Study of the SO₂ oxidation in solution and its role in atmospheric chemistry

The mechanism of SO 2 oxidation in diluted catalytic solutions was studied. It was found that the oxidation stops after a certain pH value is reached. In the same catalytic solutions, the maximum possible SO 4 − formation is a linear function of the SO 2 partial pressure in the air. This mechanism of SO 4 − formation can account for observed SO 4 − concentrations in rain, fog, and smog only if some neutralizing cations in the aerosols or traces of NH 3 in the air are present. It is shown that in the latter case the system SO 2 NH 3 ‐catalytic solution can explain the main features of SO 4 − formation in our atmosphere.