Oxidation of S IV by Dissolved

Although ozone reacts very slowly with S02 in the gas phase, the aqueous-phase reaction 

FIGURE 7.15 Second-order reaction rate constant for the S(IV)-03 reaction defined according to t/[S(VI)]/( = /c[Oi(aq)] [S(IV)], as a function of solution pH al 298 K. The curve shown is the three-component expression of (7.80) and the symbols are the corresponding measurements by a number of investigators. 

Effect of Ionic Strength Lagrange et al. (1994) suggested that the rate of the 

S(1VM 3 reaction increases linearly with the ionic concentration of the solution. 

FIGURE 7.16 Rate of aqueous-phase oxidation of S(IV) by ozone (30 ppb) and hydrogen peroxide (I ppb), as a function of solution pH at 298 K. Gas-aqueous equilibria aie assumed for all reagents. R/ so. represents the aqueous phase reaction rate per ppb of gas-phase SOj. R/L represents rate of reaction referred to gas-phase SO2 pressure per (gm 3) of cloud liquid water content. 

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