Application of ultraviolet technology in water treatment
The advantages of using ultraviolet rays to kill aquatic infectious bacteria have been widely recognized. In fact, the industry is one of the first pioneers to use this technology. Today, almost all industries apply UV technology to water treatment systems, including the food and beverage industry, pharmaceutical industry, cosmetics industry, health products industry, manufacturing industry, high-tech industry, etc. Sterilization is the main application of ultraviolet technology in the field of water and wastewater. At the same time, the industry has also applied this technology in many other areas, including ozone elimination, total organic carbon (TOC) reduction, liquid sugar disinfection, degraded chlorine gas, surface and air, and cooling tower disinfection. This article will give a brief overview of some uses of UV in industry
Application of ultraviolet technology in water treatment-elimination of ozone
In industrial production, ozone is often used to disinfect and purify water bodies. However, due to the extremely strong oxidizing ability of ozone, the remaining ozone in the water may affect the next process if it is not removed. Therefore, the ozone-treated water must usually remove the remaining ozone in the water before entering the main process. Removed. Ultraviolet rays with a wavelength of 254 nanometers are very effective in destroying residual ozone, which can decompose ozone into oxygen. Although different systems require different scales, generally speaking, a typical ozone elimination system requires about three times the amount of ultraviolet radiation as a traditional sterilization system.
Application of ultraviolet technology in water treatment-sterilization
Ultraviolet sterilization mainly uses ultraviolet light with a wavelength of 254 nanometers. Ultraviolet light of this wavelength, even under a small amount of ultraviolet radiation, can destroy the life core of a cell-DNA, thus preventing cell regeneration and losing the regeneration ability to make bacteria harmless, so as to achieve the effect of sterilization. Like all other UV application technologies, the scale of this system depends on the intensity of the UV (intensity and power of the irradiator) and the duration of exposure (the length of time water, liquid, or air is exposed to UV).
Application of ultraviolet technology in water treatment-reduce total organic carbon
In many high-tech and laboratory installations, organic matter can hinder the production of high-purity water. There are many ways to remove organic matter from the water, the more common methods include the use of activated carbon and reverse osmosis. Short-wavelength ultraviolet light (185 nanometers) can also effectively reduce the amount of total organic carbon (the value mentioned is that these emitters also generate 254 nanometer wavelength ultraviolet light, so they can be disinfected at the same time). Ultraviolet rays with shorter wavelengths have more energy, so they can decompose organic matter. Although the reaction process of ultraviolet oxidation of organic is very complicated, the main principle is to oxidize organic matter into water and carbon dioxide by generating free hydrogen and oxygen with strong oxidizing ability. Like the ozone removal system, the ultraviolet radiation of this organic carbon-degrading ultraviolet system is three to four times that of the traditional disinfection system.
Application of ultraviolet technology in water treatment-liquid sugar disinfection
Most food and beverage manufacturers use large amounts of liquid sugar. Since sugar is a food that is easily used by bacteria, it is easy to promote the reproduction of bacteria. In addition, liquid sugar is opaque, so it is difficult to thoroughly disinfect. Ultraviolet rays with a wavelength of 254 nanometers can be used to disinfect liquid sugar products. In order to compensate for the energy loss caused by the viscosity and color of the liquid, many UV emitters need to be arranged closely to form a so-called “thin film” reactor. The close combination of such radiators can provide the very high ultraviolet radiation required, so that the liquid sugar can be effectively sterilized. Its ultraviolet energy output is about 7 to 10 times that of traditional disinfection systems.
Application of ultraviolet technology in water treatment-degradation of residual chlorine
In municipal water treatment and water supply systems, chlorine disinfection is very necessary. However, in the industrial production process, in order to avoid adverse effects on products, the removal of residual chlorine in water is often necessary pre-treatment. The basic methods of eliminating residual chlorine include activated carbon bed and chemical treatment. The disadvantage of activated carbon treatment is that it requires continuous regeneration, and often encounters the problem of bacterial growth. Both 185 nm and 254 nm wavelengths of ultraviolet light have been shown to effectively destroy the chemical bonds between residual chlorine and chloramine. Although it needs huge ultraviolet energy to work, its advantage is that this method does not need to add any drugs to the water, does not need to store chemicals, is easy to maintain, and also has the function of sterilization and removal of organic matter.
Application of ultraviolet technology in water treatment-surface and air disinfection
Using ultraviolet light for air disinfection has the same history as ultraviolet light for water disinfection. Air disinfection equipment has been used in hospitals, clinics and clean rooms for many years. Now, factories, offices and homes are also using air disinfection equipment.
The principle of air disinfection is the same as water disinfection. Generally, the UV lamp can be installed in the air duct, at the front of the coil, or on a shelf fixed on the wall. When the air passes by, the microorganisms in the air are killed and become harmless. The principle of surface disinfection is the same. In the food and beverage production industry, the products on the conveyor belt are sterilized by surface disinfection equipment.
Application of ultraviolet technology in water treatment-cooling tower disinfection
In order to reduce the cost of biocides (purchase, storage, insurance) and the health hazards of chemical treatment, the ultraviolet system can be installed in the water circulation system of the cooling tower to play a sterilizing role. If used with a filter, ultraviolet light can effectively control the growth of microorganisms in the cooling tower. Although a certain concentration of biocide still needs to be retained in the cooling tower, the use of ultraviolet light can greatly reduce its use.