Atmospheric Chemistry of Sulfur Dioxide

Various studies have been done on the atmospheric oxidation of S (IV) in the recent past, in aerosols and in bulk aqueous phase. The trace metal ions which are part of all atmospheric systems and are catalysing the oxidation of aqueous SO2 in to acid sulfate. The metal oxides, which are present in the atmosphere are integral part of suspended particulate matter. The role of various metal oxides such as CoO; Co2O3; Ni2O3; CuO; MnO2; and Cu2O; and MnO2 in acidic medium has been studied and given a two term rate law. Gupta et al studied the inhibiting effect of alcohol on the CoO, Co2O3 and Ni2O3catalysed autoxidation reaction in alkaline medium and proposed a radical mechanism. The effect of alcohols has been studied on several catalysed S(IV) autoxidation in the effect of silver (I) catalyzed autoxidation of S(IV) in acetate buffer medium. To explain these results and inhibition effect of organic compounds, the radical mechanism involving SO3 , SO4 and SO5radicals was proposed. Further experiments were conducted for finding reactivity of oxysulphur radicals with organics, which proved that these compounds react with SO4.