RU2522616C2 - Humic-mineral reagent, method of its production and method of its use for cleaning of contaminated soils - Google Patents

Abstract

FIELD: ecology.

SUBSTANCE: humic-mineral reagent is prepared by mixing humified organic raw materials with the solution of hydroxide of alkaline or alkaline-earth metals, followed by extraction. The extraction of humic substances is carried out at 165-220°C and pressure of 1.8-2.5 MPa while simultaneous supplying air at a rate not exceeding 5 litres per minute for 10 kg of raw material for no longer than 3 hours. The resulting reagent comprises humic acids and/or their salts, a mixture of mineral components, comprising ferric oxide, sodium oxide, magnesium oxide, aluminium oxide, calcium oxide, and less than 1.5 wt % impurities.

EFFECT: invention enables to obtain new environmentally and economically effective humic-mineral agent with a high yield of organic wastes, the use of which provides effective cleaning of contaminated soils, and to accelerate remediation processes.

7 cl, 3 dwg, 1 tbl, 3 ex

Description

The invention relates to the field of ecology and environmental restoration, in particular to methods for producing preparations of humic substances from natural organic substrates. Humic preparations are used in the national economy for the purification of contaminated territories, including disturbed lands, as well as the restoration and remediation of contaminated soils and lands. To a large extent, the efficiency of cleaning contaminated areas, including soil and soil objects and the soil-ecological effectiveness of remediation, depends on the bioprotective activity of humic preparations and their binding ability with respect to ecotoxicants properties.

It is known that the problem of remediation of contaminated territories is extremely urgent in the field of nature management and nature restoration on disturbed lands on a global scale. Therefore, there are several different approaches to its solution.

One of these approaches is the use of specific or nonspecific strains of microorganisms-destructors [1]. Essential features of such methods are activation of soil microbiocenosis and acceleration of the decomposition of target substances (components of oils, pesticides, herbicides, etc.) [2, 3].

The disadvantage of this group of methods is the short duration of action, climatic restrictions, the lack of influence on the dynamics of inorganic ecotoxicants in the soil [4, 5].

Along with microbiological preparations, preparations based on humic substances are widely used [6, 7].

These biological natural components are used in remediation on a comparable scale. The main known methods of remediation are aimed at cleaning contaminated soils from the following pollutants: oil and oil products, sewage sludge and sludge, other organic compounds except oil (polyvinyl chloride, nitrobenzenes, manure, etc.), pesticides, heavy metals and their oxides, sodium arsenide and nickel, etc. The main technical results aimed at remidiating contaminated soils are improved cleaning efficiency, restoration of fertility and productivity, increased rate of restoration, reduction in the cost of remediation. Known methods of remediation using a humic-mineral reagent and various methods for its preparation [8, 9].

The main difficulty in using humic and mineral reagents for land remediation is the preparation of a preparation with an optimal chemical composition that provides maximum remediation effectiveness and imperfect methods for introducing a humic and mineral reagent into soils and soils.

The applicant has studied the world level of technology in this field both in patent information sources and in the scientific literature and a brief analysis of the identified analogues is given below.

A known method of producing organic fertilizers and a technological line for its implementation [7] by cavitation dispersion of caustobiolites at a temperature of 80-90 ° C. The disadvantage of this method is the inconsistency of the formula of the humic-mineral preparation, and in this regard, the low reproducibility of the effects of remediation of contaminated lands.

Carbon sorbents [10] of industrial origin are known that stimulate the microflora of non-polluted lands. The disadvantage of this method is the high alkalinity of the aqueous suspension of the drug (up to 9 pH units), which can lead to a decrease in soil productivity due to the high alkalization of the remediated soils and soils.

A known method of purification of oil-contaminated soils and soils using the drug "Ecohum" [11], the humic-mineral reagent is obtained from brown coal and introduced in the form of an aqueous suspension into the soil. The disadvantage of this method is the high alkalinity of the aqueous suspension introduced into the soil, which is a negative factor in the purification of oil-contaminated soils and soils, often having an alkaline reaction initially.

