Which of the following is NOT a measurement related to chlorine treatment?

Chlorine treatment in water treatment processes involves several key measurements, including dosage, residual, and demand.

Dosage refers to the amount of chlorine added to the water to achieve effective disinfection. It is crucial for determining how much chlorine is necessary to meet operational goals.

Residual is the amount of chlorine that remains in the water after the disinfection process has taken place. This measurement is important to ensure that the water remains safe to use and that disinfection is effective over time.

Demand represents the amount of chlorine that is used up by reactions with organic matter, inorganic compounds, and microorganisms in the water before a residual can be established. Understanding demand helps operators determine the proper dosage needed to achieve the desired residual.

Evaporation, on the other hand, is not directly related to chlorine treatment measurements. It pertains to the physical process of liquid turning into vapor, which does not provide information about the effectiveness of chlorine disinfection or water treatment operations. Therefore, it is the measurement that does not fit in the context of chlorine treatment processes.