UV, mercury lamp and ozone disinfection principle
1. Understanding of ultraviolet rays and antivirus principles
Ultraviolet (Ultra Violet, UV) is very common. It is light with a wavelength of 100 to 400 nm in sunlight. According to different wavelength bands, it can be divided into UVA, UVB, UVC and vacuum UV. Among them, the UVA wavelength range is 315-400 nm, the UVB wavelength range is 280-315nm, and the UVC wavelength range is 200-280nm.
1.1 Principles of UV disinfection
The UVC band has the characteristics of short wavelength and high energy. It can penetrate the cell membrane and cell nucleus of organisms, cause damage to DNA, and destroy the molecular structure of microorganisms (bacteria, viruses and other pathogens) in a short time. By destroying the DNA and RNA of microorganisms to prevent their reproduction, it can achieve high-efficiency and rapid broad-spectrum sterilization effects, such as bacterial propagules, spores, viruses, fungi, etc., so as to sterilize water, air and surface of objects, making cells unable to regenerate. Among them, the ultraviolet output with 265nm as the center band can be quickly absorbed by bacteria, which is an effective sterilization method.
1.2 Advantages of UVC antivirus
High-efficiency sterilization: The sterilization effect of ultraviolet rays on bacteria and viruses is generally completed within a few seconds, almost transiently, and the sterilization and disinfection capacity is 600 to 3000 times greater than that of chlorine.
Broad-spectrum sterilization: UV technology has the highest broad-spectrum sterilization among all current sterilization technologies. It can kill almost all bacteria and viruses with high efficiency.
More thorough sterilization: the combined use of ultraviolet rays and ozone (UVC+O3) can exert a more powerful and thorough sterilization power. Ultraviolet rays irradiate the air and the surface of objects in a straight line to achieve strong sterilization; ozone penetrates into all corners of the room with the air to completely kill indoor bacteria.
Complete environmental protection: The ultraviolet light emits ultraviolet rays for sterilization and disinfection. The ultraviolet rays irradiate the oxygen in the air to generate ozone, and the ozone is strongly oxidized to kill bacteria and viruses. The entire sterilization process does not need to add any chemicals, truly achieving complete environmental protection.
There is no drug resistance: ultraviolet light or ozone directly destroys the DNA, RNA, protein, etc. in the bacterial virus cell, causing the cell to die directly and unable to reproduce, and there is no drug resistance. The sterilization of other chemical agents will cause the bacteria and viruses to become resistant, and the sterilization effect of the chemical agent will be invalid.
No secondary pollution: Ultraviolet rays and ozone cause the direct death of bacteria and viruses without any other chemical pollutants; meanwhile, ozone is converted into oxygen at room temperature for 15-30 minutes (ozone half-life) without any residual secondary pollution.
1.3 Disadvantages of UVC antivirus
The main part of human body damage caused by UVC ultraviolet rays is the eyes and bare skin. Short-term high-intensity irradiation can burn eyes and skin, and long-term high-intensity irradiation can even cause skin cancer.
The penetration of UVC is extremely weak, and ordinary transparent glass, clothes, plastic, dust, etc. can be completely blocked. Therefore, wearing glasses (if you don't have glasses, avoid looking directly at the ultraviolet light) and covering your bare skin as much as possible, you can protect your eyes and skin from UVC ultraviolet rays.
1.4 UVC antivirus application
The main parameter to measure the sterilization efficiency is the radiation dose received by the bacteria (radiation dose (mJ/cm2) = radiation time (s) * deep ultraviolet radiation intensity (mW/cm2), the greater the radiation dose, the higher the sterilization efficiency. Data It is shown that with only 30mW/cm2 UVC ultraviolet radiation intensity, almost 100% of most bacteria can be killed in one second, and the effect is very significant, which can be widely used in the field of medical and health. In personal health and family hygiene In the field, ultraviolet light can be used for disinfection of water cups and chopsticks, air purification and sterilization, killing worms, sterilization and deodorization of footwear and socks, and sterilization of baby bottles.
