kiyak 5 - 6 kg / ha, and the remaining cultivated species are 8 - 12 kg / ha. In the second year, shrubs and shrubs are planted to clean the land and moving sands of the Dzhuzgun type, leafless, teresken gray, sandy raisins, branched tamariks, narrow-leaved goose, black wormwood, gray quinoa and others. In the second year of biological reclamation, residual salt concentrations do not prevent the beginning of the fixation of mobile sand by salt tolerant representatives of the vegetation cover. As a result of agrotechnical and phyto-reclamation measures, a geochemical situation is created in which the impact of remediation measures leads to the displacement of sodium from the absorption complex, its content decreases to 5 - 7%. The cultivation of salt-tolerant shrubs with a developed root system contributes to the structuring of soil, which creates certain conditions for microbiological activity and biological activity. In the third year, shrubs and shrubs are planted to clean the land and fix moving sands of the Dzhuzgun type, leafless gray, teresken gray, tamarix branched and sowing grasses such as Siberian horticulture, kiyak, thistle, blue grass, calf calf, clover, and others for pasture restoration.

2. If the contamination of the land is moderate, 15 l / m ² , the land is treated with sorbents in the first year, followed by loosening to a depth of 22 - 25 cm, then chiseling is carried out to a depth of 22 - 25 cm, followed by chemical ameliorants, and shrubs are planted in the second year and shrubs of the Dzhuzgun type, leafless, teresken gray, sandy sand, tamarisk branched, goose narrow-leaved, in the third year they plant shrubs and half-shrubs of the same ones as in the second year with sowing such herbs as Siberian grain, thistle, blue grass, donny to.

3. If the soil is heavily contaminated - 20 l / m ² in the first year, the land is treated with sorbents, followed by loosening to a depth of 22 - 25 cm and followed by monthly chiselling to a depth of 22 - 25 cm, then washed by sprinkling followed by application chemical meliorants and plowing to a depth of 25 - 27 cm, in the second year they plant shrubs and shrubs of the Dzhuzgun type leafless, teresken gray, sandy raspberry, tamarix branched, narrow-leaved goose, in the third year they plant the same ones as in the second year, the bush rnikov and dwarf shrubs with sowing of herbs like Siberian wheatgrass, prostrate summer cypress, dove wheat grass, clover.

 This method of biological reclamation of sandy lands contaminated with oil in conjunction with produced water to varying degrees accelerates the biological degradation of hydrocarbons and stratification of contaminated lands with the displacement of excess salts from the root layer of soil soils, fixing mobile sands in oil fields. The test results of the method at various geographical points of deserts and semi-deserts showed that over a three-year period, the contaminated territories are cleaned and a stable vegetation cover is formed.

 From a geobotanical point of view, the formation of grass stands and the growth of valuable fodder plants occur normally, the content of 3,4-benzpyrene in their biomass does not exceed the MPC. The moving sands of the deflation foci are sufficiently fixed by plants - phytomeliorants.

 On the mobile sands of oil fields fixed by shrubs, shrubs and valuable fodder grasses, the settlement of natural grassy vegetation begins 2–3 years after the stabilization of the bulk of the sandy substrate. In the ash sand and dust strip under shrubs and shrubs, grass seeds are contained, favorable conditions are created for the emergence of seedlings and plant life. Sand cover, kachim, scherda, jaundice, groundworms, common groundwort, ground reed dominate in the first years, and ephemera and ephemeroids in the next years.

 Thus, the period of biological reclamation of sandy soils contaminated with oil is three years, but the operation of forest pastures after this period is not allowed, since the full period of formation of forest pastures on moving sands from planting shrubs and shrubs and the beginning of controlled grazing in destructive areas of the desertification zone takes 4 - 5 years, in destructive-accumulative - 5 - 7 years, in accumulative - 8 - 10 years.

 Based on the foregoing, the use of the proposed method provides, in comparison with the known ones, a complete cycle of cleaning oil-contaminated sandy lands together with produced water of sandy lands, securing mobile sands and restoring forest reclamation pastures on them with an optimally selected combination of agrotechnical and phyto-reclamation measures.

Claims (3)

 1. The method of biological reclamation of sandy soil contaminated with oil in conjunction with produced water, including cultivating the land, characterized in that the reclamation is carried out in stages for 3 years and in the first year the cultivation is carried out by loosening to a depth of 22 - 25 cm, followed by chiseling, the second year they carry out phyto-reclamation measures in the form of plantings of shrubs and shrubs, and in the third year they also plant shrubs, shrubs and sow grass.  2. The method according to p. 1, characterized in that in the first year before loosening, sorbents are applied to the surface of the earth.  3. The method according to claim 2, characterized in that after applying the sorbents and loosening, washing is carried out by sprinkling and plowing to a depth of 25-27 cm.

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