Investigation of Photocatalytic Degradation of Phenol through UV/TiO2 Process

Document Type : Research Paper

Authors

1 Associate Prof., School of Public Health, Hamedan University of Medical Sciences

2 Public Health Expert, School of Public Health, Hamedan University of Medical Sciences

Abstract

Phenol is one of the important contaminating materials that has high toxicity level receiving in water resources. Photocatalytic degradation process is one of the developing technologies in treatment of wastes containing persistent organic materials. Investigations show that oxidative degradation of organic compounds with oxygen reduction is caused under irradiation of photocatalysts such as TiO2 suspended in aqueous solution containing organic compounds and oxygen. The main objective of this research is the study of photocatalytic oxidation of phenol in the presence of TiO2 and the factors affecting the process. In this study phenol solution (50 mg/L) was prepared and in separate stages was exposed to air, UV, TiO2 and a combination of them and various parameters such as exposure time, pH, and amount of TiO2 were studied in terms of their effects on reaction progress. The results show that UV/TiO2 process is most effective. This study shows that 83% of phenol was degraded by irradiation and air exposure for 9 hr in the presence of 0.1g TiO2 in alkaline medium (pH=11). It is also showed that the efficiency of phenol degradation is less than 9 % with a 3 hr exposure and pH of 11. Based on the results, UV/TiO2 process may be effectively applied in phenol removal from polluted water which is both technically and economically efficient.

Keywords


1- Akbal, F., and Nur Onar, A. (2003). “Photocatalytic degradation of phenol.” J. Environmental monitoring and assessment, 83, 295-302.
2- ARB / SSD / SES. (1997). Phenol, toxic air contaminant identification, list summaries, New Mexico University, 767–770.
3- Agency for Toxic Substances and Disease Registry Division of Toxicology (ATSDR). (1999). Managing hazardous materials incidents, volume III – Medical management guidelines for acute chemical exposures, TOX FAQs for Phenol.
4- Wang, K.H., Hsieh, Y.H., Chou, M.Y., and Chang, C.Y. (1999). “Photocatalytic degradation of 2-chloro and 2-nitrophenol by titanium dioxide suspensions in aqueous solution.” J. Applied Catalysis B: Environmental, 21, 1-8.
5- Sawyer, C.N., McCarty, P.L., and Parkin, G.F. (2003). Chemistry for environmental engineering and science, 5th Ed., McGraw-Hill, 251, 252, 297, 339.
6- آرامی,‌ م., محمودی,‌ ن.م.، سلمان تبریزی, ن.، و بحرینی, ذ. (1382). رنگبری و تجزیه فتوکاتالیزوری رنگزای راکتیو قرمز 198 با فرآیندUV / TiO2 / H2O2, طرح تحقیقاتی دانشکده مهندسی نساجی، دانشگاه صنعتی امیر کبیر, تهران.
7- Bekkouche, S., Bouhelassa, M., Hadj Salah, N., and Meghlaoui, F.Z. (2004). “Study of adsorption of phenol on titanium oxide (TiO2).” J. Desalination, 166, 355-362.
8- Theurich, J., Lindner, M. and Behnemann, D. W. (1996). “Photocatalytic degradation of 4-chlorophenol in aerated aqueous titanium dioxide suspensions: A kinetic and mechanistic study.” J. American Chemical Society, langmuir, 12 (26), 6368 – 6376.
9- Jafari, J. A. (2004). “Simultaneous photo-oxidative degradation of EDTA and extra-oxidative recovery of copper from industrial effluents.” J. Iran Chem. & Chem. Eng., 23 (2), 65-71.
10- Tennakone, K., Tilakaratne, C.T.K., and Kottegoda, I.R.M. (1995). “Photocatalytic degradation of organic contaminants in water with TiO2 supported of polyethylene films.” J. Photochemistry and Photobiology A: Chemistry, 87 (2), 177-179.
11- Lakshmi, S., Renganathan, R., and Fujita, S. (1995). “Study on TiO2-mediated photocatalytic degradation of methylene blue.” J. Photochem. Photobiol., 88, 163–167.
12- Vidal, A., Diaz, A.I., Hraiki, E.A., Romero, M., Muguruza, I., Senhaji, F., and Gonzalez, J. (1999). “Solar photocatalysis for detoxification and disinfection of contaminated water: Pilot plant studies.”J. Catalysis Today, 54(2), 283-290.
13- Poudyal, K., Clark, D., and Brag, A. (2002). “Titanium dioxide photocatalysis of metals.” ENVE 436-01, Bulletin: Hazardous Waste Management, 1-4.
14- Raquel, F.P.N., and Welson, F.J. (1996). “TiO2-fixed-bed reactor for water decontamination using solar light.” J. Solar Energy, 56 (5), 471-477.
15- Clesceria, L. S., Greenberg, A.E., and Eaton, A. D., eds.(1998). Standard methods for the examination of water and wastewater, APHA, WEF, AWWA, 20th Ed., Washington DC.
16- Iliev, V., Mihaylova, A., and Bilyarska, L. (2002). “Photooxidation of phenols in aqueous solution.” J. Molecular Catalysis A: Chemical, 184 (1-2), 121-130.
17- بوید, م.، مترجمان: بکاولی، م., هروی، م.، و رحیم زاده، م. (1376). شیمی آلی, ویرایش ششم, نشر مشهد، جلد دوم, 1029 – 1039 .