RU2672355C2 - Method of two-stage dry disinfection by heterogeneous gas-air mixture of hydrogen peroxide aqueous solution of enclosed spaces - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to the field of medicine, namely to disinfectology, and is intended for the disinfection of enclosed spaces. For a two-stage dry disinfection, an aqueous solution of hydrogen peroxide in the air of a closed space is disaggregated into a gaseous state by the high-speed energy of the compressed air stream, exceeding 40 Joules per second per gram of an aqueous solution of hydrogen peroxide injected into said compressed air stream. Process of disaggregating an aqueous solution of hydrogen peroxide into the molecular gaseous state and diffusion of these water molecules and peroxide into the air environment of the enclosed space are completed when the relative humidity of said air medium reaches within 60 ÷ 65 %. Further increase in the number of water molecules and hydrogen peroxide in the air environment of the closed space occurs as a result of the continuation of the process of disinfection with a heterogeneous gas-air mixture of a disaggregated aqueous solution of hydrogen peroxide. In this air, the process of formation of sorption centers for water molecules and hydrogen peroxide and their transition to microcenter condensation of aerosol particles of the hydrogen peroxide solution is carried out. This process is carried out until the relative humidity of the air environment of a given confined space is reached within 90 ÷ 95 %.EFFECT: use of the invention does not adversely affect the integrity of disinfected surfaces, the protective effectiveness of barrier engineering and technical systems of biological safety, on the efficiency of electronic and optical systems, does not have a significant effect on human health, while it makes it possible to increase the efficiency of disinfection of confined spaces.3 cl, 1 tbl

Description

The invention relates to the disinfection of enclosed spaces, including healthcare facilities, pharmaceutical, medical and food industries, microbiological laboratories, etc.

For disinfection of a wide range of objects, chemical disinfection methods based on the use of disinfecting chemicals (formaldehyde, over acetic acid, phenolic compounds, etc.) are most suitable. However, their main drawback is that these methods are not environmentally friendly, since they involve the use of chemical agents that are slowly degrading in the environment and are equally harmful to all forms of protein life - from bacteria to humans, since they have a depressing effect on humans, animals, and plants (and depending on their concentration, the effect may be more or less strong).

A known method of producing aerosol used in the disinfection of premises [A.S. No. 365150]. To obtain an aerosol, the disinfecting effect of which is manifested at room temperature, chlorine lime is mixed with ammonium nitrate in the presence of water, immediately there is a rapid evolution of gaseous products: chlorine, hydrogen chlorine and ammonium chloride, which, when condensed with water vapor released during heating of the mixture, form fine aerosol. The disadvantage of this method is the contamination of the processed objects with toxic products, the removal of which requires additional measures.

Known disinfection methods in which an aqueous saline solution is used as a disinfectant treated in the anode chamber of a diaphragm electrolyzer (anolyte) is AC 1341743, 1437400, 1534772, 1667891. However, the disadvantage of these disinfection methods is the significant consumption of the disinfecting solution and insufficient environmental cleanliness after carrying out the disinfection process.

A known method of aerosol disinfection of enclosed spaces, including air and objects, as well as animals, birds, plants and humans in these spaces, using electrochemical activated solutions [Patent FROM No. 21448414], comprising filling these spaces with aerosol obtained by spraying a disinfectant substances, which is used as a solution obtained using the processing of a solution of alkali metal chloride with a concentration of 0.5-5.0 g / l in the anode chamber of the diaphragm electron lyser, and spraying is carried out in the mode of mass aerosol concentration of not more than 50 mg / m3, with a dispersion of 5-50 microns, while the temperature of the sprayed substances should be higher than the temperature of the environment of enclosed spaces, and the relative humidity of the environment of these spaces should be in the range of 80-90 %

The disadvantage of this method is:

- a relatively large size of aerosol particles (5-50 microns) of the sprayed disinfectant deposited on the treated surface;

- sophisticated technology for aerosol disinfecting solution using the anode chamber of a diaphragm electrolyzer.

The closest in technical essence is the method of aerosol disinfection of enclosed spaces [Patent from No. 2587063].

