Catalytic effect of the ferric hydroxides on the oxidation of ferrous iron by aeration has been demonstrated and the kinetics of this catalytic reaction has been formulated by the recent studies. It has been reported that the oxidation rate is linearly increasing with Fe(III) concentrations up to 100 mg/l.
In this study, the oxidation of Fe(II) is studied in batch reactors in which the concentration of Fe(III) was in the range of 0-600 mg/l. A quadratic equation has been given to determine the catalytic reaction rate constant as a function of Fe(III) concentration. It was experimentally demonstrated that there was no significant effect of Fe(III) on the ferrous iron oxidation at Fe(III) concentrations beyond 600 mg/l.