In this work we report on possible utilisation of sulphonated phthalocyanines as efficient oxidation catalysts for the removal of various traces of chlorinated compounds from an aquatic environment. Photocatalytic oxidations were carried out with visible and ultraviolet light in agreement with location of their distinctive absorption bands in both these regions. The reaction rate of decomposition of the substrate was measured as a function of pH. Special attention was paid to describe aggregation of the photocatalyst resulting in significant decreasing of the photooxidation activity. Suppression of this undesirable phenomenon by addition of some alcohol to the reaction mixture was studied in detail. Photocatalytic efficiency was verified according to calculated quantum yields. (C) 2007 Elsevier B.V. All rights reserved.