Effect of magnetite transformations on degradation efficiency of cerium dioxide-magnetite composite

Present investigations are focused on synthesis of magnetite/cerium dioxide reactive sorbents in various weight ratios of components and their characterization of chemical and magnetic properties. The morphology and changes in magnetic transformations in dependence on composition are followed by electron microscopy, X-ray diffraction, Mössbauer spectroscopy and magnetic measurements at room and low temperatures. Degradation efficiency is evaluated from a decomposition of the organophosphorus pesticide parathion methyl using prepared reactive sorbents. The experimental results reveal that the degradation efficiency, expressed by rate constant (mol/h) in dependence on amount of cerium dioxide content (vol.%), is independent on kind of iron oxide but increases with cerium dioxide content. On the contrary, saturation and remanent magnetizations are highly sensitive to relative ratio of iron oxides; magnetite, maghemite and hematite, originating from the initial magnetite transformations in dependence on sample composition.