RU2799568C1 - Sorbent for cleaning soil and water bodies polluted with petroleum products and method for producing sorbent - Google Patents

Abstract

FIELD: solid bulk sorbents.

SUBSTANCE: group of inventions is related to compositions of solid bulk sorbents intended for cleaning soils and water bodies contaminated with oil products, separating and removing such pollutants. The sorbent for removing oil products is sphagnum moss treated with a silicone aqueous emulsion of ethylhydridesiloxane. In the method of making the sorbent, sphagnum moss is placed in a container with an aqueous solution of an organosilicon emulsion of ethylhydridesiloxane. Then, after the excess emulsion drains, the hydrophobic element is heat-fixed on the moss in drying cabinets. After that, it is finally dried in an oven at a temperature lower than the heat setting temperature.

EFFECT: achievement of optimal characteristics of the absorbent qualities of the modified natural sorbent, at which the modifier is of low toxicity, moisture absorption is low, and absorption or sorption of oil products and their particles is high.

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Description

SUBSTANCE: group of inventions relates to compositions of solid bulk sorbents intended for cleaning soils and water bodies contaminated with oil products, separating and removing such pollutants.

It is known that an emulsion of organosilicon liquid is used for hydrophobization (see RU 2229458, application: 2002117351/03, 06/28/2002). It is known to use dried sphagnum plants for cleaning from pollutants consisting of hydrophobic compounds, such as oil, including when cleaning reservoirs (RU 2183501, application: 98104470/12, 23.08.1996). At the same time, the authors of this technical solution acknowledge that the initially hydrophobic and buoyant properties of this material require improvement, but claim that they improve with a sufficiently long drying of the plant.

A sorbent of hydrocarbons and lipids is known, which contains a finely dispersed water-absorbing material, on the surface of the particles of which siloxane fragments are fixed, while the particles of the finely dispersed material are modified with an organosilicon (hydride siloxane) liquid, and the material itself is white soot, chemically precipitated chalk, river sand, peat, magnetite, wood in the form of shavings or sawdust (RU 2331469, application: 2006140441/15, 11/16/2006; RU 2367515; application: 2007148683/15, 12/28/2007).

The disadvantages of these patents is a not entirely clear method for choosing the basis of the sorbent, since it is obvious that when choosing, for example, sand or wood shavings, both the method of modifying them with an organosilicon composition and the method of their application in sorption will differ. Considering that the examples of patent use refer to drying the sample on a baking sheet in the oven and stirring with a spatula, it is clear that the patents are based on laboratory developments, and not in the process of trying to clean the reservoir.

It is known from the general level of technology that the use of any water repellents in general increases the oil capacity of moss [1]. However, industrial solutions require the search for an optimal water repellent (modifier), including a low-toxic one.

It is known to use an organosilicon preparation of the KE-30-04 type as an acid-repellent agent (RU 1692, application 94025681/12, 07/08/1994).

It is also widely known to use sodium methyl siliconate to create sorbents (RU 2761627, application: 2020139330, 01.12.2020).

Known biodegradable composite sorbent of oil and petroleum products containing plants of the genus Sphagnum (Sphagnum), incorporated in a thermoplastic polymer selected from the group including polypropylene or its copolymer with ethylene, acrylonitrile copolymer with methyl acrylate; The sorbent is proposed to be used for non-waste cleaning of natural and artificial reservoirs, wastewater, liquid industrial waste, solid surfaces from emergency spills of oil and oil products, and also as a preventive measure (RU 2528863, application: 2013125542/10, 03.06.2013). The disadvantage of the proposed solution is the obvious difficulty in the implementation of non-waste cleaning, since the composition of the proposed material is proposed to use from 10% to 90% of the polymer (by weight). It is also obvious that the consumption of such a sorbent will be quite high, since the polymer itself does not have absorbent properties.

The objective of the invention is to create a solid, relatively light, floating, low-toxicity hydrophobic sorbent designed to remove oil products and their particles or similar floating substances for cleaning the surface of water bodies from these materials by separating and removing these materials by sorption purification.

The technical result is to achieve optimal characteristics of such absorbent properties of the modified natural sorbent, in which the modifier (water repellent) would be of low toxicity, moisture absorption would be low, and the absorption or sorption of oil products and their particles would be high.

According to the invention, to create a sorbent designed to remove oil products, the dried mass of a plant (moss) of the Sphagnum genus (Shpagnum), that is, sphagnum moss, is treated with an organosilicon water-repellent liquid, namely, a silicone aqueous emulsion of ethylhydridesiloxane.

