Which of the following is NOT a common method of disinfecting drinking water?

Filtration with sand is primarily used as a physical method for removing particles, sediments, and some pathogens from water but does not inherently disinfect it. Disinfection involves the destruction or inactivation of pathogenic microorganisms, which requires a chemical or physical process that targets these organisms specifically.

Chlorination, ozonation, and ultraviolet (UV) treatment are recognized disinfection methods. Chlorination uses chlorine or chlorine compounds to eliminate harmful bacteria and viruses, while ozonation employs ozone gas, a powerful oxidizer, to achieve the same goal. UV treatment utilizes ultraviolet light to disrupt the DNA of microorganisms, effectively preventing them from replicating. These methods directly address the need to eliminate pathogens to ensure the safety of drinking water.

In contrast, sand filtration does not actively destroy microorganisms but rather relies on the physical removal of suspended solids. While it can enhance overall water quality, it does not serve as a disinfection method on its own. Therefore, filtration with sand is not considered a common method of disinfecting drinking water.