Disinfectants

AbstractDisinfection of drinking water was instituted at a time when waterborne infectious diseases were the primary focus in public health. The use of disinfectants such as chlorine, chloramine, chlorine dioxide, ozone, and ultraviolet radiation has resulted in a reduction in the outbreak of diseases such as cholera and polio in many parts of the world. The choice of disinfectant is dependent on their availability, ease of use, cost, and their efficacy in disinfecting water. Some disinfectants commonly used in water treatment plants are not stable in water for long periods of time, which reduces their disinfection efficacy. Current practices to control pathogens in drinking water include using a combination of disinfectants, coagulation, and filtration. A main disadvantage of using disinfectants in drinking water is their ability to react with organic and inorganic matter in water to form disinfection byproducts that may be of health concern. The disinfectants can also be hazardous at high concentrations, but toxicological studies suggest that their toxicity is likely not relevant at the low concentrations encountered in drinking water.