Investigation of the photocatalytic degradation of organochlorine pesticides on a nano-TiO2 coated film

The photocatalytic degradation of organochlorine pesticides including alpha-, beta-, gamma-, delta-hexachlorobenzene (BHC), dicofol and cypermethrin were carried out on a nano-TiO2 coated films under UV irradiation in the air. The photocatalytic conditions, including the amount of TiO2, irradiation time and the intensity of light were optimized. The pesticides were most effectively degraded under the condition of 2.24 mg/cm(2) on TiO2 film and a 400 W UV irradiation of high-pressure mercury lamp with a wavelength of 365 nm. A typical organochlorine pesticide, 20 mu g alpha-BHC, was dipped onto the TiO2 film surface and degraded completely within 20 min. In addition, the photocatalytic degradation pathways on the nano-TiO2 coated film were discussed. (C) 2007 Elsevier B.V. All rights reserved.