Pre-analysis separation and concentration of actinides in groundwater using a magnetic filtration/sorption method I. Background and concept

A wide variety of iron oxides has been used for the removal of radioactive and toxic metals from aqueous solutions. We have utilized natural magnetite and iron ferrite (FeO·Fe₂O₃) in a batch mode to remove actinides (Pu and Am) from wastewater. Compared to the batch process, enhanced capacity for actinide removal was observed using supported magnetite in a column surrounded by an external magnetic field (0.3 tesla). The enhanced magnetite capacity in the column is primarily due to magnetic filtration of colloidal and submicron actinide particles along with some actinide complex and ion exchange sorption mechanisms. The removal of the magnetic field from around the column and use of a regenerating solution will easily remove the actinides loaded on the magnetite. The magnetic field-enhanced column process is under development for a variety of applications. This paper will review previous work on using ferrites for water treatment and discuss the potential for using the magnetic field-enhanced column process as a pre-analysis separation and concentration method for actinides in groundwater.