Water disinfection with ultraviolet: what is it, how does it work, application

Quality water purification and disinfection is critical to human health. The method of chlorination has been a priority for many years, but the substance itself is harmful to human health. It is only suitable for industrial use. New technologies, in particular the use of ultraviolet rays, have come to the forefront.

Features of UV water disinfection

UV radiation is a type of electromagnetic radiation, and the wavelength is in the range of 10-400 nm. Depending on the range, experts talk about near, medium and far radiation. The medium range of 250 to 270 nm is used for disinfection. Large volumes of water are treated, and not only drinking, but also waste water. Ultraviolet water disinfection unit finds application:

• at water supply facilities;
• at sewage treatment plants;
• food production;
• in swimming pools and water parks;
• in educational institutions;
• Health care facilities;
• for household purposes.

The technology is based on photochemical reactions during which dangerous microorganisms are inactivated. In other words, bacteria and viruses lose their ability to reproduce and spread due to DNA and RNA damage.

Because UV disinfection is short-lived and there is a high probability of recontamination, the method is combined with the use of chloramine and other chlorinated components to create a multi-barrier effect. Plus, the reagent consumption is reduced several times.

When preparing water for a swimming pool, you also can't get limited to UV alone. Chlorination also takes place, but additional disinfection is not necessary or even desirable for wastewater. Chlorine enters the sewage, and then - in water bodies, where it causes significant damage to the ecosystem.

The ultraviolet disinfection of water is carried out in strict accordance with the regulations. The responsible services are obliged to follow the regulations and to control the process of drinking water purification at all stages.

Advantages and disadvantages of the method of UV water purification

Consider that among the advantages of UV purification:

• environmental friendliness and safety;
• efficiency;
• preservation of water structure and taste;
• easy control of the operation of the installation;
• high speed of treatment;
• no need for additional tanks, etc.

If the reagent must be strictly dosed and exceeding the volume is fraught with the fact that the water becomes unusable. Changing the dosage of UV irradiation will not negatively affect the condition of the finished product.

The negative aspects of UV irradiation are as follows:

• UV-resistant microorganisms exist;
• the water must be free of impurities, suspended solids and especially iron;
• the technology does not have a prolonged effect.

Characteristics of ultraviolet water purification equipment

Installation has a form of stainless steel or plastic chamber. Inside there is an ultraviolet lamp in a protective quartz housing, or several such lamps if we are talking about industrial devices. The flow passes through the chamber and is exposed to radiation. The process is controlled by an automatic control unit. The treatment plants are additionally equipped with mechanical filters.