Physical Sciences and Mathematics Commons^™

Mobility Of Arsenic And Selected Metals During Re-Flooding Of Iron- And Organic-Rich Acid-Sulfate Soil, Edward D. Burton, Richard T. Bush, Leigh A. Sullivan, Scott G. Johnston, Rosalie K. Hocking

Associate Professor Edward D Burton

The drainage-induced oxidation of iron-sulfide minerals in acid-sulfate soils has adversely affected large areas of coastal floodplains. Re-flooding of these soils, via the re-establishment of more natural drainage regimes, is a potential remediation approach. Here we describe the mobility of Al, As, Fe, Mn, Ni and Zn during controlled re-flooding of an Fe- and organic-rich acid-sulfate soil material. Soil re-flooding caused the onset of microbially-mediated Fe(III)-reduction, which raised the pH of the initially acidic (pH 3.4) soil to pH 6.0 to 6.5, thereby immobilizing Al. The process of Fe(III)-reduction released high concentrations of FeII and was associated with significant mobilization …