RU2400286C1 - Filter material for cleaning liquid and gaseous substances and method of obtaining said material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to technological processes of chemical treatment of surfaces, particularly to design of agents and methods of modifying surfaces of natural and artificial solid bodies. The invention can be used in production of filter materials. The filter material contains a porous base with highly developed specific surface area and porosity, a selective layer made from polyvinyl alcohol or acrylamide polymer whose entire volume contains nanostructured silver particles obtained from a micellar solution, thereby forming an additional discrete layer with the following ratio of components in wt %: polyvinyl alcohol or acrylamide polymer 0.01-1.00, nanostructured silver particles 99.99-99.00. The method of obtaining material which is modified by silver nanoparticles involves preparation of a modifying solution of silver nanoparticles, holding the material in this solution and washing the material with distilled water.

EFFECT: more efficient integrated treatment of liquid and gaseous substances from toxic impurities and micro-biological contaminants, broader functional capabilities of filter material, reduced expenses, high quality of modified filter material.

4 cl, 2 tbl, 12 dwg

Description

Filtering material for the purification of liquid and gaseous substances and a method for its preparation

The invention relates to technological processes for the chemical treatment of surfaces, in particular, to the creation of means and methods for modifying the surfaces of natural and artificial solids, which can be used to produce filter materials for cleaning liquid and gaseous substances and is aimed at improving the environmental safety of the human environment by creating conditions for the comprehensive purification of drinking water and air inside buildings inhabited by people, structures and technical facilities units

In the last 10 years there has been a pronounced tendency to the moral aging of technologies and means for purifying water and air from organic impurities and microbiological contaminants.

Currently used water and air purifiers in conditions of increasing pollution of natural sources do not fully meet the increased requirements for the quality of drinking water and air, resistance to external influences, quality and ease of maintenance of equipment and its overall dimensions, reliability and durability.

In this regard, the most urgent is the development and creation of the latest environmentally friendly and resource-saving technologies and filtering materials for the purification of liquid and gaseous substances from toxic impurities and microbiological contaminants, which can improve the quality of water and air, the degree of their purification, increase their service life while reducing overall dimensions of the equipment and machinery used.

The need to create these tools and technologies is due to the population’s need for advanced means of purifying water and air from modern materials with improved performance characteristics produced by the domestic industry, which provide for the purification of water and air without impairing its sanitary and hygienic qualities, and they are not released into water during their operation or the air environment of substances harmful to human health.

Currently, tools and methods have been developed for modifying the surface of solid materials with nanostructured metal particles, allowing to obtain materials with bacteriological and catalytic properties.

Known methods for surface modification by nanostructured metal particles, in which it is possible to influence the modified surface on microbiological impurities in water placed in the tank, as well as obtaining modified surfaces of solid structural and other materials with predetermined antimicrobial and catalytic properties [patents of the Russian Federation, No. 2135262, B01D 39/08, publ. 1999, No. 2182934, С23С 10/20, publ. 2002, No. 2147487, B22F 9/24, publ. 2000].

The technical result of the known methods is to obtain a filter material that allows you to remove from the water contained in it microbiological impurities.

The disadvantages of such methods of obtaining filter material are primarily the high complexity and time to obtain them (up to 9-12 days), the low efficiency of water purification from microbiological contaminants, the relatively short operating time of the filter element due to the rapid washing out of silver nanoparticles from the surface of the filter material, and the limitations of their use in everyday life and especially in the food, biological and medical industries due to flushing into water from modifying surfaces along with nan silver particles and other components of the modifier solution, for example surface-active compounds (surfactants), sodium bis-2-ethyl-geksilsulfosuktsinata (trade name AOT) at a concentration higher than MAC standard.

Currently, air purifiers are widely used for air purification, conventionally divided by methods of air filtration into several main categories [Yu.D. Sibikin. Heating, ventilation and air conditioning. - M.: Academy, 2004, p.212-213; V.M.Svistunov, N.K. Pushnyakov. Heating, ventilation and air conditioning of agricultural facilities and housing and communal services. - St. Petersburg: Publishing. Politics, 2007, p. 274-279; V.P. Khokhryakov. Ventilation, heating and dust removal in the cabs of cars. - M.: "Engineering", 1987, S. 55-61]:

- adsorption filters;

- dust filters;

- ionizing cleaners or electrostatic precipitators;

- photocatalytic filters.

An analysis of the operational characteristics of these devices showed that they have a number of significant drawbacks, which include, first of all:

- incomplete air purification from volatile organic impurities and microbiological contaminants;

- limited application capacity of the main filter elements (filter materials);

- they themselves are sources of air pollution after adsorption by a porous carrier of harmful organic impurities and microbiological pollution;

- high operating costs and the cost of the equipment itself.

Currently, there are no developments of filter materials modified by nanostructured particles of silver or other metals, which are used to clean the air from organic impurities and microbiological contaminants.

Therefore, the problem of increasing the efficiency of integrated air purification from toxic impurities and microbiological contaminants while reducing operating costs for equipment and simplifying the method of air purification is relevant.

Of the known devices, the closest to the claimed technical solution (prototype) is “Filter material for cleaning liquid and gaseous substances”, made in the form of a porous base with a selective layer based on transition metal oxides. This material is equipped with an additional discrete layer made of radiation-generated silver nanostructured particles constituting no more than 0.02% by weight of the filter material, having a concentration of radiation-generated silver nanostructured particles of not more than 50 mg / kg of the base and located on the porous surface of the filter material with the formation of ultrafiltration material with bactericidal properties.

A layer of silver nanostructured nanoparticles is deposited on a porous base by adsorption of these particles from their aqueous solution.

