Determination of bacterial manganese oxidation rates in sediments using an in-situ dialysis technique I. Laboratory studies

Abstract

An in-situ dialysis technique has been developed to examine chemical and bacterial rates of manganese binding and oxidation under diffusion-limited conditions in sediments. With this method, the microbial and abiotic components of manganese binding were delineated quantitatively in laboratory sediments spiked with manganese oxidizing bacteria. The abiotic removal of manganese by the same sediments has also been determined independently to define the relative importance of adsorption, ion exchange and autocatalytic oxidation in the removal of Mn 2+ from solution. Independent measurements of both bacterial and abiotic manganese binding were in good agreement with the diffusion-controlled rate data, validating the use of this dialysis technique as a means of examining manganese oxidation in-situ.