RU2506232C2 - Method of inactivating viruses in water media - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used for preparation of ultra-pure water, safe for consumption by people, as a result of sorption purification of drinkable water from viruses. Method includes filtration of water through zones with sorption materials, where, at least, one of zones represents porous filtering element based on resins, obtained by condensation of aldehydes with aromatic phenols and amines. Sorption material possesses the following characteristics: ratio of absolute value of zeta potential of porous filtering element to value of effective radius of liquid flow canal constitutes not less than 10⁴ V/m. Porous filtering element, based on resin, obtained by condensation of formaldehyde with resorcin or melamine, is used as such sorption material of, at least, one of zones. Porous filtering element can preferably contain onwashed layer of sorption material, characterised by ratio of absolute value of material zeta potential to value of effective radius of flow canal not less than 10⁵ V/m.

EFFECT: method ensures high degree of neutralisation of viruses.

7 cl, 17 ex, 12 tbl

Description

FIELD OF TECHNOLOGY

The invention relates to the field of purification of aqueous media, mainly drinking water from viruses, and can be used in the manufacture of filters for the preparation of ultrapure water, safe for human consumption.

BACKGROUND

Virus (lat. Virus - poison) is a subcellular infectious agent that can be reproduced only inside living cells of the body. By nature, viruses are autonomous genetic elements that have an extracellular stage in the development cycle. Viruses are microscopic particles consisting of nucleic acid molecules - DNA or RNA, enclosed in a protein coat. Viruses are able to infect living organisms and are obligate parasites, as they are not able to multiply outside the cell. Outside the cell, viral particles do not show signs of life and behave like particles of organic polymers.

Many viruses that can cause serious diseases can enter the human body with drinking water. In the field of water purification technologies, the removal or inactivation of viruses is given special attention related to both the importance of solving this problem and the technical complexity of this solution.

Traditional methods of removing viruses from water can be divided into three groups:

1) Adsorption of viruses on active surfaces;

2) Filtration of viruses through porous media with an effective pore diameter less than the size of the virus.

3) Strong chemical and physical effects that destroy the virus.

Adsorption methods for removing viruses, as a rule, involve the use of finely dispersed materials with a high surface charge and a developed area of contact with water. Fixation of the virus occurs mainly due to electrostatic interactions. However, it should be borne in mind that the virus in water is a particle with a predominantly protein surface with a low intrinsic charge, depending on the pH of the medium. Therefore, the binding force of the virus on the surface is small, therefore, the virus is not fixed irreversibly at the point of contact with the surface of the adsorbent, but with a constant flow of liquid along the surface, the virus migrates, and with local fluctuations in the composition of water, its desorption is possible.

In addition to viruses, water contains a significant amount of substances of organic origin with the same surface charge: natural polymers (humic acids), technogenic substances (surfactants), microorganisms and their metabolic products. Therefore, the fixation of viruses proceeds in the form of competitive adsorption with substances of a similar nature, the mass content of which is much greater than viruses.

Filtration of viruses is possible using porous media with a small pore size: osmotic and nanofiltration membranes, which entails the use of high pressures, as well as the formation of a concentrate containing a higher concentration of viruses as a result of the filtration process than in the source water. In addition, the clipping of particles on the membranes is not absolute and there is always a certain probability of the virus passing through the membrane due to the presence of defects in its structure.

The chemical and physical effects include, in particular, the use of general methods of bactericidal treatment of liquids in order to remove viruses. Such methods are ineffective, because unlike microorganisms, viruses are much more resistant to UV radiation, chlorine-containing bactericides, silver, and polymer bactericides.

The prior art "Filter material, its production method and filtering method" according to the application 2005125140 RU dated 08.08.2005. The essence of the method lies in the fact that the polymer fiber material is modified with particles of aluminum oxide hydrate, for which the initial fiber material is applied to the polymer fiber material aluminum-based material, then hydrolysis of the latter is carried out, during which particles of aluminum oxide hydrate are formed and fixed on the polymeric fibrous material.

The disadvantage of this solution is that during operation, finely divided hydrate of aluminum oxide dissolves, which leads to a loss of the ability of the filter material to inactivate viruses.

A solution is known according to USA patent 7,390,343 dated June 24, 2008, where a filtering device is proposed containing at least one fibrous structure, which is a mixture of aluminum hydroxide nanofibers and other fibers, placed in a matrix to create asymmetric pores for filtration particles from small to nano size. The claimed device, when passing water through it, is capable of suppressing bacteria and viruses.

