RU2331488C1 - Method of reclamation of soil contaminated by oil and oil product and facility system for its implementation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method involves soil dyke-type bunding along the contamination contour. Both inside and outside the bunded area trenches are made and filled with a sorbent waste of activated coal production of 0.1-5.0 mm fraction with negative and/or positive floatability. Inside the bunding the trenches are filled with sorbent with both negative and positive floatability, while outside the bunding the trenches are filled with sorbent with negative floatability only. Reference wells are made along the ground water course. The facility system for the method implementation includes dyke-type bunding of oil spill area and a number of trenches inside and outside the bunded area filled with sorbent with both negative and positive floatability. Reference wells are located along the ground water course.

EFFECT: streamlined soil reclamation and waste recycling process.

2 cl, 3 dwg

Description

Technical field

The invention relates to environmental protection and can be used for cleaning soil contaminated with oil and oil products.

State of the art

During the extraction, processing and storage of oil and oil products spill and pollute soil, surface and groundwater. To protect against environmental pollution in the fields, an embankment of the production site is done, which localizes oil pollution, but does not exclude it (Pat. RF No. 2182215, IPC ЕВВ 21/01, bull. No. 13, 2002).

Known is an improved method for removing harmful substances from the soil, mainly oil and its derivatives, using aqueous extractants (US Pat. Germany No. 3738264, IPC A62D 3/00 ony6l.30.03.03).

According to this method, an extractant containing sodium pyrophosphate or sodium oxalate with a concentration of 0.1-1.0% is used to extract harmful impurities. Contaminated soil is isolated with watertight partitions, and the extractant is piped into the soil. The volume of extractant 50-100 l / m ² soil per day. Then carry out the removal of the extractant by pumping. In another embodiment, the extractant is applied to the surface of the soil by spraying. Over time, the extractant seeps into the lower layers of the isolated area, and then is pumped out as an extract. This method requires equipment for pumping and pumping mortar, pipes, partitions to isolate the contaminated area, etc. All this significantly increases the cost of cleaning. In addition, the consumption of extractant for tillage is very high. In the description of the patent, as an example, the results of processing the soil with a low degree of pollution - 1 g / kg of soil (0.1%). Therefore, the question arises of the lack of effectiveness of this method with high soil contamination.

The closest in technical essence and the achieved result to the proposed technical solution is a method for cleaning soil contaminated with oil or oil products (US Pat. RF No. 2071671, IPC V09C 1/00, publ. 10.01.1997) by washing them with water, collecting oil or oil product . Before washing the oil in the soil mass along the contour of its pollution from the level of the aquifer, an ice-ground wall is frozen with an embankment on the surface, while the washing out of the oil is carried out by pumping water into the underlying aquifer through injection wells until the level of ground water with oil and oil products rises to the day surface . The leaching of oil from the soil is carried out by pumping water with the addition of surfactants. The washing out of oil from the soil is carried out by its vibration. The collection of oil or oil product from the soil surface is carried out by pumping or sorption. After collecting oil and oil products, the soil surface is treated with a strain of oil refining microorganisms and mineral fertilizers during aeration of the soil mass with air supplied through staggered blow-out wells.

The disadvantages of the prototype method are the technological complexity and significant costs for its implementation.

The objective of the invention is to simplify the process of cleaning contaminated with oil and oil products soil, as well as the possibility of using wastes from the production of activated carbon in order to protect the environment.

The problem is solved using the signs specified in paragraph 1 of the claims common to the prototype, such as a method for cleaning soil contaminated with oil and oil products, including embankment of the soil in the form of a dam along the contour of its contamination, and distinctive, essential features: both inside and and outside the embankment, trenches are laid, filled with sorbent — waste products of activated carbon fractions of 0.1-5.0 mm with negative and / or positive buoyancy, while trenches inside the embankment are filled with a sorbent having ak negative and positive buoyancy, while the trench located outside the embankment fill sorbent having only negative buoyancy, wherein during the movement of groundwater monitoring wells operate. The problem is solved using the signs specified in paragraph 2 of the claims common to the prototype, such as a system of facilities for cleaning contaminated with oil and oil products soil containing the embankment of the oil spill in the form of a dam, and distinctive, essential features, such as a system of structures additionally contains a series of trenches inside and outside the embankment, filled with a sorbent of both negative and positive buoyancy, and also control wells located along the ground water

The technical result from the use of the above set of essential features of the invention is to simplify the process of cleaning contaminated with oil and oil products soil, as well as the possibility of using wastes from the production of activated carbon in order to protect the environment.

