Carbonyl iron loaded TiO2 photocatalyst by hydrophobic modification for degradation of petroleum hydrocarbon pollutants in water
The magnetic carbonyl iron particles were used as the carrier and loaded with nano TiO2 to prepare composite photocatalysts,and the surface of the composite catalysts was hydrophobically and lipophilically modified to prepare the loaded nano TiO2 composite photocatalysts with hydrophobicity and lipophilicity characteristics,and the crystalline phase composition and microscopic morphology of the composite photocatalysts were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),infrared spectroscopy(FTIR),and ultraviolet-visible spectroscopy(UV).The hydrophobic and lipophilic properties of the catalytic materials were evaluated,the magnetic recycling properties were evaluated.The degradation effects of the common zeolite-loaded TiO2 catalysts and the hydrophobically modified carbonyl iron loaded TiO2 catalysts were comparatively investigated on the three petroleum hydrocarbon pollutants,and the influences of the loading amount of the catalysts and recycling on the degradation efficiencies of the petroleum hydrocarbons were further examined.The results showed that the hydrophobically modified carbonyl iron loaded TiO2 catalyst has hydrophobic and lipophilic properties,which can make the non-polar petroleum hydrocarbon pollutants contact with the active sites of the catalytic material in a better way,and it is easy to be recycled under the magnetic field due to the magnetic nature of the catalytic material particles;the novel catalytic material has a better degradation efficiency of petroleum hydrocarbon pollutants in water,the maximum removal rate of the conventional TiO2/zeolite catalysts for the pollutants was about 75％,while the maximum removal rate of TiO2/modified carbonyl iron could reach 95％,and the degradation rate was faster.Degradation effect was improved with the increase of the catalyst concentration,but the degradation effect was decreased when the concentration was further increased to 4 g·L-1,During repeated use,the activity of the composite photocatalytic material does not decrease significantly,indicating that the composite catalytic material has good stability.
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