A method of synthesizing for an iron based magnetic composite material includes the steps of stirring together potassium hydroxide, iron (II, III) oxide, and water. The method also includes the steps of heating the resulting Fe3O4—KOH mixture for a predetermined amount of time. Further, the method includes the step of heating the Fe3O4—KOH mixture until consecutive measurements of the Fe3O4—KOH mixture are within 10% of each other. Also included in the method if adding calcium hypochlorite and mixing until a magnetic Fe(VI)/Fe3O4 composite material is formed. Additionally, the method involves preparing and analyzing the magnetic Fe(VI)/Fe3O4 composite material to determine the amount of ferrate synthesized during from the method.
