ABSTRACT
Chemicals commonly considered for use as disinfectants in municipal drinking water treatment are chlorine, chloramines, chlorine dioxide, and ozone. This chapter addresses the various perceived impacts of the application of disinfectant chemicals on drinking water quality in a comparative way and, to the extent it is understood, to relate these observations to the known chemistry of each disinfectant. The reason for the use of disinfectants in the treatment of drinking water is to ensure the destruction of pathogenic microorganisms during the treatment process, thereby preventing the transmission of disease by drinking water. The comparative biocidal efficiencies of disinfectants frequently are expressed as the relative concentration (mg/L) of different disinfectants needed to obtain equivalent disinfection rates, or as the relative inactivation rates produced by the same concentration of different disinfecting agents. The beneficial use of each of chemicals as a biocide in drinking water treatment may have its own less desirable side effects.