A known method of producing humic fertilizer from brown coal [12] for the purpose of further application to the soil, however, the description does not contain information that could be used to judge the positive effect of this humic preparation in relation to specifically contaminated lands.

It is known to use humic derivatives as passive remediation agents in mining [13], the disadvantage of this method is the use of humic substances only as passive reaction barriers, but not for active cleaning of soils and soils.

In the analysis of analogues, the applicant identified the closest of them to achieve technical for each of the three claimed independent claims.

Known gum-mineral reagent closest to the proposed humic-mineral reagent [14], selected as a prototype (for the first independent point of the claimed invention). Its essence is to obtain a gum-mineral reagent from natural gummites and coal-grade caustobioliths, while nitrogen-containing substances are added to the raw material to obtain a gum-mineral preparation.

The disadvantage of the prototype is the low proportion of humic substances in the composition of the reagent and the too high content of volatile substances contained in the produced substance-reagent. The low content of humic substances with a high proportion of volatile substances leads to a decrease in the effectiveness of remediation per dose of the applied humic-mineral reagent.

A known method of producing humic substances in laboratory conditions by alkaline extraction from any natural environment containing humified organic matter [15]. Its essence is that the humified organic substance is subjected to treatment with an aqueous solution of sodium hydroxide in an organic substance-alkali solution ratio of from 1: 5 to 1:10 (sometimes 1:20) at room temperature and atmospheric pressure. Meanwhile, low temperature and pressure values lead to the fact that the yield of humic substances as a percentage of the initial mass of humified organic matter is not constant and predicted

This method is closest to the task at hand and is selected as a prototype of the second independent point of the claimed invention.

The disadvantage of this method is the low yield of humic substances from natural environments and its inapplicability on an industrial scale.

A known method of remediation of soils contaminated with mineralized waters [16], which consists in introducing organic residual sludge into the soil of pressed briquettes and further mechanical sifting of the soil. Its essence lies in the fact that as a chemical improver use crumbly wet excess sludge.

This method is a prototype for the third independent claim of the claimed invention.

The disadvantage of this method is the need for mechanical removal of sludge briquettes after sorption of ecotoxicants occurs, which increases labor costs. The disadvantage of this method is the need to move large masses of soil for further screening in order to remove the sorbent.

The claimed invention is free from these disadvantages.

The technical result of the invention is to increase the yield of humic-mineral reagent in relation to the amount of source of organic raw materials. The involvement of organic waste in the biological cycle on disturbed and polluted lands contributes to the use of cheap raw materials and its disposal. This leads to the fact that the masses of soil to be cleaned do not require moving for further cleaning, and the cleaning itself occurs at the site of contamination, which in turn leads to cheaper chemical remediation of contaminated soils and lands and a decrease in the volume of soils involved in mining reclamation processes. Due to the involvement of livestock waste in the biological cycle during land remediation, the cost of disposing of organic waste from livestock farms is significantly reduced.

The specified technical result is achieved in that the humic-mineral reagent containing humic acids and / or their salts and mineral components, in accordance with the claimed first independent claim, iron oxide, sodium oxide, magnesium oxide, aluminum oxide are taken as mineral components, calcium oxide and the composition contains, by weight. %:

humic acids and / or their salts - at least 60 in total, including aromatic humic acids - at least 17.5;

mineral components - less than 40 in total, including iron oxide - up to 4.0, sodium oxide - up to 17.0, magnesium oxide - up to 6.0, aluminum oxide - up to 4.0 and calcium oxide - up to 34.5;

impurities - less than 1.5 in total, including volatile substances - up to 1, chlorides up to 0.5, heavy metals - up to 0.1

In addition, this technical result is achieved in that the total quantitative composition of humic acids and / or their salts is not more than 75%, and the total quantitative composition of mineral components (iron oxide, sodium oxide, magnesium oxide, aluminum oxide, calcium oxide) is not less than 25%.

