How does cold water temperature affect the effectiveness of chlorine?

How does cold water temperature affect the effectiveness of chlorine?

• A. Less contact time would be required
• B. Less chlorine concentration would be required
• C. More contact time would be required
• D. Water temperature does not affect the effectiveness of chlorine

Answer: (C)

The effectiveness of chlorine as a disinfectant is influenced by water temperature, with colder temperatures generally requiring more contact time to achieve the desired level of disinfection. This occurs because lower temperatures can slow down the chemical reactions involved in the disinfection process. Chlorine works by reacting with microorganisms to oxidize and kill them, but at lower temperatures, the kinetic energy of the molecules is reduced, which can hinder the speed and efficiency of these reactions. Consequently, to ensure adequate disinfection and to allow sufficient time for chlorine to interact with pathogens, a longer contact time is necessary when the water temperature is cold. This principle is important for operators to understand when designing treatment processes and managing water quality in distribution systems.

The effectiveness of chlorine as a disinfectant is influenced by water temperature, with colder temperatures generally requiring more contact time to achieve the desired level of disinfection. This occurs because lower temperatures can slow down the chemical reactions involved in the disinfection process. Chlorine works by reacting with microorganisms to oxidize and kill them, but at lower temperatures, the kinetic energy of the molecules is reduced, which can hinder the speed and efficiency of these reactions. Consequently, to ensure adequate disinfection and to allow sufficient time for chlorine to interact with pathogens, a longer contact time is necessary when the water temperature is cold. This principle is important for operators to understand when designing treatment processes and managing water quality in distribution systems.