AUTOXIDATION OF SULFUR-DIOXIDE IN AQUEOUS FLY-ASH SUSPENSIONS

The fact that the thermal power and other plants continuously belch SO2 and flyash concurrently made us to look into the chemistry of autoxidation of aqueous sulphur dioxide in agueous suspensions of four different flyash samples obtained from three different thermal power and a fertilizer plants. The particle sizes and metal contents of each flyash sample were determined. Detailed kinetics investigation showed the major catalysis to be due to leached trace metal ions, and in agreement with the general rate law. R(obs) = k[Flyash](a) [S(IV)](b) [H+](c) where, a = less than or equal to 0.5; b = 1.5-2; c = 0.4-1.5 The atmospheric calculations indicated the conversion rates of around 0.34 to 1. 79% due to wetted flyash aerosols.