The specified technical result is achieved by the claimed second independent claim on a method for producing a humic-mineral reagent obtained according to the first independent claim, which consists in mixing organic materials with a hydroxide solution, extracting humic substances, filtering the resulting solution and treating it with acid, separating and washing the resulting precipitate, in accordance with the claimed invention according to the second independent claim, in that, as the hydroxide used hydroxides of alkali or alkaline earth metals, the extraction of humic substances is carried out at a temperature of 165-220 ° C and a pressure of 1.8 - 2.5 MPa with simultaneous air supply with a flow rate of not more than 5 liters per minute per 10 kg of raw material for no more than 3 hours.

In addition, this technical result is achieved by the fact that in the method according to the second independent claim of the claimed invention, sodium or potassium or calcium hydroxides are used as the hydroxide of an alkaline or alkaline-earth element.

In addition, this technical result is achieved by the fact that in the method according to the second independent claim of the claimed invention, mixtures of at least two hydroxides of sodium or potassium or calcium are used as hydroxide of an alkaline or alkaline-earth element.

In addition, this technical result is achieved by the fact that in the method according to the second independent claim of the invention, acetic acid is used as the acid in the ratio of one part of a 5% acid solution to 10 parts of the solution.

The specified technical result is achieved by the declared independent third point of the invention on the method of using the humic-mineral reagent, which consists in intensive cultivation and adding sorbent and chemical ameliorant to the prepared soil for cleaning, intensive irrigation by irrigation and subsequent sowing of phytomeliorants, in accordance with the claimed invention according to the third independent point, insoluble waste from the production of a humic-mineral reagent is used as a sorbent, and it is used as a chemical ameliorant zuyut-humic mineral reagent prepared according to the first independent claim of the invention is carried out watering sprinkler 0.003% aqueous-humic mineral reagent.

In addition, this technical result is achieved by the fact that in the method according to the independent third paragraph of the claimed invention, loosening is carried out after the vegetation of the corresponding type of phytomeliorant used to a depth of at least 20 cm and at the same time insoluble waste is introduced into the cleaned contaminated soil, after which irrigation is carried out by sprinkling of 0.003% an aqueous solution of a humic-mineral reagent, which is additionally repeated at least two times, the first of which is carried out when planting a phytomeliorant, and the second oh no more than three weeks after the appearance of their shoots.

The claimed invention allows to obtain a humic-mineral reagents with a constant composition, which ensures maximum efficiency of remediation of contaminated soils and lands. When a humic-mineral reagent is introduced into contaminated soil, it detoxifies, increases biological activity, optimizes physicochemical parameters and stimulates plant growth. The proposed reagent and the method for its preparation differs from most existing methods in that it ensures high production efficiency and reproducibility of a constant quality, which is achieved by the constancy of the component composition of the mineral components, and, most importantly, the organic humic component. The claimed invention relates to a cheaper and more efficient method of producing humic preparations of the claimed composition in comparison with known analogues and technologies, which can be recommended for use in regions where the problem of land remediation is especially acute.

The claimed invention on the basis of St. Petersburg State University was tested on model samples during laboratory studies, as a result of which specific examples of the invention reflecting the results of testing were obtained.

Examples of specific implementations of the composition of a humic-mineral preparation, a method for its preparation, and a method for cleaning soils are given below and illustrated in FIGS. 1-3.

Figure 1 shows the dependence constructed in the coordinates: X - the number of treatments of contaminated soils with a humic-mineral reagent and the waste of its production, Y - carbon content,%, where 1 - curve of the total carbon content in contaminated soils on the number of treatments and 2 - the curve of the carbon content of humic acids and / or their salts in contaminated soils on the number of treatments.