In this solution, in order to achieve the desired result, the active component inactivating viruses must be applied to an inert carrier. However, due to the physical properties of the inert carrier, it is not possible to apply the active component in the amount required to remove viruses in large quantities.

Known methods and devices for filtering according to patents 6,852,224 USA from 02/08/2005; 7,749,394 USA dated 07/06/2010; 6,783,713 USA dated 08/31/2004; 2237022 RU dated September 27, 2004, the essence of which is to filter water through dense layers of activated carbon particles of various sizes, shapes and porosities. The capture of pathogens of nanoscale, in particular viruses, by activated carbon particles, according to the authors, is determined by electrostatic, van der Waals and hydrophobic forces. Thus, the mechanism of action of known solutions is reduced to physical adsorption of viruses and is limited by the volume of adsorption capacity of the material, especially in conditions of competitive adsorption of viruses with other impurities of an organic nature.

A known method of purification of drinking water according to the application 93050424 RU from 09.11.1993, the Summary of the invention lies in the fact that drinking water is filtered through alternating layers of chemisorption fibers or materials based on them containing carboxyl groups in H-, Na-, Ag -forms and ammonium bases in Cl- and CO-forms having complex iodine compounds with a mass ratio of fibers from 1: 3 to 3: 1, respectively, and a filtration rate of up to 20 l / h.

The active components of this solution are antibacterial and do not have a specific inactivation effect on viruses.

The closest solution to the claimed one is the invention “A method for purifying tap water” according to patent RU 2049078 dated November 27, 1995, comprising sequentially passing pressurized water through treatment zones with activated carbon, a cation exchange resin, anion exchange resin, and ultrafiltration polymer membranes, moreover, as ultrafiltration polymer membranes use hollow fibers from aromatic polyamide phenylone, while the water to be purified is fed into the internal cavities of the hollow fibers, and the filtrate is removed from their internal Exterior lateral surface.

Materials in this cleaning process are arranged in layers. The particle sizes and the corresponding effective sizes of the liquid flow channels in the layers of ion exchange resins and activated carbon are too large in comparison with the size of viruses. Thus, the removal of viruses is practically carried out on ultrafiltration membranes made of aromatic polyamide having a very high hydraulic resistance, which in turn leads to rapid clogging of the membranes in the absence of washing, and thereby reduces the efficiency of the process.

The technical task of the claimed solution is the creation of a highly effective method of inactivation of viruses by filtration through a medium with moderate hydraulic resistance and high efficiency by inactivating properties.

The technical result of the invention is a high degree of neutralization of viruses in the filtering process.

The technical result is achieved by the fact that in the method of inactivation of viruses in aqueous media, including the passage of liquid under pressure through zones with sorption materials, at least one of the zones has the following characteristics: the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is not less than 10000 V / m.

SUMMARY OF THE INVENTION

According to the data available in the literature and the results of their own experiments, the authors found that the best results both in the completeness of the removal of viruses from water and in the preservation of this property over time show polymer materials with a developed surface and a sufficiently high charge density. The assumption of a purely adsorption mechanism of virus binding does not explain the lack of filter saturation with viruses, as well as the small effect of the content of organic impurities in water on the completeness of virus capture.

According to the inventors, the mechanism of neutralization (inactivation) of viruses in the process of filtration through porous media can be explained as follows. When a liquid is filtered through a porous medium with a sufficiently high density of a fixed charge on the pore surface, virus particles near the surface are exposed to electric forces caused by the movement of mobile counterions together with the fluid flow. Electrokinetic phenomena known in colloid chemistry are associated with the manifestation of such forces: electroosmosis, electrophoresis, the occurrence of potential differences during flow and sedimentation.

In the case of liquid filtration through a porous medium, the measure of this interaction is the value of the percolation potential. The corresponding intrinsic characteristic of the material is the value of the ζ potential calculated from the value of the flow potential and the parameters of the liquid in accordance with equation (1)

where Δφ is the measured value of the flow potential; ΔP - pressure loss during fluid flow through a porous material; η is the dynamic viscosity of the liquid; λ _S is the intrinsic electrical conductivity of the porous medium; ε and ε ₀ - dielectric constant of the medium and vacuum.

