Abstract
In this paper, photocatalytic degradation of methamidophos (o,s-dimethylphosramidothooate) by nano-TiO2 was studied, and the effect factors (such as the nature and the concentration of the TiO2 photocatalyst, and the environment (pH, oxidant additives) of treatment solution, etc.) of this process were systemically investigated. It was found that nano-TiO2 has higher photocatalytic activity than that of bulk-sized counterparts, and the pretreatment temperature and the concentration of the nano-TiO2 used in photocatalysis both exhibited a direct effect on this process; in addition, in the presence of nano-TiO2, the change of initial pH value of the treatment solution and addition of oxidants (KIO4, K2S2O8, and H2O2) to this solution both showed an obviously positive effect on this degradation process, markedly enhancing the degradation rate of methamidophos. Under optimal condition (such as 0.04% KIO4 to the treatment solution), the degradation rate of methamidophos could reach about 83.55% in the first 5 min, which is obviously faster than the degradation speed reported in the literature. Langmuir-Hinshelowood rate expression was employed for the degradation of methamidophos by the UV/TiO2 system and adsorption equilibrium constant and rate constant were determined to be 2.02 m/M and 0.0027 mM/min, respectively.
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Xu, Y.H., Gu, G.B., and Lin, X.H., Determination of the Efficiency of Photocatalytic Degradation of Organophosphorous Pesticides, J. Chongqing Environ. Sci., 2001, vol. 23, no. 4, pp. 61–66.
Huang, Y.E. and Ju, X.S., Treatment Technology for Wastewater from Synthetic Rubber Production, J. Environ. Prod. Chem. Ind., 2002, vol. 22, no. 1, pp. 23–27.
Chen, S.F., Zhao, M.Y., and Tao, Y.W., Study on the Photocatalytic Degradation of Organophosphorous Pesticides Wastewater, J. Environ. Sci., 1996, vol. 17, no. 4, pp. 44–48.
Zhang, X.R., Yang, P., and Zhao, M.Y., Research on Photocatalytic Degradation of Organophosphorous Pesticides Using TiO2 · SiO2/Beads, J. Ind. Water Treatment, 2001, vol. 21, no. 3, pp. 13–16.
Zhou, Y.Q. and Yue, L.H., A Study on Photocatalytic Degradation of Methylparathion by Ag/ZnO, J. Environ. Pollution Control, 1998, vol. 20, no. 3, pp. 5–8.
Wang, Y.L. and Zhang, Q.F., Ways to Enhance the Efficiency of TiO2-Based Photocatalysis in Wastewater Treatment, J. Ind. Water Treatment, 2001, vol. 21, no. 12, pp. 5–8.
Robert, D., Piscopo, A., and Weber, J-V., First Approach of the Selective Treatment of Water by Heterogeneous Photocatalysis, J. Environ. Chem. Lett., 2004, no. 2, pp. 5–8.
Tennakone, K. and Wijayantha, K.G.U., Photocatalysis of CFC Degradation by Titanium Dioxide, J. App. Catal. B: Environ., 2004, no. 57, pp. 9–12.
Rachel, A., Sarakha, M., Subrahmanyam, M., and Boule, P., Comparison of Several Titanium Dioxides for the Photocatalytic Degradation of Benzenesulfonic Acids, J. Appl. Catal. B: Environ., 2002, no. 37, pp. 293–300.
Yuan, R.S., Guan, R.B., Shen, W.Z., and Zheng, J.T., Photocatalytic Degradation of Methylene Blue by a Combination of TiO2 and Activated Carbon Fibers, J. Colloid Interface Sci., 2005, no. 282, pp. 87–91.
Jing, L.Q., Li, X.Q., and Li, S.D., XPS and SPS Studies on Nanometer Au/TiO2 Photocatalyst, Chin. J. Catal., 2005, vol. 26, no. 3, pp. 189–193.
Mrowetz, M., Pirola, C., and Selli, E., Degradation of Organic Water Pollutants through Sonophotocatalysis in the Presence of TiO2, J. Ultrason. Sonochem., 2003, no. 10, pp. 247–254.
Fang, J.F., Zeng, X.N., and Xiong, Z.H., The Degradation of Organophosphorous Pesticides by Hydrogen Peroxide, J. Agric. Univ. (Natl. Sci. Ed.), 2004, vol. 25, no. 1, pp. 44–47.
Matthew, R.W., Photo-Oxidation of Organic Material in Aqueous Suspensions of Titanium Dioxide, J. Water Res., 1986, no. 20, pp. 569–577.
Mills, A. and Le Hunte, S., An Overview of Semiconductor Photocatalysis, J. Photochem. Photobiol., A., 1997, no. 108, pp. 1–35.
Piscopo, A., Robert, D., and Weber, J.V., Influence of pH and Chloride Anion on the Photocatalytic Degradation of Organic Compounds. Part I: Effect on the Benzamide and Para Hydroxybenzoic Acid in TiO2 Aqueous Solution, J. Appl. Catal. B: Environ., 2001, no. 21, pp. 1–8.
Robert, D., Industrial and Environmental Applications of Photocatalysis (Special Issue), Int. J. Photoenergy, 2003, no. 5, pp. 43–197.
Wang, K.H., Hsieh, Y.H., Chou, M.Y., and Chang, C.Y., Photocatalytic Degradation of 2-Chloro and 2-Nitrophenol by Titanium Dioxide Suspensions in Aqueous Solution, J. Appl. Catal. B: Environ., 1999, no. 21, pp. 1–8.
Irmak, S., Kusvuran, E., and Erbatur, O., Degradation of 4-Chloro-2-Methylpheonol in Aqueous Solution by UV Irradiation in the Presence of Titanium Dioxide, J. Appl. Catal. B: Environ., 2004, no. 54, pp. 85–91.
Zahraa, O., Sauvanaud, L., Hamard, G., and Bouchy, M., Kinetics of Atrazine Degradation by Photocatalytic Process in Aqueous Solution, Int. J. Photoenergy, 2003, no. 35, pp. 117–124.
Kim, T.K., Lee, M.N., and Lee, S.H., Development of Surface Coating Technology of TiO2 Power and Improvement of Photocatalytic Activity by Surface Modification, J. Thin Solid Films, 2005, no. 475, pp. 171–177.
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Zhang, L., Yan, F., Wang, Y. et al. Photocatalytic degradation of methamidophos by UV irradiation in the presence of nano-TiO2 . Inorg Mater 42, 1379–1387 (2006). https://doi.org/10.1134/S002016850612017X
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DOI: https://doi.org/10.1134/S002016850612017X