Minimizing Chlorite Ion and Chlorate Ion in Water Treated With Chlorine Dioxide

Abstract

Minimizing the inorganic by‐products chlorite ion and chlorate ion in drinking water treated with chlorine dioxide is important if Cl0 2 is to remain a viable alternative in potable water treatment. The use of sulfur dioxide‐sulfite ion chemistry to quantitatively remove chlorite ion to below the 0.1‐mg/L level is described, along with the use of free chlorine to remove the sulfur dioxide‐sulfite ion. The stoichiometry and the rate law are described for pH values of 5.5 to 8.5 so that the chemistry can be applied directly in existing drinking water treatment facilities.