Figure 2 presents the dependence constructed in the coordinates: X - the number of treatments of contaminated soils with a humic-mineral reagent and the waste of its production, Y - pH of contaminated soils (for curve 1) or the protease activity of contaminated soils,% (for curve 2), where 1 - curve of the pH dependence of contaminated soils on the number of treatments and 2 - curve of the protease activity of contaminated soils on the number of treatments.

Figure 3 shows the dependence constructed in the coordinates: X - the number of treatments of contaminated soils with a humic-mineral reagent and the waste of its production, Y - plant germination,% (for curve 1) or plant biomass, g (for curve 2), where 1 - a curve of plant germination on contaminated soils on the number of treatments and 2 - a curve of plant biomass on contaminated soils on the number of treatments.

Examples of the implementation of the claimed invention

Example 1A A method of obtaining a humic-mineral component from cattle manure

The feedstock with a moisture content of 90%, an ash content of 12% in an amount of 3.6 kg was mixed with 5.4 liters of a 3.7% sodium hydroxide solution. The extraction of humic substances was carried out for 2 hours at a temperature of 175 ° C, a pressure of 2.2 MPa with an air flow rate of 4.5 liters per minute. After the extraction, the mixture was cooled to 20 ° C, filtered through a paper filter. The waste, which is an insoluble precipitate of the feedstock, was dried and used for soil remediation as a sorbent, which is more specifically described in Example 3 below. A supernatant of 5 liters was treated with 5% acetic acid in an amount of 1 liter. After 24 hours, the resulting suspension was separated on a flow separator at 2000 rpm for 10 minutes. The precipitate was washed with 5.0 liters of distilled water and then separated again, and then dried. The total yield of humic-mineral reagent in terms of a completely dry sample is 250 grams, which is more than 40% of the starting organic matter in the feed. The composition of the obtained humic-mineral component is described in example 2, the method of application, respectively, in example 3.

Example 1B A method of obtaining a humic-mineral component from sludge sediment

The feedstock with a moisture content of 68%, an ash content of 14% in an amount of 2.4 kg was mixed with 6.6 liters of a 4% suspension of calcium hydroxide. The extraction of humic substances was carried out for 3 hours at 190 ° C, a pressure of 2.4 MPa with an air flow rate of 4.5 liters per minute. After the extraction, the mixture was cooled to 20 ° C, filtered through a paper filter. A supernatant of 4 liters was treated with 5% acetic acid in an amount of 0.8 liters. After 16 hours, the resulting suspension was centrifuged at 2500 rpm for 15 minutes. The precipitate was washed with 5.0 liters of distilled water and then centrifuged again, and then dried. The total yield of the humic-mineral reagent is 300 grams, calculated on an absolutely dry sample, which is more than 40% of the starting organic matter in the feed. The composition of the obtained humic-mineral component is described in example 2.

Example 2. Humic-mineral reagent (composition)

Obtained in examples 1A and 1B, humic-mineral reagents were characterized by the following composition in terms of the dry weight of the products:

Indicator Reagent of Example 1 Reagent of Example 2 Humic acids and their salts, including: 64.2% 71.6% Aromatic humic acids and their salts 26.4% 19.8% Minerals, including: 34.5% 27% Iron oxide 1.3% 3.8% Sodium oxide 16.5% 2.2% Magnesium oxide 2.4% 3.9% Aluminium oxide 1.2% 2.8% Calcium oxide 4.4% 12.4%; Impurities, including: 1.3% 1.4 Chloride ion 0.3% 0.4 Heavy metals 0.1% 0.1% Low molecular weight impurities 0.9% 0.5%

Example 3. Humic-mineral reagent (application)

