RU2496820C2 - Sorbent-ameliorant for cleaning oil-contaminated soil - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: three types of clay of different chemical composition is used with addition of molasses and Linex biopreparation in the following ratios, wt %: Dialbeculit clay -38-40; Irlit clay 1 - 28-32; Irlit clay 7 - 16-20; molasses - 8-12; Linex biopreparation -2-4. Adding such a composition to the soil reduces the amount of oil pollutants by 72%.

EFFECT: low toxicity of soil and expenses on amelioration.

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Description

The invention relates to soil reclamation and can be used in the rehabilitation of soils contaminated with oil.

Known ameliorant, consisting of clay and a humus layer with the addition of coarse sand (patent No. 2253225 from 06/10/2005, IPC A016 25/00, A01B 79/02).

A well-known ameliorant is created at high cost, since inclined trenches are carried out to accommodate sorbing substances to a depth of 2-3 m.

Known ameliorant, which allows to reduce soil pollution by oil products by sowing plants of phytoremidants that are treated with strains of microorganisms (patent 2403102 from 10.11.2010, IPC B09C 1/10).

However, the implementation of the technical solution requires a significant amount of seed, which also increases costs.

Known composition for soil reclamation "Sorbex" on an organic basis with the addition of mineral components, while sapropel is used as an organic base, and zeolite and alumina are used as mineral components in the following ratio of components, mass. %: sapropel 60-70, zeolite 23-27, alumina 8-11 (patent No.2019107 from 11/27/1995, IPC С09К 17/00).

The known composition is costly, and during the extraction of sapropel there is a violation of the landscape, which violates the ecology of the territory.

The closest composition to the proposed one is a sorbent ameliorant, consisting of bentonite clays (36%), ash and slag mixture (47%), blue clays (17%), (patent 2303623 dated 07.27.2007, IPC С09К 17/00).

The disadvantage of the known ameliorant - prototype is its high cost, since ash and slag mixture in large quantities and blue clay located in remote places must be delivered to the place of pollution.

EFFECT: reduction of soil costs and toxicity.

The technical solution consists in the fact that they use zeolite-containing clays of local origin containing a complex of macro- and microelements with the addition of sugar from molasses sugar production and Linex biological product in the following ratio of components,%:

clay dialbeculite - 38-40;

clay irlite 1 - 28-32;

clay irlite 7 - 16-20;

molasses - 8-12;

Linex biological product - 2-4.

The advantage of the proposed sorbent is that zeolite-containing clays of local origin are located in the tributaries of the Terek River, in the upper and lower parts, having different chemical composition.

Dialbeculite clay consists of silicon (46.5%), iron (7.1%), potassium (1.1%), calcium (37%), cobalt (0.1%), zinc (1.1%), nickel (1.7%), phosphorus (1.7%). The reaction is alkaline (pH 9.1).

Irlit 7, unlike dialbekulite, contains: silicon 54%, aluminum - 16%, iron - 4%, sulfur - 2.5%, potassium - 2%, vital elements (copper, cobalt, molybdenum, zinc, selenium) in the range of 0.1-0.9%. The reaction is acidic (pH - 3.8).

Irlit 1 consists of silicon (54%), aluminum (28%), iron (7%), sulfur (2%), calcium (3%), magnesium (1.7%), manganese (1.7%), potassium (2.1%), sodium (1.1%), sulfur (2.0%), selenium (0.8%). The reaction of the medium is neutral. All clays have high sorption properties due to the high silicon content (46-54%), the ability to absorb moisture and other substances.

The combination of clay with a different reaction of the medium evens out the action of trace elements. Silicon promotes the release of phosphorus for plants by displacing its ions from poorly soluble soil phosphates, while silicic acid anions are able to block free carbonates of the soil solution, which reduces the retrograde of soluble phosphates. Silicon-containing clays increase the mobility of phosphation in the soil. When soils are contaminated with oil, the mobility of phosphorus decreases, therefore, the introduction of clays with a high silicon content restores phosphorus compounds, thereby reducing the amount of oil products in the soil.

