Chlorine is a versatile and effective disinfectant that is widely used in water treatment to control Legionella bacteria. It is a strong oxidizing agent that kills Legionella by damaging the cell wall and disrupting its metabolism.

How Chlorine Controls Legionella

Legionella is killed by:

  • Reacting with the cell wall and damaging it.
  • Disrupting the cell’s metabolism.
  • Oxidizing enzymes and other proteins essential for cell function.

It is more effective at killing Legionella in warm water than in cold water. This is because Legionella bacteria are more active and metabolically active in warm water.

How is it Used in Water Treatment

Chlorine is added to water at various stages of the water treatment process, including:

  • At the beginning of the treatment process to kill any pathogens that may be present in the raw water.
  • After the treatment process is complete to maintain a residual chlorine level in the water that will continue to disinfect the water as it travels through the distribution system.

The amount of chlorine that is added to water depends on a number of factors, including the quality of the raw water, the size and complexity of the water distribution system, and the desired level of disinfection.

Benefits of Using It to Control Legionella

There are several benefits to using chlorine to control Legionella:

  • Is a very effective disinfectant against Legionella and other pathogens.
  • Is relatively inexpensive and easy to use.
  • Is a well-established disinfectant with a long history of safe use.

Challenges of Using to Control Legionella

There are a few challenges to using chlorine to control Legionella:

  • Can react with other chemicals in water to form harmful byproducts, such as trihalomethanes (THMs).
  • Can corrode some metals, such as copper and brass.
  • Can have a slight taste and odor, which may be objectionable to some people.

Overall, it is a safe and effective disinfectant for controlling Legionella in drinking water. However, it is important to carefully monitor the water system to ensure that chlorine levels are maintained at the appropriate level and that any potential byproduct formation or corrosion is managed.

Here are some additional tips for controling Legionella:

  • Maintain a free chlorine residual of 0.2-1.0 milligrams per liter (mg/L) throughout the water distribution system.
  • Flush stagnant water from plumbing systems regularly.
  • Clean and disinfect plumbing fixtures and equipment regularly.
  • Maintain water temperatures above 140 degrees Fahrenheit (60 degrees Celsius) in hot water systems.
  • Monitor chlorine levels regularly and adjust as needed.
  • Test water for Legionella regularly, especially in high-risk settings.

If you have any concerns about Legionella or the use of chlorine, please contact us today.

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