Moreover, the porous base is made of large-porous oxide ceramics with pore sizes from 15 to 20 microns, or in the form of a metal mesh having a lumen size of not more than 5 microns [certificate for utility model of the Russian Federation No. 134949, B01D 69/10, publ. 2000].

However, the known filter material, having bactericidal properties, can be used to purify liquid and gaseous substances only from microbiological pollutants at a very low filtration rate of substances through ultrafiltration material, and in view of its physical properties, it is not intended to purify air from toxic impurities (various organic and inorganic substances and their mixtures).

In addition, the method of producing silver nanostructured particles by the radio-chemical method is an expensive, unsafe, unique method of its kind, requiring special training of specialists, equipment and technology for working with it. It is for these reasons that this method has not yet found in practice its widespread adoption.

Of the known methods, the closest to the proposed technical solution (prototype) is the "Method of obtaining modified carbon nanoparticles of silver material with biocidal properties." In the known method for producing a silver nanoparticle-modified carbon material, comprising preparing a silver nanoparticle modifying solution, exposing the carbon material in a silver nanoparticle modifying solution, washing the carbon material according to the invention, their aqueous dispersion is used as a modifying solution of silver nanoparticles, obtained from a reverse micellar solution of silver nanoparticles on based surfactant in a non-polar solvent in which the concentration of silver nanoparticles is selected rayut in the range of 2.10 × 10 -3 ^{-4 -3} g-ion / l and the surfactants concentration is not more than 1.5%, a carbon material is kept modifying the silver nanoparticles solution for at least 8 hours, washed with distilled water carbon material until surfactant concentration in wash water is not more than 0.1 mg / l. Thus, the problem formulated in the known invention is solved by the fact that to modify the surface of the carbon material, a stable aqueous dispersion of silver nanoparticles obtained from their inverse micellar solution is used at a correspondingly selected concentration of silver nanoparticles and surfactants, and the concentration of surfactants in the aqueous dispersion of nanoparticles and in water is controlled flowing during washing through a modified material [patent of the Russian Federation No. 2202400, B01D 39/00, B01j 20/20, publ. 2003].

At the same time, along with many positive aspects of the above-mentioned method (as applied to the curled method), it has a number of serious limitations that limit its widespread use in practice.

These limitations include, first of all: Firstly, to implement the known method for preparing an aqueous dispersion of nanostructured silver particles obtained from a reverse micellar solution after separating the aqueous dispersion mixture from a non-polar solvent in a mixture volume of more than 1 l, further purification of the aqueous dispersion of silver nanoparticles from an excess of non-polar solvent and surfactant is a labor-intensive process and usually takes 3-5 days. This leads to high energy and time costs, low productivity of the finished product and increases the level of fire and explosion hazard of production. Obtaining an aqueous dispersion of silver nanoparticles by centrifuging a two-phase system of a reverse micellar solution of silver and water nanoparticles and separating the lower aqueous phase containing silver nanoparticles is in practice unacceptable with even small (more than 1 L) volumes of obtaining an aqueous solution of metal nanoparticles.

Secondly, the modification of the carbon material by silver nanoparticles by a known method, including: exposure of the carbon material in a modifying solution of silver nanostructured particles (at least 9 hours) and repeated washing of the carbon material with distilled water, is a time-consuming and time-consuming process.

Thirdly, the use of carbon material modified by the known method using the activated carbon of the AG-3 brand as an example does not lead to the complete purification of the seeded water by viable E.coli bacteria cells. The inactivation level is on average 47.25 ± 4.36%, which is on average 20.34 ± 2.12% higher than the level of inactivation of E. coli bacteria with coal without silver nanoparticles.

At the same time, the volume of purified water with such a low effect does not exceed 4 l, which in practice sharply limits the possibilities and applications of this modified coal.

Fourth, as a result of numerous experiments to expand the spectrum of the possible use of filtering porous material, we have established that this method:

- only partially suitable for producing carbon nanoparticles modified with silver nanoparticles, which include only activated carbons such as AG-2, AG-3, and others;

- partially applicable with low efficiency of modification and the final effect of inactivation of bacteria for other activated carbons, such as coconut charcoal;

- it is practically not applicable for the modification of numerous modern synthetic non-woven materials and fabrics (for example, such as polystyrene, polypropylene, fiberglass, etc.), since nanostructured silver particles from an aqueous dispersion are not adsorbed on the above materials.

Fifth, experience has shown that the application of the known method for producing a carbon material modified by nanoparticles to create cartridges for air purification from toxic impurities and microbiological contaminants when used for their intended purpose is ineffective in both time and degree of air purification due to the instability of coal adsorbed on the surface or carbon fabric of nanostructured silver particles, which reduces the environmental safety of the use of such cartridges.

The problem to which the present invention is directed, is the development and creation of a filter material and a method for its preparation for cleaning liquid and gaseous substances passing through a porous carrier with reliable adhesion of the selective layer, which allows to keep on its surface an active component of silver nanostructured particles and providing access reacting substance to the active centers of the catalyst from silver nanoparticles involved in the purification of liquid or gaseous substances in chemical transformations x of organic and inorganic air contaminants to simple forms of molecules (e.g., C, H _2, O _2, etc.) due to the occurrence of a zone of nanostructured particles the electric field of silver, and at the same time causing, due to their additional biocidal activity, destruction of various microorganisms.

The technical result of the present invention is to increase the efficiency of complex cleaning of liquid and gaseous substances from toxic impurities and microbiological contaminants, expand the functionality of its use, reduce costs, improve the quality of the modified filter material when it is used in the form of a filter element of liquid or gaseous substances.

