[en] The effect of dissolved chemical species on ferrite formation and plutonium removal was investigated. Metal ions, anions, and other dissolved materials generally did not interfere with the adsorptive removal of plutonium by preformed ferrite. However, metal ions which form insoluble hydroxides and anions which can interact with ferrous and/or ferric ions through complexation or precipitation, for example, impeded in situ ferrite formation and plutonium removal. Both in situ and preformed ferrite were also effective in significantly lowering the concentration of many metal ions