Ozone disinfection sterilization method has the following characteristics compared with conventional disinfection sterilization methods:
(1) high efficiency: ozone disinfection does not require any other auxiliary materials and additives. Disinfection is carried out when the ozone generator produces a certain amount of ozone, in a relatively sealed environment, diffusion uniformity, inclusiveness, permeability is good, overcoming the problem of disinfection of ultraviolet sterilization of the existence of the dead zone, to achieve a full range of fast, efficient disinfection sterilization purposes. In addition, because of its sterilization broad-spectrum, not only can kill bacterial propagules, germ cells, viruses, fungi and protozoa spores and other microorganisms, but also destroy botulinum and toxins and rickettsiae, etc., but also has a strong function of removing mildew, fishy, smelly and other odors.
(2) high cleanliness: ozone can be naturally decomposed into oxygen in the environment, which is a unique advantage of ozone as a disinfectant and sterilizer. Ozone generated using the oxygen in the air, disinfection and oxidation process, the excess oxygen atoms (O) in 30 minutes and then combined into molecular oxygen (O2), there is no residual material, to solve the disinfectant disinfection, the residue of the secondary pollution, while eliminating the need to disinfect the end of the cleaning again.
(3) Convenience: ozone sterilization equipment is generally installed in the indoor or central air conditioning system, air purification system, or sterilization equipment (such as ozone sterilization cabinet, transfer window, etc.). According to the concentration and time required for sterilization, ozone sterilization equipment can be automatically set up timing control, easy to operate and use. And formaldehyde, epoxyacetic acid fumigation disinfection for a long time, and ozone sterilization can be opened every day at regular intervals to use.
(4) economic: through the ozone sterilization sterilization in many pharmaceutical industry GMP applications, as well as the use of medical and health units and the operation of the comparison, ozone disinfection method compared with other methods have great economic and social benefits.
2, ozone disinfection applications
(1) water disinfection: due to the instability of ozone in water, the decomposition produces oxidizing ability is very strong (stronger than single atomic oxygen) of hydroxyl (OH) and single atomic oxygen, etc., can effectively kill a variety of bacteria and viruses in the water. Foreign ozone as the most ideal water disinfection and purification agent, many large-scale water plants commonly use ozone to treat drinking water, China's Kunming Water Company, Deepwater Group, Shanghai Water Company has also used ozone to purify and disinfect the water.
Chlorine disinfection of water, can produce carcinogenic toxins trichloromethane, if the amount of chlorine dosage increased, the generation of trichloromethane also increased, with the human carcinogenicity of the toxicity of the study in-depth, the World Water Association, the World Health Organization, etc., has been advocating the use of chlorine for drinking water disinfection. And ozone for drinking water disinfection has the following advantages:
Strong oxidizing ability, high sterilization efficiency, sterilization speed, ozone kills microorganisms in the water is 600-3000 times more efficient than chlorine, you can kill all the bacteria in the water, viruses, germ cells, spores and insects, but also kill algae, etc.;
Ozone in the water after the role of the products are Non-toxic and harmless oxygen, and ozone itself no permanent residual, but also increase the dissolved oxygen in the water; color removal, deodorization, reduce the turbidity of the water; oxidative decomposition of iron in the water, manganese, silver, cobalt, suspended particles, organic pesticides and detergents, etc., and greatly improve the quality of water.
Water treatment in the ozone dosage should be based on the physical and chemical properties of the water, the degree of pollution, contact time and other design. For domestic water and drinking water disinfection, adding 0.1-1mg / L can be, the general amount of ozone added to the water 0.5-1.5mg / L, contact 5-10 minutes, the water to maintain the remaining ozone concentration of 0.1-0.5mg / L.