The above problem is solved by the fact that in the known filtering material for cleaning liquid and gaseous substances, made in the form of a porous base with a selective layer and an additional discrete layer made of nanostructured silver particles, the selective layer is made of polyvinyl alcohol or acrylamide polymer, and an additional discrete the layer is located throughout the volume of the selective layer and contains nanostructured silver particles obtained from a micellar solution, with the following ratios of components, wt.%: vinyl alcohol or polymer acrylamide 0.01-1.00, nanostructured silver particles 99.99-99.00, and the fact that the porous base is made in the form of natural or artificial solids with a high developed specific surface area and porosity, and the fact that in a method for producing a silver nanoparticle-modified filter material for purifying liquid and gaseous substances, including preparing a modifying solution of silver nanoparticles, holding the material in a modifying solution of silver nanoparticles and washing the material with distillation water, prepare 0.01-1.00% (wt.) an aqueous solution of polyvinyl alcohol or acrylamide polymer, after which they impregnate the porous base of the material for 5-10 minutes at a temperature of plus 20-25 ° C, dried at a temperature of plus 60- 70 ° C for 3-4 hours until its constant mass is established with the formation of a selective layer on the porous surface of the filter material, after which a modifying solution of silver nanoparticles is prepared in the form of a micellar solution based on a surfactant in a non-polar solvent in which entratsiyu silver nanoparticles are selected in the range of 2.0 × 10 ^-3 -6.5 × 10 ^-3 g-ion / l and the concentration of surfactant is 1.5-6.0% (wt.), and their selective impregnated the layer previously deposited on a porous base, withstand the filter material in a modifying solution of silver nanoparticles for 1-2 hours until the formation of an additional discrete layer, after which it is filtered and dried at a temperature of + 60-70 ° C for 3 to 4 hours and at if necessary, cool to a temperature of plus 20 - 25 ° C, and the fact that the resulting filter material for cleaning liquid still washed with distilled water until a surfactant concentration of not more than 0.5 mg / l is obtained in the washings, then dried at a temperature of plus 60-70 ° C for 3-4 hours and cooled to a temperature of plus 20-25 ° C .

A fragment of a variant of the filtering material with modified nano-structural particles of silver in cross section is shown in figure 1, where:

1 - a layer of a porous base of filtering material from natural or artificial solids with a high developed specific surface area and porosity, for example, clay, pumice, geyserite, mullite, activated carbon, etc. [Scientific principles of the production of catalysts. / Ed. R.A. Buyanova. - Novosibirsk, 1982; Catalyst technology. / Ed. IP Mukhlenova, 3rd ed., - L., 1989.] As a porous base, according to the claimed invention, in addition to the above materials, can be applied: various types of synthetic fiber; polymer carbon fibers, for example, aqualen; textile filtering materials from nonwoven materials (for example, polypropylene, polyester, polyacrylonitrile and other types of fibers), which include coarse filters (class G1-G4), fine filters (class F5-F9), high-efficiency filters (class NU - HI4), ultrahigh efficiency filters (class U15-U17) [GOST R51251-99].

2 - a selective layer consisting of PVA [GOST 10779-78] or acrylamide polymer (PA) [TU 2216-010-55373366-2007].

3 - an additional discrete layer made of nanostructured silver particles obtained by a known method [RF patent No. 2147487, 7 B22, F 9/24, publ. 2000] with the introduction of a new distinguishing feature for the production and application of a range of concentrations of silver nanoparticles and surfactants in micellar solution.

A method of obtaining a filter material for cleaning, for example, gaseous substances is as follows. Prepare 0.01-1.0% (wt.) Aqueous solution of PVA [GOST 10779-78] or polymer acrylomide [TU 2216-010-55373366-2007].

Then select the filter material and impregnate the porous base of the material for 5-10 minutes at a temperature of 20-25 ° C, then dry at a temperature of plus 60-70 ° C for 3-4 hours until its constant mass is established with the formation of a selective layer on porous filter media.

The porous base of the filter material is selected based on for what purposes or in what filter device it is intended to be used.

Next, prepare a micellar solution of silver nanoparticles based on a surfactant in a non-polar solvent in accordance with the patent of the Russian Federation [No. 2147487]. The concentration of silver nanoparticles in the micellar solution is chosen in the range of 2.0 · 10 ^-3 -6.5 · 10 ^-3 g-ion / l, and the surfactant concentration is 1.5-6.0% (0.034 M - 0.135 M) and impregnated them a selective layer deposited before on the porous base of the filter material. The filter material is kept in a modifying solution of silver nanoparticles for 1-2 hours until an additional discrete layer is formed. Then the filter material is separated from the remnants of the micellar solution of silver nanoparticles, dried at a temperature of plus 60-70 ° C for 3-4 hours and cooled to a temperature of plus 20-25 ° C.

The method of obtaining filter material for cleaning liquid substances is carried out similarly to the method for producing filter material for cleaning gaseous substances. At the same time, to prevent the surfactant from being washed away from the filter material for water purification with a concentration higher than the permissible MPC, the resulting filter material is washed with distilled water until a surfactant concentration of not more than 0.5 mg / l is obtained in the wash water.

Then the washed filter material is dried at a temperature of plus 60-70 ° C for 3-4 hours and cooled to a temperature of plus 20-25 ° C.

To control the concentration of surfactants in the water flowing through the modified filter material, any control method can be used, for example, the technique described in the literature [Unified methods for studying water quality. 4.1. "Methods of chemical analysis of water." 4th Edition. - M., 1979, S. 677-683].

