Wastewater Treatment Technology Based on Iron Oxides

Iron oxides have been used in a variety of forms for wastewater treatment. In most precipitation processes ferric ions are used to treat basic aqueous solutions by forming a ferric hydroxide floc to scavenge radioactive and heavy metal contaminants. In adsorption processes, a variety of iron containing minerals have been utilised. Since 1970, we have utilised ferrites and the mineral magnetite, iron ferrite (FeOFe₂O₃), for actinide and heavy metal removal from wastewater. Natural magnetite and ferrites, prepared in a variety of ways, were used in the batch mode to treat wastewaters. Magnetite was also supported and used in a column mode. In the presence of an external magnetic field, enhanced capacity was observed in using supported magnetite for removal of plutonium and americium from wastewater. This paper will review previous work on the use of ferrites and work in progress on supported magnetite (in a magnetic field) for wastewater treatment.