The invention is illustrated by drawings. Figure 1 shows a longitudinal section of a structure for cleaning contaminated with oil and oil products soil; figure 2 is a view of the structure in plan; figure 3 is a trench in section.

The system of facilities for cleaning soil contaminated with oil and oil products contains an embankment of 1 oil spill site in the form of a dam, as well as a series of trenches inside 2 and outside 3 embankments filled with a sorbent of both negative 4 and positive 5 buoyancy. Positive buoyancy refers to the ability of sorbent particles to be on the surface of a liquid. Negative buoyancy is understood as the ability to immerse sorbent particles in a liquid. The depth of the trenches is determined by the filtration and physico-mechanical properties of soils, the conditions of occurrence of groundwater in the accident area. Over time, the trenches are filled with oil products, water (precipitation, snowmelt, top water) 10. Behind the embankment 1, control wells 6 were made, located along the groundwater flow 7. Water-resistant rocks are indicated by 8, oil-contaminated soil - 9.

An example embodiment of the invention. A method of cleaning soil contaminated with oil and oil products, for example, in the event of an accident at the pipeline (not shown in the drawing), involves embankment 1 of the soil in the form of a dam along its contamination contour (Fig. 2). Both inside and outside the embankment, trenches 2,3 pass, they are filled with a sorbent with negative 4 and / or positive 5 buoyancy. The multicomponent sorbent consists of particles of activated carbon with positive and negative buoyancy (the ratio of the components of the sorbent with positive and negative buoyancy is determined by the ratio of oil floating on the surface and oil in the water volume, analysis data are used), made from waste products of activated carbon fraction 0 , 1-5.0 mm. This sorbent allows you to remove petroleum products both from the surface and from the volume of water 10 located in the trenches (figure 1). Contaminated water drained by trenches is purified by a sorbent with negative buoyancy. Part of the sorbent after deposition forms a sorbent layer at the bottom, which, when filtering water into the soil, will work according to the principle of an alluvial filter (Fig. 3). The oil film is removed by a floating sorbent (with a positive buoyancy fraction of 0.1-0.5 mm). The sorbent consumption, depending on the type and properties of oil, is 200-250 kg per ton of oil.

To prevent possible contamination of groundwater outside the embankment due to oil leakage through the dam body and infiltration into groundwater from a storage site or accident site in the direction of groundwater movement, a trench is dug and filled with a sorbent with negative buoyancy. In addition, to control the effectiveness of cleaning along the groundwater flow, control wells are performed (Fig. 1). After cleaning the soil, the sorbent is removed from the trenches or disposed of, for example, by burning in furnaces or left in place, and technical and biological reclamation is carried out at the storage site.

Thus, all petroleum products are localized in a limited area, their distribution is prevented by surface and groundwater. The method is relatively simple to use and economical, since waste from the production of activated carbon is used for its implementation, it can be used to localize emergency oil spills. The structures with which this method is implemented do not require large capital expenditures. In addition, the sorbent, given its low cost, can be used in the form of screens placed in places with a high probability of spillage of technological products at oil producing, oil refining and oil transportation enterprises, the oil industry, during surface water pollution and other cases.

From the description and practical application of the present invention, other particular forms of its implementation will be apparent to those skilled in the art. This description and examples are considered as material illustrating the invention, the essence of which and the scope of patent claims are defined in the following claims, a combination of essential features and their equivalents.

Claims (2)

1. The method of cleaning the soil contaminated with oil and oil products, including embankment of the soil in the form of a dam along the contour of its contamination, characterized in that trenches are laid both inside and outside the embankment, they are filled with a sorbent - waste products of activated carbon fraction 0.1-5, 0 mm with negative and / or positive buoyancy, while the trenches inside the embankment are filled with a sorbent having both negative and positive buoyancy, and the trenches located outside the embankment are filled with a sorbent having only itsatelnuyu buoyancy, wherein during the movement of groundwater monitoring wells operate. 2. The system of facilities for cleaning the soil contaminated with oil and oil products, containing the embankment of the oil spill in the form of a dam, characterized in that it additionally contains a number of trenches inside and outside the embankment, filled with a sorbent of both negative and positive buoyancy, as well as the control embankment wells located along the groundwater.

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