Use of ultraviolet lamp and precautions for use of ultraviolet germicidal lamp
What are the advantages of ultraviolet sterilization? What wavelength is the most appropriate ultraviolet sterilization effect? The strongest peak of ultraviolet absorption of deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and nucleoprotein in bacteria is 254-257nm. After absorbing ultraviolet light, bacteria will cause DNA strand breakage, cause cross-linking and breakage of nucleic acid and protein, kill the biological activity of nucleic acid, and cause bacterial death. Ultraviolet sterilization is fast. Ultraviolet disinfection is widely used in hospitals, schools, nurseries, cinemas, buses, offices, families, etc. It can purify the air and disinfect the musty smell. In addition, it can also produce a certain amount of negative oxygen ions. The air in rooms disinfected by ultraviolet is particularly fresh. In public places, ultraviolet disinfection can prevent some germs from spreading through the air or through the surface of objects. The long-life ultraviolet germicidal lamp is of great significance in the application of water and environmental protection projects. Water disinfection equipment, such as pure water system, generally operates 24 hours. The life and reliability of the ultraviolet germicidal lamp are required to be high. If the life of the lamp is short, the cost of replacing the lamp is high and inconvenient.
With the change of the market and the improvement of customers' requirements for products, now all UV lamp manufacturers are developing long-life lamps. The cold cathode series of UV lamps with an outer diameter of 4, 5, 6, 10, and 12 mm are developed to replace the hot cathode series of UV lamps.
Precautions for ultraviolet germicidal lamp:
Since ultraviolet rays can kill cells, it is important to pay attention not to directly irradiate people's skin, especially people's eyes, during ultraviolet disinfection. Do not look directly at the lamp tube when the ultraviolet germicidal lamp is lit. Since the short wave ultraviolet rays do not penetrate ordinary glass, wearing eyes can avoid eye injuries. If your eyes are injured carelessly, it is generally not a big problem, just like being burned by the sun. If it is serious, you can drop eye drops or human milk to help you recover. In the presence of people, do not use lamps with ozone. High ozone concentration is bad for people.
1. Some domestic unqualified ultraviolet lamps cannot provide the remaining disinfection capacity. When the treated water leaves the reactor, some microorganisms killed by ultraviolet light will repair the damaged DNA molecules and regenerate the bacteria under the light reactivation mechanism. Therefore, it is necessary to further study the principle and conditions of photoreactivation, and determine the minimum ultraviolet radiation intensity, time or dose to avoid photoreactivation.
2. The cleaning of the outer wall of the quartz sleeve is the key to operation and maintenance. When the sewage flows through the ultraviolet sterilizer, microorganisms in it are easy to grow and form biofilms, which will inhibit the transmission of ultraviolet light and affect the disinfection effect. Therefore, it is necessary to adopt reasonable anti scaling measures and cleaning devices according to different water quality, and develop ultraviolet disinfectors with automatic cleaning function.
3. At present, the domestic ultraviolet lamp implements the national industry standard of straight tube quartz ultraviolet low pressure mercury disinfection lamp. The maximum power of the lamp is 4W, and the effective life is generally 1000-3000h. The effective operation time of the imported low-voltage lamp can reach 8000-12000h, and the medium voltage lamp can also reach 5000-6000h. In contrast, the use of domestic lamps will increase maintenance costs. Therefore, the development and production of long life ultraviolet lamps or the direct introduction of foreign advanced ultraviolet lamp production technology is a problem to be solved at present.
4. In the current bidding for the ultraviolet disinfection system of sewage plants in China, some sewage plants have deepened the chromaticity of the sewage discharged due to the introduction of a large amount of industrial sewage. However, the ultraviolet transmittance parameter of sewage in the bidding document still uses the value provided by foreign countries, resulting in a great difference from the actual situation of domestic sewage, leaving an insurmountable obstacle for the future operation of ultraviolet equipment to meet the disinfection requirements.