Photocatalytic decolorization of wastewater dyes

The photocatalytic decolorization of municipal wastewater contaminated with textile dyes was studied using a batch reactor. Degussa P25 titanium dioxide was used as the photocatalyst and proved to be effective for dye degradation when irradiated with UV light in the presence of air. In addition to removing the color from the wastewater, the photocatalytic reaction simultaneously reduced the COD which suggests that the dissolved organics had been oxidized. The activation energy for the photocatalytic decolorization reaction was only about 3 to 6 kJ/mole indicating a weak temperature dependence of the rate. These results suggest that the photocatalytic degradation of textile dyes may be a viable method for decolorizing and oxidizing organics in wastewater.