Overview of Ozone Disinfection Technology and Its Application in Household Scenarios
Principle of ozone killing microorganisms and deodorization purification
1.1 Mechanism of killing microorganisms
The inactivation effect of ozone on microorganisms is determined by its strong oxidizing ability and biofilm diffusion ability. Its mechanism of action can be summarized into the following four points: (1) ozone can oxidize and decompose the enzymes necessary for glucose inside bacteria, leading to bacterial inactivation and death; (2) Ozone acts on the four polypeptide chains of the viral capsid protein, causing damage to RNA and destroying the protein that forms it. After being oxidized by ozone, the surface of bacteriophages is broken into fragments, releasing many ribonucleic acids that interfere with their adsorption onto the host; (3) Ozone reacts with lipid double bonds in bacterial cell walls, penetrates the cell membrane tissue, invades the cell, acts on lipoproteins in the outer membrane and lipopolysaccharides in the interior, causing bacterial permeability distortion and dissolution death; (4) Ozone acts on the nuclear substances inside bacterial cells, such as purines and pyrimidines in nucleic acids, damaging their organelles and DNA, disrupting bacterial metabolism, and leading to bacterial death.
The specific steps of ozone cracking bacteria are shown in the figure, where: 1 is simulating bacterial cells; 2 is a close-up of ozone molecules on the bacterial cell wall; Ozone penetrates the cell wall and causes corrosion of the cell wall; 4 is a close-up of the effect of ozone on cell walls; 5 represents bacterial cells that come into contact with many ozone molecules; 6 represents cell destruction (lysis).
1.2 Deodorization principle
Ozone, with its strong oxidizing properties, can quickly decompose substances that produce odors and other odors, such as amines, hydrogen sulfide, methyl mercaptan, etc. Ozone oxidizes and decomposes them to produce non-toxic and odorless small molecule substances.
1.3 Principles of Preservation and Purification
Ozone has the function of killing or inhibiting the growth of mold and preventing the decay of fruits and vegetables. It can oxidize and decompose the physiological metabolism of fruits and vegetables, and produce ethylene gas as a ripening agent, which plays a role in preventing aging and preserving freshness; Secondly, ozone can inhibit the metabolism of fruits and vegetables, slow down their physiological aging process, and extend their storage period; Meanwhile, ozone can also degrade pesticides and fertilizers remaining on the surface of fruits and vegetables, and remove hormones and antibiotics remaining in meat.
Ozone undergoes a reduction reaction in water, producing highly oxidizing single atom oxygen and hydroxyl groups, instantly decomposing organic matter, bacteria, and other microorganisms in the water. Hydroxyl groups are strong oxidants and catalysts that cause chain reactions in organic compounds, resulting in very rapid reactions. Single atom oxygen and hydroxyl groups have strong bactericidal effects on various pathogenic microorganisms. Ozone can degrade sulfides, ammonia, and cyanides in water to produce non-toxic substances, achieving the goal of purifying water.
2. Advantages and disadvantages of ozone disinfection technology
2.1 Advantages
(1) Ozone disinfection is a lytic level method that thoroughly kills bacteria and has the characteristics of broad-spectrum and high efficiency. It has a significant killing effect on all bacteria and viruses. Ozone can quickly dissolve in water, killing harmful bacteria and decomposing organic matter. Its oxidation ability is twice that of chlorine, and its sterilization rate is 300-600 times that of chlorine. As shown in the table, the bactericidal effects of disinfectants such as chlorine, chlorine dioxide, and ozone on microorganisms were compared.
(2) Ozone disinfection uses air and water as media, without the need to add any other auxiliary agents. Due to the poor stability of ozone, it quickly decomposes into oxygen or individual oxygen atoms. There are no drug residues or secondary pollution during disinfection and sterilization.
2.2 Disadvantages
(1) When the ozone concentration is low, the effect on removing odors is not significant. But if ozone achieves good results in indoor disinfection and sterilization, and the residual ozone concentration is too high, it will cause harm to the human body. If people are exposed to it for a long time, it can oxidize the respiratory mucosa of the human body, causing adverse reactions and potentially leading to respiratory inflammation. At the same time, it can also harm the human immune system. Therefore, the concentration of ozone sterilization release (leakage) must comply with the national standard of ≤ 0.16mg/m ³ in GB/T 18883-2002 "Indoor Air Quality Standards".