Thus, a method is proposed for the manufacture of a sorbent for the removal of petroleum products, in which the feedstock, which is dried sphagnum moss, not crushed or crushed, is modified, namely, placed in a container with an aqueous solution of an organosilicon emulsion of ethyl hydride siloxane, then the excess emulsion solution is allowed to drain, after whereupon the thermosetting (fixing) of the hydrophobic element on the moss is carried out in drying ovens, after which the final drying is carried out in an oven with a temperature lower than the fixing temperature.

Ethylhydridesiloxane emulsion is a polydimethylsiloxane liquid consisting of a mixture of linear and cyclic polymers. It is commonly used for hydrophobization of various materials in the construction, leather and textile industries, is used to protect building materials and structures from atmospheric influences, physically and chemically binds to the carrier material, forming a durable protective coating, and increases the service life of materials.

The emulsion is well diluted in water, usually a 50% aqueous ethylhydridesiloxane emulsion is initially taken, after which it is diluted with water in a ratio of 1:3 to 1:9 to create a working solution, depending on the tasks and type of surface being treated. The working solution is usually applied to a dry, clean surface, after which drying takes place over several days (sometimes up to two weeks). The emulsion does not change the appearance of the material, retains its gas and air permeability, mixes easily with water and is environmentally friendly. It is stable in terms of thermal characteristics, does not oxidize, is chemically inert, explosion-proof, and is hardly combustible.

All these properties make the ethylhydride siloxane emulsion ideal for impregnating sorbents designed to remove petroleum products.

The toxicity of modified sphagnum moss is determined by the toxicity of the modifier used to treat the moss. The proposed modified moss does not irritate the skin and mucous membranes of the eyes and upper respiratory tract. According to the effect on the body, it belongs to substances of the 4th hazard class - a low-hazard substance, according to GOST 12.1.007. Not allergenic. Does not form harmful compounds in the air, sewage and in the presence of other substances. It has no harmful effect on organisms living in the water. Such moss does not have skin-resorptive and cumulative properties, does not emit harmful vapors and gases into the air. It is explosion-proof and hardly combustible.

The plant, sphagnum moss, serves as the feedstock for the manufacture of the Modified Sphagnum Moss product. Color - light green and other shades, moisture content - no more than 15% (if necessary, additional processing is carried out in drying cabinets), without impurities.

When dried, moss can be fermented and converted into a peat analogue.

In order to select the optimal sorbent for cleaning soils and water bodies contaminated with oil products, the initial parameters of sphagnum moss not treated with an organosilicon modifier were determined. To assess the sorption capacity, the parameters of moss water absorption and moss oil absorption were selected. Kerosene grade KO-25 was chosen as a model oil product.

It follows from the test results that moss not treated with an organosilicon modifier absorbs water much better than a model mixture of oil products. Treatment with an organosilicon modifier significantly reduces water absorption and at the same time increases the sorption capacity for petroleum products.

As an organosilicon modifier of sphagnum moss, according to the results of comparative tests, an organosilicon emulsion KE-30-04 in the form of a 5% aqueous solution was chosen.

The production of modified sphagnum moss is carried out as follows.

The feedstock (dried sphagnum moss, not crushed or crushed) is placed in a container with a 4-6% aqueous solution of the KE-30-04 organosilicon emulsion for 10-12 hours, then the moss is removed from the container and the excess emulsion solution is allowed to drain on the fabric for sieves 48/122 according to GOST 4403-91 within 25-35 minutes.

Further modification of the moss is carried out in drying cabinets with obligatory thermal fixation at a temperature of 140-160°C for 4-6 minutes. At this temperature, a stable hydrophobic network is formed on the surface and in the pores of the moss. After that, the modified moss is placed in an oven with a temperature of 55-65°C for 2.5-3.5 hours for final drying. Next comes the packaging.

The following method is used to determine the sorption capacity of sphagnum moss, modified with an organosilicon water repellent, to petroleum products.

1. Measuring instruments, reagents, materials

For testing use:

- laboratory scales according to GOST 24104 or desktop scales according to GOST 23711;

- lighting kerosene brand KO-25;

- closed sealed container;

- fabrics for sieves 48/122 according to GOST 4403-91;

- capacity for saturation;

- organosilicon water repellent brand KE-30-04.

It is allowed to use other measuring instruments, materials and reagents with metrological characteristics not worse than those given above.

2. Preparation for analysis

To control the quality of the modified sphagnum moss, one point sample is taken from each batch included in the sample. Samples are taken from the middle of the bag or bag.