In the absence of fluid motion in the pores, the flow potential is zero, and the charge on the pore walls is compensated by a diffuse layer of counterions. When fluid flows in narrow (of the order of microns) pores, the distribution of mobile ions relative to the pore wall is violated due to hydraulic mixing of the fluid during flow in a winding narrow channel. For a completely uniform distribution of mobile ions in a cylindrical pore with a charged wall, the dependence of the electric field strength on the distance from the pore center x will be

where r is the radius of the pore, or rather, the surface of the carrier of a fixed charge, on which the potential is ζ, the positive direction of the vector is chosen from the center to the outer surface of the pore. For a pore with a diameter of 2 μm at a distance of 0.5 μm from the center with a zeta potential of 10 mV, the local value of the electric field strength will be 10,000 V / m = 100 V / cm, and at a distance of 0.1 μm from the charged surface - 18,000 V / m = 180 V / cm.

The intrinsic size of viruses is 50-100 nm, and taking into account the interaction of the viral protein shirt with water, the effective size of the virus as a colloidal particle in water can be estimated in tenths of a micron. When moving in winding pores, viruses fall into the zone of action of significant electric forces. The potential drop along a virus particle with an effective size of δx will be

When an electric force enters the effective zone, the viral particle undergoes polarization and appears under conditions similar to the process of activation of the virus, when, upon approaching the host cell, the viral envelope of the virus opens and the virus nucleic acid is injected into the cell body through the transport channels of its membrane. The signal for the destruction of the quaternary protein structure of the viral shirt can only be electrostatic interaction near the surface of the cell membrane. It can be assumed that a similar violation of the structure of the viral protein shirt may occur near the charged pore surface of the filter material, but the DNA (or RNA) of the virus does not appear in the body of the host cell, but in water, where it does not have the conditions necessary for reduction. Thus, the virus is inactivated, while its components remain in water and on absorbent materials that make up the surface of the pores.

To implement the invention, water is filtered under pressure through one or more zones, and at least one zone has the necessary combination of effective pore radius and porosity with the maximum possible uniformity of these properties over the volume of the zone (no channel effects). The average characteristic of the electric field strength in a pore can be

physical meaning of the value of tension at a distance from the center equal to half the radius of the pore.

One of the most uniform filter materials is porous resins obtained by condensation of aldehydes with aromatic phenols and amines. Condensation is carried out in the form, while the porosity of the element is determined by the number and ratio of components. The most common porous filter elements obtained by condensation of formaldehyde with resorcinol and melamine in an acidic environment. It is possible to obtain elements with an effective pore radius of 0.5 to 15 microns.

The effective radius is calculated from the ratio

where ε is the porosity of the medium (the fraction of the free volume filled with water), ρ is the true density of the material, and σ is the specific surface.

The specific surface of the material σ is determined by nitrogen adsorption according to the Brunauer-Emmett-Teller method. The porosity ε is calculated from the mass difference of the material impregnated with water and after centrifugation, when water is removed from the pores.

To determine the ζ potential, the material sample is abraded in a hand mortar, then stirred in water and allowed to stand for 30 minutes, after which the suspension with small particles remaining in suspension is examined on a Zetasizer, Malvern instrument.

It was found that polymeric porous elements based on formaldehyde and resorcinol show significant (-25 to -40 mV) negative values of the ζ potential. Elements based on formaldehyde and melamine, on the contrary, show high positive values - up to +35 mV. The indicated behavior is associated with the presence on the pore surface of materials of significant amounts of weakly acidic and weakly basic groups, respectively.

To enhance the antiviral activity of filter cartridges, there is a need to create a second filter zone, which can be formed on the surface of the first in the form of an alluvial layer. This layer can be composed of finely divided material with a high value of the ζ potential. One of these materials is expanded perlite, obtained by heat treatment of a mineral based on silicon dioxide with a special crystalline structure. The material has a significant specific surface of the particles in the presence of numerous weakly acid groups on their surface.

MODES FOR CARRYING OUT THE INVENTION

EXAMPLE 1. A porous filter element was obtained by condensation of resorcinol with formaldehyde in the presence of acid. The filter element has a cylindrical shape with linear dimensions: outer diameter - 75 mm, inner diameter - 40 mm, height - 240 mm. The volume of the filter element is 0.76 liters. The fraction of free volume (porosity) in the filter module was 52%.

The specific surface area of the material determined by nitrogen adsorption by the BET method was 0.7 m ² / g. The effective radius of the channel was r _eff = 2.6 μm.

