Removal of Ortho-Toluidine from Industrial Wastewater by UV/TiO2 Process


Department of Chemistry, Faculty of Science, Arak Branch, Islamic Azad University, Arak, Iran


In this research degradation and mineralization of Ortho-Toluidine (OT) in the wastewater of petrochemical industries was investigated by UV/TiO2 process in a batch recirculating photo reactor. The influence of different variables such as initial pH, amount of TiO2 and initial concentration of OT on the reaction rate was investigated. In optimum conditions (1.75 g/l of catalyst, pH at 7 and initial concentration of OT at 20 mg/l), 93.5% of pollutant and 57% of COD were removed in 180 min of reaction. The reaction rate represented by the mechanism of Langmuir-Hinshelwood was found to follow pseudo first-order kinetics. Degradation and mineralization of the OT were tested by HPLC and COD tests.


  1. Badawy M.I., Ghaly M.Y., Gad-Allah T.A., 2006. Advanced oxidation processes for the removal of organophosphorus pesticides from wastewater. Desalination. 194, 166ââ‚‌“175.
  2. Ferlay J., Parkin D.M., Steliarova-Foucher E., 2010. Estimates of cancer incidence and mortality in Europe in 2008. Eur J Cancer. 46,765-781.
  3. Danford N., 1991. The genetic toxicology of Ortho-Toluidine, Mutation Research/Reviews in Gen. Toxicol. 258, 207-236.
  4. Richter E., Garber K., Harreus U.A., Matthias C., Kleinsasser N., 2007. Hemoglobin adducts of the human bladder carcinogen o-toluidine after treatment with the local anesthetic Prilocaine. Toxicol Lett. 229, 157-164.
  5. De A.K., Chaudhuri B., Bhattacharjee S., Dutta B.K., 1999. Estimation of OH radical reaction rate constants for phenol and chlorinated phenols using UV/H2O2 photo-oxidation. J Hazard Mater. 64, 91ââ‚‌“104.
  6. Kasiri M.B., Khataee A.R., 2011. Photo oxidative decolorization of two organic dyes with different chemical structures by UV/H2O2 process: Experimental design. Desalination. 270, 151 ââ‚‌“159.
  7. Kasprzykââ‚‌“Hordern B., ZioÅ‚ek M., Nawrocki J., 2003. Catalytic ozonation and methods of enhancing molecular ozone reactions in water treatment. J Appl Catal. 46, 639ââ‚‌“669.
  8. Al-Hamedi F.H., Rauf M.A., Ashraf S.S, 2009. Effect of UV/H2O2 oxidation on fouling in textile wastewater nano filtration. Desalination. 239, 159ââ‚‌“166.
  9. Cuiping B., Xianfeng X., Wenqi G., Dexin F., Mo X., Zhongxue G., Nian X., 2011. Removal of Rhodamine B, by ozone-based advanced oxidation process. Desalination. 278, 84ââ‚‌“90.
  10. Yahiat S., Fourcade F., Brosillon S., Amrane A., 2011. Photo catalysis as a pre-treatment prior to a biological degradation of Cyproconazole. Desalination. 281, 61ââ‚‌“67.
  11. Guettai N., Ait Amar H., 2005. Photocatalytic oxidation of methyl orange in presence of titanium dioxide in aqueous suspension. Part I: Parametric study. Desalination. 185, 427ââ‚‌“437.
  12. Shokri A., Mahanpoor K., Soodbar D., 2015. Evaluation of a modified TiO2 (GOââ‚‌“Bââ‚‌“TiO2) photo catalyst for degradation of 4-nitrophenol in petrochemical wastewater by response surface methodology based on the central composite design. J Environ Chemical Engineering (In Press).