Ozone is also widely used in wastewater treatment, due to the ozone of strong Bactericidal capacity, many foreign hospitals using ozone treatment of sewage, and achieved satisfactory results, the test proved that when the hospital discharged sewage containing 106-108 bacteria / L, add ozone concentration of 10-20mg / L role of 10-15 minutes, the bacterial propagation rate of 99.999% to 99.999% -15 minutes. Rate of 99.999% -100%, adding 25-30mg / L role in 15 minutes, the killing rate of germ cells can also reach 99.999% or more.
Ozone is used for drinking water, sewage disinfection at the same time, can also be made into a high concentration of ozone disinfection of water, vegetables, fruits, food utensils, hands and other items to clean and disinfect. In Japan, the use of high-concentration ozone disinfection water has become the focus of the disinfection field, in particular, in the summer of 1996, the pathogenic prototypes of E. coli 0517 outbreak of infections in the event of the previous use of sodium hypochlorite, ethanol, acetic acid and other biocides, in the long term concentration of 100-300 ppm, resulting in Gram-negative bacteria, such as coliform bacteria, to produce an extremely strong resistance to the bacterial Mutations, while the mechanism of action is completely different from the high concentration of ozone disinfection water is very effective. Penicillin-resistant Staphylococcus aureus infections have also become a serious problem in Japan's healthcare system, and the use of high-concentration ozone water for hand-washing by healthcare workers and disinfection of medical equipment has been emphasized as a solution.
Japan in the ozone water on the medical sector related to the bactericidal effect of microorganisms in the test, in regular contact with the usual, but also in the hospital infection of the important microorganisms as a test sample, such as bacteria: Escherichia coli IFO3301, P. aeruginosa IFO3445, Staphylococcus aureus ATCC43300, Staphylococcus epidermidis IFO12993; Viruses: herpesvirus RF, adenovirus type 3, corsage virus B5FAULKNER, aike virus type 7 WALLACE, influenza virus PR8, etc. Comparing with chlorine disinfectant water, each test bacteria can be killed completely after 10 seconds of ozonated water concentration of 4mg/L, while the control group still has more than 103mg/L of viable bacteria number remaining after 30 seconds. For viruses, the results were expressed by the viral half of the tissue culture infected amount (TCID50), and the reduction of TCID50 by more than 103 can be considered as viral inactivation. In the ozone water 4mg / L concentration under the action of 20 seconds, herpes virus, influenza virus to reduce TCID50103 or more, Cosage B5 virus, Aike 7 virus to reduce TCID50104 or more, so it can be confirmed that the ozone water for the medical, pharmaceutical and food processing fields caused by infection of bacteria, viruses have a very good killing effect.
In the cleaning of health care workers attached to the finger bacteria removal, for the test organisms for penicillin-resistant Staphylococcus aureus, the comparison group used to disinfect with ethanol, MK212. on the cleaning of the drainage to identify the bactericidal effect and drainage of the secondary pollution, the drainage of the number of bacteria, the control group of 104, ozone water is only 101. to prove that the ozone water bactericidal effect is obvious, and the outside world did not cause secondary bacterial pollution.
According to the standard of basic biological test for medical devices and medical materials:
Cytotoxicity test, solid toxicity test on animals, i.e., cytotoxicity test by human or animal cells, this time for the mouse glandular cells, Giemsa staining, the results reflect that the ozone water has no cytotoxicity or microtoxicity.
Allergy test, skin allergy test is a person in a substance repeatedly exposed to cause immune response disorders, check whether to cause allergic symptoms. The test is carried out using the maximum value, ozone water injected into the skin of groundhogs, the results are no erythema, swelling and other allergic symptoms, no allergic reaction.
Ocular mucous membrane irritation test, in the 4mg/L ozone water drops in the eye, no irritation, conjunctiva, iris, cornea are not damaged, judged no ocular mucous membrane once irritation.
Cumulative skin irritation test, the back skin of New Zealand mice in 14 days, the use of ozone water wipe, the test animals in the test period of normal behavior, hair and excreta are no change, no skin erythema and swelling, can be considered to be continuous use of ozone water on the skin without cumulative irritation.
