Biological Removal of Iron from Groundwater: Preliminary Studies
This report was produced for the Urban Water Research Association of Australia, a now discontinued research program.
Report no. UWRAA 32
The report outlines the sources and types of iron present in groundwater and the changes in iron species which can occur under different chemical conditions. The nature and behaviour of iron bacteria and their ability to reduce and precipitate iron from water is discussed. The principle that bacteria like GALLIONELLA ferruginea can oxidise divalent iron Fe(II), the common type of iron dissolved in groundwater, to trivalent iron Fe(III), is used to develop a biological iron removal process.
Two pilot plants, one with a single reactor column, detention tank and filter, the other with three columns and filter were tested with a flow rate of 1litre/min. Both plants used GALLIONELLA ferruginea and, after a start up time of 7-10 days, removed iron from ground water from a level of 2.5-3.0 mg/litre to 0.2 mg/litre.