This method of disinfection is carried out by aerosol spraying of a disinfectant solution, which is used as a solution of hydrogen peroxide, compressed air at a speed of aerosol particles of more than 150 m / sec., Providing the mode of formation of “cold steam (fog)” of the aerosol of the disinfectant solution, while filling with aerosol is performed up to the beginning of the moment of moisture condensation in the air of the enclosed space at the level of the “dew point”.

The disadvantage of this method of disinfection with "cold steam (fog)" is the lack of energy ability to disaggregate the hydrogen peroxide solution into a gaseous state, resulting in the precipitation of coarse particles of hydrogen peroxide solution on horizontal surfaces within a radius of more than one and a half meters from the center of aerosol spraying of the hydrogen peroxide solution.

The aim of the invention is the creation of a method of effective, environmentally friendly disinfection of enclosed spaces, including its air environment and the equipment, devices, electronic and optical systems, highly efficient filters, etc., without violating the integrity and performance of the above objects.

The solution to this problem is as follows.

The method of two-stage dry disinfection of enclosed spaces of a heterogeneous gas with an air mixture of a hydrogen peroxide solution is carried out in two stages: disaggregation and aggregation (formation of condensation centers) of a hydrogen peroxide solution, static disinfection and subsequent air aeration (deactivation) of the air of the enclosed space.

An aqueous solution of hydrogen peroxide in an enclosed space air is disaggregated into a gaseous state by a high-speed energy of a compressed air stream exceeding 40 J per second per gram of an aqueous solution of hydrogen peroxide injected into the specified stream of compressed air, the process of disaggregating an aqueous solution of hydrogen peroxide into a molecular gaseous state and the diffusion of these water molecules and peroxide into the closed air space is completed when the relative humidity is reached and the specified air environment within 60 ÷ 65% (Fig. 1., Table, items 2, 3 and 4).

A further increase in the number of water molecules and hydrogen peroxide in an enclosed space air as a result of the continuation of the process of disinfection of a heterogeneous gas with an air mixture of a disaggregated aqueous solution of hydrogen peroxide, in this air begins the formation of sorption centers of water molecules and hydrogen peroxide and their transition to aerosol condensation centers particles of a solution of hydrogen peroxide, the specified process is performed until the relative humidity of the air medium is reached This confined space is within 90% ÷ 95%. (Fig. 1., Table, items 5, 6, and 7).

Disinfection of the air, the environment of the enclosed space is carried out after reaching a value of 90% ÷ 95% relative humidity of the air of the enclosed space and the termination of the process of supplying a heterogeneous gas of the air mixture of a solution of hydrogen peroxide in the air of the enclosed space (Fig. 1, Table, items 8 ÷ fourteen).

Aeration (decontamination) of the air of the enclosed space is carried out after disinfection is completed by the method of supplying clean clean air to the cavity of the specified enclosed space in the required volume to achieve the standard MPC for the content of hydrogen peroxide in the air of the enclosed space. (Fig. 1, table, items 15 and 16).

The implementation of the method of two-stage disinfection of the confined space of a heterogeneous gas with an air mixture of a solution of hydrogen peroxide is as follows.

The hydrogen peroxide liquid solution is disaggregated into a gaseous state by the high-speed energy of a compressed air stream in excess of 40 J per second per gram of hydrogen peroxide solution injected into the specified compressed air stream.

According to the Brownian law of gas motion, water molecules and hydrogen peroxide of a disaggregated aqueous solution of H ₂ O ₂ are in random diffusion motion in an air environment of a confined space in proportion to their mass composition. The total number of molecules and the size of these chemicals depends on their mass concentration in the air of the enclosed space and is determined by the mass of the disaggregated chemical substance, its molecular weight and the Avogadro constant

n = (Q / m) × 6.022 × 10 ²³

Where:

n is the total number of molecules of a chemical substance,

Q is the mass of the disaggregated chemical, g;

m is the molecular atomic weight of the chemical,

for H ₂ O m = 18.015 amu;

for H ₂ O ₂ m = 34.0158 a.u.

6.022 × 10 ²³ is a constant value of Avogadro.

At the stage of reaching the relative humidity of the specified air environment within 90% -95%, the process of disaggregation of an aqueous solution of H ₂ O ₂ into the air of the confined space of a solution of hydrogen peroxide is completed.