The stable value of ζ - potential during the flow of tap water in St. Petersburg was - 28 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

EXAMPLE 2. Through the filter with the filter element of example 1 was passed water with viruses. Hepatitis A virus (HAS-15) was used as the viral culture. Viral culture suspensions were used with a concentration of 10 ² to 10 ¹⁰ particles per ml. In each test, 10 l of suspension was passed through the filter, the presence of viruses after 2 and 10 liters was determined, and the transmission rate was 8 l / min.

Virus concentration was determined by PCR (polymerase chain reaction) using AmpliSens HAV reagents (manufactured by InterLabService), the detection limit of viruses by this method is 10 ² TCD / ml (TCD - tissue cytopathic doses) Enzyme-linked immunosorbent assay using test -system "Vectogen A-Antigen Strip" (pr-in Vector-Best), the detection limit of the method is 10 ⁶ TDC / ml. The results of determining the presence of viruses in filtered water are shown in table 1.

Table 1. The concentration of virus at the entrance of the SCC / ml PCR method Linked immunosorbent assay 2nd liter 10 liter 2nd liter 10 liter 10 ² - - - - 10 ³ - - - - 10 ⁴ - - - - 10 ⁵ - - - - 10 ⁶ - - - - 10 ⁷ - - - - 10 ⁸ - - - - 10 ⁹ - + - - 10 ¹⁰ + + - -

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁷ times.

EXAMPLE 3. Water with introduced viruses was passed through a filter with a filter element of Example 1. The human rotavirus HRV / SPb / 884/10/05 was used as the viral culture. Viral culture suspensions were used with a concentration of 10 ² to 10 ¹⁰ particles per ml. In each test, 10 l of suspension was passed through the filter, the presence of viruses after 2 and 10 liters was determined, and the transmission rate was 8 l / min.

Virus concentration was determined by PCR (polymerase chain reaction) using AmpliSens Rota-viruses of group A reagents (manufactured by InterLabService), the detection limit of viruses by this method is 10 ² TCD / ml (TCD - tissue cytopathic doses). analysis using the Rota AG test system (produced by NPP AQUAPAST), the detection limit of the method is 10 ⁶ TDC / ml. The results of determining the presence of viruses in filtered water are shown in table 2.

Table 2. The concentration of virus at the entrance of TCD / ml PCR method Linked immunosorbent assay 2nd liter 10 liter 2nd liter 10 liter 10 ² - - - - 10 ³ - - - - 10 ⁴ - - - - 10 ⁵ - - - - 10 ⁶ - - - - 10 ⁷ - - - - 10 ⁸ - - - - 10 ⁹ - - - - 10 ¹⁰ + + - -

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 times.

EXAMPLE 4. Water with introduced viruses was passed through a filter with a filter element according to Example 1. Norovirus was used as the viral culture (noro-Spb / 2005). Viral culture suspensions were used with a concentration of 10 ² to 10 ¹⁰ particles per ml. In each test, 10 l of suspension was passed through the filter, the presence of viruses after 2 and 10 liters was determined, and the transmission rate was 8 l / min.

Virus concentration was determined by PCR (polymerase chain reaction) using AmpliSens Caliciviruses: Noroviruses reagents (manufactured by InterLabService), the detection limit of viruses by this method is 10 ² TCD / ml (TCD - tissue cytopathic doses). The results of determining the presence of viruses in filtered water are shown in table 3.

Table 3. The concentration of virus at the entrance of TCD / ml PCR method 2nd liter 10 liter 10 ² - - 10 ³ - - 10 ⁴ - - 10 ⁵ - - 10 ⁶ - - 10 ⁷ - - 10 ⁸ - - ^September 10th + + 10 ¹⁰ + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁶ times.

EXAMPLE 5. A porous filter element was obtained by condensation of resorcinol with formaldehyde in the presence of acid. The linear dimensions of the element are similar to Example 1. The fraction of free volume (porosity) in the filter module was 45%.

The specific surface area of the material, determined by nitrogen adsorption by the BET method, was 2.4 m ² / g. The effective radius of the channel was r _eff = 0.6 μm.

The stable value of the ζ potential during the flow of tap water in St. Petersburg was 38.0 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

EXAMPLE 6. Water with introduced viruses was passed through a filter with a filter element according to Example 5. Hepatitis A virus (HAS-15) was used as the viral culture. The experimental conditions are as in example 2. The results are shown in table 4.

