Nitrogen dioxide absorption and sulfide oxidation in aqueous sulfide

Rates of nitrogen dioxide (NO2) absorption and sulfide oxidation were measu red in a highly characterized stirred cell contactor at 55 degrees C, with O-2 present in the gas phase. The rate constant of the reaction between NO, and sulfide at 55 degrees C was determined to be 26.4 x 10(5) M(-1)sec(-1) . A reaction mechanism was proposed that is consistent with the kinetic dat a. NO2 absorption initiates sulfide oxidation in the presence of oxygen. Th e rate of sulfide oxidation increased with sulfide and oxygen concentration and with the rate of NO2 absorption. Furthermore, thiosulfate was an effec tive inhibitor of sulfide oxidation.