When the relative humidity of the air of the enclosed space reaches 90% ÷ 95%, the concentration of the heterogeneous gas of the air mixture of the hydrogen peroxide solution in the specified air is the standard value necessary for the disinfection of microbiological contamination (contamination) of the enclosed space and objects located in the enclosed space. The amount of hydrogen peroxide solution necessary to create a relative 95% humidity in 1 kg of air in an enclosed space is determined by the equation:

Δd = d ₉₅ % - d _{real. in / s.}

Where:

Δd is the amount of hydrogen peroxide solution required to achieve 95% relative humidity of 1 kg of air, depending on its temperature and moisture content, g / kg;

d _95%. - moisture content in 1 kg of air at 95% relative humidity, depending on its temperature, g / kg .;

d _{real. w / s} - the actual moisture content in 1 kg of air in a confined space before the disinfection process begins, g / kg .;

In the process of diffusion into the air of the enclosed space of molecules of the lead of hydrogen peroxide of a Н ₂ О ₂ solution, the process of saturation of the air of the enclosed space and the formation of micro condensation centers of water molecules and hydrogen peroxide takes place.

The calculation of the percentage of the initial liquid concentration of an aqueous solution of hydrogen peroxide, taking into account the moisture content of the air in the enclosed space, before the disinfection process begins, is determined by the equation:

n _calc. % _{d / p} = (d _95% × [n]% _{d / p} ) / (Δd)

Where:

n _calc. % _{d / r} - the estimated initial percentage of a liquid solution of hydrogen peroxide, before the disinfection process,%;

d _95%. - moisture content in 1 kg of air at 95% relative humidity, depending on its temperature, gr .;

[n]% _{d / p} is the standard percentage of heterogeneous gas in the air mixture of a disaggregated solution of H ₂ O ₂ for disinfection of a confined space (3% or, 6%),%;

Δd is the amount of hydrogen peroxide solution necessary to achieve a state of 95% relative humidity in 1 kg of air, depending on its temperature and its moisture content, g / kg.

The total volume of a liquid solution of hydrogen peroxide calculated initial percentage concentration required for disinfection of a confined space is determined by the equation:

Q = V × (Δd × γ _air )

Where:

Q - the total volume of a liquid solution of hydrogen peroxide with a calculated initial percentage concentration required for disinfection of a confined space, gr,

V is the total volume of enclosed space, m ³ ,

Δd is the amount of hydrogen peroxide solution of the calculated concentration necessary to achieve a state of 95% relative humidity in 1 kg of air, depending on its temperature and its moisture content, gr .;

γ _air is the specific gravity coefficient of 1 m ^{3 of} dry air, depending on its temperature.

A heterogeneous gas air mixture of a disaggregated solution of hydrogen peroxide forms a high-speed compact gas in an enclosed space, repeatedly injecting an enclosed air environment into its cavity, acting as a mixer, additionally increasing the diffusion rate of hydrogen peroxide and water molecules into the enclosed air environment. The technical result of the invention is the creation of a two-stage dry disinfection of a heterogeneous gas with an air mixture of a solution of hydrogen peroxide, slightly exposed to the gravitational force of gravity.

The advantages of a patented disinfection method are as follows:

- high disinfection efficiency;

- expanding the functionality of the method of disinfection of heterogeneous gas with an air mixture of a disaggregated solution of hydrogen peroxide, which allows disinfection of the air, rooms, ventilation systems and their filters, including electronic and optical systems, devices, etc., without violating their integrity and operability;

- environmental cleanliness of this method of disinfection, because under the influence of aeration and light, for a short time, the gas of the air mixture of the disaggregated solution of hydrogen peroxide decomposes into water and oxygen;

- a relatively short period of time for the disinfection process - (1.5 ÷ 2.0 hours) complete disinfection of a confined space;

- safety of the disinfection process execution mode, i.e. without the presence in the disinfected enclosed space of the premises of the personnel performing this work;

- low consumption of a solution of hydrogen peroxide;

- the relatively low cost of the proposed method of disinfection;

- An alternative solution to a pair of formalin disinfection (prohibited by the World Health Organization in 2014), developed surfaces of highly effective air filters of biological safety boxes and ventilation systems when working with biological pathogenic agents of 3-4 danger groups.

