International Journal of Environmental Science and Development

Abstract—Present study deals with the photocatalytic degradation of low concentrations of VOCs like methanol, acetone, dichloromethane (DCM), benzene and toluene that are found in the pharmaceutical wastewater. The synthesized N doped TiO₂ were used. N doped TiO₂ with the reduced band gap energy of 2.91ev exhibited a complete degradation of the target VOCs in the presence of visible and sunlight. Kinetic study indicated that the rate of degradation of the target solvents was high in the presence of sunlight than when compared to visible irradiation. This may be due to the presence of the UV radiation in the natural sunlight. Irrespective of irradiation, the order of degradation of VOCs for the N doped TiO₂ was: benzene > toluene > DCM > methanol >acetone. For mixed pollutant condition, individual pollutants followed similar degradation pattern as single pollutant system. This study has proven the suitability of photocatalysis as an alternative polishing treatment for pharmaceutical wastewaters.

Index Terms—Band gap energy, N doped TiO₂, pharmaceutical wastewater, visible light irradiation.

V. S. Priya and Ligy Philip are with Environmental and Water Resources Engineering Division, Department of Civil Engineering, IIT Madras, Chennai-600 036, India (e-mail: priyarajagopal06@gmail.com, ligy@iitm.ac.in).

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Cite:V. S. Priya and Ligy Philip, "Photocatalytic Degradation of Aqueous VOCs Using N Doped TiO₂: Comparison of Photocatalytic Degradation under Visible and Sunlight Irradiation," International Journal of Environmental Science and Development vol. 6, no. 4, pp. 286-291, 2015.