In summary, the use of ozone water sterilization is extremely effective and safe. For general bacteria, 1mg/L ozone water is already enough to kill. For the inactivation of viruses, we recommend that a high concentration of ozone water should be used.
Ozone water can be used to inactivate bacteria and viruses used in the test, as well as lipophilic and hydrophilic viruses (including hepatitis A HAV, hepatitis B HBV, hepatitis C HCV, and HIV), Pseudomonas aeruginosa, Pseudomonas fluorescens, Legionella, Xanthobacter, Alkaloidobacter, amoebae, and human pathogenic fungi (e.g., Candida albicans), and so on.
Similarly, ozonated water has been used as an effective treatment for disease. 1902 J. H. Clarke's Manual of Medical Practice describes the successful use of ozonated water in the treatment of anemia, diabetes, etc. In 1979 DR George Freibott began using ozone in the treatment of AIDS patients. Today, ozone therapy is widely used in Germany, France, Italy, Russia, Portugal and other EU countries. In the application of ozone water treatment of maternal postpartum care, burn patients cleaning and disinfection, China also has a preliminary study. And the British Queen Mother in the world, the reason why the secret of longevity, one is not away from the hot water bag, and then there is to adhere to the ozone water injection health care.
In the field of food production, ozone water sterilization instead of traditional disinfectants also show more excellent advantages, the United States, the European Union and other public **** water and food processing has been widely used in ozone water. In vegetable processing, the traditional sterilization method is to use high-temperature sterilization process, not only on the color of vegetables, taste, texture and other damage, but also consume a lot of energy. The use of ozone water as a cold sterilization technology can avoid the destruction of the quality of vegetables by the traditional process, improve the added value of the product, and also reduce the cost. In the relevant test, compared with chlorine dioxide control, the hygiene index of its vegetable processed products to achieve sterility requirements, sterilization effect is better than chlorine dioxide water solution.
In the disinfection of aquatic products, such as fish and other disinfection and purification, the same control chlorine disinfection and purification, in the storage time, bacterial reproduction rate, taste, protoplasm, appearance, etc., the ozone water are better than chlorine class. In the use of ozone seawater treatment of shellfish, after treatment, shellfish itself clean faster, in the study of the nine strains of bacteria including Escherichia coli, Pseudomonas genus Pseudomonas aeruginosa and Salmonella typhimurium, etc., in general, than the use of chlorine control group to reduce the 1/100-1/1000.
Ozone water can also be used in the pharmaceutical industry, the food processing industry, pipeline
Ozone water can also be used in the pharmaceutical industry, food processing industry pipelines, production equipment and containers of the immersion and cleaning, so as to achieve the purpose of disinfection and sterilization. Using high concentration ozone water for soaking and rinsing, first, the pipeline, equipment and the surface of the container bacteria, viruses are removed by a large number of shower; secondly, the residual bacteria and viruses on the surface of the surface that have not been washed away by the ozone to kill the use of simple, in the production of pharmaceuticals and food processing will not produce a dead end to avoid the use of chemical disinfectants in the production of the chemical toxic substances brought about by the emission and residual pollution and other environmental issues.
(2) air disinfection: ozone in the air can be diffused to all the items around the room and every corner of the space, diffusibility, concentration uniformity, leaving no dead ends, so more than the ultraviolet ray has the advantage of ultraviolet radiation sterilization, and ultraviolet radiation in the form of optical radiation, only in the irradiation to the location of the irradiation intensity standard to have a sterilizing effect, and ozone sterilization mechanism can be effective in the air to kill the sterilization of various microorganisms. The ozone sterilizing mechanism can effectively kill various microorganisms in the air. The ozone below the safety tolerance concentration (0.2mg/M3) has a good killing effect on general bacterial propagation. Test with 30 mg/M3 concentration of ozone, 15 minutes of action, on the sample hospital wards of natural bacteria killing rate ≥ 92.7%, on the aerosol of Staphylococcus aureus, 0.12 mg/M3 ozone 30 minutes of action, the killing rate of 99.9% or more, on the Bacillus cereus black variant of the bacterial germs of 5.67 mg/M3 concentration of ozone 60 minutes of action, the killing rate of ≥ 99%.
