A Pilot Study of RO16 Discoloration and Mineralization in Textile Effluents Using the Nanophotocatalytic Process

Document Type : Research Paper


1 Faculty Member, Department of Environmental Health, Shahroud University of Medical Sciences

2 Assis. Prof. of Environmental Health, Tehran University of Medical Sciences

3 Lab Instructor, Department of Environmental Health, Shahroud University of Medical Sciences


The nanophotocatalytic process using nano-structured semiconductors is one of the techniques used for the destructive oxidation of organic compounds such as dyes. The photocatalytic oxidation of Reactive Orange 16 aqueous solution, applied in the textile industry, was assessed by UV ray irradiation in the presence of TiO2 nanoparticles. It was found that the photons required for the process were completely absorbed when TiO2 concentration reached 0.4 g/L. Degradation of paint decreased with increasing TiO2 concentration. It is suggested that at very high concentrations, the active points on ions are covered and the number of radicals like ˙OH will, therefore, decrease on the surface of catalysts. Another explanation for this state of affairs is that UV screening may have the same function. The negative action of anions may be explained by the reaction of positive cavities accomplished by hydroxyl radicals with anions. This reaction can be described as corrosive for ˙OH and hVB+, which can prolong the process of color removal. The TiO2 in an acidic environment has a positive charge (pH


1- Konstantinou, I.K., and Albanis, T.A. (2004). “TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: Kinetic and mechanistic investigations. A review.” Appl. Catal. B: Environ., 49 (1), 1-14.
2- Zollinger, H. (1991). Synthesis, properties and applications of oraganic dyes and pigments, 2nd Ed.,VCH,USA.
3- Weber, J., Stickney, V.C. (1993). “Integrating conservation targets into water projections.” Wat. Res., 27, 63.
4- Ràfols, C., Barceló, D. (1997). “Determination of mono- and disulphonated azo dyes by liquid chromatography–atmospheric pressure ionization mass spectrometry.” J. Chromatography A., 777 (1-2), 177-192.
5- Houas, A., Lachheb, H., Ksibi, M., and et al. (2001). “Photocatalytic degradation pathway of methylene blue in water.” Appl. Catal. B: Environ., 31 (2), 145-157.
6- Pagga, U., Bruan, D. (1986). “The degradation of dyestuffs: Part II Behaviour of dyestuffs in aerobic biodegradation tests.” Chemosphere, 15 (4), 479-491.
7- Alaton, I.A. (2002). “Advanced oxidation of a rective dyesbath effluent: comparison of O3, H2O2/UV-C and TiO2/UV-A processes.” Water Res., 36 (5), 1143-1154.
8- Neppolian, B., Choi, H.C., Sakthivel, S., and et al. (2002). “Solar light induced and TiO2 assisted degradation of textile dye reactive blue 4.” Chemosphere., 46 (8), 1173-1181.
9- Saquib, M., Muneer, M. (2003). “TiO2-mediated photocatalytic degradation of a triphenylmethane dye (gentian violet), in aqueous suspensions.” Dyes Pigments., 56 (1), 37-49.
10- Caliman, A.F., Cojocaru, C., Antonidis, A., and Poulios, I.(2006). “Optimized photocatalytic degradation of Alcian Blue 8 GX in the peresence of TiO2 suspensions.” J. Hazard. Mater., 144
(1-2), 265-273.
11- Patil, S.S., and Shinde, V.M. (1988). “Biodegradation studies of aniline and nitrobenzene in aniline plant wastewater by gas chromatography.” Environ. Sci. Technol., 22, 1160.
12- Alaton, I.A. (2003). “A review of the effects of dye-assisting chemicals on advanced oxidation of reactive dyes in wastewater.” Color. Technol., 119, 345-353.
13- Pagga, U., and Taeger, K. (1994). “Development of a method for adsorption of dyestuffs on activated sludge.” Wat. Res., 28 (5), 1051.
14- Stylidi, M., Dimitris, I.K., and Xenophon, E.V. (2003). “Pathways of solar light-induced photocatalytic degradation of azo dyes in aqueous TiO2 suspensions.” Appl.Catal.B: Environ., 40 (4), 271-286.
15- Mahmoodi, N.M.Arami, M., Limaee, N.Y., and et al. (2006). “Kinetics of heterogeneous photocatalytic degradation of reactive dyes in an immobilized TiO2 photocatalytic reactor.” J.Colloid Interface Sci., 295 (1), 159-164.
16- So, C.M., Cheng, M.Y., YU, J. C., and et al. (2002). “Degradation of azo dye Procion Red MX-5B by photocatalytic oxidation.” Chemosphere., 46 (6), 905-912.
17- Kaur, S., and Singh, V. (2007). “TiO2 mediated photocatalytic degradation studies of Reactive Red 198 by UV irradiation.” J. Haz. Mat., 141 (1), 230-236.
18- Mahmoodi, N. M., Arami, M., and Yuosefi, N. (2007). “Nanophotocatalysis using immobilized titanium dioxide nanoparticle: Case study of Butachlor.” Mater. Res. Bulletin., 42 (5), 797-806.
19- Lin, C., and Lin, K. S. (2007). “Photocatalytic oxidation of toxic organohalides with TiO2/UV: The effects of humic substances and organic mixtures.” Chemosphere., 66 (10), 1872- 1877.
20- Silva, C. G., Wang, W., and Faria, J. L. (2006). “Photocatalytic and photochemical degradation of mono-,di- and tri-azo dyes in aqueous solution under UV irradiation.” J. PhotoChemistry. and Photobiology A: Chemistry, 181 (2-3), 314-324.
21- Mahmoodi, N.M.(2006). “Decolorization and mineralization of textile dyes at solution bulk by heterogeneous nanophotocatalysis using immobilized nanoparticles of titanium dioxide.” Colloid. Surface, A: Physicochem. Eng. Aspects, 290 (1-3), 125-131.
22- Tang, W.Z. (1997). “TiO2/UV photodegradation of azo dyes in aqueous solutions.” Environ. Technol., 18, 1-12.
23- Grzechulska , and J., Morawski, A.W. (2002). “Photocatalytic decomposition of azo-dye acid black 1 in water over modified titanium dioxide.” Appl. Catal. B: Environ., 36, 45-51.
24- Davis, R.J. (1994). “Photocatalytic decolorization of wastewater dyes.” Wat. Environ. Res., 66, 50.
25- Zielinska, B., Grzechulska, J., and Grzmil, B. (2001). “Photocatalytic degradation of reactive Black 5-A comparison between TiO2-Tytanpol A11 and TiO2-Degussa P25 photocatalysts.” Appl. Catal. B: Environ., 35, L1–L7.