As studies have shown, with a concentration of silver nanoparticles in a micellar solution in the range of 2.0 · 10 ^-3 -6.5 · 10 ^-3 g-ion / l, it is possible to obtain an adjustable nanoparticle density in a selective layer of PVA or acrylamide polymer, which provides sufficient a high level of its activity in the purification of liquid and gaseous substances. The formation and concentration of silver nanoparticles in a micellar solution and their stability on the selective layer of the filtering material after their adsorption are monitored spectrophotometrically based on changes in the main characteristics of the optical absorption spectra (positions of the maximum absorption band, maximum optical density and half width of the band).

In contrast to the prototype, the obtained ingredients of the concentration of silver nanoparticles in a micellar solution allow to obtain a high level of yield of the final product when using the inventive method for producing filter material with a high degree of complex purification of liquid and gaseous substances from organic impurities and microbiological contaminants.

According to the above in the description of patent RU 2147487 C1 B22F 9/24, 04/20/2000, during the preparation of a micellar solution of silver nanostructured particles according to the known method, sodium bis-2-ethylhexyl sulfosuccinate (RT aerosol) is used as a surfactant. As a non-polar solution, substances from the group of saturated hydrocarbons are used: n-hexane, or n-heptane, or n-octane, or n-decane, or cyclohexane, or isooctane.

To prepare a micellar solution of silver nanostructured particles, the following types of substances were used as an example:

- silver nitrate (AgNO ₃ ) according to GOST 1277;

- flavonoid, With AS 6151-25-3;

- surfactant sodium bis-2-ethylhexyl sulfosuccinate (OT aerosol) (C ₂₀ H ₃₇ NaO ₇ S, CAS 577-1-7);

- non-polar solvent isooctane reference in accordance with GOST 12433.

To obtain a micellar solution of nanostructured silver particles, silver nitrate ions were introduced into the reverse micellar dispersion of a flavonoid (reducing agent) in the form of an aqueous solution.

Modification of the filter material with nanostructured silver particles in practice is carried out using the proposed method.

In the experimental development of options for filter material used:

1. As a porous base -

a) Synthetic non-woven hydrophobic rolled material [GOST R 51251-99, CENEN 779-1993; CENEN 1822-1998] of the following grades: FM - 2X, h = 5 mm, cleaning class G2, fiber type polyester; FM - 3X, h = 15 mm, cleaning class G3, fiber type polyester, polypropylene; HY-W-906, h = 0.5 mm, cleaning class F7, type of fiber polypropylene.

b) Carbon paper grade 5243V4, article 00903, h = 1.5 mm.

c) Activated coconut charcoal grade 607 C (CERTIFICATE OF ANALYSIS 5344).

d) Activated birch charcoal, brand KFG-M, [TU 6-55-221-1061-2003].

d) Pumice [GOST 9757].

2. As a selective layer -

a) Acrylamide polymer [TU 2216-010-55373366-2007].

b) Polyvinyl alcohol [GOST 10779-78].

3. To create an additional discrete layer, a micellar solution of nanostructured silver particles was used [RF patent No. 2147487, 7 V 22, F / 24, publ. 2000] with introduced into the inventive method new distinctive features for obtaining a range of concentrations of silver nanoparticles and surfactants in a micellar solution.

Modification of the filter material with nanostructured silver particles was carried out according to the claimed invention.

Variants of techniques for the specific implementation of the method of obtaining filter material:

a) Filter material for water treatment.

Example 1 (prototype)

Prepare an aqueous solution of silver nanoparticles with a concentration of 3 · 10 ^-3 g-ion / L. To 22.0 g of birch coal (KFG-M brand, d = 0.34 g / cm ³ ), 500 ml of an aqueous solution of silver nanoparticles with a concentration of 3 · 10 ^-3 g-ion / l are added, the mixture is stirred and incubated for 72 hours at a temperature of 20-25 ° C. Next, the coal is filtered off and repeatedly washed with distilled water (0.2-0.5 l of water per 1 g of material) until a surfactant concentration of not more than 0.1 mg / l is obtained in the wash water.

Example 2

Prepare a 0.1% aqueous solution of PVS. To 22.0 g of birch coal (KFG-M brand, d = 0.34 g / cm ³ ) add 40 ml of a 0.1%) aqueous solution of PVA at 20-25 ° C, they are impregnated with coal, stirring the mixture for 5-10 minutes, and dried at a temperature of 60-70 ° C for 3-4 hours until a constant mass of coal is established. Prepare 70 ml of a modifying solution of silver nanoparticles in the form of their micellar solution based on surfactants in a non-polar solvent, in which the concentration of silver nanoparticles is chosen 3 · 10 ^-3 g-ion / l, and the concentration of surfactants is 2.48 wt.% (0.056 M) . Next to the previously obtained mixture of a 0.1% aqueous solution of PVA with coal, 70 ml of a micellar solution of silver nanoparticles with a concentration of 3 · 10 ^-3 g-ion / l are added, stirred at a temperature of 20-25 ° C for 1-2 hours, filtered , dried at 60-70 ° C for 3-4 hours and washed with distilled water until a surfactant concentration of not more than 0.5 mg / l is obtained in the washings, after which it is dried at a temperature of 60-70 ° C for 3-4 hours and cooled to 20-25 ° C.

Example 3

The manufacture of filter material is carried out according to example 2 with the difference that an aqueous solution of PVA is prepared and used with a concentration of 0.5%. The concentration of silver nanoparticles in the micellar solution is chosen 6.5 · 10 ^-3 g-ion / l, and the surfactant is 6.0%, mass (0.135 M).

