The UV lamp is an ancient and effective method. Drying the quilt under the sun is the most primitive use of ultraviolet rays to remove mites, disinfect and sterilize.
Li Jinmin, director of the State Key Laboratory of Semiconductor Lighting Joint Innovation, said that the principle of ultraviolet disinfection is to use high-energy ultraviolet light to break the double helix of DNA to inactivate bacteria and viruses. Ultraviolet rays need to meet certain requirements to achieve effective sterilization and disinfection. Pay attention to the wavelength, irradiation dose, and time of the ultraviolet light source, that is, it must be deep ultraviolet light in the UVC band with a wavelength below 280 nm and meet a certain irradiation dose and time for different bacteria and viruses. Otherwise, it cannot be inactivated.
According to Yan Jianchang, a researcher at the Institute of Semiconductors of the Chinese Academy of Sciences, according to the wavelength division, the ultraviolet band can be divided into different bands: UVA, UVB, and UVC. UVC is the wavelength band with the shortest wavelength and the highest energy. In fact, for sterilization and disinfection, the most effective UVC is the band called deep ultraviolet. Compared with chemical sterilization, ultraviolet light has the advantage of high sterilization efficiency, inactivation is generally completed within a few seconds, and no other chemical pollutants are produced.
Ultraviolet rays can also inactivate microorganisms. Households can purify water by installing an ultraviolet water purification system, and an air purifier equipped with ultraviolet lamps can harmlessly treat bacteria floating in the air. Sewage treatment plants, food factories, breweries, beverage factories, etc. also use ultraviolet light for sterilization.
Use UV lamp to master the skills
Because of the damaging effect of ultraviolet rays on biological cells, when using ultraviolet germicidal lamps, be careful not to directly irradiate human skin, let alone look directly at the lamp tube with your eyes.
On the premise of ensuring safety, how to use UV lamp scientifically and effectively? Wang Di said that it is necessary to pay attention to the location, create the best use environment, and pay attention to the length of use.
- First, due to the extremely weak penetration of ultraviolet rays in the air, it is difficult to achieve long-distance sterilization, so when using it, it should be placed in the main sterilization position, such as the middle of the room, or where it is easy to breed bacteria, 1.5m away from the surrounding area. 2m is appropriate.
- Second, pay attention to the influence of the environment on the sterilization effect when using it. Under normal circumstances, the output intensity of ultraviolet rays is the highest when the temperature is between 27°C and 40°C, and the sterilization effect is the best. In addition, ensure that the use environment is clean and dry. A large amount of moisture and dust in the environment will interfere and weaken the ultraviolet rays. Function to reduce the actual UV intensity. When using at home, try to seal the doors and windows, close the curtains, and turn off the lights to ensure that the room is in a darker condition, which is more conducive to the sterilization effect of ultraviolet rays. For places that are prone to bacteria and other microorganisms, such as bed covers, the bed can be unfolded, increasing the contact area, which is more conducive to ultraviolet disinfection.