The main advantages of using gas-phase ozone disinfection: the final decomposition of ozone is oxygen, no residue, no harm to the environment; there will be no residue on the disinfected items, such as utensils, cutlery, food, and so on, and the physical and chemical properties of the original items have less impact; compared to other disinfection methods, such as ultraviolet light, fumigation, etc., the operating cost is small; the scope of application is wide, there is no particular The application range is wide and there is no special restriction.
In the gas-phase conditions, the effect of ozone to kill microorganisms, depending on these main factors: ozone threshold concentration, that is, when the ozone air concentration to achieve the concentration required to have the ability to kill microorganisms; microbial species; processing time; ozone distribution; temperature and humidity conditions in the space; indoor walls, ceilings, floors, and other decorative materials, such as the impact of the reductive properties.
The killing effect of ozone on microorganisms under gas-phase conditions is different, and it has been proved by experiments that ozone has a strong bactericidal effect on pathogenic bacteria and viruses in humans and animals.
The environmental factors affecting the sterilization effect of gas-phase ozone are mainly temperature and humidity. In general, low temperature, high humidity is a good killing effect, especially the humidity conditions, relative humidity ≤ 45%, the ozone on the air suspended microorganisms almost no killing effect, relative humidity > 70%, the killing effect is really reflected. This is due to the relative humidity increases, can make the cell expansion, cell wall thinning, so that it is more susceptible to ozone penetration dissolution.
Table III Reference concentration of ozone used in the air (unit: ppm)
Use
Type
Concentration
Use
Disinfection
Cold storage
Foodstuffs workshop
Wards, operating rooms
Working clothes disinfection
After the SARS epidemic. Contaminated zone air
6-10
1.0-1.5
1.5-5
10-20
≥15
Depending on the storage capacity and the degree of contamination continuous Power on
Power on to send ozone gas after shift every day
Power on when you need to disinfect, check the total number of bacteria according to the standard
Relative temperature of 90 or so, clothes hanging on hangers
Anti-mildew and preservation
General place
Egg
Bananas
Apple
Vegetables with little chlorophyll
Fish cheese
1-2
2-2.5
2.5-3.5
2.0
1.5-1
0.5 -1
Periodic power on
Intermittent supply of ozone gas, 2-3 times a day
Intermittent supply of ozone gas, 2-3 times a day
Deodorization and purification
Morgue
Fish processing plant
Slaughterhouse
Fatty acid plant
Rubber factory
Rubbish waste treatment plant
Sewage treatment plant
3
3
2-3
10
3-10
10
1-2
There is an odor that is open deodorization
Pumping polluted gases to deal with the pipeline, in the pipeline to add ozone gas oxidation deodorization. If the workshop odor is serious, ozone gas should be added to the workshop air inlet to smell the ozone odor until
Consolidation of the above factors, we recommend the use of ozone generator for air disinfection:
Installation of ozone generator for air disinfection. Split or mobile placed in a separate space, generally to be placed high, because the specific gravity of ozone in the air is larger, easy to fall, placed high mainly to facilitate the dispersion of ozone; in the space is relatively closed, such as air self-circulating aseptic room, it is recommended to use the closed-circuit air circulation system, the addition of ozone generating devices, such as assembled in the air conditioning unit, installed in the general air supply duct or the general return air duct, in order to achieve the set Disinfection time, the use of activated carbon adsorption or catalyst reduction for air disinfection sterilization, so that both the purpose of air disinfection can be achieved, but also so that staff do not have to leave the working environment. At present, the application of this technology in the pharmaceutical industry aseptic room has been very extensive and mature, the main workflow is as follows: air compressor - oxygen generator - ozone generator - air-conditioning air supply pipe - the disinfection and purification areas.