Example 4

The manufacture of filter material is carried out according to example 2 with the difference that an aqueous solution of PVA is prepared and used with a concentration of 0.75%. The concentration of silver nanoparticles in a micellar solution is chosen 4.5 · 10 ^-3 g-ion / l, and the surfactant is 4.97 wt.%. (0.112 M).

Example 5

The manufacture of filter material is carried out according to example 2 with the difference that coconut charcoal (grades 607 C, d = 0.45 g / cm ³ ) is used and an aqueous PVA solution with a concentration of 1.0% is used. The concentration of silver nanoparticles in the micellar solution is chosen 2 · 10 ^-3 g-ion / l, and the surfactant is 1.51 wt.% (0,034 M).

b) Filter material for air purification.

Example 1 (prototype)

Prepare 1 l of an aqueous solution of silver nanoparticles with a concentration of 2 · 10 ^-3 g-ion / l, place a plate of synthetic non-woven material of the FM - 3X grade, cleaning class G3, h = 15 mm, size 330 x 330 mm at a temperature of 20 -25 ° C and maintained at this temperature for 1 hour. Next, the plate is dried at 40-50 ° C for 3-4 hours.

Example 2

Prepare 1 liter of an aqueous 0.5% aqueous solution of PVA, place a plate of non-woven fabric of the FM - ZX brand, cleaning class G3, h = 15 mm, size 330 × 330 mm, and impregnate the porous base of the material for 5-10 minutes at temperature plus 20-25 ° C, then dried at a temperature of plus 60-70 ° C for 3-4 hours to establish its constant mass. Next, 1 l of a modifying solution of silver nanoparticles is prepared in the form of a surfactant-based micellar solution in a non-polar solvent, in which the concentration of silver nanoparticles is chosen to be 2 · 10 ^-3 g-ion / l and the plate of nonwoven fabric dried with PVA is placed in this solution, impregnated with it a selective layer of PVA, previously deposited on a porous base. Next, the filter material is kept in a modifying solution of silver nanoparticles for 1 hour until the formation of an additional discrete layer, then the plate is dried at a temperature of plus 60-70 ° C for 3-4 hours.

Example 3

The manufacture of the filter material is carried out according to example 2 with the difference that 1 l of a 0.5% aqueous solution of acrylamide polymer is prepared and impregnated with a porous base of non-woven material of the FM-ZX brand, cleaning class G3, h = 15 mm, size 330 × 330 mm in for 5-10 minutes at a temperature of plus 20-25 ° C. Further technological operations are carried out analogously to example 2.

Example 4

The manufacture of the filter material is carried out according to example 2 with the difference that the aqueous PVA solution is prepared with a concentration of 0.01%, a plate of non-woven material of the FM-2X brand is placed in it, cleaning class G2, h = 5 mm, size 330 × 330 mm. Further technological operations are carried out analogously to example 2.

Example 5

The manufacture of the filter material is carried out according to example 2 with the difference that 1 l of a 0.15% aqueous solution of acrylamide polymer is prepared and impregnated with the porous base of the filter material of the brand HY-W-906, purification class F7, h = 0.5 mm for 5 -10 min at a temperature of plus 20-25 ° C. Further technological operations are carried out analogously to example 2.

Example 6

The manufacture of filter material is carried out according to example 2 with the difference that carbon paper of the grade 5243V4, cleaning class F5, h = 1.5 mm is used as the porous base of the filter material. Further technological operations are carried out analogously to example 2.

Example 7

The manufacture of filter material is carried out according to example 2 with the difference that they prepare 0.5 l of a 0.2% aqueous solution of acrylamide polymer and impregnate the porous base of the filter material with it for 5-10 minutes at a temperature of + 20-25 ° C. As a porous base of the filtering material, 1 kg of activated coconut charcoal of grade 607 C is used. Further technological operations are carried out analogously to example 2.

Example 8

The manufacture of filter material is carried out according to example 2 with the difference that 1 l of a 0.01% aqueous solution of PVA is prepared and impregnated with the porous base of the filter material for 5-10 minutes at a temperature of plus 20-25 ° C. As a porous base of the filter material, 1 kg of pumice is used. Further technological operations are carried out analogously to example 2.

The filtration efficiency or filtering ability of various prepared variants of activated carbon for water purification was evaluated on the international strain Escherichia coli ATCC 25922 (collection of the Legionellosis Laboratory of the NIIEM Gamalei RAMS RAMS).

Cultivation of E. coli strains was performed on nutrient agar (PA), tryptic soy agar (TCA) and in the same broths (PS and TSB, respectively) (Difco) for 18 hours at 37 ° C. Endo medium and biochemical tests were used to identify E. coli isolates isolated from water during the filtration process. An E. coli culture for performing the experiments was obtained by growing an aliquot of the overnight culture in PB or TSB in the same broths (culture to broth ratio 1:10) by joking (170 rpm) for 5 hours at 37 ° C, or on PA , or TCA for 18 hours at the same temperature.

For suspension of bacteria at a concentration of 109 CFU / ml in sterile physiological saline (RF), grown cultures and a turbidity standard of 10 units were used. When performing experiments in order to eliminate the influence of the presence of chlorine compounds in water, sterile RF was used. The initial suspension of Escherichia coli bacteria in a sterile RF at a concentration of 1000 CFU / ml, or 100,000 CFU / ml, was prepared by adding the appropriate volume of the initial culture to a certain volume of RF.

The concentration of E. coli bacteria in water before and after filtration was estimated by sampling water spilled through a column of coal in the corresponding time periods of its titration in the RF through 2, 4, 6, 8, 10, 13, 16, 19, 21, 23, 25, 30, 35 L, respectively, seeding on Petri dishes with PA or TCA in 0.1 ml and incubating them at a temperature of 37 ° C for 24-48 hours. Next, counting the number of grown colonies and determining the concentration of bacteria (CFU in ml) in accordance with the frequency of titration and the volume of culture used for sowing.

