RU2113093C1 - Method for biological recultivation of oil contaminated sandy soil in desert and near desert zones - Google Patents

Abstract

FIELD: environment control, in particular, oil industry and agriculture, equipment for restoration of forest pastures in oil fields. SUBSTANCE: method involves performing biological recultivation of sandy lands with low, average and high oil contamination extent, with recultivation being conducted in stage-by-stage way for 3 years; during the first year, ripping soil for 22-25 cm depth; chiseling for the same depth with following snow fencing; during the second year, carrying out phytoreclamative practice such as planting of bushes and subshrubs; during the third year, planting bushes and seeding grasses. Prior to ripping, sorbents are applied to soil surface. Upon applying sorbents, chiseling is conducted every month till October. EFFECT: increased efficiency in sandy soil recultivation and simplified method. 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 desert and semi-desert zones, and can be used in the oil industry in agriculture for restoration on oil-field forest reclamation pastures.

 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 nerosin, followed by sowing the seeds of psammophytes. However, the high cost of nerosin, the use of aviation for its application, as well as the ability to solidify at low temperatures create inconvenience in its use, in addition, this method does not solve the other side of the problem, namely the cleaning of sandy lands from oil pollution.

 There is also known a method of fixing movable 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 of plant seeds. However, the use of aviation for applying oil makes the method still with a high cost. In addition, this method is unacceptable in oil fields, where there is a problem of cleaning sandy lands from excessive pollution of other oils, which negatively affects the growth of plants. Closest to the proposed solution is a method of biological land reclamation in the steppe and forest-steppe zones. RD 39-30-925-83. Ministry of Oil Industry VNIISPTneft. Guidelines for the biological reclamation of lands disturbed during the collection, preparation and transportation of oil in 1984. Approved by order of the Ministry of Oil Industry dated 17.11.83 N 616 for a period up to 1.01.89. 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 is recommended for steppe and dry steppe zones on prevailing dark chestnut and meadow chestnut soils and cannot be used to clean sandy soils from oil.

 The technical task of the invention is a more efficient and accelerated biological degradation of hydrocarbons and the consolidation of sand in the oil field.

 The stated technical problem is solved due to the fact that in the method of biological reclamation of sandy lands contaminated with oil in desert and semi-desert zones, including land cultivation, reclamation is carried out in stages for 3 years, and in the first year, the soil is cultivated by cultivating to a depth of 22-25 see, then chiseling to the same depth, followed by snow retention, in the second year they carry out phytomeliorative measures in the form of planting shrubs and shrubs, in the third year they also plant shrubs and floors shrubs and sow grass, before loosening, they apply sorbents to the surface of the earth, after applying sorbents, chisel is carried out monthly until October.

 This method is illustrated by the technological scheme, reflecting the essence of the invention, made in the form of tables.

 The method is as follows. Immediately after the accidental spill, oil is liquidated from the surface of sandy lands using special equipment, sorbents and pumps. In polluted oil fields, sandy lands in the form of moving sands are mainly represented by deflation foci (in the wells, sections within 1 hectare, through oil pipelines within 2-3 hectares), in which the products of soil destruction are removed by the wind. Foci of deflation can be located in foci of desertification (areas up to 100 ha, within which both removal and deposition of digested 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 features 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, is located in the middle part of the center 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 degree of contamination of sandy lands, a certain technological sequence of agrotechnical, phytomeliorative measures, their sequence in time and seasons, planting shrubs and shrubs for fixing movable sands and sowing valuable forage grasses are used, taking into account different categories of land reclamation and types of pastures.

If contaminated land sand oil with a slight degree - 3 l / m ² on the first calendar year at a depth loosening 22 - 25 cm immediately after the land pollution and after the elimination of oil from the surface of the land if the operation starting in winter. Loosening to a depth of less than 22 cm and more than 25 cm will not optimally support the weathering of oil, evaporation, partial destruction of light fractions, photooxidation of oil components on the earth's surface, and the development of oil-oxidizing microorganisms. 2 months after loosening, if the work starts in the spring and summer, a month later, if the work starts in the fall and in June, if the work starts in the winter, chisel is carried out to a depth of 22 - 25 cm. Chisel to a depth of less than 22 cm and more than 25 cm will not optimally ensure the improvement of the water-air regime, the restoration of microbiological communities and partially soil animals. After chiselization during the winter, in the presence of snow, snow retention is carried out.

 In the second calendar year, phyto-land reclamation measures are carried out to clean the land with the simultaneous fixing of moving sands by planting bushes and shrubs of the Dzhuzgun type, leafless, teresken gray, sandy raspberry, tamarisk branched, goose narrow-leaved, white wormwood, gray quinoa, tree-like karagan.

 Four forest reclamation categories of pastures are distinguished, differing by the state of the soil and vegetation cover: 1 — desertified territories with small- and medium-sized sands and highly developed soils, 2 — pastures on medium-developed soils, 3 — pastures on soils, pliable deflation, 4 — pastures soils resistant to deflation.

