Photocatalytic degradation of TCE in water using TiO2 catalyst

Wastewater is generally released untreated into the rivers and streams in developing countries. Industrial wastewater usually contains highly toxic pollutants, cyanides, chlorinated compounds such as trichloroethylene (TCE). Ultraviolet (UV) radiation from sunlight also decomposes organic compounds by oxidation process. However, the process is less effective due to large amount of toxic effluent entering the main stream water. The solar radiation can effectively be applied to accelerate the process by using suitable catalyst for economically cleaning the major fresh water sources. This paper describes photocatalytic degradation of trichloroethylene in aqueous solution using TiO₂. Variable parameters such as initial concentration of TCE, type and concentration of TiO₂ and reaction time are investigated. The powder TiO₂ is found more effective than the sand TiO₂ for decomposing TCE. The effect of sand TiO₂ as photocatalyst is investigated at various water depths. It is observed that up to 45 mm water depth, sand TiO₂ shows photo-degradation of TCE. The degradation rate increases as the concentration of TCE is increased up to 45 μl of TCE per litre of water. Similarly the photocatalytic degradation increases with TiO₂ concentration up to 0.7 g L⁻¹ of solution but then starts decreasing. The optimum values of TiO₂ and TCE concentration obtained are 0.7 g and 35 μl L⁻¹ of the solution, respectively.