2. The principle and application of deep ultraviolet LED antivirus
Deep ultraviolet LED (UVC LED) is: a sterilizing ultraviolet diode, and the way that LED emits UVC has performance advantages such as safety, environmental protection, compactness, high efficiency, and low consumption. The UVC LED used in our products emits deep ultraviolet rays with a wavelength of 260~280nm. Deep ultraviolet rays can damage the DNA or RNA molecular structure of the genetic material in microorganisms, causing bacteria to fail to reproduce or even inactivate, thereby achieving the purpose of sterilization.
2.1 Advantages of deep ultraviolet LED sterilization
Compared with other sterilization methods such as ozone method and ultraviolet mercury lamp sterilization method, deep ultraviolet LED sterilization has many advantages:
1) Efficient sterilization, the UVC segment ultraviolet light emitted by the deep ultraviolet LED generally kills bacteria and viruses within a few seconds. The traditional water sterilization methods such as ozone and other methods generally require 20 minutes to 1 hour to reach the deep ultraviolet sterilization efficiency. ；
2) Extensive bactericidal properties. Because bacteria, virus antigens and other microorganisms are not resistant to ultraviolet light, deep ultraviolet light can kill almost all bacteria and viruses with high efficiency, and deep ultraviolet LED sterilization technology can also be used in To a certain extent, inhibit the growth of some higher aquatic organisms, such as algae, bloodworms, and paramecium.
3) Safety and environmental protection (without mercury). Compared with the mercury-excited ultraviolet lamps currently on the market, the most obvious advantage of deep ultraviolet LED devices is that the germicidal light source does not contain mercury. Mercury is a heavy metal substance, commonly known as mercury. It can evaporate. Mercury vapor and mercury compounds are highly toxic (chronic). In the sterilization process of traditional ultraviolet mercury lamp germicidal lamps, once the lamp tube is broken, it will cause serious water pollution. Deep ultraviolet LED devices are a safe and reliable device. Contains heavy metals, simple operation, safe and reliable operation.
4) Energy saving, long life and low maintenance cost. Deep ultraviolet LED sterilizers are gradually replacing the common mercury lamp ultraviolet sterilizers on the market. One of the important reasons is that ultraviolet LEDs have low power consumption and are very energy-efficient. The power of deep ultraviolet LEDs is about One-tenth of the mercury lamp, this ratio greatly saves costs;
5) Small size, flexible design, convenient installation, deep ultraviolet LED device, small size, and flexible design of its sterilization device, which can be used in small spaces where traditional ultraviolet mercury lamps cannot be used.
3. the principle of mercury lamp disinfection
The mercury lamp disinfection is actually a kind of low-pressure mercury. The low-pressure mercury lamp uses a lower mercury vapor pressure (<10-2Pa) to be modified to emit ultraviolet waves. There are two main emission spectral lines: one is 253.7nm wavelength; The other has a wavelength of 185nm, both of which are invisible to the naked eye. The wavelength of 250nm-260nm can play a very good sterilization effect, so the ultraviolet light with the wavelength of 253.7rm passes through the glass tube wall and is transmitted to achieve the purpose of ultraviolet sterilization.
The ultraviolet germicidal lamp tube is made of quartz glass. The mercury lamp is divided into three types according to the mercury vapor pressure in the lamp tube after lighting and the difference in the ultraviolet output intensity: low pressure low intensity mercury lamp, medium pressure high intensity mercury lamp And low-pressure high-intensity mercury lamps. The sterilization effect is determined by the radiation dose received by the microorganisms. At the same time, it is also affected by the output energy of ultraviolet rays, which is related to the type of lamp, light intensity and use time. As the lamp ages, it will lose 30%-50% of its intensity .
Mercury lamp sterilization is currently a more widely used sterilization method. But mercury is highly toxic. Mercury can evaporate at room temperature. Mercury vapor and mercury compounds are highly toxic (chronic). In the sterilization process of traditional ultraviolet mercury lamp germicidal lamps, once the lamp tube is broken, it will cause serious water pollution and poor control. Will have serious consequences.
