Soil contamination by non-aqueous phase liquid compounds (NAPLs), mainly from petroleum hydrocarbons, has been a matter of great concern, especially due to aromatic and polycyclic aromatic hydrocarbon contamination, which can pose a health risk due to its carcinogenic and mutagenic properties. In this study, oil sludge treatment was carried out using heterogeneous photocatalysis (H2O2/UV/TiO2). A 2(3) factorial design experimental plan was used, applying black and white light reactors; in addition the effects of hydrogen peroxide (H2O2) concentration, TiO2 mass and irradiation time were evaluated using TOC removal as a response. Heterogeneous photocatalysis provided efficient degradation and mineralization of a large part of the organic matter. Moreover, the method also proved to be an alternative treatment for removing PAH from oil sludge, eliminating 100% of all PAH content from the oil sludge sample after 96 h of irradiation. (C) 2009 Elsevier B. V. All rights reserved.