Table 4. The concentration of virus at the entrance of TPD / ml PCR method Linked immunosorbent assay 2nd liter 10 liter 2nd liter 10 liter 10 ² - - - - 10 ³ - - - - 10 ⁴ - - - - 10 ⁵ - - - - 10 ⁶ - - - - ^July 10th - - - - 10 ⁸ - - - - ^September 10th - - - - 10 ¹⁰ - - - -

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁸ times.

EXAMPLE 7. Water with introduced viruses was passed through a filter with a filter element of Example 5. The human rotavirus HRV / SPb / 884/10/05 was used as the viral culture. The experimental conditions are as in example 3. The results are shown in table 5.

Table 5. The concentration of virus at the entrance of TCD / ml PCR method Linked immunosorbent assay 2nd liter 10 liter 2nd liter 10 liter 10 ² - - - - March ¹⁰ - - - - 10 ⁴ - - - - 10 ⁵ - - - - 10 ⁶ - - - - 10 ⁷ - - - - 10 ⁸ - - - - 10 ⁹ - - - - 10 ¹⁰ - - - -

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁸ times.

EXAMPLE 8. Through the filter with the filter element of example 5 was passed water with viruses. Norovirus was used as the viral culture (noro-Spb / 2005). The experimental conditions are as in example 4. The results are shown in table 6.

Table 6. The concentration of virus at the entrance of TCD / ml PCR method 2nd liter 10 liter ^February 10th - - March ¹⁰ - - 10 ⁴ - - 10 ⁵ - - 10 ⁶ - - 10 ⁷ - - 10 ⁸ - - 10 ⁹ - - 10 ¹⁰ + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁷ times.

EXAMPLE 9. Water with introduced viruses was passed through a filter with a filter element of Example 1. The human rotavirus HRV / SPb / 884/10/05 was used as the viral culture. Determination of the virus content in the source and filtered water by PCR according to example 3.

A suspension of the virus was filtered at a concentration of 10 ⁶ TDC / ml. at various filtration rates. The experimental results are shown in table 7.

Table 7. Filtration rate, l / min The concentration of viruses, TDC / ml Contact time with water, s. At the entrance At the exit 8.7 10 ⁶ - 5.2 9.7 10 ⁶ - 4.7 13.3 10 ⁶ - 3.4 30,2 10 ⁶ 10 ² 1,5

It was found that the breakthrough of active viruses occurs when the contact time of the filter material with water is less than 2 seconds.

EXAMPLE 10. A porous filter element was obtained by condensation of resorcinol with formaldehyde in the presence of acid. The linear dimensions of the element are similar to Example 1. The fraction of free volume (porosity) in the filter module was 60%.

The specific surface area of the material, determined by nitrogen adsorption by the BET method, was 0.2 m ² / g. The effective radius of the channel was r _eff = 12.5 μm.

The stable value of the ζ potential during the flow of tap water in St. Petersburg was 25 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

EXAMPLE 11. Through the filter with the filter element of example 10 was passed water with viruses. Norovirus was used as the viral culture (noro-Spb / 2005). The experimental conditions are similar to Example 4.

The results of determining the presence of viruses in filtered water are shown in table 8.

Table 8. The concentration of virus at the entrance of the SCC / ml PCR method 2nd liter 10 liter 10 ² - - 10 ³ - - 10 ⁴ - + 10 ⁵ + + 10 ⁶ + + 10 ⁷ + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by no more than 10 times. Thus, the filter element exhibit low efficiency in the inactivation of viruses.

EXAMPLE 12. Water with introduced viruses was passed through the filter element of Example 9, on the surface of which an alluvial layer composed of expanded perlite particles was additionally formed.

The thickness of the perlite layer was 3 mm, its total weight was 155 g, which at an intrinsic particle density of 2.65 g / cm ³ corresponds to a porosity of the layer of 0.65. The specific surface area of the material determined by the BET method was 4 m ² / g. Thus, the effective radius of the flow channel r _eff = 0.35 μm.

The stable value of the ζ potential during the flow of tap water in St. Petersburg was 54 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

Norovirus was used as the viral culture (noro-Spb / 2005). The experimental conditions are similar to Example 4.

The results of determining the presence of viruses in filtered water are shown in table 9.

Table 9. The concentration of virus at the entrance of TCD / ml PCR method 2nd liter 10 liter 10 ² - - 10 ³ - - 10 ⁴ - - 10 ⁵ - - 10 ⁶ - - 10 ⁷ - - 10 ⁸ - - 10 ⁹ - + ^October 10th + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁶ times.

