Kinetic Analysis on As(III) Oxidation in a Fixed-Bed Flow Reactor Filled with a Supported Platinum Catalyst

In this study, the oxidation of As(III) was examined in a fixed-bed flow reactor filled with a SiO2-supported Pt catalyst, and the reaction kinetics were analyzed. The results of the experiments with different concentrations of As(III) at small W/F suggest that the reaction follows the Langmuir-Hinshelwood (L-H) mechanism. However, at large W/F, the kinetic equations different from the L-H equation were obtained because the O2 supply to the catalyst surface was rate-limiting. It was also demonstrated using this reactor that As(III) of an equivalent concentration as the mine effluent was almost completely oxidized to As(V) with only dissolved O2.