Research has shown that ultraviolet radiation mainly causes radiation damage to microorganisms (bacteria, viruses, spores, and other pathogens) and destroys the function of nucleic acids to kill microorganisms, thereby achieving the purpose of disinfection. The effect of ultraviolet radiation on nucleic acids can lead to bond and chain breakage, inter strand cross-linking, and the formation of photochemical products, thereby altering the biological activity of DNA and preventing microorganisms from replicating themselves. This type of ultraviolet damage is also lethal.

Usually, ultraviolet disinfection can be used in areas with difficult supply of chlorine and hypochlorite, as well as in situations where disinfection by-products of chlorine are strictly limited after water treatment. It is generally believed that using ultraviolet radiation for disinfection is more economical when the water temperature is low.

The advantages of ultraviolet disinfection are as follows:
Without introducing impurities into water, the physical and chemical properties of water remain basically unchanged;
The chemical composition of water (such as chlorine content) and temperature changes generally do not affect the disinfection effect;
No additional odor or odor in the water, and no disinfection by-products such as trihalomethane are produced;
The sterilization range is wide and rapid, and the processing time is short. Under a certain radiation intensity, pathogenic microorganisms can generally be killed in just a few seconds. It can kill some bacteria that cannot be inactivated by chlorine disinfection, and can also control some higher aquatic organisms such as algae and red worms to a certain extent;
Overtreatment generally does not result in water quality issues;
The integrated equipment has a simple structure, is easy to install, is compact and lightweight, has minimal head loss, and occupies less land;
Easy to operate and manage, easy to achieve automation, and with well-designed systems, the workload of equipment operation and maintenance is minimal;
The operation management is relatively safe, and there are basically no safety hazards that may be caused by the use, transportation, and storage of other chemicals, such as toxicity, flammability, explosion, and corrosiveness;
The disinfection system has no other sources of noise except for the water pump that must be operated.