At the same time, the rate of water spilled through the charcoal filter was 100 ml / min. The diameter of the column is 30 mm, the height is 60 mm.

The results of evaluating the effectiveness of water purification from bacteria of E. coli strain ATCC 25022 are shown in table 1.

As a result of laboratory tests of the manufactured filter material options for water purification, it was found that in comparison with the prototype (see table 1, p. 2), all filter material options obtained in accordance with the inventive method for their preparation (see table 1 , items 3, 4, 5, 6) during the entire volume of transmission through the column with modifying carbon, a steady decrease in the concentration of viable E.coli bacteria cells is observed. The level of bacterial inactivation, depending on the method of applying silver nanoparticles to activated carbon, is 100% of their initial concentration in water when it is passed through the column in an amount of 19 to 35 liters, while the prototype only has up to 4 liters. In General, the level of inactivation of E. coli bacteria in the prototype is 88.5%. At the same time, in the control column (see table 1, p. 1) with coal without silver nanoparticles, the level of inactivation of E. coli bacteria is much lower and averages 74% for 35 liters of filtered water through the column.

The filtration efficiency or the filtering ability of the prepared filter material options for purifying air from test air pollutants using the example of AHS acetone, carbon dioxide, formaldehyde and their mixtures was carried out in a special laboratory-measuring complex.

The complex consists of the following parts:

- sealed box of 200 liters made of stainless steel;

- a computer that records and displays sensor signals in real time.

In the box there is an electric heater for evaporating a liquid test substance.

In the side wall of the box there are fittings for introducing gaseous test contaminants into the box and connecting an external gas sensor. In addition, the box is equipped with:

- external optical infrared gas sensor CO ₂ type IGS-016-00;

- FLORA-SV formaldehyde gas analyzer;

- gas thermocatalytic hydrocarbon sensor.

Outside the box, there is a power supply and signal processing unit for gas sensors and an electronic unit for signal processing and communication with a computer.

As an experimental sample of an air purifier, we used a modified commercially available case with a fan from the Aero Barrier photocatalytic air purifier, model AP270FC.

In a modified housing of the Aego Wagieg air purifier, successively manufactured versions of the filter material were installed as an air cartridge undergoing tests.

An air cleaner with an installed cartridge option was placed in the box.

The air purifier was turned on, the operation mode of its fan was set AIR MEDIA (About ~ 150 m3 / h), after which the box was closed. All other equipment turned on.

After some time (~ 10 min), a test contaminant was injected into the box through an air nozzle: carbon dioxide, or formaldehyde, or TSP of acetone, or their binary or ternary mixtures.

To record the concentration of carbon dioxide, an external optical infrared gas sensor IGS-016-00 was used, which has a built-in microprocessor for recirculating air from the box. The measurement range of the relative concentration of carbon dioxide is 0-1%. Sensor accuracy ± 0.1%.

To register the concentration of formaldehyde vapors, a FLORA-SV formaldehyde gas analyzer was used, which has a measurement range of formaldehyde concentrations of 0-8 mg / m3. Sensor accuracy ± 20%.

To register formaldehyde vapors, a test pollutant was injected and evaporated into a box on a heated evaporator in a 2% aqueous formaldehyde solution.

To record the concentration of acetone vapor, a gas thermocatalytic hydrocarbon sensor was used.

Previously, the thermocatalytic hydrocarbon sensor was calibrated in a test box using VHF acetone vapor (mV / mg). Sensor accuracy ± 10%.

To register VOC acetone vapors, a test pollutant was injected and evaporated into the box on a heated evaporator (100 mg VAC acetone).

The sensors were recorded and recorded for a specified time with a measurement accuracy of 1 s. The tests were carried out both with one test pollutant, and with a mixture of two or three pollutants.

To register convertible oxygen in the box, stationary gas analyzers of the IGS-98 series were placed inside the box, having an external signal output for recording their readings:

- oxygen analyzer (O ₂ ) "KLEVER-SV", measuring range 0-30 vol.%, measurement accuracy ± 0.5 vol.%;

- gas analyzer of carbon monoxide (CO) "MAK-SV", measuring range 0-300 mg / m3., measurement accuracy ± 1 mg / m3;

- gas analyzer of nitrogen dioxide (NO ₂ ) "AGAT-SV", measuring range 0-30 mg / m3., measurement accuracy ± 1 mg / m3.

All gas analyzers are certified and passed state verification.

The results were recorded in the computer's memory and presented as a dependence showing the change in the concentration of the test pollutant in the box, for example, carbon dioxide, or formaldehyde vapor, or VOC acetone vapor, or their binary or ternary mixtures over time.

The rate of conversion and accumulation in the box of molecular oxygen O ₂ was also recorded during the destruction of large concentrations (up to 6%) of carbon dioxide CO ₂ .

Thus, when testing the manufactured versions of the filtering material for air purification, we obtained the efficiency of each option for the destruction of test pollutants or the conversion of oxygen from carbon dioxide over time. The results of the tests on test pollutants: carbon dioxide, formaldehyde vapor, VOC acetone vapor and mixtures thereof are shown in figure 2-12 and table 2, where:

Figure 2 - a characteristic view of the experimental curves of the destruction of a three-component mixture of test pollutants over time in a closed box of 200 liters when it is filtered through a modified nanoparticles of silver filter material brand FM-3X, class G3, a thickness of 15 mm

The upper curve is carbon dioxide;

middle curve - acetone vapors;

the lower curve is formaldehyde vapor.

