Does UV light kill bacteria in water?

Ultraviolet (UV) disinfection is an extremely effective way of inactivating and killing bacteria in water, as no known known bacteria or virus is resilient to UV light. This includes pathogens such as Cryptosporidium and Giardia, which water treatment alternatives such as chlorine is unable to treat.

Reducing the number of pathogens in water is a critical step towards biosecurity, which makes UV disinfection play an important role in our society. Due to this, UV has become a globally accepted solution for water disinfection in various water treatment applications.

Using UV light disinfection, the cell walls of bacteria, virus, and protozoa are penetrated, permanently altering the DNA of the microorganisms. This effectively inactivates the microorganisms, making them unable to infect and reproduce. As the cells are not able to reproduce, they will not be able to cause any infection, thus killing the bacteria and viruses.

UV disinfection has become the preferred water disinfection solution to inactivate and kill microorganisms, bacteria and viruses due to its many advantages, such as:

  • Low maintenance and administration costs
  • No dangerous chemicals involved (no residuals, handling and storage)
  • No by-products being added in the process
  • No change of the water properties such as pH and temperature
  • Short reaction time
  • Safe and simple implementation

The video below shows how bacteria in water is effectively inactived by UV light.

The amount of UV light required to kill bacteria varies dependent on several factors, including radiation dose, the UV transmission, and the organism to be killed. To achieve maximum efficiency in the specific water treatment applications, these factors are taken into account when choosing the suitable UV disinfection system. The systems from ULTRAAQUA are specifically designed to ensure maximum cost and energy efficiency.

Employing the vast number of advantages within UV technology, the environment moves towards a more sustainable state, solving the increasing water safety challenges one UV system at a time.

If you are interested in hearing how our UV systems can assist your water treatment setup, please contact our sales team at