Alternative Disinfection Practices and Future Directions for Disinfection By‐product Minimization

Abstract

AbstractDisinfection of public water supplies is required in many countries to inactivate microbial pathogens and protect public health. Chlorine is the predominant disinfectant used worldwide for this purpose. While chlorine disinfection provides significant benefit, it can create certain disinfection by‐products (DBPs) such as trihalomethanes and haloacetic acids that may cause adverse health effects. The formation of DBPs depends on the type of disinfectant used, the presence of precursors, and operational parameters such as disinfectant dose, pH, and temperature. Thus, there are essentially three approaches to reduce the occurrence of any particular DBP: (1) alternative disinfection with, for example, chloramine, chlorine dioxide, ozone or ultraviolet radiation; (2) other treatment options (e.g., that reduce either the presence of DBP precursors or the amount of disinfectant needed); (3) approaches aimed at source water, such as watershed protection to limit the addition of DBP precursors to waterways, or the use of source water with naturally low precursor levels. The advantages and disadvantages of these options are discussed, including usage information, operational concerns, disinfectant properties, and potential impact on the occurrence of specific DBPs in drinking water supplies.