Calculation of the selection of ozone generating device for air sterilization. The use of ozone disinfection needs to be at least to achieve the threshold concentration, the occurrence of concentration below the threshold concentration, is not able to achieve the sterilization effect, and the concentration is too high will result in an increase in operating costs, so it should be calculated to select the appropriate range of concentration of ozone generating device. According to the "Disinfection Technical Specification" and practical application data, in the GMP pharmaceutical workshop clean area, clean level 300,000 cancel poison need to maintain the ozone concentration N = 5mg/M3, 100,000 take N = 10 mg/M3, 10,000 take N = 30mg/M3, 100 take N = 40mg/M3. Total ozone dosage is calculated as follows: W = NV / (1 - S), where, W - W - ozone generating device, the concentration is lower than the threshold concentration, and the concentration is higher than the operating cost increases. S), where W - the total amount of ozone (mg / M3); S - ozone attenuation rate of S = 40%; V - the total volume (M3); N - clean area disinfection needs to maintain the concentration of ozone (mg / M3). Where V = V1 + V2 + V3, V1 - total volume of the clean area; V2 - air conditioning duct volume; V3 - supplemental fresh air volume caused by ozone loss of the effective volume (V3 = total air volume × 20% of the conventional fresh air replacement rate × 10% (to maintain positive pressure in the clean area of the supplemental fresh air volume) × 60 (% = total air volume × 1.2%).
Appropriate humidity. Ozone sterilization effect in the humidity of 70-80% of the most ideal conditions, in the humidity below 45% of the effect is poor, so the general use, especially in the pharmaceutical workshop aseptic room, wards, etc. should pay attention to the use of the environment in the appropriate increase in humidity.
Ozone concentration. Concentration mastery is the key to the use of air-type ozone generator, different uses should not be the concentration and time to match. For example, general deodorant, deodorization, concentration mastery is generally no more than 0.05ppm. If used for indoor sterilization disinfection is generally mastered in 0.1-1ppm; if used for food preservation or surface disinfection is generally mastered in 1-5ppm concentration. Of course, these concentration indexes are related to the amount of time, referring to the entire space-borne dispersal concentration, rather than the local concentration. Object surfaces or ward areas generally require higher concentrations.
Selection of ozone generators for air sterilization. As ozone can only be produced in situ, the current most economical and technically mature way to generate ozone for the corona discharge, and for air disinfection with ozone generator is mostly used in ceramic chip high-frequency discharge mode, which has the advantages of simple structure, reliable performance, low operating costs and flexible regulation.
Ozone air sterilization safety. Ozone safety in a wide range of animal and human tests, the main exposure route for inhalation, sustained, long-term inhalation tests show that ozone is not carcinogenic (NTP, 1995); but on the respiratory system of animals and humans have a significant irritation, in the exposure environment, can affect respiratory function. Therefore, we recommend that the use of ozone to disinfect air should be carried out in an unoccupied environment, and personnel should not enter until half an hour after disinfection has been completed.
Applicable fields of ozone air disinfection:
GMP validation air disinfection in pharmaceutical industry. Clean production area of the central air-conditioning purification system, ozone sterilization cabinets, other no central air-conditioning system for the production of space sterilization, which is part of the use of ozone disinfection of pharmaceutical companies, Shenyang Jishi Pharmaceutical Company Limited, Dalian Zhen'ao Pharmaceutical Company Limited, Shanghai Qing'an Pharmaceutical Co., Ltd, Jilin Aodong Pharmaceutical Group Yanji Co., Ltd, Fujian Xing'an Pharmaceutical Company Limited, etc., the ozone as the main means of air sterilization Ozone as the main means of air sterilization has made an important contribution to the GMP verification of these enterprises.