Practical testing of the method of the present invention was carried out using a disaggregated solution of hydrogen peroxide (H ₂ O ₂ ) on the basis of microbiological laboratories of the leading institutes in Moscow.

As a test microbiological culture applied to the surface of equipment, instruments, building structures, and engineering and biological safety systems, we used a wild strain of Staphylococcus aureus (Staphylococcus aureus) and Pseudomonas aeruginosa strain (strain 170015) with an initial concentration of 1.0 × 10 ⁷ CFU / ml. ÷ 1.0 × 10 ⁸ cfu / ml.

The total microbial contamination of the air of the disinfected enclosed space prior to the beginning of the disinfecting treatment, including the spore and vegetative forms of microorganisms, was 1.5 × 10 ⁶ cf / m ³ ÷ 0.5 × 10 ⁷ cf / m ³ .

The concentration in the air of the enclosed space of the premises of microbiological laboratories of heterogeneous gas in the air mixture of a disaggregated solution of hydrogen peroxide, at 95% relative humidity of their air environment, was 6%.

Microbiological control of the results of the proposed method for disinfection of a heterogeneous gas of an air mixture of a disaggregated solution of hydrogen peroxide in the air, building structures, laboratory equipment, devices located in the confined space of microbiological laboratories, showed a complete absence of viable microorganisms, both in the air in the laboratory and on the seeded test microbiological culture of Staphylococcus aureus and Pseudomonas aeruginosa culture, (strain 170015) surfaces, i.e. sterility of the surface of the floor, walls, windowsill, thermostats, refrigerators, tables, air ducts of ventilation systems, filter material of high-performance filters of class H14 ventilation systems of laminar cabinets-boxes of the second class of biological safety type BAVp-01- “Laminar-S”.

Moreover, the above method of disinfection did not adversely affect the performance of electronic systems for automation of laminar cabinets-boxes BAVp-01- “Laminar-S”, the protective efficiency of their highly efficient filters, the performance of computer systems and the optics of microscopes located in these disinfected rooms.

Claims (3)

1. The method of two-stage dry disinfection of a heterogeneous gas-air mixture of an aqueous solution of hydrogen peroxide in confined spaces, characterized in that the aqueous solution of hydrogen peroxide in the air of an enclosed space is disaggregated into a gaseous state by a high-speed compressed air flow energy exceeding 40 J per second per gram injected into the specified stream of compressed air of an aqueous solution of hydrogen peroxide, the process of disaggregation of an aqueous solution of hydrogen peroxide in molecular gas the state and diffusion of these water molecules and peroxide into the air of the enclosed space are completed when the relative humidity of the specified air reaches 60–65%, a further increase in the number of water molecules and hydrogen peroxide in the air of the confined space occurs as a result of the continuation of the heterogeneous disinfection process gas-air mixture of a disaggregated aqueous solution of hydrogen peroxide, in the specified air, the process of formation of sorption centers olekul water and hydrogen peroxide and transition them microcentres condensation aerosol particles of a hydrogen peroxide solution, said process is performed until the relative humidity of the ambient air within the enclosed space 90 ÷ 95%. 2. The method of two-stage dry disinfection of a heterogeneous gas-air mixture of an aqueous solution of hydrogen peroxide in confined spaces according to claim 1, characterized in that the concentration of hydrogen peroxide in a heterogeneous gas-air mixture of a disaggregated aqueous solution of hydrogen peroxide in the specified air environment of an enclosed space is the amount necessary for the disinfection of microbiological contaminants contained in the specified enclosed space, and is determined taking into account the moisture content of the closed air environment a space of real-time performance of disinfection at an appropriate temperature at the time of said ambient air of the enclosed space and its moisture content at a relative humidity of 95% 3. The method of two-stage dry disinfection of a heterogeneous gas-air mixture of an aqueous solution of hydrogen peroxide in confined spaces according to claim 1, characterized in that the heterogeneous gas-air mixture of a disaggregated solution of hydrogen peroxide forms a high-speed compact air-gas stream in an enclosed space, which injects closed space surrounding air into its cavity

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