Kinetics of absorption of hydrogen sulfide into aqueous Fe(III) solutions

In our recent studies, absorption of H2S into the aqueous Fe2(SO4)3 and FeCl3 solutions with various values of ionic strength and pH was investigated in an agitated vessel with a flat interface. The experimental results for both systems revealed that the species which reacts with H2S is FeOH2+. The absorption rates were explained by the theory of gas absorption with an irreversible (l,l)-th order reaction between H2S and FeOH2+. The reaction rate constants were independent of the ionic strength of the solution and correlated as a function of temperature. In this paper, kinetics and mechanism of these absorption reactions are reviewed and the identity for both systems is emphasized.