 Within the range of forest reclamation categories, forest reclamation types of pastures are distinguished, differing in the supply of forest stands and perennial plants - phreatophytes with physiologically accessible moisture, which is determined by the presence of additional sources of moisture - available, limited groundwater and redistributed atmospheric precipitation.

 Forest reclamation type “a” includes territories with fresh (mineralization of less than 1 g / 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, loam), if there are no screen (alkaline, saline, etc. horizons (solonetz, salt, 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 a number of days with a snow cover of at least 80. The productivity and durability of phytocenoses under these conditions depends on the amount of redistributed precipitation.

 The forest reclamation type “g” includes all other varieties of pasture areas 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.

 In the second year of biological reclamation of sandy lands in destructive areas, planting is carried out only with standard seedlings of shrubs and shrubs in early spring in March - April, in the autumn in November and early spring of next year, unplanted seedlings are planted. Sand-strengthening plantations, which constitute the anti-erosion basis of the territory, are laid in rows oriented perpendicular to the direction of erosion winds, the row spacing is 6-8 m, the distance between seedlings is 1.5 m. plantings of seedlings and cuttings of seedlings in early spring in March - April, in autumn in November and early spring of next year, unplanted seedlings (plants) 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 the plants in the row is 1–1.5 m. In accumulative areas, taking into account forest reclamation categories and types of pastures, planting is carried out by cuttings by deep planting in early spring in March - April, autumn in November and early spring of the following years planted unplanted plants. Plantations are laid in rows oriented perpendicular to the direction of erosion-hazardous winds. The row spacing is 4–6 mm, 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 biological reclamation of sandy lands in early spring in March - April, in all ecological and morphological areas, unplanted shrubs and shrubs are planted with allowance for various forest reclamation categories and types of pastures. In parallel with the addition of shrubs and shrubs and their row-spacings to form productive forest pastures, valuable forage grasses are sown, for example Siberian wheatgrass, bluegrass 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-grass 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 rest of cultivated species - 8 - 12 kg / ha.

If contaminated land in the average degree - 15 l / m ² for the first year calendar treatment is conducted lands sorbents after the contamination of land and then carried loosening to the depth of 22 - 25 cm, followed chizelivaniem a depth 22 - 25 cm every month until October when the early work in the spring and in the summer, after loosening at the beginning of work in the fall and monthly until October, if work begins in winter, then re-loosening to a depth of 22 - 25 cm in October.

 In the second calendar year, shrubs and shrubs are planted, in the third calendar year of biological reclamation of sandy lands, shrubs are planted and valuable forage grasses are planted.

If contaminated land at great degree - 30 l / m ² on the first calendar year produce refinement sorbents land immediately after contamination of land with subsequent loosening to the depth of 22 - 25 cm at the beginning of the work in the spring and summer, in April - at the start of work in winter, is then carried out chiseling to a depth of 22 - 25 cm monthly until October when starting work in the spring and summer, after loosening - when starting work in the fall, monthly until October when starting work in the winter, then loosening to a depth of 22 - 25 cm, in October in the second year they plant shrubs and half-shrub In the third year of planting shrubs and produce crop of forage grasses. After agrotechnical processing of contaminated lands during the first calendar year, there is no intensive formation of foci of deflation. At this stage, there is an intensification of the processes of physico-chemical degradation of hydrocarbons in soils and the removal of the most low molecular weight components of oil - volatile and gaseous compounds. By the end of the first year, biochemical oxidation of residual oil structures occurs.

 In the second calendar year, 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 is a food source for microorganisms. The root systems of shrubs and shrubs contribute to the improvement of the agrophysical properties of sandy lands and the intensification of the process of biodegradation of hydrocarbons. A surge in the microbiological activity of soil by the end of the second year drops markedly, the number of groups of microorganisms approaches the background indicators, with the exception of actinomycetes.

 In the third calendar year, agro-technical and phyto-reclamation measures determine the destruction of polycyclic aromatic hydrocarbons that are resistant to microbiological processes. From a geobotanical point of view, the formation of grass stands and the growth of valuable fodder plants are normal, 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 to the start of controlled grazing in destructive areas of desertification foci 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, fixing mobile sands and restoring forest reclamation pastures on them with an optimally selected combination of agrotechnical and phytomeliorative measures.

Claims (3)

 1. A method for the biological reclamation of sandy lands contaminated with oil in desert and semi-desert zones, including cultivating the land, characterized in that the reclamation is carried out in stages over 3 years and in the first year the land is cultivated by loosening to a depth of 25 - 25 cm, then chiseling on the same depth, followed by snow retention, in the second year they carry out phytomeliorative measures in the form of planting shrubs and shrubs, in the third year they also plant shrubs, shrubs and sow grass.  2. The method according to claim 1, characterized in that 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, the chiseling is carried out monthly until October.

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