  13. Shokri A., Mahanpoor K., Soodbar D., 2015. Degradation of Ortho-Toluidine in petrochemical wastewater by Ozonation, UV/O3, O3/H2O2 and UV/O3/H2O2 processes. Des Water Treat. 1ââ‚‌“10.
  14. APHA standard methods for examination of water and wastewater, twentieth edition. American public health association, Washington DC, (1999).
  15. Sakthivel S., Neppolian B., Shankar M.V., Arabindoo B., Palanichamy M., Murugesan V. Sol., 2003. Solar photo catalytic degradation of azo dye: comparison of photo catalytic efficiency of ZnO and TiO2. Energy Mater Sol Cells. 77, 65ââ‚‌“83.
  16. Lizama C., Freer J., Baeza J., Mansilla H.D., 2002. Optimized photo degradation of Reactive Blue 19 on TiO2 and ZnO suspensions. Catal Today. 76, 235ââ‚‌“246.
  17. Bayarri B., Giménez J., Esplugas S., Curco D., 2005. Photocatalytic degradation of 2, 4-Dichlorophenol by TiO 2/UV: kinetics, actinometries and models. Catal Today. 101, 227ââ‚‌“236.
  18. Fox M.A., Dulay M.T., 1993. Heterogeneous photocatalysis. Chem Res. 93, 341ââ‚‌“357.
  19. Piscopo A., Robert D., Weber J.V., 2001. Influence of pH and chloride anion on the photo catalytic degradation of organic compounds: Part I. Effect on the Benzamide and para-hydroxybenzoic acid in TiO2. Appl Catal. 35, 117ââ‚‌“124.
  20. Parra S., Stanca S.E., Guasaquillo I., Thampi K.R., 2004. Photocatalytic degradation of Atrazine using suspended and supported TiO2. Appl Catal B Environ. 51, 107ââ‚‌“116.
  21. Zhao H., Xu S., Zhong J., Bao X., 2004. Kinetic study on the photo-catalytic degradation of Pyridine in TiO2 suspension systems. Catal Today. 93, 857ââ‚‌“861.
  22. Mogyorosi K., Farkas A., Dekany I., 2002. Removal of 2-Chlorophenol from water by adsorption combined with TiO2 photocatalysis. Environ Sci Technol. 36, 3618ââ‚‌“3624.
  23. Al-Ekabi H., Mayo P.De., 1986. Surface photo chemistry: on the mechanism of the semiconductor photo induced valence isomerization of hexamethyl Dewar benzene to hexamethylbenzene. J Phys Chem. 90, 4075ââ‚‌“4080.
  24. Daneshvar N., Aber S., Seyed Dorraji M.S., Khataee A.R., Rasoulifard M.H., 2007. Photocatalytic degradation of the insecticide diazinon in the presence of prepared nanocrystalline ZnO powders under irradiation of UV-C light. Sep Purif Technol. 58, 91ââ‚‌“98.
  25. Shokri A., Mahanpoor K., Soodbar D., 2015. Degradation of 2-nitrophenol from petrochemical wastewater by UV/NiFe2O4/Clinoptilolite process. Fress Environ Bull (In press).
  26. Lathasree S., Rao A.N., SivaSankar B., Sadasivam, V., Rengaraj, K., 2004. Heterogeneous photo catalytic mineralization of phenols in aqueous solutions. J Mol Catal A Chem. 223, 101ââ‚‌“105.
  27. Barka N., Bakas I., Qourzal s., Assabbane A., Ait-ichou Y., 2013. Degradation of Phenol in Water by Titanium Dioxide Photocatalysis. Orient J Chem. 29, 1055ââ‚‌“1060.
  28. Shen Y.S., Ku Y., Lee K.C., 1995. The effect of light absorbance on the decomposition of Chlorophenols by ultraviolet radiation and UV/H2O2 processes. Water Res. 29, 907ââ‚‌“914.
  29. Benitez F.J., Beltran-Heredia J., Acero J.L., Javier Rubio F., 2000. Contribution of free radicals to Chlorophenols decomposition by several advanced oxidation processes. Chemosphere. 41, 1271ââ‚‌“1277.