Photodegradation of Alachlor Over Fe-TiO2 on Granular Activated Carbon Support under UV and Visible Light

Fe-TiO2 on granular activated carbon support was synthesized via hydrothermal method without calcination. The crystalline phases were identified using X-ray diffraction whereas the surface morphologies were examined using scanning electron microscopy. Peaks of anatase TiO2 and graphite were present in the Fe-TiO2-GAC sample. Comparisons of the surface features of GAC and Fe-TiO2-GAC show that Fe-TiO2 has been immobilized in the pores and on the outer layer of the GAC. Alachlor photodegradation using Fe-TiO2-GAC under UV and visible light were compared to removal by adsorption using GAC only. Both photocatalytic experiments gave higher removal efficiencies than the adsorption process. Photocatalysis under UV and visible light can remove alachlor at the same rate after 30 min of reaction. Complete removal of alachlor was observed from all three experiments after 150 min of reaction. The mechanism of alachlor removal using Fe-TiO2-GAC has been a combination of adsorption and photocatalysis. Keywords—Alachlor, Fe-TiO2, Granular activated carbon support, Photocatalysis.

[1]  Xiaoping Wang,et al.  Solvothermal synthesis of Fe–C codoped TiO2 nanoparticles for visible-light photocatalytic removal of emerging organic contaminants in water , 2011 .

[2]  C. Castro,et al.  Iron promotion of the TiO2 photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation , 2011 .

[3]  N. Grisdanurak,et al.  Visible light-irradiated degradation of alachlor on Fe-TiO2 with assistance of H2O2 , 2011 .

[4]  N. Grisdanurak,et al.  Calcination temperature effect on solvothermal Fe–TiO2 and its performance under visible light irradiation , 2010 .

[5]  Wei Chen,et al.  Activated carbon supported TiO2-photocatalysis doped with Fe ions for continuous treatment of dye wastewater in a dynamic reactor. , 2010, Journal of environmental sciences.

[6]  Zhong-liang Shi,et al.  Immobilization of TiO2 nanoparticles on activated carbon fiber and its photodegradation performance for organic pollutants , 2010 .

[7]  A. Ramesh,et al.  Dissipation of alachlor in cotton plant, soil and water and its bioaccumulation in fish. , 2004, Chemosphere.

[8]  W. Chu,et al.  The direct photolysis and photocatalytic degradation of alachlor at different TiO2 and UV sources. , 2003, Chemosphere.

[9]  D. Wolbert,et al.  Adsorption of Pesticides onto Granular Activated Carbon: Determination of Surface Diffusivities Using Simple Batch Experiments , 2000 .

[10]  S. Galassi,et al.  Alachlor and its metabolites in surface water , 1996 .