The application of deep ultraviolet LED in disinfection water treatment:
1. Types of water treatment and disinfection technologies
Water disinfection technology mainly includes ultraviolet disinfection, chemical disinfection, and chemical disinfection also includes chlorine disinfection, chlorine dioxide disinfection, peracetic acid disinfection, ozone disinfection, chloramine disinfection, hydrogen peroxide disinfection, etc. At present, the application of ultraviolet systems in municipal sewage treatment in my country has been launched on a large scale, and more than 50% of sewage treatment plants use ultraviolet disinfection technology. "
Comparison of several common disinfection methods
Second, the principle of deep ultraviolet LED disinfection
Ultraviolet technology is a fast, economical and efficient disinfection technology that emerged in the 1990s. It uses a specially designed high-efficiency, high-intensity and long-life band (110-280) ultraviolet light generator to generate ultraviolet radiation to kill various bacteria, viruses, parasites, algae, etc. in the water. The mechanism is that a certain dose of ultraviolet radiation can destroy the structure of biological cells, and kill aquatic organisms by destroying biological genetic material, so as to achieve the purpose of purifying water quality.
Ultraviolet disinfection is a physical method. It does not add any substance to the water, has no side effects, and does not produce disinfection by-products. However, it lacks the ability of continuous sterilization, so it is generally used in combination with other sterilization methods.
3. Types of UV disinfection lamps
At present, the commonly used ultraviolet germicidal lamps in sewage ultraviolet disinfection systems include: low-pressure low-intensity mercury lamps (LP), low-pressure high-intensity mercury lamps (LPHO, also known as low-pressure high-intensity lamps), and medium-pressure high-intensity mercury lamps (MP).
Among them, the low-pressure lamp system refers to the output power of a single ultraviolet lamp in the ultraviolet disinfection equipment is 30W-40W, which is mainly used in the application of small water treatment plants or low-flow water treatment systems. The low-pressure high-intensity lamp system refers to the output of a single ultraviolet lamp in the ultraviolet disinfection equipment is about 100W, and it is mainly suitable for the application of medium-sized sewage treatment plants. The medium-pressure lamp system refers to the output of a single ultraviolet lamp in the ultraviolet disinfection equipment above 420W. It is mainly used in large sewage treatment plants and water treatment systems with high suspended solids and low ultraviolet transmittance (WT).
Deep ultraviolet LED will become a development trend.
(1) Mercury lamp sterilization is currently a widely used method of sterilization and disinfection. However, due to its toxic mercury content, high power consumption and short life span, mercury lamp ultraviolet sterilization is gradually being replaced by UVC LED light sources.
(2) The "Minamata Convention" has officially entered into force, and mercury products represented by mercury lamps will accelerate the elimination process.
(3) UV LED has many advantages in terms of size, weight, energy consumption and service life:
UV LED can generate light with the best wavelength required by users, while the wavelength of light generated by traditional light sources is fixed;
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The instant start and close of UV LED will not reduce the service life, and it is safer and more convenient to use;
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Based on potential new designs, UV LEDs can create new disinfection applications.
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(4) Other advantages of UV disinfection: non-toxic, immediate effect, harmless to the environment and users, odorless, etc.
4. Deep ultraviolet LED disinfection market
According to statistics from international organizations, the market size of UV disinfection/purification systems in the water treatment field in 2017 was approximately US$942 million. At present, about 25% of industrial and sewage treatment plants in Western countries have adopted UV sterilization technology.
The 2003 SARS incident stimulated the promotion and application of ultraviolet disinfection technology in sewage treatment in my country. In addition, my country's sewage treatment plants started relatively late, and they can fully learn from the successful experience of foreign countries during the construction and development period. At present, the application of ultraviolet disinfection system in my country's sewage treatment has been launched on a large scale, and more than 50% of sewage treatment plants use ultraviolet disinfection technology.
In the UV LED market application, UV-A has the largest market share, up to 90%. Its main application market is curing, which involves nail art, teeth, ink printing and other fields. In addition, UV-A also introduces commercial lighting, which can make white clothes look whiter.
1. Application fields of UVA LED in light curing system:
Typical applications of the UVA band are UV curing and UV inkjet printing. The representative wavelengths are 395nm and 365nm. UV LED light curing applications include the curing of UV adhesives in display, electronic medical, instrumentation and other industries; building materials, furniture, home appliances, UV coating curing in automobile and other industries; UV ink curing in printing and packaging industries...
2. UVA LED plant factory field:
According to researcher Liu Wenke from the Institute of Agricultural Environment and Sustainable Development of the Chinese Academy of Agricultural Sciences, closed soilless cultivation is prone to accumulate autotoxic substances, while TiO2 photocatalysis can degrade root exudates and rice husks in the nutrient solution of substrate cultivation. The product, sunlight only contains 3% of ultraviolet light, and facility covering materials such as glass filter out more than 60%, which cannot be used in facilities; vegetables are cultivated off-season and low temperature in winter, which makes them inefficient and stable, which cannot meet the requirements of facility vegetable factories. The demand for chemical production. Therefore, UVA has a wide range of applications in plant factories.
3.UVA LED gem identification field:
Different types of gemstones, the same gemstone of different colors, and gemstones of the same color with different coloring mechanisms have different UV-visible absorption spectra. Although some optimized gemstones have the same color as their corresponding natural gemstones, they have different absorption spectra due to different color mechanisms or color-causing substances. UVA LED can help identify gemstones and distinguish certain natural gemstones from synthetic gemstones. It can also distinguish certain natural gemstones from artificially processed gemstones by ultraviolet light.