4. The principle of ozone disinfection
At room temperature, ozone gas is a lavender gas with a special fishy smell, and its solubility increases as the temperature decreases. Because ozone has strong oxidizing properties, it exhibits outstanding effects of sterilization, disinfection, and degradation of pesticides. It is an efficient and broad-spectrum fungicide. Ozone can also kill hepatitis viruses, cold viruses, etc. Ozone diffuses quickly and evenly in the air, disinfecting without dead ends. Its shortcomings: the sterilization time is longer, generally should reach 50-60min; in addition, if the surface of the items to be disinfected has water, the disinfection effect of ozone will be weakened.
However, when the concentration is too high, the decomposition time of ozone is prolonged, the ozone that is not completely decomposed has a great smell, and it has greater damage to the human respiratory tract, nervous system, and immune system.
Ozone is a strong oxidant, and the sterilization process is a biochemical oxidation reaction. There are three forms of ozone sterilization:
1. Ozone can oxidize and decompose the enzymes necessary for the degradation of glucose inside the bacteria, inactivate the enzymes necessary for cell activities, and inactivate the bacteria.
2. Directly interact with bacteria and viruses, destroy their organelles, DNA and RNA, destroy the metabolism of bacteria and cause the death of bacteria.
3. Through the cell membrane tissue, invade into the cell, acting on the lipoprotein of the outer membrane and the lipopolysaccharide inside, changing the cell permeability, leading to cell lysis and death.
4.1 Ozone effect
1. Sterilization: Ozone can quickly kill bacteria, molds, yeasts, viruses and other microorganisms in the air and water. When the ozone concentration in the water is 0.05ppm, keep it for ten minutes, and the killing rate of bacteria is more than 99%.
2. Detoxification: The environment is full of various substances harmful to the human body, such as carbon monoxide, pesticides, heavy metals, fertilizers, organic matter, odor, pigments, etc. After ozone treatment, these toxic substances will be decomposed into harmless substances to the human body .
3. Keeping healthy products fresh: Using ozone sterilizers in food production can reduce the chance of food spoilage and extend the shelf life of food. Using ozone in health products such as medicines and cosmetics can also extend the shelf life of food.
4. Bleaching: Ozone has a strong bleaching effect and can be used for laundry, food, and wastewater treatment.
5. Deodorization: Ozone has super oxidizing properties, which can quickly decompose the substances in the bad smell, thereby eliminating the peculiar smell.
4.2 Which is better, ozone disinfection or ultraviolet disinfection?
Ultraviolet disinfection and ozone disinfection actually have their own characteristics. Ozone disinfection has a strong oxidizing effect. It does not produce excess by-products like ultraviolet rays. It oxidizes the enzymes inside the bacteria and destroys its metabolism and eventually leads to death. Ozone itself is a gas, which can fill the entire space with almost no dead ends. However, ozone disinfection is the same as ultraviolet disinfection, and the penetrating power of sterilization is not strong. If you want to achieve the best results, it takes about 30-60 minutes, otherwise it will not be thorough enough, and various fungi and pathogens will be revived in a short time. After the sterilizer is turned off, it should be closed for 30 minutes, so that the effect will be the best. The principle of ultraviolet sterilization is to destroy the structure of DNA (deoxyribonucleic acid) in the body through ultraviolet radiation to bacteria, viruses and other microorganisms, causing them to die or lose their activity immediately.
In summary, if we combine ultraviolet rays and ozone to perform loop antivirus, the effect will be more reliable than a single antivirus method.
紫外線(Ultra Violet，UV)很常見，它是陽光中波長100至400 nm的光線，根據不同波段可分為UVA、UVB、UVC及真空UV。其中UVA波長範圍315-400 nm，UVB波長範圍280-315nm,UVC波長範圍200-280nm。
深紫外LED（UVC LED）就是：殺菌紫外線二極體，而LED發出UVC的方式，具有安全、環保、小巧、高效、低耗等性能優勢。我司產品所用UVC LED發出波長260~280nm的深紫外線，深紫外線能破壞微生物體內遺傳物質DNA或者RNA分子結構，導致細菌無法繁殖甚至失活，從而達到殺菌消毒的目的。