The photocatalytic decolourisation and degradation of an azo dye Reactive Yellow (RY14) in aqueous solution with TiO2 as photocatalyst in slurry form has been carried out using UV-A radiation (365 nm). The effect of various parameters such as catalyst loading, radiation intensity and initial dye concentration on the dye removal was investigated to find optimum conditions. The decolourisation and degradation kinetics have been analysed. Both follow modified Langmuir-Hinshelwood kinetic (L-H) model. A study on the effect of electron acceptors on photooxidation reveals that both decolourisation and degradation increase in the presence of H2O2, (NH4)(2)S2O8, KBrO3, to certain dosage beyond which the enhancement effect is negligible. But negative effects are observed in the presence of NaCl or Na2CO3. (c) 2005 Elsevier B.V. All rights reserved.