OXIDATION OF AQUEOUS SULFUR DIOXIDE.

Aqueous SO//2 (sulfurous acid) functions as a reagent in various hydrometallurgical systems but also represents an undesirable constituent in pyro- and hydrometallurgical effluent solutions. When present in such streams, SO//2 can be oxidized to the more stable sulfate form to avoid exsolution of SO//2 as a source of fugitive emissions and to simplify standard water treatment plant operation. This study provides information on the stoichiometry, kinetics, and mechanism of SO//2 oxidation using oxygen and an iron salt catalyst with solutions containing 0. 05-20 g/L (0. 002-0. 7 oz per gal) SO//2. The effects of iron salt concentration, oxygen pressure, temperature, degree of agitation, and pH on SO//2 oxidation are also described.