(2) Ozone, as a strong oxidant, inevitably has an oxidizing and corrosive effect on the materials it comes into contact with while disinfecting. Its strong oxidizing properties can cause aging, discoloration, reduced elasticity, and clothing discoloration of rubber and other components. Therefore, in the design, full consideration should be given to the corrosive effect of its oxidation on the pipes it passes through.
(3) Ozone itself is unstable, easily decomposed, and has a short half-life (only 30-60 minutes), making it unsuitable for storage as a general product and requiring on-site manufacturing.
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Application of Ozone Disinfection Technology in Home Environment
3.1 Application in Air Purification
Nowadays, air health is increasingly becoming a problem that cannot be ignored. Especially in the case of pneumonia caused by novel coronavirus, we need to open windows and ventilate at home frequently to maintain indoor air circulation. At the same time, in addition to proper ventilation, air purifiers with filtering and sterilization functions can also effectively ensure the health of indoor air. In terms of disinfection and sterilization, if the air purifier is equipped with active sterilization functions such as ultraviolet lamps and ozone, its effectiveness in preventing viral infections will be better.
Ozone is an isomer of oxygen, which exists in a high-energy state. Due to its instability, it can decompose and reduce to oxygen at room temperature at any time. When reduced to oxygen, oxygen atoms will separate, and at this time, the oxygen atoms have extremely strong oxidizing and decomposing abilities. Air purifiers with ozone function produce low concentration ozone gas and release it in different areas of the home to achieve disinfection and purification purposes.
3.2 Application in household water purification
Water is the source of life, and people attach great importance to its safety. In recent years, people have gradually used various types of water purifiers, and the application of corresponding disinfection technologies in water purifiers has become increasingly widespread. Among them, ozone disinfection technology is recognized as a technology in the international disinfection field. According to reports, when the concentration of ozone in water reaches 0.3-0.4ppm, the killing rate of bacteria, dental cells, etc. is very significant; When it reaches 4ppm, the inactivation rate of hepatitis B virus can reach 100% .
Water purifiers can be said to be the last line of safety at the end of drinking water, providing people with safe and clean drinking water. Ozone disinfection technology can be applied in water purifiers due to its strong oxidizing effect and the absence of any other products during the application process. The ozone disinfection equipment in the water purifier adopts ozone generation device, high-efficiency microporous diffusion bubble disc, and exhaust gas collection device, etc., to fully contact ozone with water, quickly dissolve and react, and achieve the effect of disinfection and sterilization. At the same time, it can also disinfect and sterilize the water purifier itself (the part in contact with drinking water).
3.3 Application in dietary life
(1) Application of disinfection cabinet and dishwasher The disinfection and sterilization principle of disinfection cabinet and dishwasher is based on high temperature, ultraviolet ray and ozone disinfection technology. Among them, the ozone disinfection cabinet is a household appliance that generates a certain concentration of ozone gas through physical methods, relies on biochemical reactions to kill pathogenic microorganisms, and disinfects food (drinking) utensils. This is also one of the main products in China that first applied ozone technology to the field of household appliances since the 1980s. Ozone disinfection, as a gas-phase disinfection, does not have a "shadow zone" or disinfection blind spot compared to ultraviolet disinfection with straight line irradiation, and has a better disinfection effect on food (drinking) utensils. Plastic utensils that are not resistant to high temperatures can also be disinfected with ozone.
(2) In the application of refrigerators, unpleasant odors are generated inside the refrigerator during use, causing mutual contamination between foods, resulting in a decrease in preservation ability, and also causing poor consumer experience. Ozone can oxidize many organic compounds and easily react with - SH,=S, - NH2, - NH, - OH, and - CHO. It has strong deodorizing ability and can be used to remove odors from refrigerators. Ozone reacts with odorous gases such as ammonia, hydrogen sulfide, and thiols to oxidize and decompose organic odors in the refrigerator, thereby achieving the effect of removing refrigerator odors and purifying.
(3) The application of ozone sterilization technology in washing machines. Before washing and during the last rinse, the internal ozone generator injects an appropriate amount of ozone into the inner cylinder to disinfect and sterilize clothes in a short period of time. After sterilization is completed, it automatically converts into oxygen and can remove 99.99% of bacteria without disinfectant, which is 10 times more effective than UV sterilization. Compared with other sterilization technologies, ozone sterilization is efficient, fast, thorough, and free of secondary pollution. However, its strong oxidizing properties may cause aging of rubber and other components, as well as color fading of clothing. Therefore, it is necessary to use it carefully when washing dark colored clothing .
