Abstract：The kinetics of Fe (III) reduction and As (III) oxidation by Shewanella oneidensis MR-1 and influenced factors were studied under laboratory conditions. Results showed that the oxidization of As (III) to As (V) occurred in accompanying with Fe (III) reduction, S. oneidensis MR-1 could grow well at low concentration of As (III), but its growth was suppressed at high concentration of As (III). As (III) inhibited dissimilatory iron reduction by affecting the growth and activity of S. oneidensis MR-1. Moreover, moderate Fe (III) could strongly promote As (III) oxidization, while high Fe (III) concentration might inhibit As (III) oxidization because of excess Fe (II). In addition, weak alkaline environment was more conducive to As (III) oxidization.
