What is the main source of chlorite in drinking water?

What is the main source of chlorite in drinking water?

• A. Softening process
• B. Fluoridation process
• C. Chlorine dioxide used for disinfection
• D. Membrane treatment processes

Answer: (C)

Chlorite in drinking water mainly comes from using chlorine dioxide as a disinfectant. When chlorine dioxide is applied to water, some of it remains as a residual and can react with natural organic matter and other substances, producing chlorite ions as a byproduct. This disinfection-byproduct formation is specific to chlorine dioxide, which is why it’s the primary source. Other processes—softening, fluoridation, or membrane treatment—do not create chlorite (softening and fluoridation add or remove things, and membranes typically reduce contaminants), so they are not sources of chlorite.

Chlorite in drinking water mainly comes from using chlorine dioxide as a disinfectant. When chlorine dioxide is applied to water, some of it remains as a residual and can react with natural organic matter and other substances, producing chlorite ions as a byproduct. This disinfection-byproduct formation is specific to chlorine dioxide, which is why it’s the primary source. Other processes—softening, fluoridation, or membrane treatment—do not create chlorite (softening and fluoridation add or remove things, and membranes typically reduce contaminants), so they are not sources of chlorite.