For the experiment, 8 vessels 40 × 40 × 20 cm in size were used. Controlled parameters of the experiment: organic matter content, including humic acids, pH, microbiological (protease) activity, plant survival, plant biomass (total per vessel). Vessel 1 was used as a control. At the bottom of 2-8 vessels was placed the waste from the extraction of humic substances according to Example 1A in an amount of 100 g in terms of dry weight (first treatment of contaminated soil). The waste is unoxidized plant residues consisting mainly of cellulose and lignin and has a reaction of 10.4. Pounded air-dry pyritiferous acidic medium loam of the Borovichi deposit of refractory clays of 2 kg in each vessel was placed in all the vessels. The mixture in the vessels was vigorously stirred for 5 minutes. Next, the mixture in vessels 1 and 2 was moistened with a watering can in an amount of 0.5 liters, and the mixture in vessels 3-5 - 0.003% aqueous solution of the humic-mineral reagent according to Example 1 A, the mixture in vessels 6-8 - 0.003% aqueous a solution of a humic-mineral reagent according to example 1B (second treatment of contaminated soil). The mixture in the vessels was composted for 21 days at room temperature. After that, the mixture in vessels 1, 2, 3 and 6 was moistened with watering can with a watering can, and the mixture in vessels 4-5 was treated in the same way with a 0.003% aqueous solution of the humic-mineral reagent according to Example 1A, and in vessels 7-8, 0.003% aqueous a solution of a humic-mineral reagent according to example 1B (third treatment). Then, oats plants were planted in all vessels in the amount of 100 seeds per vessel; the experiment was continued under standardized lighting conditions. After 1 week from the moment of planting, the vessels were irrigated using a watering can, and vessels 1, 2, 3, 4, 6 and 7 were moistened with water, vessel 5 - 0.003% aqueous solution of the humic-mineral reagent according to Example 1A and vessel 8 - 0.003% an aqueous solution of a humic-mineral reagent according to example 1B (fourth treatment). The experiment was completed on day 28 from planting. The results obtained in this period for vessel 1 were used for the “0 treatment” option, for vessel 2 - “1 treatment”, the averaged results for vessels 3 and 6 - “2 treatment”, for vessels 4 and 7 - “3 treatment” , for vessels 5 and 8 - “4 processing”.

As can be seen from Figure 1, the introduction of waste from the production of a humic-mineral reagent contributes to a significant increase in the content of organic matter in the soil, and treatment with a liquid humic-mineral reagent helps to fix this organic substance in the form of the most kinetically stable compounds - humic substances.

Figure 2 illustrates the pH changes of the initial acidic mixtures and their microbiological activity during processing with a humic-mineral reagent. The most effective way to normalize the pH is to introduce a waste from the production of humic-mineral reagent, followed by three-time watering of the mixture with a 0.003% aqueous solution of humic-mineral reagents according to examples 1A and 1B. The introduction of reagents significantly increases the microbiological activity of soils, in close connection with the change in pH of the medium.

As can be seen from Figure 3, the original pyrite-containing loam is unsuitable for phytoremediation (there are no seedlings of plants). The introduction of waste from obtaining a humic-mineral reagent (1 treatment) allows you to get seedlings of plants, and triple treatment with a humic-mineral reagent - to achieve maximum plant biomass.

Thus, as shown by the results of numerous studies simulating environmental conditions in the laboratory, the inventive humic-mineral reagent is constant in composition and effective in cleaning contaminated soils as a chemical improver that increases the microbiological activity of soils, survival rate and plant biomass. The method of its production is characterized by the speed and high yield of humic substances, along with organic waste.

The technical and economic efficiency of the claimed invention consists in the development of an environmentally effective preparation of humic substances obtained from waste, as well as in the development of a cheaper method of introducing humic substances into contaminated soils in comparison with known analogues and in the development of a method for producing a humic preparation with a constant composition, which On the whole, it is a self-sufficient and complete technological cycle, which allows with a high yield of reagent obtained on the basis of raw materials requiring utilization of high labor costs, environmental certification and conduct systematic monitoring of the quality control of the treated contaminated land. In this case, as shown by studies in real conditions, there is practically no need for a costly operation of the utilization of raw materials that have been successfully used to obtain a cheap and high yield effective humic-mineral reagent according to the independent first point of the claimed invention. The claimed invention can be widely used and recommended as an effective technology for solving environmental problems by cleaning, depending on the characteristics of contaminated soils.

