Waterborne infections caused by bacteria or viruses are combated using disinfection devices. Pathogens are neutralized in these methods by treating source water with chemical additions or by exposing it to UV radiation. These treatment systems are frequently low-cost and readily scaled down for low-volume treatment facilities.
Common disinfectants include free chlorine, chloramines, and chlorine dioxide. The most common (and oldest) type of chemical addition is chlorination. Because chlorine is an oxidant, it aids in the removal of iron, hydrogen sulfide, and other minerals.
Ozone, a colorless gas, is similar to chlorination in that it removes organic and inorganic pollutants, but it is significantly more powerful against bacteria and other pathogens. Ozone systems are uncommon in many parts of the world since they need extensive infrastructure and can be costly to construct.
Mercury lamps are commonly used to create ultraviolet light, an invisible region of the electromagnetic spectrum that kills germs and viruses in water exposed to its rays. Although the UV procedure is inexpensive and popular among small-scale institutions, it is not as efficient as other disinfectants on surface water sources with a high concentration of suspended particles.