Clay dialbekulite differs from other known zeolite-containing substances in a lighter specific gravity (1.4-1.45 g / cm ³ ), which determines the peculiarity of its mineralogical composition (the presence of a large number of hydromica). Dialbekulite contains a noticeable amount of water-soluble salts, approaching in this indicator to low-mineralized silt sulphide muds with high sorption properties.

Therefore, in the composition of the proposed mixture, these clays predominate (38-40%). Given the composition of other types of clays (Irlit 1 and Irlit 7), their reaction of the medium and the complex of microelements supplementing the clay dialbekulite in the proposed proportions, the dosage of each type is justified.

Linex biopreparation is a combined preparation that consists of 3 components of natural microflora (Lactobacillus acidophilus, Bifidobacterium infantis, Enterococcus faecium), resistant to chemical preparations.

This drug is usually used to align the intestinal microflora of living organisms. The lactic acid bacteria that make up Linex support and regulate the physiological process of microorganisms in the soil.

The molasses introduced is a waste from sugar production, it contains 20-25% water, about 9% nitrogen compounds, mainly amides, 58-60% carbohydrates, mainly sugar and 7-10% ash. Used as a carbohydrate feed. In this object, as a food product for lactic acid bacteria of the drug Linex.

The ability of clays to retain moisture, heat provide favorable conditions for the development of microorganisms in the soil. Sulfur and other vital elements contained in clays provide the activity of anaerobic microorganisms of the Linex type.

The composition for reclamation was prepared as follows:

Clays dialbekulit (tributary of the Terek-Ursdon River) in the amount of 3.8-4.0 t / ha were mixed with Irlit 1 (2.8-3.2 t / ha), with Irlit 7 (1.6-2.0 t / ha) - the origin of the Alagir region of the Fiagdon River. Molasses in an amount of 0.8-1.2 t / ha was mixed with Linex biological product in an amount of 0.2-0.4 t / ha immediately before application.

Before entering the soil, crushed clays were placed in a fertilizer seeder in a mixture with molasses and Linex and applied directly to the soil to a depth of 10-15 cm.

The results of the experiments after a single application of such an amount of sorbent (9-10 t / ha) showed that the content of oil products in the soil significantly decreased. The results of the experiments are summarized in a table (in a 0-20 cm soil layer 6 weeks after application).

Experiment Options Hydrocarbons, kg / m ² The concentration of oil polluting substances, g / kg Reduction of oil polluting substances,% Oil pollution (control) 2048 65.0 - Clay dialkulitis 1421 41.2 36.7 Clay Irlite 1 1756 52,4 19.9 Clay Irlite 7 1814 56.8 13.6 A mixture of 3 clay 918 36,2 44,4 A mixture of 3 clay + molasses 826 28.5 56.2 A mixture of 3 clay + Linex 586 25,4 60.3 The proposed option (a mixture of 3 clays, molasses + Linex) 350 18.2 72.0

According to AFNOQ 90114, the level of hydrocarbons should not exceed 500 mg / kg of soil. As follows from the data in the table, the proposed option provides a reduction in hydrocarbons to 350 mg / kg. At the same time, the amount of oil contaminants is reduced by 72%.

Consequently, the introduction of clay species of different contents in a mixture with bacteria and molasses ensures the reclamation of soils contaminated with oil.

Claims (1)

Sorbent ameliorant for cleaning oil-contaminated lands, consisting of clay mixtures, characterized in that it contains
Dialbeculite clay with a content, wt.%: Si - 46.5, Ca - 37, Fe - 7.1, K - 1.1, Co - 0.1, Zn - 1.1, Ni - 1.7, P - 1.7 and pH 9.1,
clay Irlit 1 with a content, wt.%: Si - 54, Al - 28, Fe - 7, S - 2, Ca - 3, Mg - 1.7, Mn - 1.7, K - 2.1, Se - 0.8, Na - 1.1 with a neutral pH and
clay Irlit 7 with a content, wt.%: Si - 54, Al - 16, Fe - 4, S - 2.5, K - 2, vital elements - copper, cobalt, molybdenum, zinc, selenium - within 0, 1-0.9 with an acidic reaction of pH 3.8,
waste sugar production molasses and
Linex biological product in the following ratio of components, wt.%:
clay dialkulit 38-40 clay Irlit 1 28-32 clay Irlit 7 16-20 molasses 8-12 Linex biological product 2-4