PHOTOCATALYTIC DEGRADATION OF PARAQUAT BY USING TITANIUM DIOXIDE ON RICE HUSK SILICA AND ZEOLITE Y IN SODIUM FORM
Keywords:
Paraquat, photocatalyst, photocatalytic degradation, rice husk silica, zeolite Y, precipitationAbstract
Photocatalysts were prepared by using TiO2 at 10 and 30 wt% grafted on rice husk silica (RHS) and zeolite NaY. The photocatalysts were characterized by X-ray diffraction and N2 adsorption-desorption analysis. The TiO2 in the anatase phase was well dispersed on the external surface area of the supports. Paraquat adsorption on the catalysts (determined before the photocatalytic testing) mainly occurred on the supports. The adsorption on the TiO2/NaY was much higher than that on the TiO2/RHS. In photocatalytic testing, both the 10 and 30% TiO2/NaY catalysts were not active probably due to high adsorption of the paraquat on the supports. In contrast, both of the TiO2/RHS catalysts were active and the best photocatalyst was the 30% TiO2/RHS. The supported catalyst showed a higher activity than the bare TiO2 indicating the enhancement from the dispersion of the RHS. Moreover, the photocatalytic degradation of paraquat on the 30% TiO2/RHS was similar to commercial TiO2 (P25) with the same TiO2 content.
References
Artkla, S., Wantala, K., Srinameb, B., Grisdanurak, N., Klysubun, W., and Wittayakun, J. (2009). Characteristics and photocatalytic degradation of methyl orange on Ti-RH-MCM-41 and TiO2/RH-MCM-4. Korean J. Chem. Eng., 26:1556-1562.
Bhattacharyya, A., Kawi, S., and Ray, M.B. (2004). Photocatalytic degradation of orange II by TiO2 catalysts supported on adsorbents. Catal. Today, 98:431-439.
Brigante, M. and Schulz, P.C. (2011). Adsorption of paraquat on mesoporous silica modification with titania: effects of pH, ionic strength and temperature. J. Colloid Interf. Sci., 363:355-361.
Florêncio, M.H., Pires, E., Castro, A.L., Nunes, M.R., Borges, C., and Costa, F.M. (2004). Photodegra¬dation of diquat and paraquat in aqueous solutions by titanium dioxide: evolution of degradation reactions and characterization of intermediates. Chemosphere, 55:345-355.
Iglesias, A., Lopez, R., Gondar, D., Antelo, J., Fiol, S., and Arce, F. (2010). Adsorption of paraquat on goethite and humic acid-coated goethite. J. Hazard. Mater., 183:664-668.
Kaneko, M. and Okura, I. (2002). Photocatalysis: Science and Technology. Springer, New York, NY, USA, 360p.
Moctezuma, E., Leyva, E., Monreal, E., Villegas, N., and Infante, D. (1999). Photocatalytic degradation of the herbicide “paraquat”. Chemophere. 39: 511-517.
Nur, H., Manan, A.F.N.A., Wei, L., Muhid, M.N.M., and Hamdan, H. (2005). Simultaneous adsorption of a mixture of paraquat and dye by NaY zeolite covered with alkylsilane. J. Hazard. Mater., B117:35-40.
Raj, K.J.A. and Viswanathan, B. (2009). Effect of surface area, pore volume and particle size of P25 titania on the phase transformation of anatase to rutile. Indian J. Chem. 48A:1378-1382.
Rongchapo, W., Sophiphun, O., Rintramee, K., Prayoon¬pokarach, S., and Wittayakun, J. (2013). Paraquat adsorption on porous materials synthesized from rice husk silica. Water Sci. Technol., 68:863-869.
Rouquerol, F., Rouquerol, J., and Sing, K. (1999). Adsorption by Powders and Porous Solids. Academic Press, London, UK, 467p.
Sobczyński, A. and Dobosz, A. (2001). Water purification by photocatalysis on semiconductors. Pol. J. Environ. Stud., 10:195-205.
United States Environmental Protection Agency. (1994). Imidacloprid Pesticide Fact Sheet, U.S. Environmental Protection Agency. Washington, DC., USA.
Vohra, M.S. and Tanaka, K. (2003). Photocatalytic degradation of aqueous pollutants using silica-modified TiO2. Water Res., 37:3992-3996.
Zhang, F., Sun, D., Yu, C., Yin, Y., Dai, H., and Shao, G. (2015). A sol-gel route to synthesize SiO2/TiO2 well-ordered nanocrystalline mesoporous photocatalysts through ionic liquid control. New J. Chem., 39:3065-3070.