The total mass of selected incremental samples should provide a combined sample sufficient for at least two determinations of each of all controlled moss quality indicators.

Selected incremental samples are combined and thoroughly mixed manually or mechanically to obtain a pooled sample. It is not allowed to make a combined sample from moss from different lots.

The pooled sample should be stored in a sealed container prior to testing to prevent moisture.

Before testing, the pooled sample is reduced by the quartering method. For quartering, the combined sample (after mixing it) is divided by mutually perpendicular lines passing through the center into four parts. Any two opposite quarters are sampled. By successive quartering, the sample is reduced by two to four times, etc. until a homogeneous laboratory sample is obtained, which is used to determine a specific indicator.

A new sample of sphagnum moss should be used for each test. Tests are carried out at temperature (20±2°C) and relative humidity (60±10%). To evaluate the results of the action of the modifier, a control sample is prepared - moss without the addition of a modifier.

3. Testing

The sample is first weighed on a laboratory scale with an error of 0.005 g. Then it is immersed in a container with KO-25 kerosene. The height of the kerosene layer above the sample must be at least 5 mm. Dive time - 1 hour. After immersion, remove the sample from the container and allow excess kerosene to drain on the 48/122 sieve cloth for a minute. Weigh again on a laboratory balance with an error of 0.005 g.

4. Processing of results

Oil absorption (W) of the samples is calculated by the formula:

M1 is the mass of the sample saturated with kerosene, g;

Μ is the mass of the sample before immersion in kerosene, g.

The arithmetic mean of the results of three parallel measurements is taken as the final test result.

Silicone-modified sphagnum moss has organosiloxane compounds on its surface that enhance the moss's ability to float (and not sink) and absorb significant amounts of oil or oil.

Experimental verification of the effectiveness of the modified sphagnum moss in comparison with the original sample showed a decrease in water absorption up to 2.5 times, and at the same time, an increase in the sorption capacity for oil products increased up to 10 times.

Modified sphagnum moss (hereinafter - Sorbent) absorbs oil products in a wide range of their viscosity. At the same time, the Sorbent does not have a harmful effect on the environment, is stable during long-term storage, and does not have an allergenic effect when used. The sorbent can be used in conjunction with biodestructors, while the sorbent does not lose its properties and does not disturb the natural ecological balance in case of prolonged exposure to water and soil.

The use of the Sorbent does not require special training. It is applied to contaminated areas both using sorbent sprayers (mechanically) and manually. It has a high sorption rate and capacity, it is used in a wide temperature range (from -40°С to +60°С).

In addition to absorbing and holding capacity, the sorbent promotes the biological decomposition of oil products in the natural environment and can be used in the process of recultivation of lands contaminated with oil products, including in conjunction with biodestructors of various origins.

Thus, an effective and environmentally friendly sorbent for water purification from oil products has been created, which ensures high purification efficiency, the arsenal of methods for obtaining sorbents and sorbents for water and soil purification has been expanded.

[1] ABSTRACT "USE OF NATURAL SORBENTS (MOS) FOR OIL SPILL RESPONSE IN THE SEA". Skiba O.N., Novorossiysk, 2014.

Claims (4)

1. Sorbent for removing oil products, which is sphagnum moss, treated with an organosilicon hydrophobizing liquid, namely, a silicone aqueous emulsion of ethylhydridesiloxane. 2. The sorbent according to claim 1, characterized in that crushed or non-crushed sphagnum moss with a moisture content of not more than 15% is selected as the feedstock, which is treated with a 4-6% aqueous solution of an organosilicon emulsion, after which it is subjected to heat fixation. 3. A method of manufacturing a sorbent for removing oil products, in which the feedstock, which is dried sphagnum moss, not crushed or crushed, is modified, namely, placed in a container with an aqueous solution of an organosilicon emulsion of ethylhydridesiloxane, then the excess emulsion solution is allowed to drain, after which the thermosetting of the hydrophobic element on moss is carried out in drying cabinets, after which the final drying is carried out in a drying cabinet with a temperature lower than the fixing temperature. 4. The method according to p. 3, characterized in that the feedstock is placed in a container with a 4-6% aqueous solution of an organosilicon emulsion of ethylhydridesiloxane for 10-12 hours, the excess emulsion solution drains for 25-35 minutes, the hydrophobic element is fixed carried out in drying cabinets at a temperature of 140-160°C for 4-6 minutes, the modified moss undergoes final drying in a drying cabinet with a temperature of 55-65°C for 2.5-3.5 hours.