Monitoring Disinfectants

Disinfection is a process that deliberately reduces the number of pathogenic microorganisms in water to achieve the principal objective of drinking water treatment: protection of public health. Disinfection of water is often needed to assure its drinkability. The use of chemical disinfectants was made in as large quantities as required to achieve the desired quality. Currently, there are several options for the disinfection of drinking water, each with its own merits as a disinfectant and the presence of by-products that must be minimized. The disinfection process is expected to satisfy the following three requirements: inactivation of the pathogenic and other harmful microorganisms in water (primary disinfection), disinfectant residual maintenance in the distribution system (secondary disinfection), and keeping the amount of by-products to a minimum. Different disinfectants offer different performances toward the achievement of these three requirements. Regular monitoring is the responsibility of the public water system. A certified drinking water laboratory must analyze collected samples. It is required that disinfectant residual be measured monthly at the end of each treatment process that uses chlorine.