Hospital air disinfection. Hospital wards, outpatient operating rooms, treatment rooms, etc., Japan's use of ozone as air disinfection of hospitals on the Sapporo Self-Defense Force Hospital, Nagoya University of Health Sciences and other 28 hospitals, the use of ozone technology to deal with food, health care units and hospitals up to as many as 53, Taiwan's use of ozone in the Veteran's General Hospital and other 51, the domestic Beijing Hospital, Beijing You'an Hospital, etc..
Military air sterilization. Western countries have developed military ozone air disinfection products, such as in the capsule, submarines, tanks and other military vehicles and ships in the hull of the installation of ozone generating devices, purify the space environment, disinfection and sterilization. Such products are powered by batteries or photocells.
Home air disinfection. With the intensification of urban environmental pollution, the family air purifier market prospects, the ozone generator transplanted in the air conditioning, ozone catalytic decomposition, adsorption device installed at the air outlet, so that both refrigeration and heating, but also the use of indoor circulating wind to disinfect the air, purification, decomposition of oxygen and negative ions can be made to keep the indoor air fresh. In addition, air disinfection with ozone generator can also be used in hotels, restaurants, shopping malls, theaters and other public **** space. In the family and public **** environment should be noted when the application of ozone for air disinfection: the sterilization effect of ozone K for the actual concentration of ozone C and the role of the product of time T that is, K = C × T, and the actual concentration of ozone C to reach the bactericidal threshold concentration of Cmin, even if the extension of the time, the actual operation, I'm afraid that is not bactericidal effect. Ozone used for air disinfection should be applied to different spaces, different sterilization purposes, and the configuration of different ozone production and ozone concentration of ozone generator, ozone concentration refers to the natural diffusion of a fixed volume of 30 minutes according to the concentration of counting, the unit of mg/m3, ozone production is calculated by the concentration of ozone generation and the time of the cumulative ozone production, ozone production, ozone concentration is the most basic parameter standards. Ozone production and ozone generation concentration are the most basic parameter standards. Ozone production and ozone generation concentration are the most basic parameter standards. Therefore, ozone disinfection products aiming at air disinfection should be labeled with the indicators of disinfection concentration and disinfection time. There are also two general indicators, namely, the application of space ozone safety indicators and product life indicators, also need to be indicated to the user.
(3) ozone disinfection of the surface of the goods:
Ozone on the surface of the goods of micro-organisms also has the same effect of killing, the application is also very broad such as tableware, toys, utensils, medical instruments, etc., disinfection, sterilization, ozone disinfection cabinets now on the market, the ozone can be diffused in the utensils around the sterilization, less power consumption, sterilization effect is significant, to make up for the lack of high-temperature high-pressure steam, infrared and ultraviolet disinfection cabinets. and ultraviolet ray sterilizer shortcomings. Such as sterile rooms, clean rooms, hospitals, the disinfection of work clothes, the traditional use of high-temperature autoclave sterilization, sterilization of cotton clothing will be white to yellow, many times after the sterilization, clothing fibers become brittle and fall off. Directly affect the life of the clothes and aseptic rooms, clean rooms, cleanliness, and now the silk work clothes are more inappropriate to use high temperature steam sterilization, and the use of ozone sterilization treatment, it is lower on the degree of damage to the clothing, and no residue, marks and odor, and higher temperature steam sterilization sterilization disinfection effect is the same or slightly better, the test, the test for sterile work clothes with human contamination of the bacterial flora, the overall killing rate of ≥ 95%.
There are also experimental studies (Jingmen Poultry Eggs Joint Processing Plant), ozone gas used for egg disinfection, shorter than conventional formalin fumigation, residual gas decomposition fast, the use of economic, convenient, and ozone also has a delayed sterilizing effect on eggs, so that the hatching rate of egg incubation is significantly increased.