Kinetics of Manganese and Iron Oxidation by Potassium Permanganate and Chlorine Dioxide

This article describes research to quantify the kinetics of Mn(II) and Fe(II) oxidation by potassium permanganate and chlorine dioxide; illustrates the effects of reduced metal ion concentration, pH, temperature, and the presence of dissolved organic carbon (DOC) on these kinetics; and investigates aspects of oxidation through modeling analyses. Among conclusions based on experimental results were the following: oxidation of reduced Mn(II) was rapid except at low solution temperatures; rates of Mn(II) oxidation are acceptable in the presence of humic or fulvic acids, but those acids strongly inhibit Fe(II) oxidation efficiency; poor manganese removal may be caused by inefficient capture of colloidal MnO X (s). The sequence in which oxidants are added may be an important issue for design and operation.