Figure 3 - the dependence of the destruction of the test pollutant of carbon dioxide over time in a closed box of 200 liters when it is filtered through a modified nanoparticles of silver filter material brand FM-3X, class G3, a thickness of 15 mm

Figure 4 - the dependence of the destruction of the test pollutant vapor VHF acetone in time in a closed box with a volume of 200 liters when it is filtered through a modified nanoparticles of silver filter material brand FM-3X, class G3, a thickness of 15 mm

Figure 5 - the dependence of the destruction of the test pollutant of formaldehyde vapor in time in a closed box with a volume of 200 liters when it is filtered through a filter material modified with silver nanoparticles grade FM-3X, class G3, a thickness of 15 mm

Figure 6 shows the time dependence of the destruction of the test pollutant of VHF acetone vapors in a closed box of 200 liters when it is filtered through a filter material modified with silver nanoparticles, grade FM-2X, class G2, 5 mm thick.

Fig. 7 shows the dependence of the destruction of a mixture of test carbon dioxide pollutants (upper curve) and VHF acetone vapor (lower curve) over time in a 200-liter closed box when it is filtered through a NY-W-906 grade F7 grade filter material modified with silver nanoparticles , 0.5 mm thick.

Figure 8 shows the time dependence of the destruction of a mixture of test carbon dioxide pollutants (upper curve) and the sorption of VHF acetone (lower curve) in time in a closed box of 200 liters when it is filtered through a 5243V4 carbon paper filter material modified with silver nanoparticles, class G7, 1.5 mm thick.

Fig. 9 shows the time dependence of the degradation of a test carbon dioxide pollutant in a closed box with a volume of 200 liters when it is filtered through activated coconut charcoal grade 607 C modified with silver nanoparticles, layer thickness 15 mm.

Figure 10 - the dependence of the destruction of the test pollutant of carbon dioxide over time in a closed box of 200 liters when it is filtered through modified with silver nanoparticles pumice GOST 9757, layer thickness 15 mm

11 - the dependence of the conversion of oxygen during the destruction of the test pollutant of carbon dioxide over time in a closed box of 200 liters when it is filtered through a modified nanoparticles of silver filter material brand FM-3X, class G3, a thickness of 15 mm

Fig - time dependence of the destruction of a mixture of test carbon dioxide pollutants (upper curve) and VHF acetone vapors (lower curve) in time in a closed box of 200 liters when it is filtered through a filter medium modified with silver nanoparticles grade FM-2X, class G2, thickness 5 mm.

For all tested variants of the filtering material, its geometric dimensions were 330 × 330 mm.

As a result of laboratory tests of the manufactured filter material options for air purification, the following was established.

Firstly, the modification of the porous base of the filter material of the FM-3X grade of G3 purification class with silver nanoparticles obtained by a known method [see RF patent No. 2202400] from an aqueous dispersion is inefficient, since silver nanoparticles are not evenly adsorbed on the non-woven synthetic material used in this example, and therefore the use of such a filter material as a filter does not provide air purification from toxic impurities.

Secondly, it was found that filtering materials manufactured in accordance with the claimed method acquired new properties. In addition to filtering the air from mechanical impurities, they began to effectively clean the air from all kinds of organic contaminants (see figure 2-12, table 2). Coal materials, while maintaining their sorbing properties, have acquired the property of purifying air from light molecular pollutants that are not amenable to sorption. Carbon-filled and charcoal filtering materials and pumice (see Fig. 8, 9, 10, Table 2) showed good results in the destruction of carbon dioxide and simultaneous sorption of vapors of OHS acetone.

The service life of modified carbons can be significantly increased.

When the air purifier is used for all filter media obtained in accordance with the inventive method for their preparation (see Table 2), during a given air filtration time, a significant decrease in the concentration of test carbon dioxide pollutants, formaldehyde vapor, VOC acetone vapor, and their mixtures from the concentration originally created in boxing.

As a result of a series of tests, it was found that during the operation of the experimental sample of the air purifier, there is a significant decrease in the concentration of hydrocarbons in acetone from the concentration initially created in the chamber (500 mg / m3) with a destruction rate of up to 20 mg / hour, and significant destruction of carbon dioxide occurs gas speeds of up to 200 mg / hr, at an initial concentration ~ 0.25% CO ₂ (all of the filter material of the geometrical dimensions of the test variants were 330 × 330 mm) that exceeds the level of the eyes heel, for example, the existing fleet of photocatalytic air purifier type of acetone, and has no analogues of carbon dioxide:

MIDEA, model KJ180-T, made in China;

DAIKIN, model MC704VM, made in Japan;

BORK, model APRJH1515SI, made in Germany;

VITEK, model VT-1775, production Austria;

NHW, model 968, made in China.

The type of experimental curves (see FIGS. 2-12) for the destruction of a mixture of test pollutants allows us to judge that the destruction of each pollutant occurs according to a scheme identical to the destruction of a single pollutant, that is, the efficiency of the filter material depends little on the amount of pollutants in the air without the influence of the destruction of one substance on another.

Of particular note is the phenomenon of the dependence of carbon dioxide destruction over time (see FIGS. 2-12) first established in the field of air purification from pollutants while converting molecular oxygen O ₂ and atomic carbon C without the formation of nitrogen dioxide N02 and carbon monoxide CO (see 11, table 2).

The experimentally established effect of cleaning the air from toxic impurities with their destruction to simple forms of molecules (C, H ₂ , O ₂ , etc.) opens up new possibilities in the field of environmental support of the human environment in closed buildings for various purposes.

