Transformation of arsenate- and arsenite-loaded ferrihydrite by iron-reducing bacteria and As mobility

Abstract

Iron-reducing bacteria can reduce iron in ferrihydrite, and cause secondary mineralization. Bacterial iron reduction may affect remobilization of contaminant, whereas newly formed minerals may retain it. We investigated the fate of arsenic adsorbed on two-line ferrifydrite during bacterial-iron reduction. Mineralization processes varied depending on whether ferrihydrite initially adsorbs arsenate or arsenite.