What is the "sterilization range" of ultraviolet light?
According to the International Ultraviolet Association: "The important part of the ultraviolet spectrum ("sterilization" area) for water and air disinfection is the range that is absorbed by DNA (RNA in some viruses). The sterilization range is about 200-300nm."
It is known that the sterilization range can be extended to more than 280nm, and now it is generally considered to be extended to 300nm, although it may change with more research. Scientists have proved that the wavelength between 280nm and 300nm has a bactericidal effect and can be used for disinfection and sterilization.
What is the best wavelength for disinfection?
254nm is the best wavelength for disinfection, which is a misunderstanding, because the peak wavelength of the low-pressure mercury lamp (determined simply by the physical properties of the lamp) is 253.7nm. The 265nm wavelength is the most ideal wavelength because it is the peak of the DNA absorption curve. However, disinfection and sterilization occur within a certain wavelength range.
Ultraviolet mercury lamps are considered to be the best choice for disinfection and sterilization. why is that?
Historically, mercury lamps have always been the only option for disinfection and sterilization. With the advancement of UV LED technology, new options are provided that are smaller, stronger, non-toxic, long-lived, energy-saving, and allow unlimited on/off switching. This makes the solution smaller, battery-powered, portable and instant full light
Spectral emissivity of low pressure mercury ultraviolet lamp (solid line) and medium pressure mercury ultraviolet lamp (dashed line)
How do the wavelengths of UVC LEDs and mercury lamps compare?
The monochromatic light emitted by the low-pressure mercury lamp is almost 253.7nm. Low-pressure mercury lamps (fluorescent tubes) and high-pressure mercury lamps are also used for disinfection and sterilization. These lamps have a wider spectral distribution, which includes sterilization wavelengths. UVC LEDs can be manufactured to target very specific and narrow wavelengths. This allows the solution to be customized for specific application requirements.
Does the peak DNA absorption wavelength vary with bacteria?
Yes, although the peak absorption rate of most bacteria is around 265nm, the peak absorption rate does vary from bacteria to bacteria.
Can a single wavelength be used to disinfect all bacteria?
Yes, a single wavelength can be used. However, bacteria have different optimal absorption wavelengths.
How to determine the bactericidal effect?
Power intensity, wavelength and duration of exposure are usually used to determine the bactericidal effect. For example, in water, there may be a variety of bacteria with different optimal absorption wavelengths. For any given wavelength of germicidal ultraviolet light, it is necessary to calculate the power and duration of exposure to achieve the required disinfection level.