Thus, as a result of the use of the inventive filter material for the purification of liquid and gaseous substances and the method for its preparation, the problem was solved and new technological results were achieved.

The most successfully claimed method of producing filter material with new improved physical properties is industrially applicable in the technological processes of chemical treatment of natural and artificial solid materials with a high developed specific surface area and porosity to obtain a new generation of filter materials from organic impurities and microbiological contaminants.

Table 1 The results of evaluating the effectiveness of water purification from bacteria of E. coli strain ATCC 25022 No. p / p Filter material The concentration of bacteria in physical. solution (CFU / ml) The number of live bacteria (CFU / ml) after filtration through a column in water samples through, l 2 four 6 8 10 13 16 19 21 23 25 thirty 35 one. The control. Coal birch grade KFG-M without LF Ag * 3 · 10 ³ 500 600 600 700 600 700 800 900 10 ³ 10 ³ 10 ³ 10 ³ 10 ³ 2. Example 1 (prototype) Coal birch grade KFG-M with LF Ag 3 · 10 ³ 0 0 10 thirty 70 80 80 one hundred 150 250 10 ³ 10 ³ 10 ³ 3. Example 2. Coal birch grade KFG-M with NP Ag 2.5 · 10 ³ 0 0 0 0 0 0 0 0 70 800 fifty 400 10 ³ four. Example 3. Coal birch grade KFG-M with Ag NP 3 · 10 ³ 0 0 0 0 0 0 0 0 0 0 0 0 0 5. Example 4. Birch coal brand KFG-M with Ag NP 2.6 · 10 ⁵ 0 0 0 0 0 0 0 0 0 0 0 0 90 6. Example 5. Coconut coal grade 607C LF 2.0 · 10 ³ 0 0 0 0 0 0 0 fifty 70 160 180 300 600 * Ag NPs - nanostructured silver particles

table 2 The results of evaluating the effectiveness of air purification from test pollutants №№ p.p. figures Test substance Initial test pollutant concentration The final concentration of the test pollutant Destruction rate Test time Figure 2 Mixture: carbon dioxide; 0.54% 0.38% 0.068% / hour acetone vapor: 100 mg 69 mg 13.2 mg / hour 2.35 hour formaldehyde vapor 0.496 mg 0.192 mg 0.65 mg / hour Figure 3 Carbon dioxide 0.635% 0.45% 0.11% / hour 1.67 hour Figure 4 Acetone vapor 100 mg 61 mg 20.4 mg / hour 1.9 hour Figure 5 Formaldehyde vapor 0.3 mg 0.12 mg 0.08 mg / hour 2.3 hour 6 Acetone vapor 100 mg 73 mg 11.6 mg / hour 2.35 hour 7 Carbon dioxide 0.205% 0.148% 0.04% / hour 1.43 hours Acetone vapor 100 mg 76 mg 16.4 mg / hour Fig. 8 Carbon dioxide 0.2% 0.15% 0.05% / hour 1.03 hour Fig.9 Carbon dioxide 0.23% 0.2% 0.02% / hour 1.65 hour Figure 10 Carbon dioxide 0.153% 0.11% 0.038% / hour 1.12 hour 11 Oxygen 11.3% 17.2% 1.3% 4.53 hour Carbon dioxide 45.4% 16.9% 6.29% 12 Mixture: carbon dioxide; 0.505% 0.363% 0.064% / hour 2.23 hour acetone vapor 100 mg 53 mg 21.4 mg / hour

Claims (4)

1. Filtering material for cleaning liquid and gaseous substances, made in the form of a porous base with a selective layer and an additional discrete layer made of nanostructured silver particles, characterized in that the selective layer is made of polyvinyl alcohol or acrylamide polymer, and an additional discrete layer is located at the entire volume of the selective layer and contains nanostructured silver particles obtained from a micellar solution, in the following ratios of components, wt.%: polyvinyl alcohol or polymer acrylamide 0.01-1.00, nanostructured silver particles 99.99-99.00. 2. The filter material according to claim 1, characterized in that the porous base is made in the form of natural or artificial solids with a high developed specific surface area and porosity. 3. A method of obtaining a modified silver nanoparticles filter material for the purification of liquid and gaseous substances, comprising preparing a modifying solution of silver nanoparticles, holding the material in a modifying solution of silver nanoparticles and washing the material with distilled water, characterized in that 0.01-1.00 wt. %, an aqueous solution of polyvinyl alcohol or acrylamide polymer, after which the porous base of the material is impregnated for 5-10 minutes at a temperature of plus 20-25 ° C, dried at a temperature of plus 60-70 ° C for 3-4 hours until its constant mass is established with the formation of a selective layer on the porous surface of the filter material, after which a modifying solution of silver nanoparticles is prepared in the form of a micellar solution based on a surfactant in a non-polar solvent in which the concentration of silver nanoparticles is chosen in the range of 2.0 · 10 ^-3 -6.5 · 10 ^-3 g-ion / l, and the concentration of the surfactant is 1.5-6.0 wt.%, and impregnated with it a selective layer, applied before on a porous base, withstand fi Cleaning material in a modifying solution of silver nanoparticles for 1-2 hours before the formation of an additional discrete layer, after which it is filtered and dried at a temperature of plus 60-70 ° C for 3-4 hours and, if necessary, cooled to a temperature of plus 20-25 ° C. 4. The method of obtaining modified silver nanoparticles of the filter material according to claim 3, characterized in that the obtained filter material for cleaning liquid substances is washed with distilled water to obtain a surfactant concentration of not more than 0.5 mg / l in the wash water, and then dried at a temperature of plus 60-70 ° C for 3-4 hours and cooled to a temperature of plus 20-25 ° C.

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