What is the primary purpose of measuring contact time (CT) in water treatment?

The primary purpose of measuring contact time (CT) in water treatment is to inactivate harmful microorganisms. CT is a critical factor in disinfection processes, particularly in the chlorination of drinking water. It refers to the amount of time that disinfectant remains in contact with the water, which allows it to adequately interact with and destroy pathogens like bacteria, viruses, and protozoa that can cause waterborne diseases.

When disinfectants, such as chlorine, are added to water, the effectiveness of the disinfection process is significantly influenced by both the concentration of the disinfectant and the duration of contact time. Insufficient contact time may lead to inadequate disinfection, increasing health risks.

Other options like enhancing taste or regulating temperature do not directly relate to the fundamental purpose of CT measurement in ensuring public health safety. Additionally, increasing turbidity would negate the effectiveness of disinfection by providing more particles for microorganisms to hide behind, making it harder for disinfectants to reach and deactivate them. Thus, focusing on CT quantifies the efficacy of water treatment processes aimed at eliminating health hazards posed by microorganisms.