EXAMPLE 13. A porous filter element was obtained in the process of condensation of melamine with formaldehyde in the presence of acid. The linear dimensions of the element are similar to example 1. The fraction of free volume (porosity) in the filter module was 50%.

The specific surface area of the material, determined by nitrogen adsorption by the BET method, was 0.6 m ² / g. The effective radius of the channel was r _eff = 5.5 μm.

The stable value of the ζ potential during the flow of tap water in St. Petersburg was 36 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

EXAMPLE 14. Through the filter with the filter element of example 13 was passed water with viruses. Norovirus was used as the viral culture (noro-Spb / 2005). The experimental conditions are similar to Example 4.

The results of determining the presence of viruses in filtered water are shown in table 10.

Table 10. The concentration of virus at the entrance of TPD / ml PCR method 2nd liter 10 liter 10 ² - - 10 ³ - - 10 ⁴ - - 10 ⁵ - - 10 ⁶ - - 10 ⁷ - - 10 ⁸ - - 10 ⁹ - - 10 ¹⁰ + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁷ times.

EXAMPLE 15. A porous filter element was obtained in the process of condensation of urea with formaldehyde in the presence of acid. The linear dimensions of the element are similar to Example 1. The fraction of free volume (porosity) in the filter module was 54%.

The specific surface area of the material, determined by nitrogen adsorption by the BET method, was 1.5 m ² / g. The effective radius of the channel was r _eff = 1.3 μm.

The stable value of the ζ potential during the flow of tap water in St. Petersburg was 12 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

EXAMPLE 16. Water with introduced viruses was passed through a filter with a filter element according to Example 15. Norovirus was used as the viral culture (noro-Spb / 2005). The experimental conditions are similar to Example 4.

The results of determining the presence of viruses in filtered water are shown in table 11.

Table 11. The concentration of virus at the entrance of TCD / ml PCR method 2nd liter 10 liter 10 ² - - 10 ³ - - 10 ⁴ - - May ¹⁰ - + 10 ⁶ + + 10 ⁷ + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by no more than 10 ³ times. Thus, the filter element exhibit low efficiency in the inactivation of viruses.

EXAMPLE 17

Water with viruses introduced was passed through the filter element of Example 9, on the surface of which an additional wash-up layer composed of finely dispersed titanium dioxide with an average particle size of 1 μm was additionally formed.

The thickness of the layer of titanium dioxide was 5 mm, its total weight was 538 g, which with an intrinsic particle density of 4.235 g / cm ³ corresponds to a porosity of the layer of 0.55. The specific surface area of the material determined by the BET method was 1.4 m ² / g. Thus, the effective radius of the flow channel r _eff = 0.4 μm.

The stable value of the ζ potential during the flow of tap water in St. Petersburg was 42 mV. Thus, the ratio of the absolute value of the zeta potential of the sorption material to the value of the effective radius of the liquid flow channel is

Norovirus was used as the viral culture (noro-Spb / 2005). The experimental conditions are similar to Example 4.

The results of determining the presence of viruses in filtered water are shown in table 12.

Table 12. The concentration of virus at the entrance of the SCC / ml PCR method 2nd liter 10 liter 10 ² - - 10 ³ - - 10 ⁴ - - 10 ⁵ - - 10 ⁶ - - ^July 10th - - 10 ⁸ - + ^September 10th + + ^October 10th + +

It was found that the filter element under experimental conditions provides a decrease in the concentration of viruses by at least 10 ⁶ times.

Claims (4)

1. The method of inactivation of viruses in aqueous media, including the passage under pressure of a liquid through zones with sorption materials, characterized in that as a sorption material of at least one of the zones using a porous filter element based on resins obtained by condensation of aldehydes with aromatic phenols or amines having the following characteristics: the ratio of the absolute value of the zeta potential of the porous filter element to the value of the effective radius of the channel of the fluid flow is at least 10 ⁴ V / m. 2. The method according to claim 1, characterized in that as a sorption material of at least one of the zones using a porous filter element based on a resin obtained by condensation of formaldehyde with resorcinol. 3. The method according to claim 1, characterized in that as the sorption material of at least one of the zones use a porous filter element based on resins obtained by condensation of formaldehyde with melamine. 4. The method according to claim 1, characterized in that the porous filter element may contain an alluvial layer of sorption material, characterized by the ratio of the absolute value of the zeta potential of the material to the value of the effective radius of the flow channel at least 10 ⁵ V / m