What Is Ozone Disinfection?
Ozone is a strong oxidant, and its sterilization process is a biochemical oxidation reaction. O3 sterilization takes three forms:
While ozone is used to disinfect and purify the air inside livestock houses, ozone water is also prepared and supplied to poultry as drinking water. This is an important step as well. When poultry drink ozone water, the micro-ecological environment of their intestines can change. Ozone reduces the number of bacteria in the poultry gut that live on host nutrients, thereby reducing host nutrient consumption. It also enhances the activity of amylase secreted by the body, improving the utilization of food nutrients by poultry, especially young birds, and promoting healthy growth. Drinking ozone water also relatively changes the drug resistance of poultry, effectively preventing intestinal diseases such as pullorum disease in chicks. It should be noted that the half-life of ozone in water is about twenty minutes, so preparing it fresh and drinking it immediately works best. However, ozone will decompose chemical drugs. Drug supply and ozone water supply should be kept separate, and more advanced matching is required.
2. It directly acts on bacteria and viruses, damaging their organelles and DNA/RNA, disrupting bacterial metabolism and causing bacterial death.
3. It penetrates cell membrane tissues and invades cells, acting on the outer membrane lipoproteins and inner lipopolysaccharides, causing permeability distortion of bacteria and dissolution and death.
Ozone sterilization is a bacteriolytic method. It is thorough, leaves no residue, and has a broad spectrum. It can kill bacterial vegetative forms and spores, viruses, fungi, etc., and can destroy botulinum toxin. In addition, O3 also has a very strong killing effect on molds. Because of its poor stability, O3 quickly decomposes on its own into oxygen or single oxygen atoms, and single oxygen atoms can combine on their own into oxygen molecules. No toxic residue exists, so O3 is a pollution-free disinfectant. O3 is a gas and can rapidly diffuse through the entire sterilization space, with no dead corners. Traditional sterilization and disinfection methods, whether ultraviolet light or chemical fumigation, have shortcomings such as being incomplete, leaving dead corners, requiring heavy workload, leaving residual pollution or odor, and possibly harming human health. For example, ultraviolet disinfection has no effect where light cannot reach, and has disadvantages such as decay, weak penetration, and short service life. Chemical fumigation also has shortcomings; for bacteria and viruses with strong drug resistance, its sterilization effect is not obvious.
As an alternative to chlorine disinfection, ozone disinfection is increasingly applied in drinking water treatment. Tests show that ozone has an obvious inactivation effect on almost all bacteria, viruses, fungi, protozoa, and oocysts. The disadvantages are: large investment and higher cost than chlorination; O3 in water is unstable, and controlling and detecting O3 requires certain technology; after disinfection it has a corrosive effect on pipes, so there is no residual O3 in the finished water and a secondary disinfectant is needed; it reacts with iron, manganese, organic matter, etc., which can produce micro-flocculation and increase water turbidity; when ozone oxidizes raw water containing bromide ions, bromate is produced. Bromate has been classified by the International Agency for Research on Cancer as a Group 2B potential carcinogen. WHO recommends a maximum bromate content of 25 μg/L in drinking water, and the US EPA drinking water standard sets the maximum allowable bromate concentration at 10 μg/L. In the ozone oxidation process, bromate formation has two pathways: ozone oxidation and ozone/hydroxyl radical oxidation. Bromate control can be carried out from two aspects: controlling its formation and removing it after formation. Lowering pH, adding ammonia, the chlorine-ammonia process, and optimizing ozonation conditions are methods to control bromate formation. After bromate is formed, physical, chemical, and biological methods can be used to remove it. Therefore, achieving a balance among ozone, pathogenic bacteria, and bromate requires further study of the ozone sterilization mechanism and bromate control methods.
So after buying bottled water and bringing it home, do not rush to drink it. The safe approach is to let it sit for a day or two, allowing the bromate in the water to decompose into harmless bromide before drinking.
Precautions for ozone air disinfection
1. Ozone irritates the human respiratory mucosa. When the ozone concentration in air reaches 0.15 ppm, it can be smelled; according to international standards, 0.5-1 ppm can cause discomfort such as dry mouth; 1-4 ppm can cause coughing; 4-10 ppm can cause severe coughing. Therefore, when using ozone to disinfect air, people must not be present, and no one should enter until at least 30 minutes after disinfection.
2. Ozone is a strong oxidant and damages many items. The higher the concentration, the more serious the damage. It can cause green rust spots on copper sheets, aging of rubber, discoloration, reduced elasticity, and even brittleness and fracture, and can bleach and fade fabrics.
The speed and effect of ozone sterilization are unmatched. Its high oxidation-reduction potential determines its wide application in oxidation, decolorization, and deodorization. Some studies point out that ozone dissolved in water can kill almost all substances harmful to human health, such as iron, manganese, chromium, sulfate, phenol, benzene, oxides, etc., and can also decompose organic matter and kill algae.
Compared with conventional sterilization methods, ozone disinfection and sterilization has the following features:
(1) High efficiency. Ozone disinfection and sterilization uses air as the medium and requires no other auxiliary materials or additives. It has good containment and thorough sterilization, and also strongly removes mold, fishy, and foul odors.
(2) High cleanliness. The characteristic of ozone rapidly decomposing into oxygen is a unique advantage of ozone as a disinfectant and sterilant. Ozone is generated from oxygen in the air. During disinfection, the surplus oxygen recombines into oxygen molecules after 30 minutes. No residue exists, which solves the secondary pollution problem caused by chemical disinfectants and also eliminates the need for re-cleaning after disinfection.
(3) Convenience. Ozone sterilizers are generally installed in clean rooms or air purification systems or sterilization chambers (such as ozone sterilization cabinets, transfer windows, etc.). According to the validated sterilization concentration and time, the sterilizer's timed start and operating time are set, making operation and use convenient.
(4) Economy. Through the use and operation comparison of ozone disinfection and sterilization in many pharmaceutical industries and medical and health institutions, the ozone disinfection method has great economic and social benefits compared with other methods. In today's rapid industrial development, environmental protection issues are particularly important.
