Kinetics of absorption of hydrogen sulfide into aqueous ferric sulfate solutions

Absorption experiments of H 2 S into aqueous Fe 2 (SO 4 ) 3 solutions, concerned with a unique process capable of regenerating by biological oxidation the reactant from the products, were performed at 20–40°C in an agitated vessel with a flat interface. The absorbents were aqueous solutions of Fe 2 (SO 4 ) 3 with and without the addition of K 2 SO 4 , KOH or H 2 SO 4 of various concentrations, which was added to change the ionic strength or pH of the solutions. The experimental results revealed that the species which reacts with H 2 S is FeOH 2+ . While comparing the observed absorption rates with the theoretical predictions, it was found that the reaction is irreversible and first order with respect to H 2 S and FeOH 2+ . The reaction rate constants were measured and correlated.