AUTOXIDATION OF SULFUR-DIOXIDE IN AQUEOUS FLY-ASH SUSPENSIONS

The fact that the thermal power and other plants continuously belch SO 2 and flyash concurrently made us to look into the chemistry of autoxi dation of aqueous sulphur dioxide in agueous suspensions of four diffe rent flyash samples obtained from three different thermal power and a fertilizer plants. The particle sizes and metal contents of each flyas h sample were determined. Detailed kinetics investigation showed the m ajor 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) w here, a = less than or equal to 0.5; b = 1.5-2; c = 0.4-1.5 The atmosp heric calculations indicated the conversion rates of around 0.34 to 1. 79% due to wetted flyash aerosols.