Information sources

1. Patent of the Russian Federation RU 2376084 C1

2. Patent of the Russian Federation RU 2376083 C1

3. Patent of the Russian Federation RU 2355488 C1

4. Patent of the Russian Federation RU 2320430 C1

5. Patent of the Russian Federation RU 2311237 C2

6. Patent of the Russian Federation RU 2365077 C1

7. Patent of the Russian Federation RU 2296731 C2

8. Patent of the Russian Federation RU 2258687 C1

9. Patent of the Russian Federation RU 2205158 C1 Yu. Patent of the Russian Federation RU 2 414 313 C2 11. Patent of the Russian Federation RU 2174454 C2 12. Patent of the Russian Federation RU 2201416 C2 13. Patent of the Russian Federation RU 2429068 C2

14. Patent of the Russian Federation RU 2002131896 (prototype for the first independent claim)

15. Orlov D.S., Grishina L.A. Workshop on the chemistry of humus. Publisher: Moscow State University, 1981 ISBN: UDC: 631. 273 pages (prototype for the second independent point)

16. Patent of the Russian Federation RU 2459398 (prototype for the third independent claim)

Claims (7)

1. A method of obtaining a humic-mineral reagent, which consists in the fact that humified organic raw materials are mixed with a hydroxide solution, the humic substances are extracted, the resulting solution is filtered and treated with acid, and then the precipitate is separated and washed, characterized in that it is used as hydroxide hydroxides of alkali or alkaline earth metals, the extraction of humic substances is carried out at a temperature of 165-220 ° C and a pressure of 1.8-2.5 MPa with a simultaneous air supply with a flow rate of not more than 5 liters per m Nute 10 kg of raw material for no longer than 3 hours. 2. The method according to claim 1, characterized in that as the hydroxide of an alkaline or alkaline-earth element, sodium or potassium or calcium hydroxides are used. 3. The method according to claim 2, characterized in that as a hydroxide of an alkaline or alkaline-earth element using a mixture of at least two hydroxides of sodium or potassium, or calcium. 4. The method according to claim 1, characterized in that the acid used is acetic acid in the ratio of one part of a 5% acid solution to 10 parts of the solution. 5. Humic-mineral reagent obtained by the method according to claims 1 to 4, containing humic acids and / or their salts, a mixture of mineral components, including iron oxide, sodium oxide, magnesium oxide, aluminum oxide, calcium oxide, and impurities, including volatile substances, chlorides and heavy metals, with the following content of components, wt.%:
humic acids and / or their salts of not less than 60 - not more than 75, including aromatic humic acids of not less than 17.5
the specified mixture of mineral components is not less than 25 - less than 40,
including iron oxide up to 4.0, sodium oxide up to 17.0, magnesium oxide up to 6.0, aluminum oxide up to 4.0 and calcium oxide up to 34.5
impurities less than 1.5, including volatile substances up to 1, chlorides up to 0.5, heavy metals up to 0.1. 6. The method of using the humic-mineral reagent for cleaning contaminated soils, which consists in intensive cultivation and adding a sorbent and chemical improver to the prepared soil, intensive irrigation by irrigation and subsequent sowing of phytomeliorants, characterized in that insoluble waste from the production of humic mineral reagent, and as a chemical improver, use the humic-mineral reagent according to claim 5, irrigate by sprinkling a 0.003% aqueous solution of humic-mineral r agent. 7. The method according to claim 6, characterized in that the cultivation is carried out after completion of the growing season of the corresponding type of phytomeliorant used to a depth of at least 20 cm and at the same time insoluble waste is introduced into the cleaned contaminated soil, after which irrigation is carried out by sprinkling with a 0.003% aqueous solution of humic-mineral reagent , which is additionally repeated at least two times, the first of which is carried out when planting a phytomeliorant, and the second no more than three weeks after the appearance of their seedlings.

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